Abstract:
Systems and methods are described for improved yield and line width performance for liquid polymers and other materials. A method for minimizing precipitation of developing reactant by lowering a sudden change in pH includes: developing at least a portion of a polymer layer on a substrate with an initial charge of a developer fluid; then rinsing the polymer with an additional charge of the developer fluid so as to controllably minimize a subsequent sudden change in pH; and then rinsing the polymer with a charge of another fluid. An apparatus for minimizing fluid impingement force on a polymer layer to be developed on a substrate includes: a nozzle including: a developer manifold adapted to supply a developer fluid; a plurality of developer fluid conduits coupled to the developer manifold; a rinse manifold adapted to supply a rinse fluid; and a plurality of rinse fluid conduits coupled to the developer manifold. The developer manifold and the rinse manifold can be staggered so as to reduce an external width of the nozzle compared to a nominal external width of the nozzle achievable without either intersecting the fluid manifold and the another manifold or staggering the fluid manifold and the another manifold. The systems and methods provide advantages including improve yield via reduced process-induced defect and partial counts, and improved critical dimension (CD) control capability.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a Divisional Application of application Ser. No. 11/006,876 filed Dec. 7, 2004 now U.S. Pat. No. 7,208,262, which is a Divisional Application of Ser. No. 10/664,095 filed Sep. 16, 2003, which is a Divisional Application of Ser. No. 09/800,060 filed Mar. 5, 2001, now U.S. Pat. No. 6,669,779, which is a Divisional Application of Ser. No. 09/221,060 filed Dec. 28, 1998, now U.S. Pat. No. 6,248,171 which is a continuation-in-part under 35 USC §120 of U.S. Ser. No. 60/100,738, filed Sep. 17, 1998, the entire contents of which are hereby incorporated herein by reference as if fully set forth herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates generally to the field of microelectronic fabrication. More particularly, the invention relates to improving the yield and line width performance of liquid polymers. 
     2. Discussion of the Related Art 
     Lithography process is one of the major drivers of semiconductor industry in its relentless progress in achieving smaller feature sizes with improved yields. More specifically, improved critical dimension (CD) control and reduced process-induced defect and particle counts need to be satisfied simultaneously. 
     The develop fluid module process plays a significant role in the patterning of increasingly smaller line widths. Regions of high and low dissolution rates are created on the resist film as a result of the sequence of photolithography process steps preceding the develop process. During a develop process, images transferred to the resists film are developed into three dimensional structures by a wet process. The subsequent etch process (mostly dry) transfers this image onto the substrate (Si, SiO 2 , poly Si, etc.). 
     There are many variations of a good develop process. In general, a typical develop process has two main parts. In the first part, developer fluid is dispensed over a wafer spinning at a low rpm followed by a static puddle formation and a long static or oscillating step at which regions of high dissolution rate are etched away, creating 3-dimensional images on the film. Quality of patterned images, value of side wall angles and CD control, are all strongly affected by the first part of the develop process. The chemical wet etch step is immediately followed by a deionized (DI) water rinse step whose main function is to wash away dissolved resist and developer fluid mixture with minimum particle and defect count on the patterned wafer. Naturally, the rinse step is extremely crucial in improving yield of a lithography process. 
     Heretofore, the requirements of improved critical dimension control, reduced process-induced defect counts and reduced process-induced particle counts referred to above have not been fully met. What is needed is a solution that simultaneously addresses all of these requirements. 
     SUMMARY OF THE INVENTION 
     A primary goal of the invention is to improve yield. Another primary goal of the invention is improved CD control capability. This invention provides a solution for both of these problems in the developer fluid module of a wafer track tool. 
     A first aspect of the invention is implemented in an embodiment that is based on a method for minimizing precipitation of developing reactant by lowering a sudden change in pH, said method comprising: developing at least a portion of a polymer layer on a substrate with a charge of developer fluid; then permitting at least a portion of said charge of developer fluid to dwell on said polymer so as to controllably minimize a subsequent sudden change in pH; and then rinsing said polymer with a charge of another fluid. A second aspect of the invention is implemented in an embodiment that is based on a method for minimizing precipitation of developing reactant by lowering a sudden change in pH, said method comprising: developing at least a portion of a polymer layer on a substrate with an initial charge of a developer fluid; then rinsing said polymer with an additional charge of said developer fluid so as to controllably minimize a subsequent sudden change in pH; and then rinsing said polymer with a charge of another fluid. A third aspect of the invention is implemented in an embodiment that is based on a method for minimizing precipitation of developing reactant by lowering a sudden change in pH, said method comprising: developing at least a portion of a polymer layer on a substrate with a charge of developer fluid; then contacting said substrate with a charge of buffer, thereby mixing at least a portion of said developer fluid with at least a portion of said charge of buffer, so as to controllably minimize a subsequent sudden change in pH; and then rinsing said polymer with a charge of another fluid. 
     A fourth aspect of the invention is implemented in an embodiment that is based on an apparatus for minimizing fluid impingement force on a polymer layer to be developed on a substrate, thereby improving yield and line width control performance, said apparatus comprising: a nozzle including: a manifold adapted to supply a fluid; a plurality of fluid conduits coupled to said manifold; and a plurality of tubular inserts located within said plurality of fluid conduits. A fifth aspect of the invention is implemented in an embodiment that is based on an apparatus for minimizing fluid impingement force on a polymer layer to be developed on a substrate, thereby improving yield and line width control performance, said apparatus comprising: a nozzle including: a developer manifold adapted to supply a developer fluid; a plurality of developer fluid orifices coupled to said developer manifold; a rinse manifold adapted to supply a rinse fluid; and a plurality of rinse fluid orifices coupled to said developer manifold, wherein said developer manifold and said rinse manifold are staggered to reduce an exterior width of said nozzle. A sixth aspect of the invention is implemented in an embodiment that is based on an apparatus for minimizing fluid impingement force on a polymer layer to be developed on a substrate, thereby improving yield and line width control performance, said apparatus comprising: a nozzle including: a developer manifold adapted to supply a developer fluid; a plurality of developer fluid orifices coupled to said developer manifold; a rinse manifold adapted to supply a rinse fluid; a plurality of rinse fluid orifices coupled to said rinse manifold, and said plurality of rinse fluid orifices arranged to define at least one rinse fluid axis, wherein said nozzle is connected to a bracket adapted to raise and lower said nozzle with regard to said substrate and reposition said at least one rinse axis so as to be substantially coplanar with a normal to a center of said substrate. 
     These, and other, goals and aspects of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the invention without departing from the spirit thereof, and the invention includes all such modifications. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A clear conception of the advantages and features constituting the invention, and of the components and operation of model systems provided with the invention, will become more readily apparent by referring to the exemplary, and therefore nonlimiting, embodiments illustrated in the drawings accompanying and forming a part of this specification, wherein like reference characters (if they occur in more than one view) designate the same parts. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale. 
         FIG. 1  illustrates a bottom perspective view of a multiport nozzle, representing an embodiment of the invention. 
         FIG. 2  illustrates a top perspective view of a multiport nozzle, representing an embodiment of the invention. 
         FIG. 3  illustrates a sectional view of the multiport nozzle shown in  FIG. 2 . 
         FIG. 4  illustrates a top view of a multiport nozzle, representing an embodiment of the invention. 
         FIG. 5  illustrates an end view of the multiport nozzle shown in  FIG. 4 . 
         FIG. 6  illustrates a sectional view of the multiport nozzle show in  FIG. 4  taken along section line A-A. 
         FIG. 7  illustrates a bottom view of the multiport nozzle shown in  FIG. 4 . 
         FIG. 8  illustrates a top perspective view of the multiport nozzle shown in  FIG. 4 . 
         FIG. 9  illustrates a sectional view of the multiport nozzle shown in  FIG. 4  taken along section line B-B. 
         FIG. 10  illustrates a sectional view of the multiport nozzle shown in  FIG. 4  taken along section line C-C. 
         FIG. 11  illustrates a sectional view of the multiport nozzle shown in  FIG. 4  taken along section line D-D. 
         FIG. 12A  illustrates an end view of a nozzle insert, representing an embodiment of the invention. 
         FIG. 12B  illustrates a sectional view of the nozzle insert shown in  FIG. 12A  taken along section line F-F. 
         FIG. 13A  illustrates an end view of a nozzle insert, representing an embodiment of the invention. 
         FIG. 13B  illustrates a sectional view of the nozzle insert shown in  FIG. 13A , taken along section line E-E. 
         FIG. 14  illustrates a perspective sectional view of the multiport nozzle shown in  FIG. 4 , taken along section line A-A. 
         FIG. 15  illustrates develop rate as a function of the distance from the center of the substrate for a developer axis offset of 0 mm, representing an embodiment of the invention. 
         FIG. 16  illustrates develop rate as a function of the distance from the center of the substrate for a developer axis offset of 5 mm, representing an embodiment of the invention. 
         FIG. 17  illustrates develop rate as a function of the distance from the center of the substrate for a developer axis offset of 10 mm, representing an embodiment of the invention. 
         FIG. 18  illustrates develop rate as a function of the distance from the center of the substrate for a developer axis offset of 20 mm, representing an embodiment of the invention. 
         FIGS. 19A-19D  illustrate develop rate as a function of spatial position on the substrate for a developer axis offset of 0 mm, representing an embodiment of the invention. 
         FIGS. 20A-20D  illustrate develop rate as a functional of spatial position on the substrate for a developer axis offset of 5 mm, representing an embodiment of the invention. 
         FIGS. 21A-21D  illustrate develop rate as a function of spatial position on the substrate for a developer axis offset of 10 mm, representing an embodiment of the invention. 
         FIGS. 22A-22D  illustrate develop rate as a function of spatial position on the substrate for a developer axis offset of 20 mm, representing an embodiment of the invention. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     The invention and the various features and advantageous details thereof are explained more fully with reference to the nonlimiting embodiments that are illustrated in the accompanying drawings and detailed in the following description of preferred embodiments. Descriptions of well known components and processing techniques are omitted so as not to unnecessarily obscure the invention in detail. 
     The context of the invention includes photolithography processing of micro structures (e.g., microelectronic structures). These structures are typically etched and the polymers of interest function as masks to shield portions of the structures that are to remain at least largely unaffected by the etchant. The polymers that are being developed can be negative and/or positive photoresists. The invention can also utilize data processing methods that transform signals that characterize the state of the polymer processing so as to actuate interconnected discrete hardware elements; for example, to reposition the nozzle or change the spin rate. 
     The invention includes reducing defect density during the develop process of a liquid polymer used in a photolithography step by employing a new multiport delivery apparatus (nozzle). An important aspect of the multiport delivery apparatus is reducing droplet impact. This delivery system resides in a developer fluid module in which uniform laminar air flow field exists as a prerequisite. This apparatus allows significant reduction of the defect density due to its superior rinsing action. In addition, this multiport nozzle system allows two different developer fluid chemistries (in addition to a rinse chemistry) to be supported without any cross contamination. This delivery system for both developer fluid and deionized water reduces the impact force of the liquid(s) thus preventing pattern collapse which is a significant yield management problem for small feature sizes. 
     The invention can be part of a developer fluid module of a wafer track tool. In this application, the invention can be classified as involving 1) multiport nozzle system which supports the dispense of two different developer fluid fluids without any cross-talk, 2) a second multiport nozzle system of same or similar geometry which is used for the dispense of the deionized water during the rinse step, 3) implementing either parts 1) or 2) to support dual chemistry developer fluid as well as low impingement requirement throughout the develop process. The invention includes reducing the critical dimension (CD) variation contribution of the developer fluid module by distributing the developer fluid over the exposed wafer uniformly. This improves the overall CD control capability of a wafer track system when it includes such an apparatus in its developer fluid module. The track system can be coupled to a stepper. The term coupled, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically. 
     The invention includes helping prevent collapse of developed resist structure or structures and it includes reducing a sudden change in pH. The term sudden, as used herein to characterize a change in pH, is defined as a change in pH with respect to time that includes two inflection points separated by a period of time of less than approximately 1 second, preferably less than approximately 0.1 second, and more preferably less than approximately 0.01 seconds. Such a nearly congruent occurrence of two inflection points can be termed a step function. 
     This invention includes many designs for a multi-port nozzle that can be used to deliver both developer fluid and deionized water over a polymer layer to be developed on a substrate. The nozzle provides a geometry of outlets that are arranged to provide an optimal spatial liquid flow rate while minimizing dripping. The invention includes helping to prevent collapse of developed resist structure or structures by reducing impact force of the liquid on the film. The invention includes providing a multiport nozzle with a nozzle insert in at least one of the ports. The inserts can be made of a material that has a low coefficient of friction (either static or dynamic) with respect to the working fluid of the nozzle. 
     The invention includes extending the inserts beyond the material in which they are located. This extension can be internal, whereby the inserts extend into the input manifold. The extensions can be external, whereby the inserts extend beyond the bottom of the body of the nozzle. 
     An advantage of extending the inserts is to permit the internal manifold to function as an air equalized reservoir, thereby affecting an equalization of static pressure with respect to the ports. An advantage of extending the inserts externally is to prevent accumulation of residual working fluid on the bottom surface of the body of the nozzle, notwithstanding any operational attempts to mitigate such residual accumulation by reversing the working fluid pressure to achieve suck-back. 
     The invention includes staggering the working fluid manifolds. By staggering the working fluid manifolds, the principle axes of the manifolds can be brought closer together than would otherwise be permitted by a non-staggered, non-intersecting configuration of the inner section of radial bores. An advantage of staggering the manifolds is that the overall width of the multiport nozzle becomes narrower. Staggering the manifolds is useful even if there are only two manifolds, especially where the volume defined by the extent of the manifold is increased due to the functional requirements of static pressure equalization among the ports. 
     The invention includes a single nozzle head that dispenses two develop fluids having distinct chemistries, and one rinsing deionized water (DI) chemistry through rows of holes that are strategically placed so that all dispensing can be done with one head position. This allows use of a rotary cylinder actuator for head motion from a drain location to a single dispense location. No servo positioning control is required. The DI row of holes is centered for rinse of the entire wafer. The developer chemistry rows are preferably placed 5 mm offset because process data discussed below in more detail indicates that a 5 mm develop chemistry offset actually improves process results. The dispense holes can have pressed in tubes with small radius ends. There are at least two qualities of these tubes that provide benefits. First, small radius ends provide no surface that would allow liquid to cling. Any liquid clinging at this bottom surface can cause dispensing streams to be pulled off center. Also, liquid on the bottom, horizontal surface can cause two streams to join into one larger stream. This is especially problematic when it is critical that there is no contamination between the different chemistries on the head. Second, forming the tips to be radial edges or ends, as with pressed in tubes, allows a very smooth inner surface and eliminates aberrations that cause fluid clinging. Miniscule surface aberrations can cause streams to be misdirected. Rough surfaces cause uncontrolled liquid clinging which can lead to chemistry drying and contamination. The chance of sucking back a bubble is decreased since liquid-air interface shape is well controlled. The “plenum” bore positions are staggered to allow 5 mm offset of developer to be maintained and allow three chemistry rows on a 1.5″ wide head. All holes are strategically placed so that the dispense head is one piece. 
       FIG. 1  illustrates an embodiment of a multipart nozzle  100  for dispensing a single chemistry fluid. The nozzle  100  may have a maximum width measured from a front face  105  to a back face equal to the radius of the wafer receiving the fluid. The nozzle  100  includes a main arm  110  having a plurality of conduits aligned along a vertical axis with respect to a bottom face  115  of the nozzle  100 . An inlet manifold  130  receives an intake fluid, and the fluid is then distributed through the nozzle and onto a rotating wafer via a plurality of outlets  101 . In this embodiment, the outlets  101  are shown to align linearly across the width of the main arm  110 . The width of the nozzle  100  allows the dispensed fluid to cover the whole wafer in one full rotation of the wafer. As such, the nozzle  100  provides a uniform and fast distribution of the fluid, which for developing fluid applications is a crucial requirement for improved CD control. 
       FIG. 2  shows another embodiment of the present invention where a multipart nozzle  200  includes an intake manifold  230  for receiving either one fluid or two fluids having distinct chemistries. The fluid from the inlet manifold may be distributed between a first arm  210  and a second arm  220 . Each arm  210 ,  220  may have distinct or identical arrangement of outlets  301  (shown in  FIG. 3 ) depending on the application of the nozzle  200 . The nozzle  200  may also have a width between a front face  205  and a back face equal to the diameter of the wafer, thereby allowing the dispensed fluid to cover the whole wafer in one full rotation of the wafer 
       FIG. 3  is a cross-sectional view of the nozzle  200 , showing the inlet manifold  230  being divided to preferably receive two fluids having distinct chemistries, such as developing fluid and deionized water. A partition  335  divides the fluid streams in the inlet manifold  230 .  FIG. 2  shows the inlet manifold  230  guiding one fluid stream into a first inlet channel  340 . The first inlet channel  340  includes a bend  342  that merges with a conduit  345  in the first arm  210 . The manifold guides another fluid stream into a second inlet channel  360 . The second inlet channel  360  includes a bend  362  that merges with a second tubular insert  365  in the second arm  220 . Preferably, the outlets  301  on a bottom face  380  of the nozzle  200  are aligned linearly across the width of the nozzle  200 , although alternative arrangements are possible and will be further described. The configuration of the nozzle  200  accommodates the use of two different developer fluid chemistries with temperature control without any cross contamination during dispensing. The nozzle  200  may be adapted to allow for deionized water dispensing, with or separately from developing fluid dispensing. However, the nozzle  200  of or a similar variation thereto, may also be integrated into a single or dual chemistry version of the developer fluid. 
     Another important feature of this invention is that the impingement force of this nozzle is significantly reduced as compared to a single hole nozzle due to its multi-port nature. The reduced impact force is important for smaller CD sizes that tend to have high aspect ratios. This makes them vulnerable to pattern collapse due to impact of the fluid. Embodiments of this invention reduce impact forces for the developer fluids and the deionized water. This as such, the impingement forces throughout the develop process, may be minimized thus ensuring a reliable method of patterning smaller feature sizes with higher yield than that provided by the know art. Another significant advantage of the multiport nozzle for use with both developer fluid and deionized water is that it increases process latitude. In addition, the improved liquid delivery and distribution capability of the multiport nozzle ensures better overall process compliance for mechanical process variables such as spin speed and fluid dispensing rate. Therefore, another added advantage provided by this invention is the potential to reduce the total develop process time while maintaining CD control as well as good defect and particle performance. 
       FIG. 4  illustrates another embodiment of the invention in which a multiport nozzle  400  may dispense either one or two developing fluids, and/or deionized water. Preferably, the nozzle  400  dispenses two developing fluids and deionized water so that all dispensing may be accomplished by positioning the nozzle  400  in just one position. A head  420  of the nozzle  400  includes a top surface  425  having three inlets or inlet manifolds for receiving dispensing fluids and/or deionized water. In  FIG. 4 , one preferred arrangement provides for a first inlet  405  for a first developing fluid, a second inlet  410  for deionized water, and a third inlet  415  for a second developing fluid. Preferably, two or more of the inlets are staggered with respect to the top surface  425  to conserve space and reduce the overall size of the nozzle  400 . In  FIG. 4 , the first inlet  405  may be staggered from the third inlet  415 , with the second inlet centrally located and/or offset between the first inlet  405  and the third inlet  415 .  FIG. 5  shows an end surface  520  of the head  420  with internal manifolds shown as bored chambers that correspond to the inlets. Preferably, the end surface  520  includes a first manifold  505  merged with the first inlet  405  for the first developing fluid, a second manifold  510  merged with the second inlet  410  for deionized water, and a third manifold  515  merged with the third inlet  415  for a second developing fluid. To further reduce the dimensions of the nozzle, two or more of the manifolds may be staggered with respect to one another across the end surface. Preferably, the first manifold  510  is centrally located on the end face  520 , with the second manifold  510  and third manifold  515  symmetrically distributed on either side of the first manifold  505  in triangular fashion. 
       FIG. 6  is a cross-section cut along line A-A of  FIG. 4 , showing as an example the third manifold  515  to include a plurality of conduits  670  which bore vertically through the bottom surface  680  along a vertical axis. The structure of the third manifold  515  is preferably identical to the first and/or second manifolds  505 ,  510  and will be described in greater detail as a representation of the entire embodiment. As exemplified for the third manifold  515 , each of the conduits  670  may include a tubular insert  650  having an internal end  660  and an external end  655 . Preferably, the internal end  660  of each tubular insert  650  extends a height internally into the third manifold  515 . Fluid entering the third manifold  515  will not drain unless the level of the fluid compiled within the third manifold  515  exceeds the height of the internal end  660 . As such, the internal ends  660  may define a reservoir having a depth defined from the internal end  660  of the tubular insert  650  to a bottom manifold surface  665 . In this manner, the height of the internal end  660  may also be used to maintain the static pressure within the third manifold  615  constant or equal with respect to the corresponding fluid conduit  670 . Likewise, the external ends  655  of the insert tubes  650  may extend beyond the bottom surface  680  of the nozzle  400 . 
     The tubular inserts  650  may be formed to provide a very smooth internal surface that minimizes or eliminate surface flaws which may otherwise misdirect a stream of developing fluids or deionized water. The smooth surface the tubular inserts  650  also avoid the sucking back of bubbles, since the liquid-air interface within the tubular inserts  650  may be controlled. The tubular inserts  650  also provide thin radial edges both inside the manifolds and outside of the nozzle which reduce the area of the tubular inserts that may contact the fluids passing through. This enables the nozzle  400  to avoid problems associated with fluid streams of developing fluids and/or deionized water that contact conduits, such as fluid clinging or other problems that cause streams to pull of center. In addition, the external ends  655  extend sufficiently beyond the nozzle  400  to avoid streams being pulled together on the bottom surface  680 . 
       FIG. 7  illustrates a preferred arrangement of outlets on the bottom surface  680  of the nozzle  400 . The outlets may be arranged linearly as shown, or staggered to conserve real estate. In an embodiment, a center row  705  of outlets  701  distributes deionized water so that the entire wafer being treated may be rinsed. A second and third row  710  and  715  of outlets  701  may be coupled to the second manifold  510  and the third manifold  515  respectively to dispense at least one, and preferably two, developing fluids. 
       FIG. 8  illustrates a perspective view of the nozzle  400  incorporating staggered or offset inlets  405 ,  410 ,  415 . The nozzle  400  may include pivotable mounting brackets  810  on a first longitudinal end  820  for securing the nozzle to an arm or stand above a wafer. The nozzle is also compact, with a preferred vertical height extending from the top surface  425  to the bottom surface  680  of 1.5 inches. The nozzle  400  may include pivotable mounting brackets  810  on a first longitudinal end  820  for securing the nozzle to an arm or stand above a wafer. The nozzle is also compact, with a preferred vertical height extending from the top surface  425  to the bottom surface  680  of 1.5 inches. 
       FIG. 9  is a cross-section of the nozzle  400  taken along lines B-B of  FIG. 4 . The nozzle  400  is shown in  FIG. 9  to include the first manifold  505  coupled to a first plurality of tubular inserts  650   a . Likewise, the second manifold  510  is coupled to a second plurality of tubular inserts  650   b , and the third manifold  515  is coupled to a third plurality of tubular inserts  650   c . Each of the first, second, and third tubular inserts  650   a ,  650   b ,  650   c  preferably extend inwards into the respective first, second, and third manifold  505 ,  510 ,  515  so that the inward extensions  660   a ,  660   b ,  660   c  of each tubular inserts define a reservoir with the corresponding manifolds. The height of each reservoir within the manifolds  505 ,  510 , and  515  may be individually set by the length of the respective inward extensions  660   a ,  660   b ,  660   c , as described in  FIGS. 12 &amp; 13  and the accompanying text. 
       FIG. 10  is a cross-section of the nozzle  400  taken along lines B-B of  FIG. 4 . As shown by  FIG. 10 , each inlet may be coupled to a manifold using one or more chambers associated with or forming a part of the manifold. In particular,  FIG. 10  shows the first inlet  405  is coupled to the first manifold  505  with a first inlet chamber  1005 , and the third inlet is coupled to the third manifold  515  with a third inlet chamber  1015 .  FIG. 11  is a cross-section of the nozzle  400  taken along lines B-B of  FIG. 4 . As with the other inlets and manifolds,  FIG. 11  shows the second inlet  410  may couple to the second manifold  510  with a second inlet chamber  1110 . In other embodiments, additional inlets may couple to corresponding manifolds using similar configurations, including chambers.  FIGS. 10 and 11  also provide another perspective of the tubular inserts  650   a ,  650   b ,  650  extending from the bottom surface  680  of the nozzle  400  to avoid combining streams stemming from different manifolds. 
       FIGS. 12A and 12B  illustrate one embodiment for a tubular inserts  650  for use with this invention. As shown by  FIG. 12A , the tubular inserts may include a round cross-section  1210 . However, other embodiments of the invention may use non-circular cross-sections, including square or polygonal geometries. The height of the tubular insert  650  may be set by either the vertical position of the manifold that retains the tubular insert, or the desired depth of the reservoir defined by the internal end  660  of the tubular insert.  FIG. 12A  shows the tubular insert  650  having a shorter height for manifolds that are closer the bottom surface  680 , such as the first manifold  505  or the third manifold  515 . Alternatively, the tubular insert of  FIG. 12A  may be used to define a shallow reservoir within the second manifold  510 . 
       FIGS. 13A and 13B  illustrate another embodiment for tubular inserts. As with the previous embodiment, the tubular insert of  FIG. 13A  includes a rounded cross-section. The longer length of the tubular insert shown in  FIG. 13B  is preferred for a manifold that is distanced from the bottom surface  680  with respect to the other manifolds. As such, the tubular insert  650  of  FIG. 13A  is preferred for the second manifold  510 . The tubular insert of  FIG. 13B  may also be used to create a deeper reservoir within the first manifold  505  or the third manifold  515 . For an optimal nozzle having a depth of 1.5 inches, the tubular insert  650  may range between 0.352 inches and 0.665 inches, as shown by  FIGS. 12B and 13B . 
       FIG. 14  is a perspective cross-section of the nozzle  400 . The first inlet  405  and the second inlet  410  are shown in an off-center or staggered arrangement on the top surface  425  of the nozzle  400 . The end face  520  includes the first manifold  505  and the second manifold  510 . The second manifold  510  may, for this embodiment, be viewed as exemplary for other manifolds in this embodiment, and will be described in greater detail. The second manifold  510  includes an enlarged chamber  1410 . The enlarged chamber  1410  merges with a bored segment  1420  forming the remainder of the second manifold  510 . The second inlet chamber  1010  couples second inlet  410  with the second manifold  510 . The tubular inserts  650   b  extend through the conduits  670  so that the exterior end  655  extends beyond the bottom surface  680 . Similarly, the interior end  660  forms a height  1430  over the second manifold bottom surface  665  that defines a depth of the reservoir for when the second manifold  510  receives fluid. In this way, fluid such as deionized water may be received through the second inlet  410  and expand through the bored segment  1420  of the second manifold  510 . Prior to the level of the fluid exceeding the height  1430 , the fluid forms a reservoir within the second manifold  510 . Once the fluid passes the height  1430 , fluid enters the tubular insert  650   b  through the interior end  660  and passes through and out of the exterior end  655 . The resulting outflow of the nozzle  400  may, in the case of deionized water, provide a fine disbursement of rinsing fluid. 
     While not being limited to any particular performance indicator or diagnostic identifier, preferred embodiments of the invention can be identified one at a time by testing for the presence of a substantially uniform develop rate across the surface of a wafer. The test for the presence of a substantially uniform develop rate can be carried out without undue experimentation by the use of the simple and conventional IPEC Awmap rate map or spinning rate test. 
     A spinning rate test was performed to determine how much offset between the center of a spinning wafer and the nearest develop stream could be tolerated during developer dispense. The criteria used was to increase offset until the develop uniformity suffered. This is important to know as such an offset is inherent in most of the dispense nozzle designs being considered for the develop module. 
       FIGS. 15-18  provide results of a develop test on wafers with nozzle offsets of 0, 5, 10 and 20 mm at the same time while varying the spin during dispense between 60 and 2500 rpm. The test found that an offset at least as great as 5 mm had no adverse impact on develop uniformity across the wafer. Presumably a nozzle design with an offset of 5 mm or less should not cause develop non-uniformity at the center of the wafer. At some point between 5 and 10 mm, fluid no longer wets the center of the wafer and develop there is greatly suppressed. The spin speed of the wafer interacts with the offset somewhat, and is most apparent at the marginal offset of 10 mm. 
     A preferred embodiment of the invention includes three parallel rows of holes in a bar one wafer radius long. This single nozzle would dispense both deionized (DI) water and developer. Since the radial position of the arm over the wafer is done with a pneumatic cylinder, there will be only one placement of the nozzle relative to the wafer, regardless of which fluid is dispensed. Therefore, only one set of holes can be exactly over the center of the wafer, and it is expected that DI dispense should take precedence in which fluid gets to be closest to the wafer center. The typical develop process dispenses fluid on a spinning wafer, so centrifugal force will prevent fluid from reaching the center if it is dispensed too far out. This test was performed to determine how far off-center the develop dispense could be before develop rate uniformity across the wafer was affected. 
     Developer was dispensed at fixed offsets of 0, 5, 10 and 20 mm from the center. Initial spin during the dispense was also varied, as the difference in centrifugal force could interact with the centering offset to affect developer reaching the center of the wafer. Speeds of 60, 600, 1200 (standard), and 2500 rpm were used. 
     Referring to  FIGS. 19A-22D , a sub-develop technique was chosen as a measure of develop quality for several reasons, including: (1) sub-develop technique is fast relative to line width measurements; (2) sub-develop technique has more resolution that line width or E° measurement, and is less subjective than E° measurement; (3) the entire wafer area can be used, as opposed to a few discrete locations; and (4) with exposures and develop rates well above those for E°, the effect of the develop process is much more dominant compared to the contributors to develop rate, such as the swing curve, Microscan intensity uniformity, PEB uniformity, etc. As the resist film approaches complete deprotection, development trends toward a simple etch process. In addition to the qualitative measure of color uniformity across the wafer after development, resist removal differences across the wafer were quantified with IPEC Acumap thickness measurement system. Although this tool measures thickness at 1 mm intervals across the entire wafer (greater than 30,000 locations), as a practical matter only the thickness at the center of 121 exposure fields were used for the calculations in this report. 
     The baseline chemistry, TOK9, and process were used for the test. The develop recipe was modified to remove arm movement during develop and DI dispenses. A preferred embodiment of the nozzle was used for develop dispense. It was adjusted so the centermost hole was over the center of the wafer with 0 offset in the arm program. The puddle portion of the development process was shortened from 60.5 to 5.5 seconds. The exposure dose used was 12 mJ/cm. (E° dose is approximately 6.5-7.0 mJ/cm). The developer flowmeter was set to approximately 3.8, and although volume was not checked, past experience with this meter is that it should be about 50 ml. All wafers were processed at one time through PEB, then separately into the developer, where parameters were varied for each wafer in randomized order. 
     Develop rates were determined by first subtracting the resist thickness at the 121 locations after develop from the thickness measured on two of the wafers after PEB, just prior to develop. In this approach, it was assumed that wafer-wafer differences in pre-develop thickness were relatively negligible, and a representative wafer could be the “before” wafer for all rate calculations. The resist removed was divided by the develop time (dispense+puddle+refresh), 10 seconds for all wafers in this test. 
     Measuring initial thickness between PEB and develop is notable for two reasons. First, many of the prior develop rate calculations have been done using the thickness before exposure. Since the thickness loss was about 1000 Å from the original 8500 Å, this should be a more accurate estimate of the develop rate. Second, the exposed areas were clearly visible, and a characteristic pattern across the wafer was seen on every wafer. This is useful as a metric of relative deprotection across the wafer, and some papers have also noted this. It has the desirable property of being independent of the develop process. 
     The develop portion of the recipe used is as follows: 
     
       
         
               
               
               
               
             
           
               
                   
               
               
                 Operation 
                 Time (sec.) 
                 Speed (rpm) 
                 Arm X (mm) 
               
               
                   
               
             
             
               
                 Spin 
                 1.0 
                 60-2500 
                 0-20 
               
               
                 Develop Dispense 
                 1.0 
                 Same 
                 Same 
               
               
                 Develop Dispense 
                 2.0 
                 20 
                 Same 
               
               
                 Spin 
                 6.5 
                  0 
                 Same 
               
               
                 Spin 
                 0.5 
                 1200  
                 Same 
               
               
                 /// 
               
               
                 /// 
               
               
                 /// 
               
               
                   
               
             
          
         
       
     
     Results for this test are summarized in the table below: 
     
       
         
               
               
               
               
               
               
               
               
               
             
               
             
               
               
               
               
               
               
               
               
               
             
               
             
               
               
               
               
               
               
               
               
               
             
               
             
               
               
               
               
               
               
               
               
               
             
           
               
                   
               
               
                 Arm X 
                 Speed 
                 Ave. 
                 Stdev. 
                 % unif 
                 % unif 
                 Max. Rate 
                 Min. Rate 
                 Range Rate 
               
               
                 Mm 
                 rpm 
                 Rate Å/sec. 
                 Rate Å/sec. 
                 (σ/ave) 
                 (mg/ave) 
                 Å/sec. 
                 Å/sec. 
                 Å/sec. 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Each row below corresponds to individual wafers 
               
             
          
           
               
                 0 
                 60 
                 610.9 
                 28.2 
                 4.6% 
                 20.5% 
                 679.8 
                 554.6 
                 125.2 
               
               
                 0 
                 600 
                 639.3 
                 2406 
                 3.8% 
                 16.6% 
                 698.7 
                 592.6 
                 106.1 
               
               
                 0 
                 1200 
                 608.9 
                 21.9 
                 3.6% 
                 14.4% 
                 660.7 
                 572.8 
                 87.9 
               
               
                 0 
                 1200 
                 611.2 
                 24.1 
                 3.9% 
                 17.6% 
                 677.0 
                 569.6 
                 107.4 
               
               
                 0 
                 2500 
                 646.6 
                 26.4 
                 4.1% 
                 20.6% 
                 728.3 
                 595.1 
                 133.2 
               
               
                 5 
                 60 
                 610.0 
                 31.1 
                 5.1% 
                 20.6% 
                 685.7 
                 560.3 
                 125.4 
               
               
                 5 
                 600 
                 622.7 
                 28.9 
                 4.6% 
                 20.8% 
                 707.1 
                 577.8 
                 129.3 
               
               
                 5 
                 1200 
                 638.8 
                 24.4 
                 3.8% 
                 16.8% 
                 698.0 
                 590.8 
                 107.2 
               
               
                 5 
                 2500 
                 647.7 
                 23.4 
                 3.6% 
                 17.1% 
                 711.9 
                 600.8 
                 111.1 
               
               
                 10 
                 60 
                 582.6 
                 29.2 
                 5.0% 
                 21.1% 
                 656.3 
                 533.6 
                 122.7 
               
               
                 10 
                 600 
                 639.9 
                 25.9 
                 4.0% 
                 20.2% 
                 724.3 
                 595.1 
                 129.2 
               
               
                 10 
                 1200 
                 606.3 
                 30.7 
                 5.1% 
                 42.0% 
                 690.4 
                 435.9 
                 254.5 
               
               
                 10 
                 2500 
                 639.8 
                 32.7 
                 5.1% 
                 46.7% 
                 712.4 
                 413.4 
                 299.0 
               
               
                 20 
                 60 
                 607.9 
                 63.8 
                 10.5% 
                 112.9% 
                 686.8 
                 0.7 
                 686.1 
               
               
                 20 
                 600 
                 593.8 
                 60.0 
                 10.1% 
                 113.4% 
                 672.5 
                 −1.0 
                 673.4 
               
               
                 20 
                 1200 
                 629.4 
                 66.6 
                 10.6% 
                 114.9% 
                 723.1 
                 −0.3 
                 723.4 
               
               
                 20 
                 2500 
                 639.0 
                 64.9 
                 10.2% 
                 112.0% 
                 717.1 
                 1.2 
                 716.0 
               
             
          
           
               
                 rows below group previous data by either arm position or spin speed 
               
             
          
           
               
                 All 
                 60 
                 602.8 
                 42.4 
                 7.0% 
                 113.8% 
                 686.8 
                 0.7 
                 686.1 
               
               
                 All 
                 600 
                 623.9 
                 42.1 
                 6.7% 
                 116.2% 
                 724.3 
                 −1.0 
                 725.2 
               
               
                 All 
                 1200 
                 618.9 
                 39.5 
                 6.4% 
                 116.9% 
                 723.1 
                 −0.3 
                 723.4 
               
               
                 All 
                 2500 
                 643.3 
                 40.4 
                 6.3% 
                 113.0% 
                 728.3 
                 1.2 
                 727.2 
               
               
                 0 
                 all 
                 623.4 
                 29.8 
                 4.8% 
                 27.9% 
                 728.3 
                 554.6 
                 173.7 
               
               
                 5 
                 all 
                 629.8 
                 30.7 
                 4.9% 
                 24.1% 
                 711.9 
                 560.3 
                 151.6 
               
               
                 10 
                 all 
                 617.2 
                 38.3 
                 6.2% 
                 50.4% 
                 724.3 
                 413.4 
                 310.9 
               
               
                 20 
                 all 
                 617.5 
                 66.1 
                 10.7% 
                 117.2% 
                 723.1 
                 −1.0 
                 724.1 
               
             
          
           
               
                 Rows below are grouped as in previous section; but with center data point removed 
               
             
          
           
               
                 All 
                 60 
                 604.1 
                 32.4 
                 5.4% 
                 30.1% 
                 686.6 
                 505.0 
                 181.8 
               
               
                 All 
                 600 
                 625.1 
                 30.8 
                 4.9% 
                 37.8% 
                 724.3 
                 487.7 
                 236.6 
               
               
                 All 
                 1200 
                 620.3 
                 29.6 
                 4.8% 
                 33.7% 
                 723.1 
                 513.9 
                 209.2 
               
               
                 All 
                 2500 
                 645.1 
                 26.0 
                 4.0% 
                 33.2% 
                 728.3 
                 514.0 
                 214.3 
               
               
                 0 
                 all 
                 623.4 
                 29.9 
                 4.8% 
                 27.9% 
                 728.3 
                 554.6 
                 173.7 
               
               
                 5 
                 all 
                 629.9 
                 30.8 
                 4.9% 
                 24.1% 
                 711.9 
                 560.3 
                 151.6 
               
               
                 10 
                 all 
                 617.9 
                 35.9 
                 5.8% 
                 30.9% 
                 724.3 
                 533.6 
                 190.7 
               
               
                 20 
                 all 
                 622.7 
                 34.6 
                 5.6% 
                 37.8% 
                 723.1 
                 487.7 
                 235.4 
               
               
                   
               
             
          
         
       
     
     Overall, the clear break in the data is between 5 and 10 mm offset. Five may be slightly better than 0; 20 is the worst. The primary effect is the arm position, but the spin speed during dispense can be seen, particularly for the 10 mm offset. Predictably, the single point at the center is responsible for much of the non-uniformity especially for 10 and 20 mm. To capture the variation between the center and the rest of the wafer, the range is a more useful measure of uniformity here than is standard deviation, where the other 120 points tend to dilute the center. 
     A third order polynomial line is fitted through the data to ease comparison between the different spin speeds, as there is quite a bit of scatter in the data  FIGS. 15-18  confirm the trends seen in the tables: the primary non-uniformity is between the center and the rest of the data for the higher speeds, 0 and 5 mm are clearly more uniform than the higher offsets, and at 10 mm there is an interaction between offset and speed. 
       FIGS. 19A-22D  show the IPEC maps for all the wafers, except for one repetition. (The maps look much better on a monitor that a printout. The monitor also has the advantage of being able to zoom in.). The rate range spanning the different colors is held constant so that relative uniformity can be compared between wafers. The gray and white areas are off the scale. It can be see here, as was apparent visually on the wafers as well, that starting with 10 mm offset, a “hole” forms in the center where little or no develop fluid contacts the wafer, and which has a much lower develop rate. 
     The test confirmed that some offset from the center is tolerable for developer dispense, at least up to 5 mm. At some point between 5 and 10 mm offset from the center and the nearest develop stream, fluid ceases to contact the center of the wafer, resulting in an area with greatly suppressed develop rate, and no doubt catastrophic yield loss on a customer wafer. Larger offsets exacerbate the effect. There is a mild interaction with the spin speed used as the fluid first touches the wafer, showing up mainly at the apparently marginal condition of a 10 mm offset. The uniformities measured were actually slightly better for the 5 mm offset than for 0, but it is probably not a significant difference in this test. 
     These results indicate that said nozzle design should not cause develop rate non-uniformities at the center of the wafer so long as the centermost stream is not more than 5 mm from the center. 
     ADVANTAGES OF THE INVENTION 
     A process and/or nozzle, representing an embodiment of the invention, can be cost effective and advantageous for at least the following reasons. This invention improves the CD control capability of the developer fluid module. This invention reduces defects and particles during the develop process thereby improving the yield of the final devices. This invention combines low impingement force nozzle for both develop and rinse parts of the process and minimizes the impinging force on the features which are being developed, which in turn, minimizes the pattern collapsing, thus improving device yields. This invention has wide process latitude and reduced sensitivity to process variables. This invention includes improved rinsing action which reduces the total develop process time, thus increasing the throughput. The advantages of the nozzle include the enablement of an all-in-one design: three rows of holes for two developer chemistries and one row of holes for deionized water chemistry in a single head, if needed. The advantages of the nozzle include a compact design, for example, a nozzle width of only 1½ inches for a triple head. The advantages of the nozzle include low cost. The advantages of the nozzle include a one piece body design that is easy to manufacture. The advantages of the nozzle include tube inserts with smooth inner surfaces for improved particle performance. 
     All the disclosed embodiments of the invention described herein can be realized and practiced without undue experimentation. Although the best mode of carrying out the invention contemplated by the inventors is disclosed above, practice of the invention is not limited thereto. Accordingly, it will be appreciated by those skilled in the art that the invention may be practiced otherwise than as specifically described herein. 
     For example, the individual components need not be formed in the disclosed shapes, or assembled in the disclosed configuration, but could be provided in virtually any shape, and assembled in virtually any configuration. Further, the individual components need not be fabricated from the disclosed materials, but could be fabricated from virtually any suitable materials. Further, although the multiport nozzle described herein can be a physically separate module, it will be manifest that the multiport nozzle may be integrated into the apparatus with which it is associated. Furthermore, all the disclosed elements and features of each disclosed embodiment can be combined with, or substituted for, the disclosed elements and features of every other disclosed embodiment except where such elements or features are mutually exclusive. 
     It will be manifest that various additions, modifications and rearrangements of the features of the invention may be made without deviating from the spirit and scope of the underlying inventive concept. It is intended that the scope of the invention as defined by the appended claims and their equivalents cover all such additions, modifications, and rearrangements. The appended claims are not to be interpreted as including means-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase “means-for.” Expedient embodiments of the invention are differentiated by the appended subclaims.