UNIFIED MODULAR CHEMICAL DELIVERY BLOCKS

Abstract: A modular chemical delivery block is presented. The unified modular block preferably includes first and second fluid flow paths having first and second axial bore holes. The first fluid flow path may be configured to transport fluid flow through the unified modular block at least partially in a first direction, and the second fluid flow path may be configured to transport fluid flow through the modular block at least partially in a second direction horizontally transverse to the first direction. A lowermost portion of the second fluid flow path is preferably elevationally below a lowermost portion of the first fluid flow path. The unified modular block may be further configured to be coupled to other modular blocks laterally adjacent to the first axial bore hole and the second axial borehole.

Description: TITLE: UNIFIED MODULAR CHEMICAL DELIVERY BLOCKS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to chemical delivery systems and, more particularly, to modular chemical delivery blocks, systems incorporating modular chemical delivery blocks, and methods relating to modular chemical delivery blocks. 2. Description of the Related Art Chemical delivery systems are used in numerous industries to control the flow of fluids, including gas reactants and other chemicals (e.g., liquids). One industry that heavily relies on chemical delivery systems is the semiconductor processing industry. In semiconductor processing, these systems are commonly used to control the flow of gases to and from processing chambers. Such processing often makes demanding requirements of chemical delivery systems. In chemical etch processes, for example, gas lines usually must be periodically changed out because of line corrosion and/or partial or complete system reconfiguration during maintenance. To minimize the downtime of the etch tool to which a chemical delivery system is attached, the gas lines of the chemical delivery system should be capable of quick removal and replacement. Conventional chemical delivery systems, however, often fail in this regard. Fig. 1 shows a conventional chemical delivery system 100 configured to supply gases to an etch process tool used in semiconductor fabrication. Gas paths are provided in system 100 using stainless steel conduit or tubing paths 102 (typically 1/4" O.D., 3/8" O.D., or 1/2" O.D.), which are welded between each gas controlling component 104. Because of the configuration of system 100, the time required to change-out or repair components 104 is too long and the cost to reconfigure conduit (tubing) paths 102 is too high. To overcome the problems of conventional welded tubing designs, modular chemical delivery blocks may be used. Modular chemical delivery blocks are substrates onto which a chemical control component can be mounted. The blocks can then be directly attached to each other, eliminating the need for welded fittings. By using modular chemical delivery systems that incorporate modular blocks and components, not only can worn components be more easily replaced, but the gas delivery system design also can be more readily reconfigured. But many designs for modular chemical delivery systems are not, however, without their own deficiencies. For example, Fig. 2 shows a modular chemical delivery system in which individual modular blocks 112 are fastened together with horizontal, full length bolts 114, 130 throughout an entire modular block assembly 110. While allowing for rather quick assembly (typically only two 2-inch bolts per axial connection), this design raises several safety, disassembly and repair concerns. One problem with the design shown in Fig. 2 is that when full length bolts 114 are subjected to the torque required to provide appropriate sealing integrity between the sealing joints 118, the deflection of full length bolts 114 is too great. Effectively, the basic deflection force of a bolt 12 can be calculated with the following formula: DEFLECTION = PL/AE, wherein P is the amount of force load upon an axial connection of any adjoining blocks 112 in series (the deflection potential), L is the length of bolt 114, A is the cross-sectional area of bolt 114, and E is the modulus of elasticity of bolt 114 based on its material composition. If it is assumed that all equipment suppliers of such modular block technology use 300 series or better materials for the fastener components, then E is a constant for any length bolt 114. Likewise, in these types of modular gas system designs a designer is often mechanically constrained to using fastener diameters of 1/4" (6.35mm) or smaller, and thus A can be considered relatively constant. In summary, if A and E are constant, then as the designer increases the length L of the bolt 114, there will be a corresponding linear increase in the deflection force of the bolt 114 which is conveyed to the fastened substrate joints. If the deflection force is high enough, the seat integrity at the axial (joint-to-joint) connections 118 could be lost. As might be expected, such a loss of integrity could be extremely dangerous, especially when toxic chemicals are being delivered. Another concern with the extended length fastener design shown in Fig. 2 is related to the manner in which bolts 114 fasten blocks 112 together. If a user were to require removal of any block 1 12 in modular block assembly 110, then the respective sealing joints 1 18 throughout block assembly 1 10 would be exposed to atmosphere. Such exposure potential raises, among other things, safety and contamination issues with corrosive and toxic chemical delivery applications. Figs. 3 A and 3B are cross-sectional and top views, respectively, of another modular block design in which the individual blocks 122 are fastened together via localized bolting at each block-to-block or axial joint connection 124 to form a modular block assembly 120. Modular block assembly 120 is then connected to mounting brackets 126. This design dramatically reduces or eliminates the concern for deflection potential by localizing fastener sealing strength, integrity, and length. Use of such a localized fastener design also reduces the number of sealing joints 128 exposed to atmosphere when any given block 122 is removed. However, the design shown in Figure 3A also has a limitation regarding disassembly. As shown in Fig. 3B, if a user were to place multiple modular block assemblies side-by-side (typically on 1.6" (40.64mm) to 2" (50.8mm) spacing), many of the axial fasteners 130 could not be accessed because the fastener locations lie under the top accessible surface of the blocks (i.e., the collective surface of a modular block that may be accessed from directly above the modular block). Consequently, if the removal of a given modular block is desired, then the modular blocks adjacent to that modular block may undesirably have to be removed first. Therefore, it would be desirable to design a modular chemical delivery block in which connection locations for allowing the modular chemical delivery block to be coupled to a laterally adjacent chemical delivery block were not obstructed by other portions of the modular block. It would also be advantageous to design a modular chemical delivery system in which localized fasteners connecting laterally adjacent modular blocks were not prevented from being accessed from directly above the top surface of the modular blocks connected by the fasteners. Such a system could allow the flow paths provided by the modular blocks to be more easily and rapidly reconfigured than in other chemical delivery systems. The above-described information is not admitted to be prior art by its presence in this Background section. SUMMARY The problems described above are in large part addressed by a top-accessible modular chemical delivery block configured to direct fluid flow therethrough. Broadly speaking, a top-accessible modular block is one that may be coupled to or decoupled from an adjacent modular block using access from directly above the top- accessible modular block In a preferred embodiment the top-accessible modular chemical dehverv block inclu e an axial connection location configured to allow the modular block to be coupled to a laterally adjacent modulai block. The interior surface of the axial connection location is preferably substantially parallel to the exterior surface of the axial connection location and unobstructed by other portions of the modular block from the top surface of the modular block. This configuration preferably allows the axial connection location to be accessed from directly above the modular block. A top-accessible modular block may provide several advantages when incorporated m a modular chemical delivery system. For instance, a top-accessible modular block preferably affords easy access to an axial connection location even when located m an area where lateral access to the block is restricted A top-accessible modular block as descπbed herein is preferably configured to be coupled to laterally adjacent modular blocks without using welded fittings. Consequently, the flow paths of a modular chemical delivery system that includes a plurality of top-accessible modular blocks may be quickly reconfigured and worn components of the system may be rapidly replaced. As a result of these benefits, the overall downtime of a modular chemical delivery system incorporating such modular blocks may be significantly reduced over that of conventional chemical delivery systems Moreover, because of the ability to access axial connection locations from directly above the block, a top- accessible modular block may be decoupled from lateially adjacent modular blocks of a plurality of modulai blcκ.k •> without removing any other blocks (unlike the system shown in Fig 2) Preferably, the top-accessible modular block may be decoupled from a pair of laterally adjacent modular blocks coupled thereto without displacing or otherwise moving the laterally adjacent modular blocks In addition, the top-accessible modular block may be configured to be decoupled from laterally adjacent modular blocks without compromising the seals between non- laterally adjacent modular blocks. Through such features, a top-accessible modular block may further facilitate the removal of worn or damaged components of a modular chemical delivery system. In a preferred embodiment, all connection locations of the modular block are also configured to be accessed from directly above the modular block. For example, the modular block may mclude mounting fastener receivmg elements configured to receive mountmg fasteners for mounting the modular block to a support structure (e.g., a mountmg palette). The mountmg fasteners may be accessed from directly above the modular block, allowing the modular block to be mounted to the support structure without usmg a mountmg bracket. Beneficially, such a feature may not only reduce the total number of parts used m a system, but may also reduce the footprint of each modular block. Furthermore, the top-accessible modular block contains a first fluid flow path configured to transport fluid flow through the modular block. As referred to herein, a fluid may be considered any substance that tends to flow and to conform to the outlme of its contamer, including gases and liquids The modular block mcludes a top surface. A top surface of a modular block may be a top surface of the modular block when the block is oriented as it would be during operation of a system in which the block is incorporated, or a top surface to which or directly above which a chemical control component may be mounted. It should be understood that a top surface of a modular block is not confined to simply the one uppermost area of an entire modular block, but may be include the top surfaces m vaπous areas throughout the block. The modular block further mcludes an axial interface flange An axial interface flange may be any lateral structure of the modular block to which another, laterally adjacent modular block may be coupled The axial interface flange may or may not be connected (by, e g , a lateral wall) to other axial interface flanges The first fluid flow path is preferably arranged adjacent to and partially with the axial interface flange The axial mterface flange preferably includes an intenor surface and an exteπor surface As refeπed to herein, intenor and extenor surfaces may be considered surfaces of the modular block or components of the modular block that at least partially face the interior or exteπor. respectively, of the modular block A exterior facing surface of the modular block does not have to be on the absolute exterior of the block as long as it faces in that dnection (e g , a surface could be recessed within a wall of a modular block and still be an exterior surface) \ fiist axial borehole of the first fluid flow path is preferably defined in the exterior surface of the axial interface flange The axial interface flange preferably includes an axial connection location configured to allow the modular block to be coupled to an adjacent modular block The axial connection location has an mtenor surface and an exteπor surface The mteπor surface of the axial connection location is preferably unobstructed by other portions of the modular block so that the interior surface of the axial connection location is accessible from the top surface In other words, there is at least one direct lme from the top surface of the modular block to the mteπor surface of the axial connection location that is unobstructed by other portions of the modular block The direct lme is preferably a vertical lme. It should be understood that, m some situations, there may be direct lmes between the top surface of the modular block and the mteπor surface of the axial connection location that are obstructed by a portion or portions of the modular block. In that event, the mtenor surface of the axial connection location may nevertheless be considered unobstructed as long as one direct line from the top surface of the modular block exists Furthermore, connection locations as descπbed herein, and axial connection locations in particular, may be considered those portions of a modular block that are in some way configured to allow the modular block to be coupled to an adjacent modular block. In a case where a connection location includes a fastener receι\ ing element such as a hole or cavity, the connection location preferably includes the fastener receiving element, the portion oi the modular block defining the fastener receiving element, and the surfaces of the modular block lmmediateK aiound the lip of the receivmg element. In a preferred embodiment, the axial connection location contains an axial fastener receivmg element configured to receive a local side-to-side fastener for couplmg the modular block to a laterally adjacent modular block. Consequently, the mteπor surface of such an axial connection location may be considered the mteπor facmg surface of the modular block immediately around the lip of an axial fastener receiving element The mtenor surface of the axial connection location is preferably substantially parallel to the exteπor surface of the axial connection location. That is, while the mtenor and extenor surfaces of the axial connection locations may not be absolutely parallel, the general orientation between the surfaces may be substantially parallel The axial fastener receivmg element preferably mcludes an mtenor openmg defined m the mteπor surface of the axial interface flange and an extenor opening defined m the exterior surface of the axial interface flange The interior openmg of the axial fastener receiving element is preferably unobstructed by other portions of the modular block so that the mteπor openmg of the axial fastener receiving element is accessible from the top surface Preferably, the axial fastener receivmg element is a first one of a plurality of axial receiving elements The first one and a second one of the plurality of axial receiving elements preferably both extend from the exteπor surface of the axial interface flange to the mtenor surface of the axial interface flange The first one and the second one of the plurality of axial receivmg elements are preferably arranged on opposite sides of the first axial bore hole of the first fluid flow path The exteπor and mteπor openings of each of the plurality of axial receivmg elements are preferably substantially parallel That is, the exterior and interior surfaces of the axial mterface flange immediately defining the mteπor and exteπor openmgs, respectively, of the axial fastener receivmg elements are preferably substantially parallel to each other It is also desirable for a modular chemical delivery system to have multiple flow paths running m multiple, horizontally transverse directions It should be understood that many modular blocks will provide some vertical flow component (e g , a vertical flow section leading to a top bore hole for transporting fluid between a surface mounted chemical control component) However, a modular block or modular block assembly configured to provide multi-directional fluid flow is one that is capable of providing fluid flow in at least first and second directions horizontally transverse to each other and substantial parallel to the top surface of the modular block oi modular block assembly (I e , the top surface of a top layer block of the assembly) Accordingly, an embodiment provides modular blocks configured as top layer modular blocks or lower layer modular blocks for use m a multilayer modular block assembly The top layer and lower layer blocks mav be configured such that an multi-layer assembly of top layer blocks coupled to underlying lower layer blocks is capable of directing fluid flow m multiple, hoπzontallv transverse directions A top layer modular block is preferably configured to mterface with a chemical control component Preferably, the top layer modular block is configured to interface with a vaπety of chemical control components, including valves, pressure regulators, pressure transducers, filters, punfiers, and mass flow controllers (MFCs) A first fluid flow path preferably includes a top bore hole defined m a top surface of the modular block The top bore hole is preferably configured to allow fluid flow to be transported between the modular block and a chemical control component mounted above the modular block The top layer block may mclude component fastener receivmg elements configured to receive fasteners for mountmg a chemical control component above the top surface of the modular block The component fastener receiving elements are preferably defined in the top surface of the top layer modular block and are preferably accessible from directly above the top layer modular block The top layer modular block may include an interface web arranged between a pair of axial mterface flanges and elevationally below the top surface of the modular block Intermediate fastener receivmg elements of a top layer are preferably aπanged within the interface web A lower layer modular block preferably configured for use m an assembly of modular blocks is also provided A lower layer modular block may have similar elements as a top layer modular block, except that a lower layer modular block will preferably be unable to directly interface with a chemical control component and thus will preferably not have component fastener receivmg elements Intermediate fastener receiving elements of a lower layer modular block may mclude holes defined in a fluid flow path wall and directly above a first fluid flow path A top layer modular block and a lower layer block are configured to be coupled together by inserting a top- to-bottom fastener through an intermediate fastener receivmg element of the top layer block mto an intermediate fastener receivmg element of the lower layer modular block A method of removmg modular chemical delivery blocks via access from directly above the modular chemical delivery blocks is also provided A first modular block configured to direct fluid flow is preferably coupled to a laterally adjacent second modular block configured to direct fluid flow by a local-side-to-side fastener The first modular block is removed from the second modular block by accessmg the local side-to-side fastener from directly above the first modular block and removing the local side-to-side fastener from the second modular block and the first modular block. By accessing the local side-to-side fastener from directly above the first modulw block, the method reduces installation time and enables removal of the modular block even when lateral access to the block is limited. In addition, when the first modular block is part of a system including a plurality of modulai blocks, the method preferably allows the first modular block to be removed without compromising the integrity of seals between all other ones of the plurality of modular blocks. Modular blocks are preferably removed without using specialized tools; that is, the method may be performed using only conventional tools such as a wrench. A method of using a modular chemical delivery system is also provided. The method involves transporting fluid flow through a plurality of modular chemical delivery blocks. Laterally adjacent ones of the plurality of modular blocks may be coupled such that sealing joints are formed therebetween. Transporting fluid flow through the plurality of modular blocks preferably involves transporting fluid flow from a fluid flow path of one modular block to a fluid flow path of another modular block through a sealing joint. The method may further involve transporting fluid flow from the plurality of modular blocks to a semiconductor processing chamber. Another embodiment involves a unified modular block configured to direct multi-directional fluid flow therethrough. A unified modular block as described herein preferably includes first and second fluid flow paths having first and second axial bore holes. A lowermost portion of the second fluid flow path is preferably elevationally below a lowermost portion of the first fluid flow path. The first fluid flow path may be configured to transport fluid flow through the unified modular block at least partially in a first direction, and the second fluid flow path may be configured to transport fluid flow through the modular block at least partially in a second direction horizontally transverse to the first direction. As referred to herein, horizontally transverse directions may be those that, when extended to infinity and viewed from above the block, appear to cross. In a prefeπed embodiment, the first direction and the second directions lie on substantially parallel planes but are not themselves parallel. Preferably, the first and second directions are substantially horizontally perpendicular. In addition, the second and first directions are preferably substantially parallel to the top surface. The unified modular block may be further configured to be coupled to other modular blocks laterally adjacent to the first axial bore hole and the second axial borehole. While a multidirectional flow can be obtained using a multilayer modular block system as described above, a unified modular block configured to provide multi-directional fluid flow may have several advantages over, e.g., a multilayer modular block assembly capable of multi-directional fluid flow. The total amount of space occupied by a modular chemical delivery system is partly determined by the size of the modular blocks in the system. Consequently, it is generally desirable to minimize the thickness (i.e., height) of a modular block. One advantage of a unified modular block is the lesser thickness of such a block compared to a multilayer modular block assembly with similar multi-directional flow capabilities. By definition, a multilayer modular block assembly includes two or more vertically adjacent modular blocks. Therefore, the total thickness of such an assembly will tend to increase in proportion to thickness of each block that makes up the assembly. Because the unified block assembly may have a thickness similar to or only slightly greater than that of a single layer block of a multilayer assembly, the thickness of a unified modular block assembly will likely be substantially less than a multilayer block assembly with similar multi-directional flow capabilities. In a preferred embodiment, the thickness of a unified modular block is less that one-half its length and less than one-half its width. Similarly, a unified modular chemical delivery block also preferably reduces the vertical length of the fluid flow paths contamed within when compared to a multilayer modular block assembly In part because a unified modular block houses all fluid flow paths in a single block rather than dividing the paths between two or more blocks (as in a multilayer design), the total vertical length of fluid flow paths may be substantially less than in a multilayer block assembly Such a reduction may substantially reduce the time lequired to dry the fluid paths of a chemical dehverv system Given a constant internal bore diameter the redu.ed vertical length of the fluid flow paths in a unif ied modular block proportionally reduces the total chemical wetted volume inside the fluid flow path bore( s I B\ reducing the total chemical wetted volume of its component fluid paths, a unified modular block can correspondmgly reduce the required dry down time when an inert earner is used to dry out the moisture conteni oi the modular chemical delivery system m which the block is incorporated Consequently, the time between process and/or purge cycles may be reduced In a preferred embodiment, the vertical length of the second fluid flow path is less than one-third a length and a width of the unified modular block Furthermore, it is also desirable to reduce the total weight of a modular chemical delivery system, and the weight of the modular blocks themselves is a large component of the total system weight The weight of a unified modular block may be similar to or slightly greater than the weight of each modular block that makes up a layer of a multilayer modular block assembly. Smce a multilayer modular block assembly mcludes two or more stacked modular blocks, a unified modular block may weigh substantially less than a multilayer block assembly with similar multi-directional flow capabilities. In addition, a multi-layer modular block assembly may require intermediate (top-to-bottom) fasteners to couple vertically adjacent modular blocks and mterlayer seals to seal the fluid path between the top layer between vertically adjacent modular blocks Intermediate seals may be required m multi-layer modular block assemblies to prevent fluid leakage, particularly when corrosive or toxic fluids are being transported However, even the best seals are not completely leakproof. In addition, under the demanding conditions of, for example, semiconductor processmg most seals will wear significantly with tune When this happens, the ability of these seals to prevent fluid leakage is further reduced Similarly, intermediate fasteners may be used m a multilayer modular block assembly to securely couple vertically adjacent blocks and ensure that the seal between such blocks remam mtact Unfortunately, the holes for the intermediate fasteners occupy scarce space on the upper surface of the modular blocks and the intermediate fasteners themselves require additional time to mstall Furthermore, the fasteners can loosen over time, reducmg the integπty of the seals between blocks. Finally, the use of additional seals and fasteners m a multilayer system may increase total costs. A unified modular block as descπbed herem, however, would eliminate the need for intermediate fasteners and seals. Smce a unified modular block does not need to transport fluid flow to another vertically adjacent modular block, seals may only be required, if at all, between laterally adjacent modular blocks and between a surface mounted chemical control component In a prefeπed embodiment, the unified modular flow block is free of intermediate fasteners and seals, thus avoiding the above-descnbed disadvantages of such elements Furthermore, the second fluid flow path of the unified modular block is preferably configured to transport fluid flow between the second axial borehole and a second top borehole defined m the top surface of the unified modular block without passmg through a seal. For many applications, a unified modular block may provide significant advantages over a multilayer modular block assembly with similar capabilities for multi-directional flow A multilayer block assembly, however, may retain some advantages over a unified modular block as described herein For example, if it is desired to modify the orientation of a top fluid flow path while leaving the orientation of a lower fluid flow path unchanged, a multilayer modular block assembly only requires that the top layei modular block be replaced. With a unified modular block assembly, however, the entire block may need to be replaced with another, suitably configured unified modular block Given the respective advantages of the various embodiments of modular blocks presented herem, modular block selection will greatly depend on the particular requirements of a chemical delivery system in which the modular block will be incorporated In an embodiment, the unified modular block preferably includes a first fluid flow path for transporting fluid flow through the modular block at least partially in a first direction The first fluid flow path preferably has a fust axial bore hole in a first exterior surface of the unified modular block The unified modular blo.k lui th-i includes a first axial connection location configured to allow the modular block to be coupled to another modular block laterally adjacent to the first axial bore hole In addition, the unified modular block preferably includes a second fluid flow path for transporting fluid flow through the modular block at least partially in a second direction A lowermost portion of the second fluid flow path is preferably elevationally below a lowermost portion of the fust fluid flow path. The second fluid flow path preferably has a second axial bore hole m a second exterior surface of the unified modular block. The second direction is horizontally tiansverse to the first direction In a preferred embodiment, the second direction is substantially horizontally perpendicular to the first direction. Further, the first and second directions are preferably substantially parallel to a top surface of the modular block. The modular block also includes a second axial connection location configured to allow the modular block to be coupled to a modular block laterally adjacent to the second axial bore hole. In addition, the first and second fluid flow paths may be configured to be m fluid communication within the unified modular blocks. The dimensions of unified modular blocks described herem preferably comply with applicable SEMI standards. A unified modular block configured to direct multi-directional fluid flow therethrough may also allow for access to an axial connection location from directly above the unified modular block In an embodiment, a unified modular block mcludes an axial connection location configured to allow the modular block to be coupled to a laterally adjacent modular block. The intenor surface of the axial connection location is preferably substantially parallel to the exteπor surface of the axial connection location and unobstructed by other portions of the modular block so that the mteπor surface of the axial connection location is accessible from the top surface. This configuration preferably allows the axial connection location to be accessed from directly above the modular block Another embodiment provides a modular chemical delivery system incorporating a plurality of unified modular blocks each configured to provide multi-directional fluid flow therethrough. Each of the plurality of unified modular blocks preferably includes a first fluid flow path for transporting fluid flow through the modular block at least partially in a first direction. The first fluid flow path preferably has a first axial bore hole m a first exterior surface of the unified modular block. Each of the plurality of unified modular blocks may further include a first axial connection location configured to allow the modular block to be coupled to another modular block laterally adjacent to the first axial bore hole In addition, each of the plurality of unified modular blocks preferablv includes a second fluid flow path for transporting fluid flow through the modular block at least partially in a second direction The second direction may be horizontally transverse to the first direction, and both the first and second directions may be substantially parallel to a top surface of the unified modular block The second fluid flow path preferably includes a second axial bore hole in a second exteπoi surface of the unified modular block Each of the plurality of unified modular blocks may further include a second axial connection location configured to allow the modular block to be coupled to a modular block laterally adjacent to the second axial bore hole The modular chemical delivery system further mcludes a plurality of local side-to-side fasteners Preferably, fasteners of the plurality of local side-to-side fasteners couple ones of the plurality of unified modular blocks to other, laterally adjacent ones of the plurality of unified modular blocks. The modular chemical delivery system is preferably resistant to shock and/or vibration; that is, performance of the system is not significantly affected by shocks or vibration dunng operation. A further embodiment is directed to a method of using a modular chemical delivery system The method involves transporting fluid flow through a plurality of unified modular blocks. The method may further mvolve transporting fluid flow from the plurality of modular blocks to a semiconductor processmg chamber In an embodiment, a second fluid flow path of a first one of the plurality of unified modular blocks compnses a second top bore hole, and the method further mcludes transporting fluid flow from a second axial bore hole to the second top bore hole of the first one of the plurality of modular blocks without passing through a seal Beneficially, the dimensions of the modular blocks descπbed herein and their component features preferably comply with applicable SEMI (Semiconductor Equipment and Materials International, Mountain View California) standards. For example, the center-to-center spacing of any component fastener receiving elements preferably complies with SEMI 2787.1, which relates to the surface mount interface of gas distribution components. In an embodiment, the center-to-center spacing of the component fastener receiving elements is less than about 1.2 in., and preferably is 1.188 m. The dimensions of other elements and of a modular block as a whole preferably comply with their respective standards. Such compliance with SEMI standards may assist the modular blocks m bemg used m modular chemical delivery systems configured to transport fluid flow from a plurality of modular blocks to a semiconductor processing chamber for use m semiconductor processmg. The semiconductor processmg chamber can be any of the variety of the specialized chamber used m semiconductor processing, including, but not limited to, etch chambers and deposition chambers. Modular blocks as descπbed herem may be made of any a vaπety of matenals suitable for use in chemical delivery applications, and particularly for delivery of corrosive and/or toxic chemicals. In an embodiment, a modular block as descnbed herem is composed of a metal The metal is preferably stainless steel, and is more preferably high purity stainless steel. Optimally, the metal is 316L stamless steel SCQ VIM VAR having a sulfur concentπ on less than 0.010%, and preferably electroplated. In another embodiment, a modular block as described herein is made of a chemically resistant plastic, prefeiably a fluorocarbon polymer such as Teflon® (commercially available from E.I. du Pont de Nemours and Company). Such materials may allow the modular block to deliver a vanety of fluids, mcludmg highly corrosive fluids. A vanety of methods for making the blocks of the present invention will be apparent to one skilled m the art having the benefit of the present disclosure. For example, the blocks of the present invention may be machmed or cast from suitable matenals. BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of the invention will become apparent upon readmg the following detailed description and upon reference to the accompanying drawings in which: Fig.1 is a top view of a conventional gas delivery system for an etch process tool. Fig. 2 is a perspective view of a modular block assembly that uses full length bolts to fasten individual modular blocks together. Fig. 3A is a cross-sectional view of a modulai block assembly that uses localized bolting ot indi \ idual blocks, in which individual bolts are obstructed by other portions of each block. Fig. 3B is a top view of the substrate design shown m Fig. 3 A. Fig. 4A is a perspective view of a modular block assembly with both directional and transverse directional flow regimes in accordance with an embodiment. Fig. 4B is a cutaway cross-sectional view of the modular block assembly of Fig 4 A. Fig. 5A is a top view of a modular block assembly in which a top layer modular block is coupled to a laterally adjacent top layer block m accordance with an embodiment. Fig. 5B is side view of the modular block assembly of Fig. 5 A taken along lme A-A. Fig. 6 is a top view of the modular block assembly of Fig. 5 A after mountmg a second one of the top layer blocks to an underlymg lower layer block. Fig. 7A is a top view of a modular block similar to those blocks shown in Fig. 6. Fig. 7B is a cross-sectional view of one of the modular blocks shown m Fig. 7A taken along lme B-B. Fig. 8 is a top view of a lower layer modular block assembly in accordance with an embodiment. Fig. 9A is a top view of one of the lower layer modular blocks shown in Fig. 8. Fig. 9B is a cross sectional view of the lower layer modular block shown in Fig. 9A taken along line C-C Fig. 10A is a perspective view of a multi-layer modular block assembly in accordance with an embodiment. Fig. 10B is an exploded view of the modular block assembly shown in Fig. 10A. Fig. 11 is a perspective view of a modular chemical delivery system in accordance with an embodiment. Fig. 12 is a perspective view of the modular chemical delivery system shown m Fig. 11, in which a surface mounted chemical control component is removed from a top layer modular block. Fig. 13 is a perspective view of the modular chemical delivery system shown in Fig. 12, in which mounting fasteners for mounting the modular blocks are removed. Fig. 14 is a perspective view of the modular chemical delivery system shown in Fig. 13, in which top-to- bottom fasteners are removed. Fig. 15 is a perspective view of the modular chemical delivery system shown m Fig. 14, in which a top layer block is removed. Fig. 16 is a perspective view of the modular chemical delivery system shown m Fig. 15, m which a lower layer block is removed. Fig. 17A is a perspective view of a unified modular chemical delivery block in accordance with an embodiment. Fig. 17B is a cutaway cross-sectional view of the unified modular block shown m Fig. 17A. Fig 17C is a side view of the unified modular block shown in Fig 17A Fig 17D is a top view of the unified modular block shown m Fig 17A Fig 17E is a front view of the unified modular block shown in Fig 17A Fig 18 A is a perspective view of a modular block assembly in accordance with an embodiment Fig 18B is an exploded view of the modular block assembly shown m Fig 18A Fig 19 is a perspective view of a chemical delivery system mcorporatmg the modular block assembly of Fig 20A is a perspective view of a unified modular block m accordance with an embodiment Fig 20B is a partial cross-sectional view of the unified modular block of Fig 20A Fig 21 A is a perspective view of a unified modular block in accordance with an embodiment Fig 2 IB is a partial cross-sectional view of the unified modular block of Fig 21 A Fig 22A is a perspective view of a unified modular block in accordance with an embodiment Fig 22B is a partial cross-sectional view of the unified modular block of Fig 22A Fig 23 A is a perspective view of a unified modular block in accordance with an embodiment Fig 23B is a partial cross-sectional view of the unified modular block of Fig 23 A Fig 24A is a perspective view of a unified modular block in accordance with an embodiment Fig 24B is a partial cross-sectional view of the unified modular block of Fig 24A Fig 25 A is a perspective view of a unified modular block in accordance with an embodiment Fig 25B is a partial cross-sectional view of the unified modular block of Fig 25 A Fig 26A is a perspective view of a unified modular block m accordance with an embodiment Fig 26B is a partial cross-sectional view of the umfied modular block of Fig 26A Fig 27A is a perspective view of a umfied modular block in accordance with an embodiment Fig 27B is a partial cross-sectional view of the umfied modular block of Fig 27A Fig 28A is a perspective view of a unified modular block m accordance with an embodiment Fig 28B is a partial cross-sectional view of the unified modular block of Fig 28A Fig 29A is a perspective view of a unified modular block in accordance with an embodiment Fig 29B is a partial cross-sectional view of the unified modular block of Fig 29A Fig 30A is a perspective view of a unified modular block in accordance with an embodiment Fig 30B is a partial cross-sectional view of the unified modular block of Fig 30A Fig 31 A is a perspective view of a unified modular block in accordance with an embodiment Fig 3 IB is a partial cross-sectional view of the umfied modular block of Fig 31 A Fig 32A is a perspective view of a unified modular block in accordance with an embodiment Fig 32B is a partial cross-sectional view of the unified modular block of Fig 32A Fig 33 A is a perspective view of a unified modular block in accordance with an embodiment Fig 33B is a partial cross-sectional view of the umfied modular block of Fig 33 A Fig 34A is a perspective view of a unified modular block in accordance with an embodiment Fig 34B is a partial cross-sectional view of the unified modular block of Fig 34A Fig 35A is a perspective view of a unified modular block in accordance with an embodiment Fig 35B is a partial cross-sectional view of the unified modular block of Fig 35 A Fig 36A is a perspective view of a unified modular block in accordance with an embodiment Fig 36B is a partial cross-sectional view of the unified modular block of Fig 36A Fig 37A is a perspective view of a unified modular block in accordance with an embodiment Fig 37B is a partial cross-sectional view of the unified modular block of Fig 37 A Fig 38A is a perspective view of a top pass thru modular block in accordance with an embodiment Fig 38B is a partial cross-sectional view of the top pass thru modular block of Fig 38A Fig 39A is a perspective view of a bottom pass thru modular block in accordance with an embodiment Fig 39B is a partial cross-sectional view of the bottom pass thru modular block of Fig 39A Fig 40A is a perspective view of a top-accessible modular block m accordance with an embodiment Fig 40B is a partial cross-sectional view of the top-accessible modular block of Fig 40A Fig 41 A is a perspective view of an MFC outlet block m accordance with an embodiment Fig 41B is a partial cross-sectional view of the MFC outlet block of Fig 41A Fig 42A is a perspective view of an MFC inlet block in accordance with an embodiment Fig 42B is a partial cross-sectional view of the MFC mlet block of Fig 42 A Fig 43 A is a perspective view of a Top VCR™ fitting configured to interface with the top surface of a modular block in accordance with an embodiment Fig 43B is a partial cross-sectional view of the Top VCR™ fitting of Fig 43 A Fig 44A is a perspective view of a pass thru cap configured to interface with the top surface of a modular block in accordance with an embodiment Fig 44B is a partial cross-sectional view of the pass thru cap of Fig 43 A Fig 45 is a perspective view of seals configured to be used with modular blocks descπbed herein Fig 46 is a perspective view of a bracket assembly, a lock washer, and fasteners configured to be used with modular blocks descnbed herem Fig 47 is a perspective view of fittings configured to be used with modular blocks descnbed herein Fig 48 A is a perspective view of a top-accessible modular block in accordance with an embodiment Fig 48B is a top view of a view of the top-accessible modular block shown m Fig 48a Fig 48C is a front view of a view of the top-accessible modular block shown m Fig 48a Fig 48D is a rear view of a view of the top-accessible modular block shown m Fig 48a While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example m the drawings and will herein be descπbed in detail It should be understood, however, that the drawmgs and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling withm the spint and scope of the present invention as defined by the appended claims DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Top-Accessible Modular Block A top-accessible modular block configured to direct fluid flow therethrough is provided The top- accessible modular block (may also be referred to as modular substrate or pod) preferably mcludes a top surface, a first axial interface flange and a first fluid flow path. The first axial interface flange preferably includes a first axial connection location configured to allow the modular block to be coupled to a laterally adjacent modular block. The axial connection location preferably includes an exterior surface and an interior surface. The interior surface of the axial connection location is preferably substantially parallel to the exterior surface of the axial connection location and unobstructed by other portions of the modular block so that the interior surface of the axial connection location is accessible from the top surface of the modular block. This configuration preferably allows the axial connection location to be accessed from directly above the top surface of modular block. The first fluid flow path is preferably configured to transport fluid flow through the modular block The first fluid flow path preferably includes a first axial bore hole defined in an exterior surface of the axial interface flange. The first fluid flow path is preferably aπanged adjacent to and partially within the axial interface flange. The axial connection location preferably includes an axial fastener receiving element configured to receive a local side-to-side fastener for coupling the modular block to a laterally adjacent modular block. The axial fastener receiving element preferably has an interior opening defined in the interior surface of the axial interface flange and an exterior opening defined in the exterior surface of the axial interface flange. The interior opening of the axial fastener receiving element is preferably unobstructed by other portions of the modular block so that the interior opening of the axial fastener receiving element is accessible from the top surface. The interior and exterior openings of the axial fastener receiving elements are preferably parallel. The first axial interface flange may contain multiple axial fastener receiving elements. In an embodiment, the first axial interface flange includes a pair of first axial connection locations. The pair of first axial connection locations may be arranged on opposite sides of the first axial bore hole, and preferably are symmetrically arranged on opposite sides of the first axial borehole. The first axial connection locations preferably each extend from an exterior surface to an interior surface of the first axial interface flange. In an embodiment, the top-accessible modular block may include multiple axial interface flanges. Preferably, the top-accessible modular block includes a first and second axial interface flange, each having an interior and an exterior surface. A second axial interface flange may have several features similar to those of a first axial interface flange. The first axial interface flange and the second axial interface flange may be lateral structures of the modular block to which laterally adjacent modular blocks may be coupled. The first and second axial interface flanges are preferably arranged in opposing directions. The first axial interface flange is preferably configured to be oriented in the direction from which fluid flow exits the modular block when the block is incoiporated in a chemical delivery system. The second axial interface flange is preferably configured to be oriented in the direction in which fluid flow enters the modular block when the block is incorporated in a chemical delivery system. The top-accessible modular block may include multiple fluid flow paths. Preferably, the modular block includes a first fluid flow path and a second fluid flow path. A second fluid flow path may be configured similarly to a first fluid flow path. The second fluid flow path is preferably configured to transport fluid flow through the modular block. The second axial interface flange is preferably aπanged adjacent to and around a portion of the second fluid flo path. The first fluid flow path preferably includes a first axial bore hole defined in the exterior surface of the first axial interface flange and a first top bore hole defined in the top surface of the modular block. Similarly, the second fluid flow path preferably includes a second axial bore hole defined m the exterior surface of the second axial mterface flange and a second top bore hole defined in the top surface of the modular block A\ιal fluid path bore holes are preferably aligned m the center of their respective axial interface flanges or slightly off- center, but may be located elsewhere The first and second fluid flow paths may or may not be configured to be in fluid communication within the modular block Each fluid flow path mcludes a bore and at least one bore hole The fluid flow path bore is preferably smooth A sealmg mterface is preferably arranged around each bore hole Sealmg interfaces are preferably configured as counterbore sealmg cavities slightly recessed below the exterior surface in which the bore hole is defined The sealmg mterfaces are preferably configured to mate with an appropriately sized seal gasket of a sealing member The diameters of all sealmg mterfaces and bore holes of a top-accessible modular block are preferably equal It should be understood that a modular block may have more than two fluid flow paths (as can be seen from the Drawings) Likewise, a modular block can have more than one axial bore hole per interface flange and more than two or three top bore holes (perhaps five or more) Preferably, however, a top-accessible modular block has one axial bore hole per axial interface flange, between one to three top bore holes, and, if the block is a top layer modular block, a bottom bore hole Such a configuration preferably allows the modular block to accomplish its desired function without bemg unnecessarily large The first axial mterface flange may include one or more first axial connection locations Preferably, the first axial mterface flange mcludes a pair of first axial connection locations symmetncally aπanged on opposite sides of the first axial bore hole The second axial mterface flange may include one or more second axial connection locations Preferably, the second axial mterface flange mcludes a pair of second axial connection locations symmetncally arranged on opposite sides of the second axial bore hole The first and second axial connection locations are preferably configured to allow the top layer modular block to be coupled to a laterally adjacent modular block In a prefeπed embodiment, the first axial connection locations each include a first axial fastener receivmg element configured to receive a local side-to-side fastener for coupling the modular block to a laterally adjacent modular block Likewise, the second axial connection locations each preferably include second axial fastener receiving elements configured to receive a local side-to-side fastener for couplmg the modular block to a laterally adjacent modular block In an embodiment, the axial fastener receivmg elements may be configured as channels extendmg from an mtenor surface of an axial mterface flange to an exterior surface Each axial fastener receivmg element may mclude an extenor openmg defined in an exteπor surface and an interior openmg defined m an mteπor surface of the axial mterface flange m which it is defined. The mtenor openmg of at least one of the first axial fastener receivmg elements may be unobstructed by other portions of the modular block so that the mtenor openmg of at least one of the first axial fastener receivmg elements is accessible from the top surface Preferably, the mteπor opening of at least one of the second axial fastener receiving elements may be unobstructed by other portions of the modular block so that the mtenor openmg of at least one of the second axial fastener receivmg elements is accessible from the top surface. More preferably, the mteπor openings of all first and second axial fastener receiving elements are unobstructed by other portions of modular block so that the mteπor openmgs of all first and second axial fastener receiving elements are accessible from the top surface Alternately, the intenor openings of one or more of the first or second axial fastener receiving elements may be substantially obstructed by other portions of the modular block from the top surface The first axial mterface flange is preferably configured such that local side-to-side fasteners ma\ be inserted through the intenor openmg of first axial fastener receivmg elements located in the first axial interface flange into the extenor openmg of the second fastener receiving elements located in the second axial interface flange of a laterally adjacent modular block Similarly, the second axial interface flange is preferably configured such that local side-to-side fasteners can be mserted through the interior openings of first axial fastener receiving elements of a laterally adjacent modular block into the exterior openings of second axial fastener receiving elements located m the second axial mterface flange To help accomplish this, the channels of the first and second axial fastener receiving elements may be polarized In an embodiment, the channels of the second axial fastener receivmg elements are threaded. In addition, the channels of the first axial fastener receivmg elements are preferably substantially untextured. Consequently, a local side-to-side fastener may pass without significant resistance through a first axial fastener receiving element without significant resistance to be threadably inserted into a second axial fastener receivmg element of a laterally adjacent modular block Distances between a lowermost portion of each of the axial fastener receivmg elements and the top surface of the modular block are each preferably at most as great as (I e , no more than) a distance between a lowermost portion of the first fluid flow path and the top surface of the modular block That is, the lowermost portion of each of the axial fastener receivmg elements is preferably not below the lowermost portion of the first fluid flow path Tins feature may help prevent the modular block from being unnecessarily thick. More preferably, the distance between a lowermost portion of each of the axial fastener receivmg elements and the top surface of the modular block is less than a distance between a lowermost portion of the first fluid flow path and the top surface of the modular block The exteπor surfaces of the axial mterface flanges are preferably devoid of protrusions That is, while certain minor topographical dispaπhes may exist, no portion of the extenor surface preferably substantially protrudes from the general exteπor surfaces Such a feature may aid m removing a modular block without compromising the seals of adjacent modular blocks, smce bemg devoid of protrusions, the block may easily be moved upward once decoupled without disturbing the seals of seals of non-laterally adjacent coupled modular blocks or substantially movmg the modular blocks from which it was decoupled There may be, however, recesses or holes formed m the axial mterface flange exterior surface, such as for an axial connection location or for an axial borehole, but is preferably nothmg that would substantially restnct the upward movement of two laterally adjacent blocks. The modular block further preferably mcludes a fluid flow path wall ananged around at least a horizontal section of the first fluid flow path and adjacent to the first and second axial mterface flanges Preferably, the width of the fluid flow path wall along the length of the fluid flow path wall is less than a center-to-center spacing between the first one and the second one of the plurality of axial fastener receiving elements The fluid flow path wall may be considered to mclude the portion of the modular block between the axial interface flanges and around and laterally outward from the horizontal portion of the first fluid flow path. So if the width of the fluid flow path wall is, along its entire length, less than a center-to-center spacing between the first one and the second one of the plurality of axial fastener receivmg elements, portions of the first and second axial interface flanges immediately laterally spaced from the outer boundaries of the upper fluid flow path walls may not be directly connected by another portion of the modular block Consequently, a gap may exist between the first and second axial mterface flanges such that a direct path may be taken through the outer boundaries of the modular block from a pomt above a top surface of the modular block to a point below a bottom surface of the modular block Such a feature preferably ensures that sufficient room to access the axial fastener receiving elements exists In addition, by reducing the quantity of material contained m the modular block, the modular block may be made lighter than conventional blocks Top-accessible blocks may be incorporated in a multilayer modular block assembly configured to direct fluid flow in multiple, horizontally transverse directions The modular block assembly may include a plurality of vertically adjacent top-accessible modular blocks Preferably, the modular block assembly mcludes a top layer modular block and a bottom layer modular block Both the top layer modular block and the bottom layer modular block are preferably configured to direct fluid flow theiethrough When connected as parts of the multilayer modular block assembly, the top layer modular block is preferably configured to transport fluid flow in a first direction and the second layer modular block is preferably configured to transport fluid flow m a second direction horizontally transverse to the first direction In addition to havmg one or more of the features described above, a top-accessible top layer modular block is preferably configured to mterface with a chemical control component mounted above its top surface In an embodiment, the top layer modular block mcludes a plurality of component fastener receivmg elements configured to receive fasteners for mountmg a chemical control element above the top surface of the modular block Preferably, the top layer modular block mcludes four component fastener receiving elements defined m the top surface of the top layer modular block Each component fastener receivmg element may be arranged near a respective corner of the modular block The center-to-center spacmg between the chemical control components preferably complies with an applicable SEMI standard regarding surface mount chemical control components Preferably, the center-to-center spacmg between laterally spaced component fastener receivmg elements is less than about 1 2 m , and is more preferably about 1 188 m Furthermore, the top fluid path bore holes of a top layer block are preferably configured to transport fluid between the top layer block and a chemical control component The top layer modular block is preferably configured to be mounted to a support structure (e g a mountmg palette) without the use of a mountmg bracket In an embodiment, the top layer block preferably mcludes a plurality of mountmg fastener receivmg elements configured to receive a mountmg fastener for mountmg the modular block to a support structure without usmg a mountmg bracket Preferably, the top layer modular block includes an mterface web configured between the first and second axial mterface flanges, wherem the plurality of mountmg fastener receivmg elements are arranged within the mterface web Each of the plurality of mountmg fastener receiving elements is preferably accessible from directly above the modular block In a preferred embodiment, each of the plurality of mounting fastener receivmg elements is arranged on a line with one of a plurality of first axial fastener receiving elements and one of a plurality of second axial fastener receiving elements The top layer modular block is preferably configured to be coupled to a vertically adjacent modular block In an embodiment, the top layer modular block includes intermediate fastener receiving elements configured to receive top-to-bottom fasteners for couplmg the top layer modular block to a vertically adjacent modulai bloiΛ Preferably, the top layer modular block includes an interface web configured between the first and second axial interface flanges and below a top surface of the top layer modular block The intermediate fastener receiving elements are preferably holes arranged in the interface web and configured to receive top-to-bottom fasteners The intermediate fastener receivmg elements are preferably accessible from directly above the top layer modular block In an embodiment, a plurality of intermediate fastener receiving elements is aπanged along a centerlme of the modular block Preferably, each of the plurality of intermediate fastener receivmg elements is aπanged on a line with two of the component fastener receivmg elements Such a configuration preferably helps to ensure that there is no mechamcal mterference between components In addition to havmg one or more of the features described above, a top-accessible lower layer modular block is preferably configured to be coupled to a vertically adjacent modular block In an embodiment, the lower layer modular block mcludes intermediate fastener receiving elements configured to receive top-to-bottom fasteners for coupling the top layer modular block to a vertically adjacent modular block Preferably, the lower layer modular block mcludes a fluid flow path wall aπanged around a first fluid flow path The intermediate fastener receiving elements preferably are holes defined in the fluid flow path wall directly above the first fluid flow path wall The intermediate fastener receivmg elements of a lower layer modular block are preferably accessible from duectly above the top layer modular block As explamed above, the dimensions of the top-accessible modular block and features of the modular blocks preferably comply with applicable SEMI standard For example, the width, length, and thickness of the modular block preferably all comply with an applicable SEMI standard regarding the width, length, and depth of modular chemical delivery blocks Preferably, a top-accessible modular block has a length of at most about two inches, a width of at most about two mches, and a thickness of less than about one mch These dimensions may significantly reduce the amount of space occupied by a modular chemical delivery system mcorporatmg such blocks Furthermore, these and other dimensions of the modular block preferably avoid compromising the mechanical structure of the device under required loads/torque when the modular block is coupled to another modular block or component Even at such relatively small dimensions, however, the top-accessible modular chemical delivery block may handle gas flows of up to, e g , 50 SLM, and may further be able to handle flows of up to, e g , 200 SLM A modular chemical delivery system mcorporatmg top-accessible modular blocks is also provided The system preferably includes a plurality of top-accessible modular blocks each configured to direct fluid flow theiethrough Each of the plurality of top-accessible modular blocks may include one or more features of the top- accessible modular blocks descnbed above In an embodiment, each of the plurality of modular blocks preferably mcludes a first axial mterface flange comprising a first axial connection location configured to allow the modular block to be coupled to a laterally adjacent modular block The first axial connection location preferably includes an mtenor surface and an extenor surface The mteπor surface of the first axial connection location is preferably unobstructed by any other portion of the modular block from the top surface Each of the plurality of modular blocks also preferably mcludes a second axial interface flange that mcludes a second axial connection location configured to allow the modular block to be coupled to a laterally adjacent modular block Adjacent modular blocks of the modular chemical delivery system may be coupled, and components may be coupled to modular block of the modular chemical delivery system, usmg fasteners Fasteners may include any of the variety of elements capable of couplmg laterally and/or vertically adjacent modular blocks and may include screws and bolts and/or nuts The fasteners aie preferably threaded The threading mav be any of a variety of tvpe . including UNF and metπc In addition a washer may be positioned on the shaft of a fastener the w ashei is Dieftiablv a lock washer When a fastener upon which the lock washer is aπanged is fully inserted into a fasten. i mg element of the modular block, the lock washer is preferably interposed between a head of the tastenei am.' a surface of the modular block The use of such fasteners prefeiably avoids the need to make connections in the system usmg welded fittings In an embodiment, the system further mcludes a plurality of local side-to-side fasteners Each fastener of the plurality of local side-to-side fasteners preferably couple ones of the plurality of modular blocks to other, laterally adjacent ones of the plurality of modular blocks Preferably, each of the plurality of local side-to-side fasteners includes a head and a shaft The shaft of each of the plurality of local side-to-side fasteners is preferably adjacent the second axial interface flange of one of the plurality of modular blocks and does not extend bevond a centerlme of a respective one of the plurality of modular blocks perpendicular to the respective shaft of each of the plurality of local side-to-side fasteners The features of each of the plurality of modular blocks preferably allows for easy reconfiguration of the blocks wifhm the system In an embodiment, each of the plurality of modular blocks are configured to allow for removal of the local side-to-side fasteners via access from directly above each of the plurality of modular blocks Preferably, each of the plurality of modular blocks is configured such that decoupling one of the plurality of laterally adjacent blocks from a laterally adjacent block does not compromise the integrity of sealing jomts existing between any other ones of the plurality of modular blocks In addition, the system may further include a mountmg (support) structure The plurality of modular blocks is preferably configured to be mounted to the mountmg structure without the use of a mountmg bracket In an embodiment, the system includes a semiconductor processmg chamber The chamber can be any of the variety of the specialized chambers used in semiconductor processmg, mcludmg, but not limited to, etch chambers and deposition chambers Preferably, the system is configured to transport fluid flow from the plurality of modular blocks to the semiconductor processing chamber for use in semiconductor processmg By usmg suitably configured assemblies of top layer and lower layer modular blocks, the system can be configured to transport fluid flow m multiple, horizontally transverse directions As stated above, each of the plurality of modular blocks may be coupled to another, laterally adjacent one of the plurality of modular blocks, preferably by local side-to-side fasteners Fluid flow paths of coupled ones of the plurality of modular blocks are preferably sealably connected by sealing jomts formed therebetween Each of the plurality of modular blocks preferably includes an axial fluid flow path bore hole defined in a lateral surface of the modular block (preferably an axial interface flange) and a sealing interface aπanged around the axial fluid flow path bore hole Sealing mterfaces are preferably configured as described above The system further a plurality of sealing members (e g , seals) aπanged between and m contact with coupled ones of the plurality of modular blocks The sealing members may be "C" seals Each of the sealmg elements preferably mcludes a sealmg gasket configured to mterface with the sealing mterfaces of the plurality of modular blocks Coupled ones of the plurality of modular blocks are preferably each directly m contact with a respective side of one of the plurality of sealmg members such that a sealmg jomt is formed A modular chemical delivery system may further mclude a plurality of modular block assemblies, each configured to transport fluid flow in multiple, horizontally transverse directions In an embodiment, the modular chemical delivery system mcludes a plurality of top layer blocks and a plurality of lower layer blocks The system further includes a plurality of top-to-bottom fasteners Preferably, ones of the plurality of top layer modular blocks are coupled to vertically adjacent ones of the plurality of lower layer blocks by ones of the plurality of top-to- bottom fasteners Top-to-bottom fasteners preferably couple ones of the plurality of top layer blocks and the plurality of lower layer blocks through intermediate fastener receivmg elements in each top layer and lower layer modular block Each of the plurality of top layer modular block is preferably configured to allow removal of ones of the plurality of top-to-bottom fasteners via access from directly above each of the plurality of top layer modular blocks In a prefeπed embodiment, a first top layer block of the plurality of top layer blocks is vertically adjacent to a fust lower layer block of the plurality of lower layer modular blocks The first top layer block is configured to tiansport fluid flow in a first direction parallel to the top surface, and the first lower layer block is configured to ttansport fluid flow in a second direction horizontally transverse to the first direction Preferably, the first lower layer block is configured to transport fluid flow to the top layer modular block The modular chemical delivery system preferably includes a plurality of chemical control elements As explained above, top layer modular blocks are preferably configured to mterface with chemical control elements The chemical control component can be any of the variety used m chemical delivery systems; suitable chemical control components include valves, pressure regulators, pressure transducers, filters, punfiers, and MFCs Each chemical control component is preferably mounted upon the top surface of a top layer modular block usmg chemical control component fasteners. The chemical control component fasteners may be threadably inserted into component fastener receivmg elements to securely mount the chemical control components The modular chemical delivery system may be part of a gas panel. Exemplary embodiments of a top-accessible modular block, a top-accessible multilayer modular block assembly, and a modular chemical delivery system having one or more of the above-descnbed features are shown in the Drawings Figs. 4A and 4B present perspective and cross-sectional views, respectively, of a multilayer modular block assembly 200 in accordance with an embodiment Modular block assembly 200 is preferably configured to direct fluid flow m multiple, horizontally transverse directions Modular block assembly 200 preferably includes top layer modular block 202 and bottom layer modular block 204 (may also be refeπed to as a secondary layer to provide transverse flow). Top layer modular block 202 preferably mcludes a first axial mterface flange 218 and a second axial interface flange 219 Interface web 220 may be aπanged between first axial mterface flange 218 and second axial interface flange 219. As shown, mterface web 220 is preferably below a top surface of top layer modular block 202 First axial mterface flange 218 preferably includes a pair of first axial connection locations 208 First axial connection locations 208 are preferably symmetncally aπanged on opposite sides of an axial bore hole Second axial interface flange 219 preferably includes second axial connection locations 209 Preferably, second axial interface flange 219 includes a pair of second axial connection locations 209 symmetncally aπanged on opposite sides of an axial bore hole. First and second axial connection locations 208 and 209 are preferably configured to allow top laver modular block 202 to be coupled to a laterally adjacent modulai block The interior surfaces of axial .onneuiυn locations 208 and 209 are preferably substantially parallel to the respective exteπor surfaces of the axial connection locations In a prefeπed embodiment, first axial connection locations 208 each include a first axial fastener receiving element configured to receive a local side-to-side fastener for couplmg top layer modular block 202 to a laterally adjacent modular block Likewise, second axial connection locations 209 each preferably include a second axial fastener receiving element configured to receive a local side-to-side fastener for coupling top layer modular block 202 to a laterally adjacent modular block Exemplary local side-to-side fasteners 210 are shown in Figs 4A and 4B In an embodiment, the axial fastener receivmg elements may be channels extendmg from an mteπor surface of an axial interface flange to an exterior surface Each axial fastener receivmg element may mclude an extenor opening defined m an extenor surface and an interior opening defined in an intenor surface The mtenor opening of at least one of the first axial fastener receiving elements may be unobstructed by other portions of top layer modular block 202 so that the mtenor opening of the at least one of the first axial fastener receivmg elements is accessible from the top surface The mtenor and exteπor openmgs of each axial fastener receiving element are preferably substantially parallel First axial interface flange 21 S is preferably configured such that local side-to- side fasteners can be inserted through the mtenor opening of the first axial fastener receivmg elements of modular block 202 into the exteπor openmg of the second fastener receivmg elements of a laterally adjacent modular block In an embodiment, the channels of the first axial fastener recen mg elements defined m second mterface flange 219 are substantially untextured Second axial mterface flange 219 is preferably configured such that local side-to-side fasteners can be inserted through the mteπor openmgs of first axial fastener receiving elements of a laterally adjacent modular block mto the extenor openmgs of second axial fastener receivmg elements of modular block 202 In an embodiment, the channels of the second axial fastener receivmg elements defined in second mterface flange 219 are threaded Top layer modular block 202 mcludes at least one fluid flow path for transporting fluid flow therethrough Top layer modular block 202 may mclude fluid flow paths 240 241, and 243 Fluid flow paths 240 and 241 each have an axial fluid path bore hole 206 defined m a lateral (exterior) surface of modular block 202 and a top fluid path bore hole 226 defined m a top surface of modular block 202 Top layer modular block 202 is preferably configured such that fluid flow from, e g , a laterally adjacent modular block enters the modular block at second axial interface flange 219 and exits the modular block to, e g , a laterally adjacent modular block at first axial interface flange 218 Fluid flow path 243 has a top fluid path bore hole 226 m a top surface of modular block 202 and a bottom fluid path bore hole m a bottom surface of modular block 202 Top layer modular block 202 is preferably configured such that fluid flow from, e g , lower layer modular block 204 enters through the bottom fluid flow path bore hole and exits through the top fluid flow path bore hole 226 of fluid flow path 243 Top layer modular block 202 is preferably configured to mterface with a chemical control component mounted above its top surface Preferably, top layer modular block 202 contams four component fastener receiving elements 212 (may also be refeπed to a fastener locations for mountmg surface components) Each component fastener receivmg element is preferably configured to receive fasteners for mounting a chemical control component above, and preferably upon the top surface of modular block 202 Preferably, component fastener receivmg elements 212 are configured to receive control component fasteners 214 Lower layer modular block 204 preferably mcludes a first axial mterface flange 232 and a second axial interface flange 233. First axial mterface flange 232 preferably mcludes a pair of first axial connection locations 230 First axial connection locations 230 may be configured in a manner similar to first axial connection locations 208 Second axial interface flange 233 preferably includes second axial connection locations (not visible) The second axial connection locations of second axial interface flange 233 may be configured in a manner similar to second axial connection locations 209 In a prefeπed embodiment, first axial connection locations 230 each include a first axial fastener receiving element configured to receive a local side-to-side fastener (e g , local side-io- side fasteners 230) for couplmg lower layer modular block 204 to a laterally adjacent modular block. Lower layer modular block 204 includes at least one fluid flow path for transporting fluid flow theiethrough Lower layer modular block 204 may include fluid flow path 245 Fluid flow path 245 has a top fluid path bore hole 226 m a top surface of modular block 204 and an axial fluid path bore hole 228 (may also be refeired to as a lower axial seal locations) in the exteπor surface of first axial interface flange 232. Lower layer modular block 204 is preferably configured to transport fluid flow to, e g , top layer modular block 204 through the top fluid flow path bore hole of fluid flow path 245 Top layer modular block 202 may be coupled to lower layer modular block 204 using top-to-bottom fasteners 216 Top-to-bottom fasteners 216 (may also be refeπed to as intermediate fastener hardware or multiple layer fastener hardware) are preferably aπanged within intermediate fastener receivmg elements of top layer modular block 202 and intermediate fastener receiving elements of lower layer modular block 204 Preferably, top- to-bottom fasteners 216 are threadably engaged with the intermediate fastener receiving elements m lower layer modular block 204 The thicknesses of each block withm modular block assembly 200 should sufficiently thick to provide proper clearance for the chemical control component fasteners 214 when inserted m component fastener receivmg elements 212 and to provide sufficient room for its axial bore holes to be properly sealed when coupled to an modular block laterally adjacent to a respective axial bore hole. The depth 238 of component fastener receiving elements 212 may be 0.3ιn. to 0.33m. Both top layer modular block 202 and bottom layer modular block 204 preferably have depths 224 and 234, respectively, that are sufficiently thick to provide proper clearance for the chemical control component fasteners 214 and the component fastener receivmg elements 212 mto which the fasteners will be inserted. Depths 224 and 234 also preferably comply with an applicable SEMI standard, preferably SEMI 2787.1. And as stated above, modular block assembly 200 preferably provides axial connection locations on both top layer modular block 202 and lower layer modular block 204 to allow the blocks to be coupled to other blocks in a modular chemical delivery system. Depths 224 and 234 are also sufficiently thick to provide space for the axial connection locations. Likewise, top layer and bottom layer modular blocks 202 and 204 are preferably sufficiently thick to provide the surface area for the axial connection locations without violating industry compliance standaids for minimal wall thickness of the flow paths listed in an applicable ASTM (American Society For Testing and Materials, West Conshohocken, PA) specification (e g , A-269, A-270, and A-632 ( 035ιn wall thickness)) Consequently, thickness 224 of top layer modular block 202 is preferably at least about 0 5m., and thickness 234 of lower layer modular block 204 is at least about 0 55m. As explamed above, it is generally desirable to limit the height of a modular chemical delivery system. Preferably, thickness 224 of top layer modular block 202 is at most about, and thickness 234 of lower layer modular block 204 is at most about 1 in The combined thickness of modular block assembly 236 (may also be refeπed to as stackmg height) is preferably at least about 1 05 and at most about 2m Limiting the thickness of top layer modular block 202 and lower layer modular block 204 may have additional benefits The length of vertical fluid flow path 244 is m large part determined by the thicknesses of top layer modular block 202 and lower layer modular block 204 In general, the longer the length of vertical flow path 244 is, the longer the dry down time when an men gas earner is used to dry out the moisture content of the chemical system will be Consequently, it may be beneficial to keep the thicknesses of top layer modular block 202 and lowei layer modular block 204 below, e g , 1 in Fig 5 A presents a top view of modular block assembl) 300, and Fig 5B presents a side view of the modular block assembly shown m Fig 5A taken along lme A-A Modular block assembly 300 mcludes top layer modular block 302, which is coupled to a laterally adjacent modular block 304 Except where otherwise mdicated top layer modular blocks 302 and 304 may be configured similarly to top layer modular block 202 Both modular blocks 302 and 304 mclude a first axial interface flange 332 and a second axial interface flange 333 Each first axial interface flange 332 preferably includes a pair of first axial connection locations 308 Top fluid flow path bore holes 313 are defined m the top surfaces of modular blocks 302 and 304 Top sealmg interfaces 311 are preferably aπanged around each top fluid flow path bore hole 313 Top sealmg mterfaces 311 are preferably counter bore sealmg cavities Axial fluid flow path bore holes are defined in the exteπor surfaces of axial interfaces 332 and 333 An axial sealmg mterfaces 312 is preferably aπanged around each axial fluid flow path bore hole Axial sealmg interfaces 312 are preferably configured similarly to top sealing interfaces 311 Interface webs 340 preferably extend between the first and second axial interface flange of each modular block Intermediate fastener receivmg elements 323 are preferably aπanged in interface webs 340 Mounting fasteners 342 may be positioned within m mountmg fastener receπ ing elements aπanged in interface webs 240 Top seal cavity ribs 324 are preferably aπanged along the top surface of modular blocks 302 and 304 For both modular blocks 302 and 304, top seal cavity ribs 324 are preferably contiguous with leak test ports 326 of modular blocks 302 and 304 The dimensions of the various connection locations, bore holes and like elements for modular blocks 302 and 304 are preferably configured such that there is minimal, and pieferably no, mechanical mterference therebetween This goal is preferably achieved while maintaining top accessibility of the modular blocks To this end, the diameter of top sealmg mterfaces 311 of top bore holes is preferably about 0 290m Likewise, the diameter 314 of axial sealmg mterfaces 312 is also preferably about 0 290m Given the prefeπed dimensions descπbed above, the areas m which fasteners can be placed will be limited if mechanical mterference is to be avoided For example, local side-to-side fasteners 307 are preferably restricted to area 310, that is, when installed the fasteners preferably do not extend beyond this area The center-to-center spacing 306 of first axial receiving elements 308 and second axial receivmg elements 309 (may also be refeπed to as top surface axial connections) may be one that ensures that the local side-to-side fasteners, when inserted do not mterfeie with other features of each modular block, such as the axial bore holes Preferably, the center-to-center spacing 306 is 620 m Such a spacmg may aid in preventmg mechanical mterference between components of the modular blocks The distance 316 between an intermediate fastener receiving element 323 and a sealing interface 312 of an axial bore hole 330 may be one that avoids causing mechanical interference and/or the violating snuctural integrity of a modular block by requiring the milling lo areas very near the mounting fastener receiving elements; preferably, distance 316 is maximally .33 in. The center-to-center spacing 322 of component fastener receiving elements 318 (may also be refeπed to as top component mounting hole locations) is preferably less than about 1.2 in., and more preferably is 1.188 in. Fig. 6 is a top view of the modular block assembly shown in Fig. 5 A after mounting one of the top layer blocks to an underlying lower layer block. As shown in Fig. 6, modular block 302 may be coupled to an underlying lower layer block (not shown) by top-to-bottom fasteners 336 (may also be refeπed to as intermediate mounting fasteners). Mounting fastener receiving elements 343 (may also be refeπed to as amounting holes) are shown arranged in mounting fastener receiving elements (not visible). For the reasons of preventing mechanical interference discussed above, the mounting fastener receiving elements are preferably restricted to areas 334 (delineated by the dotted lines around mounting fastener receiving elements 343). Restricting the mounting fastener receiving elements to this location will preferably avoid interference with components such as local side- to-side fasteners 307. Fig. 7A presents a top view of a modular block similar to those modular blocks shown in Fig. 6, and Fig. 7B presents a side view along line C-C of the modular block shown in Fig. 7A. Modular block 400 is preferably a top layer block configured to interface with a chemical control component. Consequently, modular block 400 preferably has four component fastener receiving elements 402 (may also be refeπed to as top surface mount chemical delivery component fasteners). Component fastener receiving elements 402 are preferably configured to receive chemical control component fasteners 405. Chemical control component fasteners 405 may be four- inch threaded fasteners. The tap depth 406 of each component fastener receiving element (may also be refeπed to as top surface threaded tap depth) is preferably sufficient to prevent over-travel of the top surface of fasteners 405 when inserted. Preferably, tap depth 406 is .200-.330in. (5.08mm-7.62mm) to provide a safe clearance margin for chemical control component fasteners 405. Modular block 402 also preferably includes mounting fastener receiving elements 403 and intermediate fastener receiving elements 401. Top bore holes 416 are defined in the top surface of modular block 400. Top sealing interfaces 417 are preferably aπanged around top bore holes 412. Axial bore hole 414 is defined in an exterior surface of modular block 400. Axial sealing interface 415 is preferably aπanged around axial bore hole 414. Both axial sealing interface 415 and top sealing interfaces 417 are preferably configured as counterbore sealing cavities. The bore diameter 412 for both axial bore hole 414 and top bore holes 416 is preferably about 0.180in. The sealing interface diameter 410 (may also be refeπed to as sealing counterbore diameter) for both axial sealing interface 415 and top sealing interfaces 417 is preferably about 0.290in. Modular block 400 includes a fastening interface flange 404 (may also be refeπed to as a mechanical interface flange) that is preferably about 0.150in. thick. Top layer modular block 400 has a depth 408 of preferably about 0.500in. Fig. 8 is a top view of lower layer modular block assembly 500. Modular block assembly 500 includes lower layer modular blocks 502 and 504. Modular block 502 preferably has a first axial interface flange 510 and a second axial interface flange 511. Modular block 504 preferably has a first axial interface flange. Modular block 504 preferably has a first axial bore hole (not visible) in its first axial interface, but since modular block 504 is not configured to be coupled to a laterally adjacent modular block opposite modular block 502, modular block 504 preferably does not have additional axial bore holes. A seal joint 518 is preferably formed between modular blocks 502 and 504. Top bore holes 520 are preferably defined in the top surfaces of modular blocks 502 and 504. Fluid flow path wall 516 is aπanged around the fluid flow path bores of modular block 504. Lower seal cavity rib 512 extends along the top surfaces of modular blocks 502 and 504. As described above, modular blocks such as modular blocks 502 and 504 may be sized such that mechanical interference between components is avoided. When installed for coupling modular block 502 to modular block 504, local side-to-side fasteners (also known as bottom axial fasteners) preferably do not extend beyond the delineated by area 506. Additionally, the center-to-center spacing 508 of the first axial connection locations of modular block 504 and the first and second axial connection locations of modular block 502 is may be a distance that avoids interfering with the other features of the modular blocks, such as sealing interface diameters of a respective axial bore holes. Preferably, the center-to-center spacing 508 is about .620in. Sealing interface diameter 514 is preferably about 0.290in. Fig. 9A is a top view of one of the lower layer blocks shown in Fig. 8, and Fig. 9B is a cross-sectional view along line C-C of the lower layer block shown in Fig. 9 A. Lower layer modular block 504 has a first axial interface flange 510. First axial interface flange 510 preferably has a pair of first axial connection locations 562, each having an first axial fastener receiving element. Each first axial fastener receiving element is preferably a substantially untextured channel. Lower layer modular block 504 further includes intermediate fastener receiving elements 550. Intermediate fastener receiving elements 550 (may also be refeπed to as threaded taps) are preferably configured to receive a top-to-bottom fastener for coupling lower layer modular block 504 to a vertically adjacent top layer modular block. Intermediate fastener receiving elements 550 preferably are aπanged within fluid flow path wall 516 above fluid flow path bore 551. Preferably, intermediate fastener receivmg elements 550 provide a safe clearance margin 552 sufficient deep to prevent over-travel of the top surface of the top-to-bottom fasteners when inserted. Preferably, safe clearance margin 552 is about .250in. The bottom of intermediate fastener receiving element 550 is preferably adjacent the top of fluid flow path bore 551. To prevent mechanical interference between any of its components lower layer modular block 504 preferably has a thickness 554 of at least about 0.550in., and preferably less than about 1 in. Additionally, fluid flow path bore 551 preferably has a wall thickness of about .035 in. +/- 0.005 in. Sealing interface diameter 556 is preferably about .290 in. Bore diameter 558 is preferably about .180 in. Beneficially, all of these dimensions may be achieved without violating the wall thickness of fluid path bore 551. Fig. 10A is a perspective view of a multilayer modular block assembly in accordance with an embodiment, and Fig. 10B is an exploded view of modular block assembly shown in Fig. 10A. Multilayer modular block assembly 600 is configured to direct fluid flow in multiple, horizontally transverse directions. The modular block assembly may include a plurality of vertically adjacent top-accessible modular blocks. Preferably, modular block assembly 600 includes top layer modular block 602 and bottom layer modular block 604, both configured to direct fluid flow therethrough. When connected as within modular block assembly 600. top layer modular block 602 is preferably configured to transport fluid flow in a first direction and lower layer modular block 604 is preferably configured to transport fluid flow in a second direction horizontally transverse to the first dnection Pieferably, top layer block 602 is configured to transport fluid flow along directional flow line 606 and lower layer block 604 is configured to transport fluid flow along tiansverse directional flow line 610 Top layer modular block 602 is preferably configured to mterface with chemical control component 632 mounted above the top surface of top layer block 602 Chemical control component 632 is preferably mounted above the top surface of top layer block 602 usmg chemical control component fasteners 630 threadably inserted into a plurality of component fastener receivmg elements (may also be refeπed to as chemical delivery mounting hole locations) defined m the top surface of modular block 602 Top layer modular block includes top fluid path bore holes preferably configured to transport fluid between top layer modular block 602 and chemical control component 632 (may also be refeπed to chemical delivery surface mount controls) Top layer modular block preferably includes intermediate fastener receiving elements configured to receive top-to-bottom fasteners 608 for coupling the top layer modular block to lower layer block 604 Top-to- bottom fasteners are preferably inserted through intermediate fastener receiving elements 644 m top layer modular block 602 and into intermediate fastener receivmg elements 644 in lower layer block 604 to fasten top layer block 602 to lower layer modular block 604 Top layer modular block 602 preferably includes an mterface web 640 configured between first and second axial mterface flanges and below a top surface Preferably, intermediate fastener receivmg elements 644 of top layer modular block 602 are preferably holes aπanged m the mterface web 640 and configured to receive top-to-bottom fasteners 608 Modular block assembly 600 further mcludes smgle direction flow block 646 Single direction flow block 646 may be configured similarly to a top layer modular block such as top layer modular block 602. Smgle direction flow block 646, however, is preferably not configured to be coupled with a vertically adjacent modular block, and thus preferably does not have intermediate fastener receiving elements or a bottom fluid flow path borehole Fluid flow paths of coupled modular blocks of modular block assembly 600 are preferably sealably connected by sealmg jomts 615 formed therebetween Each modular block of modular block assembly 600 preferably includes a pair of axial fluid flow path bore holes defined m extenor surfaces of respective axial mterface flanges of each modular block A axial sealmg mterface is preferably aπanged around each axial fluid flow path bore hole Each modular block also preferably includes at least one top fluid flow path bore hole 636 (gas seal porting locations) defined in the respective top surface of each block Top sealmg mterfaces are preferably aπanged around the top fluid flow path bore holes. Axial and top sealing interfaces are preferably configured as counterbore sealing cavities Sealmg members (e.g , seals) may be aπanged between and in contact with coupled ones of the plurality of modular blocks to sealably connect the adjacent fluid flow paths of each modular block. Each sealmg element preferably includes a sealmg gasket configured to mterface with the sealmg mterfaces of the fluid plow paths it is configuied to sealably connect. Intermediate seal 620 is preferably configured to sealably connect fluid flow paths of top layer modular block 602 and lower layer modular block 604. Intermediate seal gasket 622 is preferably configured to mterface with the top sealmg mterface of lower layer modular block 604 and a bottom sealing interface (not visible) of top layer modular block 602. Axial seals 624 are preferably configured to sealably connect fluid flow paths laterally adjacent modular blocks, such as top layer modular block 602 and single direction flow block 646 Axial seal gaskets 625 are preferably configured to interface with the axial sealing interfaces of the blocks whose fluid flow paths it seals. A sealing joint 615 is preferably formed between top layer modular block 602 and single flow direction modular block 646 when the two blocks are coupled together. Component interface seal 626 is preferably configured to sealably connect the fluid flow paths of top layer modular block 602 to those of chemical control component 632. Component interface seal gaskets 628 are preferably configured to interface with the top sealing interfaces of top layer modular block 602 and the respective sealing interfaces of chemical control component 632. The overall thickness 618 (may also be refeπed to as total staking height) of modular block assembly 600 is preferably between about lin. and 2in., and is more preferably about 1.054in. The distance from top of process stream 614 to bottom of block assembly 600 (may also be refeπed to as center height) is preferably less than the overall thickness 618 and may be less than about lin. A method of using a modular chemical delivery system is also provided. The method preferably involves nansporting fluid flow through a plurality of top-accessible modular chemical delivery blocks. Each of the plurality of modular blocks preferably includes a first axial interface flange having a first axial connection location configured to allow the modular block to be coupled to a laterally adjacent modular block. The first axial connection location preferably includes an interior surface and an exterior surface. The mterior surface of the first axial connection location is preferably unobstructed by any other portion of the modular block from the top surface. Each of the plurality of modular blocks further preferably includes a second axial interface flange comprising a second axial connection location configured to allow the modular block to be coupled to a laterally adjacent modular block. The modular chemical delivery system may include a plurality of local side-to-side fasteners. Each of the plurality of local side-to-side fasteners couples ones of the plurality of modular blocks to other, laterally adjacent ones of the plurality of modular blocks. Laterally adjacent ones of the plurality of modular blocks may be coupled such that sealmg joints are formed therebetween. Transporting fluid flow through the plurality of modular blocks preferably involves transporting fluid flow from a fluid flow path of one modular block to a fluid flow path of another modular block through a sealing joint. The method may further involve transporting fluid flow from the plurality of modular blocks to a semiconductor processing chamber. In an embodiment, the first axial connection location preferably includes a first axial fastener receiving element configured to receive a local side-to-side fastener for coupling the modular block to a laterally adjacent modular block. The first axial fastener receiving element preferably includes an interior opening defined in the interior surface of the first axial interface flange. The interior opening of the first axial fastener receiving element is preferably unobstructed by other portions of the modular block so that the interior opening of the first axial fastener receiving element is accessible from the top surface. In addition, the second axial connection location preferably includes a second axial fastener receiving element configured to receive a local side-to-side fastener for coupling the modular block to an adjacent modular block. Each of the plurality of local side-to-side fasteners is preferably aπanged within the first axial fastener receiving element of one of said plurality of modular blocks and within the second axial fastener receiving element of another, laterally adjacent one of said plurality of modular blocks. In addition, each of the plurality of modular blocks compπses a fluid flow path axial bore hole defined in a lateial surface of the modular block and a sealmg interface aπanged around the fluid flow path axial bore hole A plurality of sealmg elements is preferably aπanged between and m contact with coupled ones of the plurality of modular blocks Each of the sealmg elements may include a sealing gasket configured to interface with the sealing interfaces of the plurality of modular blocks Laterally adjacent blocks are directly in contact with the sealing member to form the sealmg jomts Preferably, transporting fluid flow through a plurality of modular blocks further includes transporting fluid flow horn a fluid flow path of one modular block to a fluid flow path of another modular block through a sealmg member between the modular blocks In another embodiment, a chemical control component is mounted upon a first one of the plurality of modular blocks The method further mvolves transporting fluid flow mto the first one of the plurality of modular blocks through a first axial bore hole m a lateral surface of the first one of the plurality of modular blocks, nansporting fluid flow from the first one of the plurality of modular blocks into the chemical control component through a first top fluid flow path openmg in a top surface of the first one of the plurality of modular blocks, and nansporting fluid flow from the chemical control component mto the first one of the plurality of modular blocks through a second top fluid flow path openmg in the top surface of the first one of the plurality of modular blocks Any of a variety of methods can be used to carry out the transporting of fluid flow, mcludmg pumpmg An embodiment of a method of using a modular chemical delivery system having one or more of the above described-elements may used to transport fluid flow through the modular chemical delivery system shown in Fig 1 1 Modular chemical delivery system 700 includes a plurality of top-accessible top layer modular blocks coupled to a plurality of top-access lower layer blocks One of the plurality of top layer modular blocks is top layer modular block 714 One of the plurality of lower layer modulai blocks is lower layer modular block 716 As can be seen in Fig 11, not all top layer blocks of a modular chemical delivery system will be coupled to a lower layer block, a top layer block of this type has been earlier refeπed to as a single flow direction modular block Modular chemical delivery system 700 also preferably mcludes a support structure, mountmg palette 704, to which the modular blocks of system 700 are mounted Modular chemical delivery system 700 is preferably configured to transport fluid flow through the plurality of top layer modular m multiple, horizontally transverse directions Chemical control component 702 is shown mounted upon top layer modular block 714 Fluid flow may enter system 700 through fluid flow mlet 705 attached to top layer modular block 714 Modular chemical delivery system is further configured to transport fluid flow into modular block 714, mto chemical control component 702, back mto modular block 714, and out of modular block 714 mto a laterally adjacent modular block Furthermore, modular chemical delivery system 700 is prefeiably configured to transport fluid flow from the modular blocks to a semiconductor processing chamber 701 Tiansporting fluid from the modular blocks to semiconductor piocessing chamber 701 preferably occurs through fluid flow line 703 Fluid flow line 703 may include any number of piping sections, valves, and other components A method of removing modular chemical delivery blocks \ la access from directly above the modular chemical delivery blocks is also provided A first modular block configured to direct fluid flow is preferably coupled by a local-side-to-side fastener to a laterally adjacent second modular block configured to direct fluid flow The first modular block is removed from the second modular block by accessing the local side-to-side fastener tiom directly above the first modular block and removing the local side-to-side fastener from the second modular block and the first modular block. Fasteners may be removed using a variety of tools, such as a wrench, or by hand. By accessing the local side-to-side fastener from directly above the first modular block, the method reduces installation time and enables removal of the modular block even when lateral access to the block is limited. In addition, when the first modular block is part of a system including a plurality of modular blocks, the method preferably allows the first modular block to be removed without compromising the integrity of seals between all other ones of the plurality of modular blocks. In an embodiment, the first modular block is a first top layer modular block having a top surface and a plurality of component fastener receiving elements configured to receive fasteners for mounting a chemical control component above the top surface of the first top modular block. The first top layer modular block is preferably coupled to an underlying lower layer block configured to direct fluid flow by a top-to-bottom fastener. The method then preferably includes removing the first top layer modular block from the underlying lower modular block by accessing the top-to-bottom fastener from directly above the first top modular block and removing the top- to-bottom fastener from the lower layer block and the first top layer block. Removing the local side-to-side fastener from the second modular block and the first top layer modular block may be performed prior to or subsequent to or even simultaneous with removing the top-to-bottom fastener from the lower layer block and the top layer block. In addition, a chemical control component may be mounted on a top surface of the modular block. The method preferably then includes removing the chemical control component. The chemical control component is preferably removed prior to removing the local side-to-side fastener from the second modular block and the first modular block and prior to removing the top-to-bottom fastener from the lower layer block and the top layer block. In a further embodiment, the top layer modular block and bottom layer modular block are mounted on a mounting structure by a mounting fastener. The method preferably then includes removing the top layer block and the lower layer block from the mounting structure. Removing the top layer block and the lower layer block from the mounting structure preferably involves accessing the mounting fastener from directly above the first modular block and removing the mounting fastener from the mounting structure. The above-described method may be repeated for a plurality of appropriately configured modular blocks. Additionally, both the first and second modular blocks may be top layer or bottom layer modular blocks, or a top-accessible unified modular block, as desired. A second modular block configured as a unified modular block preferably includes a first fluid flow path for transporting fluid flow through the second modular block at least partially in a first direction. The first fluid flow path preferably has a first axial bore hole in a first exterior surface of the unified modular block. In addition, the second modular block may also include a first axial fastener receiving element having an opening defined in the first exterior surface and configured to receive local side-to-side fasteners for coupling the modular block to an laterally adjacent modular block. The second modular block may also include a second fluid flow path for transporting fluid flow through the second modular block at least partially in a second direction. The second fluid flow path preferably has a second axial bore hole in a second exterior surface of the unified modular block. The second modular block may also include a second axial fastener receiving element having an opening defined in the second exterior surface and configured to receive local side-to-side fasteners for coupling the modular block to an laterally adjacent modular block. The second direction is preferably horizontally transverse to the first direction, and more preferably is substantially horizontally perpendicular to the first direction. In an embodiment, removing the local side-to-side fastener from the second modular block and the fust modular block includes removing the local side-to-side fastener from the second axial fastener receiving element of the second modular block. In a further embodiment, a third modular block configured to direct fluid flow therethrough is laterally adjacent and coupled to the first modular block. The first modular may be removed from the third modular block by accessing a local side-to-side fastener couplmg the first and third modular blocks from directly above and removing the fastener. Removmg the first modular block from the both the laterally adjacent second modular block and the laterally adjacent third modular block, preferably occurs without substantially moving the second third modular blocks. An embodiment of a method for removing modular chemical delivery blocks via access from directly above the modular chemical delivery block having one or more of the above-described features may be described by reference to the Drawings. As shown in Fig. 12, chemical control component 702 may be removed from top layei modular block 714. Control component fasteners 706 may be accessed from the top surface of the assembly top layer modular block and removed by using a wrench to loosen fasteners 706 Fig. 13 shows a subsequent step in which mounting fasteners 710 may be removed. In part because mounting fasteners 710 are attached to mounting palette 704, without use of a mountmg bracket, fasteners 710 may be easily removed via access from directly above the modular blocks. Such a method of removmg mountmg fasteners may be performed with more speed and with less difficulty than conventional methods. Sub-system mounting hardware 708, which mcludes mountmg fasteners 710, is preferably strategically placed such that mechanical interference with multiple layer modular block systems and with adjacent gas paths is avoided. Fig. 14 shows a subsequent step in which top-to-bottom fasteners 718 are removed. Top-to-bottom fasteners 718 (may also be refeπed to as top-to-bottom connection fasteners) are preferably accessed and removed from directly above top layei modular block 714. Consequently, top layer modular block 714 is preferably no longer coupled to lower layer block 716. Fig. 15 shows a step m which top layer modular block 714 is removed. To allow for the removal of top layei modular block 714, local side-to-side fasteners 720 are preferably accessed from directly above top layer modular block 714 and then removed from a laterally adjacent modular block 712 and top layer modular block 714 Since top layer modular block 714 is preferably no longer coupled to any other modular blocks, it may be easily removed In an alternate embodiment where top layer block 714 is attached directly to mounting palette 704, top layei modular block 714 may be removed directly from the mounting palette itself. Fig. 16 shows a subsequent step in which lower layer modular block 716 is removed. To allow for the removal of lower layer modular block 716 (may also be refeπed to as an underlying bottom block or a bottom layer substrate block), local side-to-side fasteners are preferably accessed from directly above modular block 716 and removed, preferably usmg a wrench. The ability to remove all top layer and/or lower layer (dual or multiple layer) blocks until one has removed the entire multi-layer assembly down to the mountmg palette via access from the top surface of the system is an advantage in assembly, disassembly, and reconfiguration of these modular chemical distribution systems. Further, this approach permits removal of an entire single or multiple layer modular block assembly portion of the chemical delivery system from the top working portion of the system with minimal exposure of the system blocks to atmospheric conditions (a known source for contamination of the internal system). This process can be repeated for connecting and disconnecting any number of blocks and layers of blocks, all through access from directly above each modular block. A method for assembling modular chemical delivery system by reversing the order of the above steps will be apparent to one skilled in the art having the benefit of this disclosure. Figs. 48A, 48B, 48C, and 48D are a perspective view, a top view, a front view, and a rear view, respectively, of top-accessible modular block 3800. Modular block 3800 may be used similarly to the modular blocks described above. Modular block 3800 is configured to transport fluid flow therethrough at rates of up, e.g., 200 SLM. The dimensions of modular block 3800 preferably comply with applicable SEMI standards, including SEMI 2787.1. In addition, the dimensions of modular block 3800 preferably serve to reduce or prevent mechanical interference between the components of modular block 3800. Modular block 3800 preferably includes a first axial interface flange 3802 and a second axial interface flange 3803. First and second axial interface flanges each preferably have a thickness 3828.Thickness 3828 is preferably about 0.375 in. First axial interface flange 3802 preferably includes first inner axial connection locations 3808 and first outer axial connection locations 3810. Second axial interface flange 3803 preferably includes second inner axial connection locations 3809 and second outer axial connection locations 3811. Having both inner and outer axial connection locations may aid modular block 3800 in maintaining strong connections during operation, especially at high flow rates. The first and second inner and outer axial connection locations preferably include an exterior surface and an interior surface. The interior surface of each of the axial connection locations is preferably substantially parallel to the exterior surface of the axial connection location and unobstructed by other portions of the modular block sυ that the interior surface of each of the axial connection locations is accessible from the top surface of the modular block. This configuration preferably allows each of the axial connection locations to be accessed from directly above the top surface of modular block 3800. Each of the axial connection locations of modular block 3800 preferably includes an axial fastener receiving element configured to configured to receive a local side-to-side fastener for coupling modular block 3800 to a laterally adjacent modular block. The axial fastener receiving elements preferably each have an interior opening defined in the interior surface of the a respective first or second axial interface flange 3802 or 3803. The interior opening of the axial fastener receiving elements are preferably unobstructed by other portions of the modular block so that the interior opening of the axial fastener receiving elements are accessible from the top surface of modular block 3800. The axial receiving elements of modular block 3800 may be polarized. In an embodiment, the axial fastener receiving elements of first inner axial connection locations 3808 may be substantially untextured. The axial fastener receiving elements of first outer axial connection locations 3809 may be threaded. The axial fastener receiving elements of second inner axial connection locations 3810 may be threaded. The axial fastener receiving elements of second outer axial connection locations 3811 may be substantially untextured. Modular block 3800 preferably includes top bore holes 3816 defined in a top surface of modular block 3800. The center-to-center spacing 3832 of top bore holes 3816 is preferably about 0.455 in. Top sealing interfaces 3817 are preferably aπanged around each top axial borehole. The distance 3830 between the top bore holes and the edge of the modular block is preferably about 0.560 in. A sealing rib 3820 preferably extends between the top bore holes. The width 3821 of sealing rib 3820 is preferably about 0.220. Modular block 3800 preferably includes first axial bore hole 3812 and second axial borehole 3813, which are defined in exterior surfaces of first and second axial interface flanges 3802 and 3803, respectively. Axial sealing interfaces 3814 may be arranged around each axial bore hole. The centers of first and second axial bore holes 3812 and 3813 are both preferably aπanged a distance 3842 from the top of modular block 3800. Distance 3842 is preferably about 0.315 in. A first fluid flow path of modular block 3800 preferably extends from first axial bore hole 3812 to a top borehole 3816. A second fluid flow path of modular block 3800 preferably extends from second axial borehole 3813 to a top bore hole 3816. Leak test ports 3814 are preferably aπanged in both first and second axial interface flanges above first axial bore hole 3812 and second axial borehole 3813. The width 3819 of leak test ports 3818 is preferably equal to the width 3821 of sealing rib 3820. Preferably, width 3819 is about 0.220 in. Each pair of first and second inner and axial connection locations is preferably symmetrically aπanged around the first and second axial bore holes 3812 and 3813, respectively. Each first and second inner axial connection location is preferably spaced a distance 3838 from a respective first or second axial borehole. Distance 383 S is preferably about 0.380 in. First and second inner axial connection locations are preferably aπanged on a centerline of respective first and second axial bore holes 3812 and 3813. More preferably, first and second inner axial connection locations are located in a vertical center of respective first and second axial interface flanges 3802 and 3803. Each pair of first and second outer axial connection locations is preferably symmetrically aπanged around the first and second axial bore holes 3812 and 3813, respectively. Each first and second outer axial connection location is preferably spaced a distance 3840 from a respective first or second axial borehole. Distance 3840 is preferably about 0.607 in. First and second outer axial connection locations are preferably aπanged below a centerline of respective first and second axial bore holes 3812 and 3813. More preferably, first and second outer axial connection locations are located a distance 3836 below a centerline of respective first and second axial bore holes 3808 and 3810. Distance 3836 is preferably about 0.041 in. Consequently, first and second outer axial connection locations are preferably aπanged off a vertical centerline of respective first and second axial interface flanges 3802 and 3803. Modular block 3800 preferably includes component fastener receiving elements 3806. Component fastener receiving elements 3806 are preferably configured to receive control component fasteners for mounting a chemical control component. The distance 3834 between each component fastener receiving element 306 and a centerline of modular block 3800 is preferably about 0.594 in. Modular block 3800 preferably has a length 3822 of between 1 in. and 2 in., and more preferably about 1.547 in. Modular block 3800 preferably has a width 3824 of between 1 in. and 2 in., and more preferably about 1.547 in. In a prefeπed embodiment, length 3822 and width 3824 are substantially equal. The thickness 3826 of modular block 3800 is preferably less than about lin., and more preferably is about 0.63 in. Unified Modular Block Another embodiment includes a unified modular block configured to direct multi-directional fluid flow therethrough. A unified modular block as described herein preferably includes first and second fluid flow paths hav ing fust and second axial bore holes, respectively The first fluid flow path may be configured to transport fluid flow through the umfied modular block at least partially in a first direction, and the second fluid flow path may be configured to transport fluid flow through the modular block at least partially m a second direction horizontally nans verse to the first direction Preferably, the first and second directions are substantially horizontally _> perpendicular In addition, the second and first dnections are pieferably substantially parallel to the top surface of the modular block The unified modular block may be further configured to be coupled to other modular blocks laterally adjacent to the first axial bore hole and the second axial bore hole In an embodiment, the unified modular block includes a first axial connection location configured to allow the unified modular block to be coupled to another 0 modular block laterally adjacent to the first axial bore hole The unified modular block also preferably mcludes a second axial connection location configured to allow the unified modular block to be coupled to a modular block lateially adjacent to the second axial bore hole Preferably, a lowermost portion of the second fluid flow path is elevationally below a lowermost portion of the first fluid flow path A first feature of a modulai block may be considered lower than a second feature of the • > modular block if the first feature is elevationally furthei from the top surface of the modular block ConsequentK fhe loss ei most portion of a fluid flow path may be considered the portion of a fluid flow path elevationallv furthest below the top surface of the modular block In addition, the unified modular block preferably includes a first axial mterface flange and a second axial interface flange In a prefeπed embodiment, the first axial mterface flange is oπented substantially perpendicular 0 to the first direction and the second axial mterface flange is oriented substantially perpendicular to the second direction The first fluid flow path preferably has a first axial bore hole m the first axial mterface flange, and the second fluid flow path preferably has a second axial bore hole m the second interface flange The first and second fluid paths may or may not be configured to be in fluid communication within the unified modular block The first fluid flow path preferably mcludes a first top borehole m a top surface of said unified modular 5 block Likewise, the second fluid flow path preferably mcludes a second top borehole m a top surface of the unified modular block In an embodiment, the first top bore hole is aπanged m a center of the top surface of the unified modular block In an alternate embodiment, the second top bore hole is aπanged m a center of the top surface of the umfied modular block A unified modular block may eliminate any need for intermediate fasteners and seals (I e , seals and 0 fasteners between laterally adjacent modular blocks) In a prefeπed embodiment, the umfied modular block is free of intermediate fasteners and seals, thus avoidmg the above-descπbed disadvantages of such elements Furthermore, the second fluid flow path of the unified modular block is preferably configured to transport fluid flow between the second axial borehole and a second top borehole defined m the top surface of the unified modular block without passmg through a seal As a result of these benefits, the likelihood of leakage or contamination of 5 the fluid flow within a unified modular block may be greatly reduced A unified modular block configured to direct multi-directional fluid flow therethrough may also allow for access to an axial connection location from directly above the unified modular block Preferably, a top-accessible unified modular block includes an axial connection location configured to allow the modular block to be coupled to a laterally adjacent modular block The mteπor surface of the axial connection location is preferably substantially parallel to the exteπor surface of the axial connection location and unobstructed by other portions of the modular block so that the intenor surface of the axial connection location is accessible from the top surface This configuration preferably allows the axial connection location to be accessed from directly above the modular block In a prefeπed embodiment, a top-accessible unified modular block includes a top surface and component fastener receiving elements configured to receive component mountmg fasteners for mountmg a chemical control -ompoiient above the top surface of the unified modular block The unified modular block also preferably includes a first axial interface flange having a first exterior surface and a first interior surface, and a second axial interface flange having a second exterior surface and a second interior surface Preferably , an uppermost surface of the first axial interface flange is elevationally above an uppermost surface of the second axial mterface flange The unified modular block may further include a first fluid flow path for transportmg fluid flow through the modular block at least partially m a first direction The first fluid flow path preferably has a first axial bore hole m the first exterior surface and a first top bore hole m the top surface The unified modular block may further mclude a second fluid flow path for transportmg fluid flow through the modular block at least partially m a second direction The second fluid flow path preferably has a second axial borehole in the second exterior surface and a second top borehole in the top surface Preferably, the second fluid flow path is at least partially aπanged elevationally below the second fluid flow path More preferably, a lowermost portion of the second fluid flow path is elevationally below a lowermost portion of the first fluid flow path Such a feature may allow more space to access axial connection locations when couplmg the modular block to a laterally adjacent modular block The second direction is preferably horizontally transverse to the first direction, and both the second and first directions are substantially parallel to a top sm face of the unified modular block The first axial interface flange preferably includes a plurality of fust axial connection locations and the second axial interface flange preferably includes a pluiahty of second axial connection locations Axial connection locations may be located m the center of or off-center of the extenor surface of the axial interface flange on which they are located The first axial connection locations each preferably mclude a first axial fastener receiving element defmed in the first axial mterface flange and configured to receive local side-to-side fasteners for couplmg the modular block to a laterally adjacent modular block More preferably, the plurality of first axial fastener receiving elements are symmetrically aπanged on opposite sides of the fiist axial bore hole The second axial connection locations each preferably mclude a second axial fastener receiving element defined m the second axial mterface flange and configured to receive local side-to-side fasteners for coupling the modular block to a laterally adjacent modular block More preferably, the plurality of second axial fastener receivmg elements is symmetncally aπanged on opposite sides of the second axial bore hole Each of the plurality of first axial fastener receivmg elements preferably contains an mteπor openmg defined in the first mtenor surface of the first axial mterface flange and an exterior openmg defined m the exteπor surface of the axial mterface flange The mtenor openmgs of each of the plurality of first axial fastener receivmg elements are unobstructed by any other portion of the modular block from the top surface Preferably, the intenor and exterior openings of the axial fastener receiving elements are subs iitially parallel Distances between a lowermost portion of each of the first axial fastener receiving elements and the top surface of the modular block are each preferably at most as great as (I e , no more than) a distance between a lowermost portion of the first fluid flow path and the top surface of the modular block Similarly, distances between a lowermost portion of each of the second axial fastener receiving elements and the top surface of the modular block are each preferably at most as great as (1 e , no more than) a distance between a lowermost portion of the second fluid flow path and the top surface of the modular block Such features may help prevent the unified modular block from bemg unnecessarily thick Preferably, first axial mterface flanges are preferably configured to be oriented m the direction from which fluid flow exits the modular block when the block is incorporated in a chemical delivery system Conversely, second axial interface flanges are preferably configured to be oriented m the direction in which fluid flow enters the modular block when the block is incorporated in a chemical delivery system To facilitate coupling of modular block by insertion of a local side -to-side fastener through first axial receiving elements of one block into second axial teceiving elements of a laterally adjacent modular block, each of the plurality of second axial fastener receiving elements preferably is a threaded channel defmed in the second axial interface flange, and each of the plurality of first axial fastener receiving elements prefeiably is a substantially untextured channel defined in the fust axial mterface flange In an embodiment, the unified modular block further includes a plurality of first axial interface flanges of which the first axial interface flange is a first one A second one of the plurality of first axial interface flanges is preferably oπented substantially perpendicular to the first direction, and mcludes second plurahty of first axial fastener receivmg elements configured to receive local side-to-side fasteners for couplmg the modular block to an laterally adjacent modular block Each of the second plurality of first axial fastener receivmg elements is pieferably a substantially untextured channel Furthermore, the unified modular block preferably mcludes a plurality of first fluid flow paths of which the first fluid flow path is a first one The unified modular block may also include a second one of the plurality of first fluid flow paths for transportmg fluid flow through the modular block at least partially m the first direction The second one of the plurality of first fluid flow paths preferably has a first axial bore hole m an exteπor surface of the second one of said plurality of first axial mterface flanges and a fiist top bore hole m the top surface of the unified modular block Preferably, the first top bore hole of the second one of the plurality of first fluid flow paths is adjacent the first top bore hole of the first one of the plurality of first fluid flow paths The exteπor surfaces of the first and second axial interface flanges are preferably devoid of protrusions That is, while certain mmor topographical disparities may exist, no portion of the exterior surface preferably substantially protrudes from the general exterior surfaces of the axial interface flanges Such a feature may aid in removing a modular block without compromising the seals of adjacent modular blocks, smce being devoid of protrusions, the block may easily be moved upward once decoupled without disturbing the seals of seals of non- laterally adjacent coupled modular blocks or substantially moving the modular blocks from which it was decoupled There may be, however, recesses or holes formed in the axial mterface flange exteπor surface, such as for an axial connection location or for an axial borehole The first axial interface flange may be a first upper axial mterface flange, and the second axial interface flange may be a second lower axial mterface flange The unified modular block may further mclude a second upper axial interface flange opposite the first upper axial interface flange and a first lower axial mterface flange opposite the second lower axial interface flange The umfied modular block further preferably mcludes an upper fluid flow path wall aπanged around at least a horizontal section of the first fluid flow path and adjacent to the first and second upper axial mterface flanges. Preferably, the width of the upper fluid flow path wall along the length of the fluid flow path wall is less than a center-to-center spacmg between the first one and the second one of the first pluia ty of axial fastener receivmg elements. The upper fluid flow path wall may be considered to mclude the portion of the modular block between upper axial interface flanges and around and laterally outward from the horizontal portion of the first fluid flow path. So if the upper fluid flow path wall is, along its entire length, less thick than a center-to-center spacmg the first one and the second one of the first plurality of axial fastener receivmg elements, portions of the first and second upper axial interface flange immediately laterally spaced from the outer boundaries of the upper fluid flow path walls may not be directly connected by another portion of the unified modulai block. Consequently, a gap may exist between the first and second axial interface flanges such that a direct path may be taken through the outer boundaries of the unified modular block from a point above a top surface of the modular block to a point below a bottom surface of the modular block. Such a feature preferably ensures that sufficient room to access the axial fastener receiving elements exists. In addition, by reducmg the quantity of material contained m the modular block, the modular block may be made lighter than conventional blocks Furthermore, the unified modular block further preferably includes a lower fluid flow path wall aπanged aiound the second fluid flow path. The unified modular block further preferably includes an lower fluid flow path wall arranged around at least a horizontal section of the second fluid flow path and adjacent to the first and second lower axial interface flanges. Preferably, the width of the lower fluid flow path wall along the length of the lowei fluid flow path wall is less than a center-to-center spacing between the first one and the second one of a second plurality of axial fastener receiving elements aπanged m the second lower axial interface flange. The lower fluid flow path wall may be considered to include the portion of the modular block between lower axial interface flanges and around and laterally outward from the horizontal portion of the second fluid flow path. Preferably, the upper surface of the lower fluid flow path wall is below the lower surface of the upper fluid flow path wall. The dimensions of a unified modular block and its components preferably comply applicable SEMI standards. In a prefeπed embodiment, the unified modular block complies with SEMI 2787.1. For example, the unified modular block preferably includes four component fastener receivmg elements configured to receive fasteners for mounting a chemical control component above the top surface. The center-to-center spacmg between the chemical control components preferably complies with an applicable SEMI standard regarding surface mount chemical control components. In an embodiment, the center-to-center spacing between the chemical control components wherem a center-to-center spacing between laterally spaced component fastener receiving elements is less than about 1.2 in., and more preferably is 1.188 in. Furthermore, a width, a length, and a thickness of the modular block all comply with an applicable SEMI standard regarding modular chemical delivery blocks As stated above, a unified modular block may be made substantially less thick than a multilayer modular block assembly with a similar capability for multi-directional fluid flow. Preferably, the second fluid flow path com], rises a vertical fluid flow segment. The length of the vertical fluid flow segment is less than one-third a length and a width of the unified modular block. In addition, a thickness of the unified modular block is less than one-half a length and a width of the unified modular block. The unified modular block preferably has a length of at least 1 in and at most about 2 in., a width of at least 1 in. and at most about 2 in., a width of at most about 2 mches, and a thickness of less than about 1 mch. More preferably, the length and width of the modular block are less than about 1 55 in In an embodiment, the spacing between a first one and a second one of the plurality of first axial fastener receiving elements is at least about 0 62 in., and may be 62 in The spacmg between a first one and a second one of the plurality of second axial fastener receivmg elements is at least about 0 6 m , and may be 0 62 in Another embodiment provides a modular chemical delivery system incorporating a plurality of unified modular blocks each configured to provide multi-directional fluid flow therethrough Each of the plurality oi unified modular blocks preferably includes a first fluid flow path for transporting fluid flow through the modular olock at least partially in a first direction The first fluid flow path preferably has a first axial bore hole in a first extenor surface of the unified modular block In addition, each of the plurality of unified modular blocks prefeiably includes a second fluid flow path for transporting fluid flow through the modular block at least partially m a second direction The second direction may be horizontally transverse to the first direction, and both the first and second directions may be substantially parallel to a top surface of the unified modular block The second fluid flow path preferably includes a second axial bore hole in a second exteπor surface of the unified modular block Each of the plurality of unified modular blocks may further include a fiist axial connection location configured to allow the modular block to be coupled to another modular block laterally adjacent to the first axial bore hole, and a second axial connection location configured to allow the modular block to be coupled to a modular block laterally adjacent to the second axial bore hole The modular chemical delivery system further mcludes a plurality of local side-to-side fasteners Local fasteners m general, and local side-to-side fasteners m particular, may be fasteners that couple only a pair of adjacent blocks Preferably, fasteners of the plurality of local side-to-side fasteners couple ones of the plurality of unified modular blocks to other, laterally adjacent ones of the plurality of unified modular blocks In an embodiment, the first axial connection location of each of the plurality of modular blocks preferably includes a first axial fastener receivmg element havmg an opening defined in the first exterior surface and configured to receive fasteners for couplmg the modular block to a laterally adjacent modular block Likewise, the second axial connection location of each of the plurality of modular blocks preferably includes a second axial fastener receiving element having an openmg defined in the second exteπor surface and configured to receive fasteners for couplmg the modular block to an laterally adjacent modular block Each of the plurality of fasteners may be aπanged within the first axial fastener receivmg element of one of said plurality of modular blocks and within the second axial fastener receivmg element of another of said plurality of unified modular blocks such that each of the plurality of modular blocks is coupled to at least one other, laterally adjacent modular block. Sealmg joints are preferably formed between laterally adjacent modular blocks to connect at least one of the fluid flow paths of each coupled one of the plurality of unified modular blocks In an embodiment, first, second and third coupled ones of the plurality of umfied modular blocks are coupled such that the first fluid flow path of the first coupled one of the plurality of unified modular blocks is connected to the first fluid flow path of the second coupled one of the plurality of unified modular blocks In addition, the second fluid flow path of the first coupled one of the plurality of unified modular blocks may be connected to the second fluid flow path of the third coupled one of the plurality of unified modular blocks Furthermore, the first coupled one of the plurality of unified modular blocks may include a third fluid flow path foi nansporting fluid flow through the modular block at least partially in the first direction The third fluid flow path of the plurality of unified modular blocks preferably mcludes a third axial bore hole in a third exterior surface of the first coupled one of the plurality of unified modular blocks. The system may then further mclude a smgle flow direction modular block havmg a first fluid flow path. The smgle flow direction modular block is preferably coupled to the first coupled one of the plurality of unified modular blocks such that the first fluid flow path of the _ ingle flow direction modular block is connected to the third fluid flow path of the first coupled one of the plurality of unified modular blocks. In a prefeπed embodiment, coupled ones of a plurality of unified modular blocks each mclude a sealmg interface aπanged around each fluid flow path bore hole. The sealing interfaces may each be configured as counterbore sealmg cavities. Preferably, the system mcludes a plurality of sealing elements aπanged between and in contact with coupled ones of the plurality of modular blocks. Each of the sealmg elements preferably includes a sealing gasket configured to interface with the sealing interfaces of the plurality of modular blocks Coupled ones of the plurality of unified modular blocks are preferably direct.) in contact with the sealing member to form the sealing joints. Each of the plurality of modular blocks is preferably configured such that decoupling one of the pluiahty of laterally adjacent modular blocks from a laterally adjacent modular block does not compromise the integi lty of sealmg joints existmg between any other ones of the plurality of modular blocks. Furthermore, each of the plurality of unified modular blocks is preferably configured to mterface with a surface mounted chemical control component. Preferably, each of the plurality of unified modular blocks mcludes a plurality of component fastener receivmg elements configured to receive fasteners for mountmg a chemical control component above the top surfaces of each of the pluralities of modular blocks. The system may also include a semiconductor processing chamber. The chamber can be any of the vanety of the specialized chamber used in semiconductor processing, including, but not limited to, etch chambers and deposition chambers. In a prefeπed embodiment, the system is configured to transport fluid flow from the plurality of unified modular blocks to the semiconductor processing chamber. Exemplary embodiments of a unified modular block and a modular chemical delivery system havmg one or more of the above-described features are shown m the Drawings. Figs. 17A, 17B, 17C, 17D, and 17E present a perspective view, a cutaway cross-sectional view, a side view, a top view, and a front view, respectively, of unified modular flow block 800. Unified modular block 800 is configured to direct multi-directional fluid flow theiethiough. Unified modular block 800 may be configured as a three port tee modular block Unified modular block 800 preferably includes first upper axial interface flange 830 and second upper axial mterface flange 831, each havmg an exteπor surface and an mtenor surface. Unified modular block 800 also preferably includes first lower axial interface flange 832 and second lower axial interface flange 833. Preferably, uppermost surfaces of the first and second upper axial mterface flanges are elevationally above an uppermost surface of the first and second lower axial interface flanges. Unified modular block 800 preferably includes upper fluid flow wall 820 and lower fluid flow wall 821. Uppei fluid flow path wall 820 preferably contains fluid flow paths 840 and 842. Fluid flow path 840 preferably has a first axial bore hole 806 (may also be refeπed to as a top axial seal connection) defined in first upper axial interface flange 830 and a top fluid path bore hole 834 defined in a top surface of modular block 800. Fluid flow path 842 preferably has a second axial bore hole 807 defined in second upper axial interface flange 831 and a top fluid path bore hole 834 defined in a top surface of modular block 800. Fluid flow may enter fluid flow paths 840 or 842 in a first direction. Lower fluid flow path wall 821 mcludes a pair of fluid flow paths (not visible) havmg fust and second axial bore holes 808 and 809 respectively in the lower axial interface flanges Lowermost portions of the fluid flow paths withm lower fluid flow path wall 821 are preferably elevationally below lowermost portion of fluid flow paths 840 and 841 Fluid flow path 844 is aπanged withm both upper fluid flow path wall 820 and low er fluid flow path wall 821 Fluid flow path 844 may be considered to form a contiguous fluid flow path with the fluid flow paths withm lower fluid flow path wall 821 Fluid flow path 844 preferably has a top fluid path bore hole 834 in a top surface of modular block 800 Fluid flow ma) enter or exit fluid flow path 844 m a second duection honzontally transverse to the first direction from a lo er axial fluid flow path bore hole 808 or 809 in one of the lower axial mterface flanges Preferably, the second direction is substantially horizontally perpendicular to the fust direction In addition, the second and first directions are preferably substantially parallel to the top surface of the modular block First and second upper axial interface flange 830 and 831 are preferably onented substantially perpendicular to the first direction, and first and second lower axial mterface flanges 832 and 833 are preferably onented substantially perpendicular to the second dnection Unified modular block 800 is preferably configured to be coupled to other modular blocks laterally adjacent to its axial bore holes Consequently, unified modular block 800 may include first axial connection locations to allow the modular block to be coupled to anothei modular block laterally adjacent to a first axial bore hole Pieferably, unified modular block 800 includes second upper axial connection locations 816 and first lower axial connection locations 836 The unified modular may also include second axial connection locations configured to allow the modular block to be coupled to a modular block laterally adjacent to a second axial bore hole Preferably, unified modular block 800 includes second upper axial connection locations 817 and second lower axial connection locations 837 (Axial connection locations may also be refeπed to as axial connections ) Umfied modular block 800 is preferably free of intermediate fasteners and seals, thus avoidmg the above- described disadvantages of such elements Furthermore, fluid flow path 844 is preferably configured to transport fluid flow between a first or second lower axial borehole and a top borehole defined in the top surface of unified modular block 800 without passmg through a seal Unified modular block 800 is preferably a top-accessible unified modular block, that is unified modular block 800 preferably affords access to an axial connection location from directly above itself Preferably, the interioi surfaces of first upper and lower axial connection locations 816 and 836 are substantially parallel to the respective exteπor surface of the axial connection locations and unobstructed by other portions of umfied modular block 800 so that the mtenor surfaces of the first axial connection locations are accessible from the top surface of unified modular block 800 Furthermore, the mteπor surfaces of the second upper and lower axial connection locations 817 and 837 are preferably substantially parallel to the respective exteπor surface of the axial connection locations and unobstructed by other portions of unified modulai block 800 so that the interior surfaces of the second axial connection locations are accessible from the top surface of unified modular block 800 First upper and lowei axial connection locations 816 and 836 each preferably include a first axial fastener receiving element defined in first upper and lower axial mterface flanges 830 and 832, respectively, and configured to receive local side-to-side fasteners for couplmg unified modular block 800 to a laterally adjacent modular block The plurality of fii st axial fastener receivmg elements are preferably symmetncally aπanged on opposite sides of the first axial bore holes 806 and 808 (may also be refeπed to as a bottom axial connection) Each of the plurality of first axial fastener receiving elements preferably contains an interior opening defined m the first interior surface and an extenor opening defined m the second exteπor surface of the first upper or lower axial mterface flange The inteiioi openmgs of each of the plurality of first axial fastener receiving elements are preferably unobstructed by any other portion of modular block 800 from the top surface In addition, the mtenor and exterior openmgs of each of the plurality of first axial fastener receiving elements are preferably substantially parallel Similarly, second upper and lower axial connection locations 833 and 837 each preferably include a second axial fastener receivmg element defined in second upper or lower axial interface flanges, respecπ \ ely and contiguied to receive local side-to-side fasteners for coupling modular block 800 to a laterally adjacent modular block Each of the plurality of second axial fastener receiving elements is symmetrically aπanged on opposite sides of second axial bore holes 807 and 809 Each of the plurality ot second axial fastener receiving elements piefeiably contains an mtenor openmg defined in the second interior surface and an extenor openmg defined in the second exterior surface of the second upper or lower axial mterface flange The mteπor openmgs of each of the plurality of second axial fastener receiving elements are preferably unobstructed by any other portion of modular block 800 from the top surface Local side-to-side fasteners 818 (may also be refeπed to as lower axial or ti ns verse axial fasteners) may be aπanged withm the first axial receiving elements of first axial connection locations 836 In addition, the mteπor and exterior openings of each of the plurality of second axial fastener receiving elements are preferably substantially parallel First axial mterface flanges are preferably configured to be onented m the direction from which fluid flow exits modular block 800 when the block is incorporated in a chemical delivery system Conversely, second axial interface flanges are preferably configured to be oriented in the direction m which fluid flow enters the modular block when the block is mcorporated m a chemical delivery system To facilitate coupling of unified modular blocks by insertion of a local side -to-side fastener through first axial receivmg elements of one block into second axial receiving elements of a laterally adjacent modular block, each of the plurality of second axial fastener receiving elements preferably is a threaded channel, and each ot the plurality of first axial fastener receiving elements is a substantially untextured channel Unified modular block 800 preferably includes a top surface and component fastener receiving elements 802 (may also be refeπed to as top surface mount component fastener locations/holes or mechanical chemical gas delivery mounting hole locations) configured to receive component mountmg fasteners for mountmg a chemical contiol component above the top surface of the unified modular block A top seal cavity rib 838 is preferably arranged along the top surface of unified modular block 800 Top seal cavity πb 834 is preferably contiguous with leak test ports 850 Unified modular block 800 may be substantially less thick than a multilayer modular block assembly with a similar capability for multi directional fluid flow Fluid flow path 844 may be considered a vertical flow segment within (I e , it is onented substantially vertically over its length The length 846 of fluid flow path 844 is preferably less than one-third a length and a width of the unified modular block In addition, a thickness of unified modular block 800 is less than one-half a length and a width of unified modular block 800 The length and width of unified modular block 800 are preferably between lm and 2 m More prefuably, the length and width of unified modular block 800 are preferably between 1 547 and 1 75 In another embodiment, the length and width of unified modular block 800 are preferably between 1 586 and 1 647 The depth of component fastener receiving elements 802 may be 0 3ιn to 0 33m Unified modular block 800 preferably has a thickness 824 sufficiently great to provide proper clearance for the chemical control component fasteners that may be inserted in component fastener receiving elements 802 and to comply with an applicable SEMI standard, preferably SEMI 2787.1. And as stated above, unified modular block 800 preferably provides both upper and lower axial connection locations that allow the block to be coupled to other laterally adjacent blocks in a modular chemical delivery system. Preferably, thickness 824 is also sufficiently thick to provide space for these axial connection locations. Likewise, thickness 824 is preferably sufficient to provide the necessary surface area for all axial connection locations without violating compliance standards for minimal wall thickness of the fluid flow paths withm the block provided in an applicable ASTM (American Society For Testing and Materials, West Conshohocken, PA) specification (e.g., A-269, A-270. and A-632 (.035 in. wall thickness)). In addition, top sealing interfaces 814 are preferably arranged about top fluid flow path bore holes 834. Axial sealing interfaces 852 are preferably aπanged around each axial bore hole of modular block 800. Fluid path bore internal diameter 822 is preferably 0.18in., and the diameters of all top sealing interfaces 814 and axial sealing interfaces 852 are preferably about 0.29 inches. Modular block 800 preferably has a thickness 824 capable of allowing for such feature sizes. Consequently, the minimum mechanical interface depth 810 is preferably at least about 0.5in. In addition, thickness 824 of unified block 800 is preferably at least about 0.6 in. and more preferably at least 0.63 in. As explained above, it is desirable to limit the height of a modular chemical delivery system. But if, for example, the depths of component fastener receiving elements 802 and/or the space required for the axial connection locations is smaller, than thickness 824 may be smaller as well. Furthermore, thickness 824 of unified modular block 800 is preferably at most about 1 in. Limiting the thickness of unified modular block 800 may have additional benefits. The length of vertical fluid flow path 846 in large part determined by thickness 824 of unified modular block 800. In general, the longer the length of vertical flow path 846, the longer the dry down time when an inert gas carrier is used to dry out the moisture content of the chemical system will be. Consequently, it may be beneficial to keep the thicknesses of unified modular block 800 below, e.g., 1 in. The dimensions of the various connection locations, bore holes and like elements for modular blocks 800 are preferably configured such that there is minimal, and preferably no, mechanical interference therebetween. This goal is preferably achieved while maintaining top accessibility modular block 800. Given the prefeπed dimensions described above, the areas in which fasteners can be placed will be somewhat limited if mechanical interference is to be avoided. The center-to-center spacing 826 of first and second upper axial receiving elements 816 and 817 and the center-to-center spacing 828 of first and second lower axial receiving elements 836 and 837 may be one that ensures that, when inserted, the local side to side fasteners do not interfere with other features of each modular block, such as the axial bore holes. Preferably, the center-to-center spacings 826 and 828 are at least about 0.6in., and may be 0.620 in. The center-to-center spacing 804 of component fastener receiving elements 802 is preferably less than about 1.2 in., and more preferably is 1.188 in. Exemplary embodiments of a modular chemical delivery system incorporating one or more unified modular blocks and having one or more of the above-described features are shown in the Drawings. Figs. 18A and 18B present a perspective and an exploded view of modular block assembly 900. Modular block assembly 900 is configured to direct fluid flow m multiple, horizontally transverse directions Modular block assembly preferably includes unified modular block 902, which may coupled to single flow direction block 904 Unified modular block 902 may be configured similarly to unified modular block 800 Pieferably, unified modular block 902 is configuied to transport fluid flow therethrough along directional flow line 906 and along transverse directional flow line 908 Flow along directional flow line 906 may be a process flow and flow along transverse directional line 908 may be a purge flow Directional flow lme 906 will preferably be parallel to the horizontal oπentation of the uppeimost fluid flow paths m modular block 900 Single flow direction modular block 904 is preferably configured to transport fluid flow along directional flow line 906 Single flow direction block 904 is preferably configured similarly to single direction flow block 646 In order to be properly and securely coupled to unified modular block 902, smgle flow direction modular block 904 preferably has similar dimensions (e g , center-to-center spacing of axial connection locations) as unified modulai block 902 Unified modular block 902 is preferably configured to interface with a chemical control component mounted above the top surface of unified modular block 902 Likewise single flow direction block 904 is prefeiably configured to interface with a chemical control component mounted upon its top surface Chemical contiol component 916 is preferably mounted above the top surface ot unified modular block 902 using chemical connol component fasteners 918 threadably inserted into a plurality of component fastener receiving elements defined in the top surface of modular block 902 Unified modular block 902 includes top fluid path bore holes prefeiably configured to transport fluid between unified modular block 902 and chemical control component 916 Unified modular block 900 and single flow direction block 904 may be coupled together using fasteners such as local side-to-side fasteners 914 Fluid flow paths of coupled modular blocks of modular block assembly 900 are preferably sealably connected by sealmg jomts formed therebetween Each modular block of modular block assembly 900 preferably mcludes a parr of axial fluid flow path bore holes defined m extenor surfaces of respecti \ e axial mterface flanges of each modular block A axial sealing mterface is preferably aπanged around each axial fluid flow path bore hole Each modular block of modular block assembly 900 also preferably includes at least on top fluid flow path bore hole defined m the respective top surface of each block Top sealmg mterfaces are preferably aπanged around the top fluid flow path bore holes Axial and top sealmg mterfaces are preferably configured as counterbore sealmg cavities Sealmg members (e g , seals) may be aπanged between and m contact with coupled ones of the plurality of modular blocks to sealably connect the adjacent fluid flow paths of each modular block Each sealmg element prefeiably includes a sealmg gasket configured to mterface with the sealing mterfaces of the fluid plow paths it is configured to sealably connect Axial seals 924 are preferably configured to sealably connect fluid flow paths laterally adjacent modular blocks, such as unified modular block 902 and single direction flow block 904 Axial seal gaskets 925 are preferably configured to interface with the axial sealing interfaces of the blocks whose fluid flow paths it seals A sealmg joint 915 is preferably formed between unified modular block 902 and single flow direction modular block 904 when the two blocks are coupled together Component interface seal 922 is preferably configuied to sealably connect the fluid flow paths of umfied modular block 902 to those of chemical control component 916 Preferably, component mterface seal 922 sealably connects the top fluid flow path bore holes of unified modular block 902 to bottom fluid flow path bore holes of chemical control component 916 Sealing joints 915 aie preferably formed between laterally adjacent modular blocks to connect at least one of the fluid flow paths of each coupled one of the plurality of unified modular blocks Component mterface seal gaskets 923 are pieferably configured to mterface with the top sealmg interfaces of top layer modular block 902 and the respective bottom sealing mterfaces of chemical control component 916 5 A further embodiment is directed to a method of using a modular chemical delivery system The method involves transportmg fluid flow through a plurality of unified modular blocks Each of the plurality of modulai blocks pieferably includes a first fluid flow path for transporting fluid flow through the modular block at least partially in a first direction The first fluid flow path preferably includes a first axial bore hole in a first exterior suitace of the unified modular block Each of the plurality of modular blocks also preferably includes a second 0 fluid flow path for transportmg fluid flow through the modular block at least partially in a second direcnon The second direction is preferably horizontally transverse to the first direction The second fluid flow path preferably has a second axial bore hole m a second exterior surface of the unified modular block. Additionally, each of the pluiahty of modular blocks may further mclude a first axial connection location configured to allow the modular block to be coupled to another modular block laterally adjacent to the first axial bore hole, and a second axial i 3 connection location configured to allow the modular block to be coupled to a modular block laterally adjacent to the second axial bore hole. A plurality of local side-to-side fasteners each preferably couples ones of the plurality of unified modular blocks to other, laterally adjacent ones of the plurality of unified modular blocks In an embodiment, the plurality of fasteners is a plurality of local side-to-side fasteners configured to couple laterally adjacent umfied modular blocks and aπanged such that each of the plurality of local side-to-side 0 fasteners is accessible from directly above the top surface of each of the plurality of modular blocks. Additionally, each of the plurality of modular blocks is preferably coupled to at least one other, laterally adjacent, modular block Sealing joints are preferably formed between laterally adjacent modular blocks to connect at least one of the fluid flow paths of each coupled one of the plurality of unified modular blocks Transporting fluid flow through a plurality of unified modular blocks then preferably includes transporting a fluid flow from a fluid flow path of one 5 of the plurality of unified modular blocks to a fluid flow path of another one of the plurality of modular blocks thiough a sealmg jomt formed between the modular blocks. In an embodiment, a first one of the plurality of umfied modular blocks is configured to interface with a chemical control component. Fluid flow may be transported mto the first one of the plurality of unified modular blocks through a first axial bore hole m a lateral surface of the first one of the plurality of modular blocks. Then, .0 the method may further mclude, transportmg fluid flow from the first one of the plurality of unified modular blocks mto the chemical control component through a first top fluid flow path bore hole m a top surface of the first one of the plurality of modular blocks. From the chemical control component, fluid flow may then be transported back mto the first one of the plurality of unified modular blocks through a second top fluid flow path bore hole m the top surface of the first one of the plurality of modular blocks. Any of a vanety of methods can be used to cany out the 5 n ansporting of fluid flow, mcludmg pumpmg. The method may further mvolve transportmg fluid flow from the plurality of modular blocks to a semiconductor processing chamber. In an embodiment, a second fluid flow path of a first one of the plurality of unified modular blocks compπses a second top bore hole, and the method further includes transportmg fluid flow from a second axial bore hole to the second top bore hole of the first one of the plurality of modular blocks without passing through a seal Embodiments of a modular chemical delivery system havmg one or more of the above-descπbed elements ai e shown m the Drawings Fig 19 presents a perspective view of chemical delivery system 901 Modular chemical delivery system 901 incorporates modular block assembly 900 Chemical control component 916 is shown mounted by control component fasteners 916 onto unified modular block 902 (not visible) Smgle flow dnection modular block 904 is preferably coupled to unified modular block 902 by local side-to-side fasteners 914 Unified modular block 902 may also be coupled to unified modular blocks 950, 952, and 954 Unified modular blocks 950. 952, and 954 are preferably configured similarly to unified modular block 900 Unified modular blocks 902, 950, 952, and 954 may be coupled m a manner similar to how unified modular block 902 and smgle flow direction modular block 904 are coupled m Figs 18A & 18B In a prefeπed embodiment, unified modular blocks 902, 950, 952, and 954 may be coupled such that a first fluid flow path of the unified modular block 902 is connected to a first fluid flow path of the unified modular block 954 In addition a second fluid flow path of unified modular block 902 may be connected to a second fluid flow path of unified modulai block 952 Furthermore, a third fluid flow path umfied modular block 902 is preferably configured for nansporting fluid flow through the modular block at least partially in the first direction The third fluid flow path of the unified modular block 902 preferably includes a third axial bore hole m a third extenor surface of the first coupled one of the plurality of umfied modular blocks Single flow direction modular block 904 is preferably coupled to unified modular block 902 such that a first fluid flow path of the single flow direction modular block is connected to the third fluid flow path of unified modular block 902 Fluid flow paths between unified modular blocks 902, 950. 952, and 954 may be sealably connected m a manner similar to that shown m Figs 18A and 18B for fluid flow paths of blocks 902 and 904 For example, each of the unified modular blocks may each mclude a sealmg interface aπanged around each fluid flow path bore hole The sealing interfaces may each be configured as counterbore sealmg cavities Preferably, system 901 mcludes a plurality of sealmg elements aπanged between and in contact with coupled ones of the modular blocks The sealing elements are preferably axial seals Each of the sealmg elements preferably includes a sealmg gasket configuied to interface with the sealmg mterfaces of the modular blocks Coupled ones of the modular blocks shown in Fig 19 are preferably directly m contact with the sealing member to form the sealing joints Each of modular blocks 902, 950, 952, and 954 is preferably configured such that decouplmg one of the modular blocks horn a laterally adjacent modular block does not compromise the integrity of sealing jomts existing between any othei ones of the modular blocks System 901 may also mclude a semiconductor processmg chamber 960 Fluid flow is preferably transported to semiconductor processing chamber 960 through fluid flow line 958 Fluid flow line 958 may include any number of piping sections, valves, and other components In a prefeπed embodiment, system 901 may be configured to transport fluid flow from the coupled unified modular blocks to the semiconductor processmg chamber An embodiment of a method of usmg a modular chemical delivery system havmg one or more of the above described-elements may used to transport fluid flow through modular chemical delivery system 901 Fluid flow may be transported through modular chemical delivery system 901 in multiple, horizontally transverse dnections Fluid flow may enter system 901 through axial bore holes of. e g , unified modular blocks 950 952 and 954 In an embodiment, fluid flow may be transported mto modulai block 950, from a fluid flow path of modulai block 950 into a fluid flow path of modular block 902 through a sealing joint formed between the modular blocks Piefeiably, fluid flow may then be transported into chemical control component 916 through a top borehole in the top sin face of unified modular block 902 From control component 916, fluid flow may then be transported back into unified modular block 902 through a second top fluid flow path bore hole in the top surface of unified modular block 902 Any of a vanety of methods can be used to cany out the transportmg of fluid flow withm system 901 , including pumping The method may further mvolve transportmg fluid flow from the modular blocks to semiconductor pi oc - sing chamber 960 over fluid lme 958 In addition, a second fluid flow path of a unified modular block 902 piefeiably has a second top bore hole, and the method preferably further mcludes transportmg fluid flow from a second axial bore hole to the second top bore hole of unified modular block 902 without passmg through a seal Figs 20A and 20B are a perspective view and a partial cross-sectional view, respectively, of unified modular block 1000 Unified modular block 1000 is preferably configured to be used as a 2-port mlet left modular block Unified modular block 1000 preferably includes a first upper axial interface flange 1002 First upper axial mteitace flange 1002 preferably mcludes first upper axial connection locations 1006 Unified modular block 1000 also pieferably mcludes a second lower axial interface flange 1005 Second lower axial interface flange 100 pieft iablv includes second lower axial connection locations 1009 Fluid flow path 1020 has an axial bore hole in an exterior surface of first upper axial mterface flange 1002 and a top bore hole in the top surface of unified modulai 1000 Fluid flow path 1021 has an axial bore hole m an extenor surface of second lower axial interface flange 1005 and a top bore hole m the top surface of unified modular 1000 Figs 21A and 21B are a perspective view and a partial cross-sectional view, respectively, of unified modular block 1100. Umfied modular block 1100 is configured to be used a 2-port mlet πght modular block Unified modular block 1100 preferably includes a first upper axial interface flange First upper axial mterface flange 1 102 preferably includes first upper axial connection locations 1106 Unified modular block 1100 also piefeiably includes a first lower axial mterface flange 1104 First lower axial mterface flange 1104 preferably includes first lower axial connection locations 1108 Fluid flow path 1120 has an axial bore hole m an exterior surface of first upper axial mterface flange 1102 and a top bore hole m the top surface of umfied modular block 1100 Fluid flow path 1121 has an axial bore hole in an exterior surface of first lower axial mterface flange 1104 and a top bore hole m the top surface of unified modular block 1100. Figs. 22A and 22B are a perspective view and a partial cross-sectional view, respectively, of unified modular block 1200 Unified modular block 1200 is configured to be used as a 2-port outlet nght modular block Unified modular block 1200 preferably mcludes and a second upper axial mterface flange 1203 Second upper axial interface flange 1203 preferably mcludes first upper axial connection locations 1207. Unified modular block 1200 also preferably includes a second lower axial mterface flange 1205 Second lower axial mterface flange 1205 preferably includes second lower axial connection locations 1209 Interface web 1215 extends from first upper axial interface flange 1202 to second upper axial interface flange 1203 Both axial connection locations 1209 and one of axial connection locations 1207 are substantially obstiucted by mterface web 1215 Fluid flow path 1220 has an axial bore hole m an extenor surface of second uppei axial interface flange 1203 and a top bore hole in the top surface of unified modular block 1200 Fluid flow path 1221 has an axial bore hole m an exterior surface of second lower axial interface flange 1205 and a top bore hole in the top surface of unified modular block 1200 Figs 23 A and 23B are a perspective view and a partial cross-sectional view, respectively, of unified modular block 1300 Unified modular block 1300 is configured to be used as a 2-port mlet tee modular block Unified modular block 1300 preferably includes a first upper axial interface flange 1302 First upper axial interface flange 1 ^02 preferably includes first upper axial connection locations 1306 Unified modular block 1 ^00 also pieU rablv includes a first lower axial interface flange 1304 and a second lower axial interface flange 1305 Fu st lowei axial interface flange 1304 preferably includes first lower axial connection locations 1308 Second lowei axial interface flange 1305 preferably includes second lower axial connection locations 1309 Fluid flow path 1320 has an axial bore hole in an extenor surface of first upper axial interface flange 1302 and a top bore hole in the top surface of unified modular block 1300 Fluid flow path 1321 has an axial bore hole m an exterior surface of second lo er axial interface flange 1305 and fluid flow path 1322 has an axial bore hole m an exterior surface of first low ei axial interface flange 1304 Fluid flow path 1321 and fluid flow path 1322 are preferably m fluid communication and both lead mto fluid flow path 1323, which has a top bore hole in the top surface of unified modulai block 1300 Figs 24 A and 24B are a perspective view and a partial cross-sectional view, respectively, of unified modular block 1400 Unified modular block 1400 is configured to be used as a 2-port outlet left modular block Unified modular block 1400 preferably mcludes a first upper axial interface flange 1402 First upper axial interface flange 1402 preferably mcludes first upper axial connection locations 1406 Unified modular block 1400 also piefeiably includes a second lower axial mterface flange 1405 Second lower axial interface flange 1405 preferably includes second lower axial connection locations 1409 Interfac e web 1415 extends from first upper axial interface flange 1402 to second upper axial interface flange 1403 One of axial connection locations 1406 may be substantially obstructed by mterface web 1415 Fluid flow path 1420 has an axial bore hole in an exterior surface of fust upper axial mterface flange 1402 and a top bore hole in the top surface of unified modular block 1400 Fluid flow path 1421 has an axial bore hole m an exterior surface of second lower axial mterface flange 1405 and a top boie hole m the top surface of unified modular block 1400 Figs 25A and 25B are a perspective view and a partial cross-sectional view, respectively, of umfied mod ilai block 1500 Unified modular block 1500 is configured to be used as a 3-port tee modular block Unified modular block 1500 preferably mcludes a first upper axial mterface flange 1502 and a second upper axial mterface flange 1503 First upper axial mterface flange 1502 preferably mcludes first upper axial connection locations 1506 Second upper axial mterface flange 1503preferably mcludes second upper axial connection locations 1507 Unified modular block 1500 also preferably includes a first lower axial mterface flange 1504 and a second lower axial interface flange 1505 First lower axial interface flange 1504 preferably includes first lower axial connection locations 1508 Second lower axial mterface flange 1505 prefeiably includes second lower axial connection locations 1509 Fluid flow path 1520 has an axial bore hole in an exterior surface of second upper axial interface flange 1 03 and a top bore hole in the top surface of unified modular block 1500 Fluid flow path 1521 has an axial boie hole m an exteπor surface of first lower axial interface flange 1504 and a top bore hole in the top surface of unified modular block 1500 Fluid flow path 1522 has an axial bore hole in an exteπor surface of first upper axial interface flange 1502 and a top bore hole m the top surface of unified modular block 1500 Figs 26A and 26B are a perspective view and a partial cross-sectional view, respectively, of unified modulai block 1600 Unified modular block 1600 is configured to be used as a 3-port right modular block Unified modular block 1600 preferably mcludes a first upper axial interface flange 1602 and a second upper axial interface flange 1603 First upper axial mterface flange 1602 pieferably includes first upper axial connection locations 1606 Second upper axial interface flange 1603 preferably includes second upper axial connection locations 1607 Unified modular block 1600 also preferably includes a first lower axial mterface flange 1604 First lowei axial interface flange 1604 preferably includes first lower axial connection locations 1608 Fluid flow path 1620 has an axial bore hole m an extenor surface of second upper axial interface flange 1603 and a top bore hole in the top sin face of unified modular block 1600 Fluid flow path 1621 has an axial bore hole in an exteπor surface of first lower axial interface flange 1604 and a top bore hole m the top surface of unified modular block 1600 Fluid flow path 1622 has an axial bore hole in an exterior surface of first upper axial mterface flange 1602 and a top bore hole in the top surface of unified modular block 1600 Figs 27A and 27B are a perspective view and a partial cross-sectional view, respectively, of unified modulai block 1700 Unified modular block 1700 is configured to be used as a 3-port left modular block Unified modular block 1700 preferably mcludes a first upper axial mterface flange 1702 and a second upper axial mterface flange 1703 First upper axial mterface flange 1702 preferably includes first upper axial connection locations 1706 Second upper axial interface flange 1703 preferably includes second upper axial connection locations 1707 Unified modular block 1700 also preferably includes a second lower axial mterface flange 1705. Second lower axial interface flange 1705 preferably mcludes second lower axial connection locations 1709 Fluid flow path 1720 has an axial bore hole m an exterior surface of first upper axial mterface flange 1702 and a top boie hole m the top surface of unified modular block 1700 Fluid flow path 1721 has an axial bore hole m an extenor surface of second upper axial mterface flange 1703 and a top bore hole m the top surface of unified modular block 1700 Fluid flow path 1722 has an axial bore hole m an exteπor surface of second lower axial interface flange 1705 and a top bore hole in the top surface of unified modular block 1700 Figs 28A and 28B are a perspective view and a partial cross-sectional view, respectively, of unified modulai block 1800 Unified modular block 1800 is configured to be used as a 2-port outlet tee modular block Unified modular block 1800 preferably mcludes a second upper axial mterface flange 1803 Second upper axial mterface flange 1803 preferably includes second upper axial connection locations 1807 Unified modular block 1800 also preferably mcludes a first lower axial interface flange 1804 and a second lower axial interface flange 1805 First lower axial mterface flange 1804 preferably includes first lower axial connection locations 1808 Second lower axial mterface flange 1805 preferably includes second lower axial connection locations 1809 Interface web 1815 extends partially between first upper axial interface flange 1803 to second upper axial interface flange 1804 One of axial connection locations 1808 and one of axial connection locations 1807 are substantially obstructed by mterface web 1815 Fluid flow path 1820 has an axial bore hole in an exteπor surface of second uppei axial interface flange 1803 and a top bore hole in the top surface of unified modular block 1800 Fluid flow path 1821 has an axial bore hole m an extenor surface of second lower axial interface flange 1805 and fluid flow path 1822 has an axial bore hole in an extenor surface of first axial interface flange 1804 Fluid flow path 1821 and fluid flow path 1822 are preferably in fluid communication, and both lead into fluid flow path 1823 which has a top boie hole in the top surface of unified modular block 1800 1 lgs 29A and 29B are a perspective view and a partial cross-sectional view, respectively, ot unitied modulai block 1900 Unified modular block 1900 is configured to be used as a downstream header tee modulai block Unified modular block 1900 preferably mcludes a first upper axial mterface flange 1902 and a second uppei axial interface flange 1903. First upper axial interface flange 1 02 preferably mcludes first upper axial connection locations 1906. Second upper axial interface flange 1903preferably includes second upper axial connection locations 1907 Unified modular block 1900 also preferably includes a first lower axial mterface flange 1904 and a second lower axial mterface flange 1905. First lower axial interface flange 1904 preferably mcludes first lower axial connection locations 1908 Second lower axial mterface flange 1905 preferably mcludes second lower axial connection locations 1909 Fluid flow path 1922 has an axial bore hole in an exterior surface of second upper axial interface flange 1903 and a top bore hole in the top surface of unified modular block 1900 Fluid flow path 1920 has an axial bore hole in an exteπor surface of first upper axial interface flange 1902 and a top bore hole m the top surface of unified modular block 1900. Fluid flow path 1921 has an axial bore hole m an exterior surface of first lower axial interface flange 1904 is in fluid communication with fluid flow path 1920 Figs. 30A and 30B are a perspective view and a partial cross-sectional view, respectively, of unified modular block 2000. Umfied modular block 2000 is configured to be used as a downstream header left modular block Unified modular block 2000 preferably includes a first upper axial interface flange 2002 and a second uppei axial interface flange 2003. First upper axial interface flange 2002 preferably includes first upper axial connection locations 2006. Second upper axial interface flange 2003 preferably includes second upper axial connection locations 2007. Unified modular block 2000 also preferably includes and a second lower axial interface flange 2005 Second lower axial mterface flange 2005 preferably includes second lower axial connection locations 2009 Fluid flow path 2021 has an axial bore hole in an exterior surface of second upper axial mterface flange 2003 and a top boie hole m the top surface of unified modular block 2000 Fluid flow path 2020 has an axial bore hole m an extenoi surface of first upper axial mterface flange 2002 and a top boie hole m the top surface of unified modular block 2000 Fluid flow path 2022 has an axial bore hole in an exterior surface of second lower axial mterface flange 2005, and preferably is m fluid communication with fluid flow path 2020. Figs. 31A and 31B are a perspective view and a partial cross-sectional view, respectively, of unified modular block 2100. Unified modular block 2100 is configured to be used as a downstream header nght modular block Unified modular block 2100 preferably mcludes a first upper axial mterface flange 2102 and a second upper axial interface flange 2103. First upper axial interface flange 2102 preferably includes first upper axial connection locations 2106. Second upper axial mterface flange 2103preferably mcludes second upper axial connection locations 2107. Unified modular block 2100 also preferably includes a first lower axial mterface flange 2104 First lowei axial interface flange 2104 preferably includes first lower axial connection locations 2108. Fluid flow path 2121 has an axial bore hole m an extenor surface of second upper axial mterface flange 2103 and a top bore hole in the top surface of unified modular block 2100. Fluid flow path 2120 has an axial bore hole m an extenor surface of fust upper axial mterface flange 2102 and a top bore hole in the top surface of unified modular block 2100 Fluid flow path 2122 has an axial bore hole in an exterior surface of first lower axial interface flange 2104, and preferably is in fluid communication with fluid flow path 2120. Figs. 32A and 32B are a perspective view and a partial cross-sectional view, respectively, of unified modular block 2200. Unified modular block 2200 is configured to be used as an upstream header tee modular block. Unified modular block 2200 preferably includes a first upper axial interface flange 2202 and a second upper axial interface flange 2203. First upper axial interface flange 2202 preferably includes first upper axial connection locations 2206. Second upper axial interface flange 2203 preferably includes second upper axial connection locations 2207. Unified modular block 2200 also preferably includes a first lower axial interface flange 2204 and a second lower axial interface flange 2205. First lower axial interface flange 2204 preferably includes first lower axial connection locations 2208. Second lower axial interface flange 2205 preferably includes second lower axial connection locations 2209. Fluid flow path 2220 has an axial bore hole in an exterior surface of first upper axial interface flange 2202 and a top bore hole in the top surface of unified modular block 2200. Fluid flow path 2221 has an axial bore hole in an exterior surface of second upper axial interface flange 2203 and a top bore hole in the top surface of unified modular block 2200. Fluid flow path 2222 has an axial bore hole in an exterior surface of first lower axial interface flange 2204, and fluid flow path 2223 has an axial bore hole in an exterior surface of second lower axial interface flange 2205. Fluid flow path 2222 and fluid flow path 2223 are preferably in fluid communication, and both lead into fluid flow path 2221. Figs. 33 A and 33B are a perspective view and a partial cross-sectional view, respectively, of unified modular block 2300. Unified modular block 2300 is configured to be used as an upstream header left modular block. Unified modular block 2300 preferably includes a first upper axial interface flange 2302 and a second upper axial interface flange 2303. First upper axial interface flange 2302 preferably includes first upper axial connection locations 2306. Second upper axial interface flange 2303preferably includes second upper axial connection locations 2307. Unified modular block 2300 also preferably includes a second lower axial interface flange 2305. Second lower axial interface flange 2305 preferably includes second lower axial connection locations 2309. Fluid flow path 2320 has an axial bore hole in an exterior surface of first upper axial interface flange 2302 and a top bore hole in the top surface of unified modular block 2300. Fluid flow path 2322 has an axial bore hole in an exterior surface of second upper axial interface flange 2303and a top bore hole in the top surface of unified modular block 2300. Fluid flow path 2321 has an axial bore hole in an exterior surface of second lower axial interface flange 2305, and is preferably in fluid communication with fluid flow path 2322. Figs. 34A and 34B are a perspective view and a partial cross-sectional view, respectively, of unified modular block 2400. Unified modular block 2400 is configured to be used as an upstream header right modular block. Unified modular block 2400 preferably includes a first upper axial interface flange 2402 and a second upper axial interface flange 2403. First upper axial interface flange 2402 preferably includes first upper axial connection locations 2406. Second upper axial interface flange 2403 prefeiably includes second upper axial connection locations 2407. Unified modular block 2400 also preferably includes a first lower axial interface flange 2404. First lower axial interface flange 2404 preferably includes first lower axial connection locations 2408. Fluid flow path 2420 has an axial bore hole in an exterior surface of first upper axial interface flange 2402 and a top bore hole in the top surface of unified modular block 2400. Fluid flow path 2421 has an axial bore hole in an exterior surface of second upper axial interface flange 2403 and a top bore hole in the top surface of unified modulai block 2400 Fluid flow path 2422 has an axial bore hole in an exterior surface of first lower axial interface flange 2404, and is preferably m fluid communication with fluid flow path 2421 Figs 35A and 35B are a perspective view and a partial cross-sectional view, respectively, of unified modular block 2600 Unified modular block 2600 is configured to be used as a pump/purge tee modular block Unified modular block 2600 preferably mcludes a first upper axial interface flange 2602 and a second upper axial tntei tace flange 2603 First upper axial mterface flange 2602 pieferably includes first upper axial connection locations 2606 Second upper axial interface flange 2603 preferably includes second upper axial connection locations 2607 Unified modular block 2600 also preferably mcludes a first lower axial mterface flange 2604 and a second lower axial mterface flange 2605 First lower axial mterface flange 2604 preferably mcludes first lower axial connection locations 2608 Second lower axial interface flange 2605 preferably mcludes second lower axial connection locations 2609 Interface web 2615 extends partially between first upper axial mterface flange 2602 and second upper axial mterface flange 2603 Both axial connection locations 2609, one of axial connection locations 2607, and one of axial connection locations 2606 are substantially obstructed by interface web 2615 Huid flow path 2620 has an axial bore hole m an extenor surface of first upper axial interface flange 2602 and fluid flow path 2621 has an axial bore hole m an exterior surface of second upper axial interface flange 2603 Additionally, fluid flow path 2622 has an axial bore hole in an exterior surface of first lower axial mterface flange 2604 and fluid flow path 2623 has an axial bore hole m an extenor surface of second lower axial mterface flange 2605 Fluid flow paths 2620, 2621, 2622, and 2623 are all preferably m fluid communication, and lead mto a top bore hole m the top surface of unified modular block 2600 Figs 36A and 36B are a perspective view and a partial cross-sectional view, respectively, of unified modular block 2700 Unified modular block 2700 is configured to be used as a pump/purge left modular block Unified modular block 2700 preferably mcludes a first upper axial interface flange 2702 and a second upper axial interface flange 2703 First upper axial mterface flange 2702 preferably includes first upper axial connection locations 2706 Second upper axial interface flange 2703 preferably includes second upper axial connection locations 2707 Umfied modular block 2700 also preferably mcludes a second lower axial mterface flange 2705 Second lower axial mterface flange 2705 preferably mcludes second lower axial connection locations 2709 Intei tace web 2715 extends partially between first upper axial mterface flange 2702 and second upper axial interface flange 2703 One of axial connection locations 2707 and one of axial connection locations 2706 are substantially obstructed from the top surface of modular block 2700 by interface web 2715 Fluid flow path 2720 has an axial bore hole in an extenor surface of first upper axial mterface flange 2702, and fluid flow path 2721 has an has an axial bore hole in an extenor surface of second upper axial interface flange 2703 Fluid flow path 2720 and fluid flow 2721 are preferably m fluid communication, and lead mto a top bore hole m the top surface of unified modular block 2700 Fluid flow path 2722 has an axial bore hole m an exteπor surface of second lower axial interface flange 2705 and a top bore hole m the top surface of unified modular block 2700 Figs 37A and 37B are a perspective view and a partial cross-sectional view, respectively, of unified modalar block 2800 Unified modular block 2800 is configured to be used as a pump/purge nght modular block Unified modular block 2800 preferably mcludes a first upper axial interface flange 2802 and a second upper axial interface flange 2803 First upper axial mterface flange 2802 pieferably includes first upper axial connection locations 2806 Second upper axial mterface flange 2803 prefeiably includes second upper axial connection locations 2807 Unified modular block 2800 also preferably includes a first lower axial interface flange 2804 First lower axial interface flange 2804 preferably includes first lower axial connection locations 2808. Interlace web 2815 extends partially between first upper axial interface flange 2802 and second upper axial interface flange 2803 Both of axial connection locations 2808, one of axial connection locations 2807 and one of axial connection locations 2806 are substantially obstructed from the top surface of modular block 2800 by interface web 2815 Fluid flow path 2820 and fluid flow 2821 are preferably in fluid communication, and lead into a top bore hole in the top suiface of unified modular block 2800 Fluid flow path 2822 has an axial bore hole in an exterior surface ol fust lowei axial interface flange 2804 and a top bore hole in the top surface of unified modular block 2800 Figs 38 A and 38B are a perspective view and a partial cross-sectional view, respectively, of top pass thru modular block 2900. Top pass through modular 2900 block is configured to direct fluid flow therethrough. Top pass through modular block 2900 includes axial connections locations 2904 configured to allow top pass through modulai block 2900 to be coupled to, e.g., an upper interface flange of a unified modular block. Top pass thru modular block mcludes bracket holes 2902 configured to allow a mountmg bracket to be attacked to top pass through modular block 2900. Figs 39A and 39B are a perspective view and a cross-sectional view, respectively, of bottom pass thru modular block 2950 Bottom pass through modular 2950 block is configured to direct fluid flow therethrough. Bottom pass through modular block 2950 includes axial connections locations 2952 configured to allow bottom pass through modular block 2950 to be coupled to, e.g , an lower interface flange of a unified modular block (may also be lefeπed to as a united modular block) Figs 40A and 40B are a perspective view and a partial cross-sectional view, respectively, of a universal modular block 3000. Umversal modular block 3000 is configured to dnect fluid flow therethrough Universal modulai block 3000 includes axial connection locations 3002 for allowing universal modular block 3000 to be coupled to, e.g., a laterally adjacent unified modular block Universal modular block 3000 includes bracket holes 3004 configured to allow a mounting bracket to be attacked to umversal modular block 3000 Figs. 41 A and 41B are a perspective view and a partial cross-sectional view, respectively, an MFC outlet block 3100 MFC outlet block 3100 may be coupled to a laterally adjacent modular block. Additionally, MFC outlet block 3100 is configured to mterface with an MFC. Figs. 42A and 42B are a perspective view and a partial cross-sectional view, respectively, an MFC mlet block 3100 MFC mlet block 3200 may be coupled to a laterally adjacent modular block. Additionally, MFC inlet block 3200 is configured to mterface with an MFC. Figs. 43 A and 43B are a perspective view and a partial cross-sectional view, respectively, of a Top VCR™ fitting 3400. Top VCR™ fitting 3400 is configured to mterface with the top surface of a modular block. Figs. 44A and 44B are a perspective view and a partial cross-sectional view, respectively, of a pass thru cap 1500 configured to mterface with the top surface of a modular block Pass thru cap 3500 may be used to pass a fluid flow through a modular block upon which it is mounted. Fig 45 is a perspective view of seals configured to be used with modular blocks descnbed herem. Component mterface seal 3600 is a 2-port seal configured to be used between the top surface of a modular block and the bottom surface of a chemical control component. Component interface seal 3602 is a 3-port seal configured to be used between the top surface of a modular block and the bottom surface of a chemical control component MFC seal 3604 is configured to be used between the top surface of a modular block and the bottom suiface of a MFC. Axial seal 3606 is configured to be used between the axial mterfaces of laterally adjacent modular blocks All of the above seals may be constructed from a variety of chemically resistant metals, including nickel and stamless steel Fig 46 is a perspective view of a bracket assembly 3608, a lock washer 3610, and fasteners 3612 and 3614 configured to be used with modular blocks described herein Biacket assembly 3608 is configured to be coupled to a biacket hole in a modular block and to a support structuie for mounting a modular block Lock washer 3610 is configuied be used on the shaft of a fastener (e.g , fasteners 3612 and 3614) Fasteners 3612 and 3614 are tastenei s configuied couple adjacent modular blocks and/or a modular block to another component For example, fasteners 3612 and 3614 may be local side-to-side fasteneis, top-to-bottom fasteners, chemical control component fasteneis oi mounting fasteners Fasteners 3612 and 3614 may be threaded or unthreaded fasteners, and may include screws oi nuts and/or bolts Fig 47 is a perspective view of mlet fittings configured to be used with modular blocks described herein Bottom fitting right 3700 mcludes axial connection locations 3701 configured to allow bottom fitting nght 3700 to be coupled to a modular block. Bottom fitting left 3702 includes axial connection locations 3703 configured to allow bottom fitting left 3702 to be coupled to a modular block Tube stub mlet 3704 mcludes axial connection locations 3740 configured to allow tube stub mlet 3704 to be coupled to a modular block, and bracket holes 3742 configured to allow a mountmg bracket to be attacked to tube stub inlet 3704. Tube stub outlet 3706 mcludes axial connection locations 3760 configured to allow tube stub outlet 3706 to be coupled to a modular block, and bracket holes 3762 configured to allow a mountmg bracket to be attacked to tube stub outlet 3706. Inlet fitting 3708 includes axial connection locations 3780 configured to allow mlet fitting 3708 to be coupled to a modular block, and bracket holes 3782 configured to allow a mountmg bracket to be attacked to mlet fitting 3708. Outlet fitting 3710 includes axial connection locations 3790 configured to allow outlet fitting 3710 to be coupled to a modular block, and bracket holes 3792 configured to allow a mountmg bracket to be attacked to outlet fitting 3710 All of the above parts may be used as part of a modular chemical delivery system. Further modifications and alternative embodiments of various aspects of the mvention will be apparent to those skilled in the art in view of this descπption. Accordmgly, this descnption is to be construed as illustrative only and is for teaching those skilled m the art the general manner of carrying out the mvention. It is to be undei stood that the forms of the mvention shown and descπbed herein are to be taken as the presently prefeπed embodiments. Elements and matenals may be substituted for those illustrated and descnbed herem, parts and piocesses may be reversed, and certain features of the invention may be utilized mdependently, all as would be apparent to one skilled m the art after having the benefit of this description of the mvention. Changes may be made in the elements described herem without departing from the spurt and scope of the mvention as descnbed in the following claims

Claims: WH AT IS CLAIMED: 1 A unified modular chemical delivery block configured to direct multi-directional fluid flow therethrough, comprising a first fluid flow path for transporting fluid flow through the modular block at least partially m a first direction, wherein the first fluid flow path compnses a first axial bore hole m a first extenor surface of the unified modular block, a first axial connection location configured to allow the modular block to be coupled to another modular block laterally adjacent to the first axial bore hole, a second fluid flow path for transporting fluid flow through the modular block at least partially in a second direction, wherem the second fluid flow path comprises a second axial bore hole in a second exteπor surface of the unified modular block, and wherein the second direction is horizontally transverse to the first direction, and wherem a lowermost portion of the second fluid flow path is elevationally below a lowermost portion of the first fluid flow path, and a second axial connection location configured to allow the modular block to be coupled to a modular block laterally adjacent to the second axial bore hole. 2 The unified modular block of claim 1 , wherem the unified modular block is free of intermediate fasteners or seals 3 The umfied modular block of claim 1 , wherein the second direction is substantially horizontally perpendicular to the first direction. 4 The umfied modular block ofclaim 1, further compnsmg a first axial mterface flange and a second axial interface flange, wherem the first axial mterface flange is oriented substantially perpendicular to the first direction and the second axial mterface flange is onented substantially perpendicular to the second direction. 5 The umfied modular block of claim 4, wherem the first fluid flow path compnses a first axial bore hole in the first axial mterface flange and the second fluid flow path compnses a second axial bore hole m the second interface flange. 6 The umfied modular block of claim 5, wherein the first fluid flow path and the second fluid flow path are configured to be m fluid communication withm the unified modular block 7 The umfied modular block of claim 5, wherem the first fluid flow path further compnses a first top borehole in a top surface of said unified modular block S 1 he unified modular block of claim 7, wherein the second fluid flow path further comprises a second top boienole in a top surface of said unified modular block 9 The umfied modular block of claim 8, wherein the first top bore hole is aπanged in a center of the top surface 10 The umfied modular block o claim 8, wherein the second top bore hole is aπanged m a center of the top stirtace 11 The unified modular block of claim 8, wherein the second fluid flow path is configured to transport fluid between the second axial borehole and the second top borehole without passmg through a seal 12 The umfied modular block of claim 11, the second fluid flow path compnses a vertical fluid flow segment, and wherem the length of the vertical fluid flow segment is less than one-third a length and a width of the unified modular block. 13 The umfied modular block ofclaim 1, wherein a thickness of the unified modular block is less than one- half a length and a width of the unified modular block. 14 The unified modular block of claim 1 , wherein the modular block compnses stainless steel 15 The umfied modular block of claim 1 , wherein the modular block compnses a fluorocarbon polymer. 16 A unified modular chemical delivery block configured to direct multi-directional fluid flow therethrough, compnsmg: a top surface, wherem the unified modular block compnses component fastener receivmg elements configured to receive component mounting fasteners for mountmg a chemical control component above the top surface of the unified modular block; a first axial interface flange compnsmg an first extenor surface and a first mtenor surface; a first fluid flow path for transporting fluid flow through the modular block at least partially m a first direction, wherem the first fluid flow path compnses a first axial bore hole m the first extenor surface and a first top bore hole in the top surface. a plurality of first axial fastener receivmg elements defined in the first axial mterface flange and configured to receive local side-to-side fasteners for couplmg the modular block to an laterally adjacent modular block, wherem each of the plurality of first axial fastener receivmg elements compnses an mtenor openmg defined in the first interior surface of the first axial mterface flange and an exteπor opening defined m the first exteπor surface of the first axial mterface flange, and wherem the mtenor openmgs of each of the plurality of first axial fastener receivmg elements are substantially parallel to respective exterior openmgs and unobstructed by other portions of the modular block from the top surface so that the mtenor openmgs of each of the plurality of first axial fastener receiving elements are accessible from the top surface, a second axial mterface flange comprising a second exterior surface and a second interior surface a second fluid flow path for transporting fluid flow through the modular block at least partially in a second direction, wherem the second fluid flow path comprises a second axial bore hole in the second exteπor surface and a second top bore hole in the top surface, a plurality of second axial fastener receiving elements defined m the second axial mterface flange and configured to receive local side-to-side fasteners for couplmg the modular block to an laterally adjacent modular block; and wherem the second direction is horizontally transverse to the first direction, and wherem the first direction and second direction are substantially parallel to a top surface of the modular block. 17 The umfied modular block of claim 16, wherem an uppermost surface of the first axial mterface flange is elevationally above an uppermost surface of the second axial interface flange 18 The umfied modular block of claim 16, wherem each of the plurality of second axial fastener receivmg elements compnses a threaded channel defined in the second axial interface flange, and wherem each of the plurality of first axial fastener receivmg elements compnses a substantially untextured channel defined m the first axial interface flange. 19 The umfied modular block of claim 18, further compnsmg a plurality of first axial mterface flanges of which the first axial mterface flange is a first one, and wherem a second one of the plurahty of first axial mterface flanges is oriented substantially perpendicular to the first direction, and wherem the second one of the plurality of fust axial mterface flanges compnses a second plurahty of first axial fastener receivmg elements configured to receive local side-to-side fasteners for couplmg the modular block to an laterally adjacent modular block 20 The umfied modular block ofclaim 19, wherem a lowermost portion of the second fluid flow path is elevationally below a lowermost portion of the first fluid flow path further compnsmg a plurality of first fluid flow paths of which the first fluid flow path is a first one, and further comprising a second one of the plurahty of first fluid flow paths for transporting fluid flow through the modular block at least partially in the first direction, wherein the second one of the plurality of first fluid flow paths comprises a first axial bore hole in an exterior surface of the second one of said plurality of first axial interface flanges and a first top bore hole in the top surface of the unified modular block, and wherein the first top bore hole of the second one of the plurality of first fluid flow paths is adjacent the first top bore hole of the first one of the plurality of first fluid flow paths. 21. The unified modular block of claim 16, wherein a width, a length, and a thickness of the modular block all comply with an applicable SEMI standard regarding modular chemical delivery blocks. 10 22. The unified modular block of claim 16, wherein the plurality of component fastener receiving elements comprise four component fastener receiving elements configured to receive fasteners for mounting a chemical control component above the top surface, wherein a center-to-center spacing between the chemical control components complies with an applicable SEMI standard regarding surface mount chemical control components. 1.3 23. The unified modular block ofclaim 16, wherein the modular block comprises a length of at most about 2 inches and a width of at most about 2 inches, and wherein the modular block comprises a thickness of less than about 1 inch, and wherein the plurality of first axial fastener receiving elements are symmetrically aπanged on opposite sides of the first axial bore hole wherein the spacing between a first one and a second one of the plurality 0 of first axial fastener receiving elements is at least .62 inches, and wherein the plurality of second axial fastener receiving elements are symmetrically aπanged on opposite sides of the second axial bore hole and wherein the spacmg between a first one and a second one of the plurality of second axial fastener receiving elements is at least .62 inches, and wherein the plurality of component fastener receiving elements comprise four component fastener receiving elements configured to receive fasteners for mounting a chemical control component above the top 5 surface, and wherein a center-to-center spacing between laterally spaced component fastener receiving elements is less than about 1.2 inches. 24. The unified modular block of claim 16, wherein distances between lowermost portions of each of the plurality of first axial fastener receiving elements and the top surface of the unified modular block are each at most 0 as great as a distance between a lowermost portion of the first fluid flow path and the top surface, and wherein distances between lowermost portions of each of the plurality of second axial fastener receiving elements and the top surface of the unified modular block are each at most as great as a distance between a lowermost portion of the first fluid flow path and the top surface. 35 25. The unified modular block ofclaim 16, wherein the exterior surfaces of the first and second axial interface flanges are substantially devoid of protrusions. 26. A modular chemical delivery system, comprising: a plurality of umfied modular blocks each configured to provide multi-directional fluid flow therethrough, each of the plurality of unified modular blocks compnsmg a first fluid flow path for transportmg fluid flow through the modular block at least partially in a first direction, wherein the first fluid flow path comprises a first axial bore hole in a first exteπor surface of the unified modular block, a first axial connection location configured to allow the modular block to be coupled to another modular block laterally adjacent to the first axial bore hole, a second fluid flow path for transporting fluid flow through the modular block at least partially in a second direction, wherem the second fluid flow path compnses a second axial bore hole m a second exterior surface of the unified modular block, and wherem a lowermost portion of the second fluid flow path is elevationally below a lowermost portion of the first fluid flow path; and a second axial connection location configured to allow the modular block to be coupled to a modular block laterally adjacent to the second axial bore hole, wherem the second direction is horizontally transverse to the first direction, and wherem the first and second directions are substantially parallel to a top surface of the umfied modular block; and a plurality of local side-to-side fasteners, wherem fasteners of the plurality of local side-to-side fasteners couple ones of the plurality of umfied modular blocks to other, laterally adjacent ones of the plurality of umfied modular blocks. 27 The system of claim 26, wherem the first axial connection location of each of the plurality of modular blocks further compnses a first axial fastener receiving element compnsmg an openmg defined m the first exteπor surface and configured to receive fasteners for couplmg the modular block to a laterally adjacent modular block, and wherem the second axial connection location of each of the plurality of modular blocks further compnses a second axial fastener receivmg element compnsmg an openmg defined m the second exteπor surface and configured to receive fasteners for couplmg the modular block to an laterally adjacent modular block, and wherein each of the plurality of fasteners is aπanged withm the first axial fastener receivmg element of one of said plurality of modular blocks and withm the second axial fastener receiving element of another of said plurality of unified modular blocks such that each of the plurality of modular blocks is coupled to at least one other, laterally adjacent modular block, and further compnsmg sealing jomts between lateially adjacent modular blocks to connect at least one ot the fluid flow paths of each coupled one of the plurality of unified modular blocks 28 The system ofclaim 27, wherem first, second and third coupled ones of the plurality of unified modular blocks are coupled such that the first fluid flow path of the first coupled one of the plurality of unified modular blocks is connected to the first fluid flow path of the second coupled one of the plurality of unified modular blocks, and wherein the second fluid flow path of the first coupled one of the plurality of unified modular blocks is connected to the second fluid flow path of the third coupled one of the plurality of unified modular blocks. 29. The system of claim 28, and wherein the first coupled one of the plurality of unified modular blocks comprises a third fluid flow path for transporting fluid flow through the modular block at least partially in the first direction, wherein the third fluid flow path of the plurality of unified modular blocks comprises a third axial bore hole in a third exterior surface of the first coupled one of the plurality of unified modular blocks, the system further comprising a single flow direction modular block comprising a first fluid flow path, and wherein the single flow direction modular block is coupled to the first coupled one of the plurality of unified modular blocks such that the first fluid flow path of the single flow direction modular block is connected to the third fluid flow path of the first coupled one of the plurality of unified modular blocks. 30. The system of claim 27, wherein each of the coupled ones of the plurality of unified modular blocks comprises a sealing interface aπanged around each fluid flow path bore hole, and further comprising a plurality of sealing elements aπanged between and in contact with coupled ones of the plurality of modular blocks, and wherein each of the sealing elements comprising a sealing gasket configured to interface with the sealing interfaces of the plurality of modular blocks, and wherein coupled ones of the plurality of modular blocks are directly in contact with a sealing member to form the sealing joints. 31. The system of claim 27, wherein each of the plurahty of modular blocks is configured such that decoupling one of the plurality of laterally adjacent modular blocks from a laterally adjacent modular block does not compromise the integrity of sealing joints existing between any other ones of the plurality of modular blocks. 32. The system of claim 26, wherein each of the plurality of unified modular blocks further comprises a plurality of component fastener receiving elements configured to receive fasteners for mounting a chemical control component above the top surfaces of each of the pluralities of modular blocks. 33. The system ofclaim 26, further comprising a semiconductor processing chamber, and wherein the system is configured to transport fluid flow from the plurality of modular blocks to the semiconductor processing chamber. 34. A method for using a modular chemical delivery system, comprising: transporting fluid flow through a plurality of unified modular blocks, wherein each of the plurality of modular blocks comprises: a first fluid flow path for transporting fluid flow through the modular block at least partially in a first direction, wherein the first fluid flow path comprises a first axial bore hole in a first exterior surface of the unified modular block; a first axial connection location configured to allow the modular block to be coupled to another modular block laterally adjacent to the first axial bore hole; a second fluid flow path for transporting fluid flow through the modular block at least partially in a second direction, wherein the second fluid flow path comprises a second axial bore hole in a second exterior surface of the unified modular block, and wherein a lowermost portion of the second fluid flow path is elevationally below a lowermost portion of the first fluid flow path; and a second axial connection location configured to allow the modular block to be coupled to a modular block laterally adjacent to the second axial bore hole, wherein the second direction is horizontally transverse to the first direction; and wherein each of a plurality of local side-to-side fasteners couples ones of the plurality of unified modular blocks to other, laterally adjacent ones of the plurality of unified modular blocks. 35. The method ofclaim 34, further comprising transporting fluid flow from the plurality of unified modular blocks to a semiconductor processing chamber. 36. The method of claim 34, wherein the plurality of fasteners is a plurality of local side-to-side fasteners configured to couple laterally adjacent unified modular blocks and aπanged such that each of the plurality of fasteners is accessible from directly above the top surface of each of the plurality of modular blocks. 37. The method ofclaim 34, wherein each of the plurality of modular blocks is coupled to at least one other, laterally adjacent, modular block, and further comprising sealing joints between laterally adjacent modular blocks to connect at least one of the fluid flow paths of each coupled one of the plurality of unified modular blocks, and wherein said transporting fluid flow through a plurality of unified modular blocks comprises transporting a fluid flow from a fluid flow path of one of the plurahty of unified modular blocks to a fluid flow path of another one of the plurality of modular blocks through a sealing joint formed between the modular blocks. 38. The method ofclaim 34, wherein a first one of the plurality of unified modular blocks is configured to interface with a chemical control component, and wherein a chemical control component is mounted above the top surface of the first one of the plurality of modular blocks, and further comprising: transporting fluid flow into the first one of the plurality of unified modular blocks through a first axial bore hole in a lateral surface of the first one of the plurality of modular blocks; transporting fluid flow from the first one of the plurality of unified modular blocks into the chemical control component through a first top fluid flow path bore hole in a top surface of the first one of the plurality of modular blocks; and transporting fluid flow from the chemical control component into the first one of the plurality of unified modular blocks through a second top fluid flow path bore hole in the top surface of the firsi one of the plurality of modular blocks. 39. The method of claim 34, wherein a second fluid flow path of a first one of the plurality of unified modular blocks comprises a second top bore hole, and further comprising transporting fluid flow from the second axial bore hole to the second top bore hole of the first one of the plurality of modular blocks without passing through a seal.

Inventors: HOLLINGSHEAD J GREGORY, HOLLINGSHEAD, J., GREGORY
Applicants: HOLLINGSHEAD J GREGORY, HOLLINGSHEAD, J., GREGORY
Application year: 1999
Main classification: F16K27
IPC codes: F16K27, F16L41