# Patent

## Title
Semiconductor chip including region having rectangular-shaped gate structures and first metal structures

## Abstract

Gate structures are positioned within a region in accordance with a gate horizontal grid that includes at least seven gate gridlines separated from each other by a gate pitch of less than or equal to about 193 nanometers. Each gate structure has a substantially rectangular shape with a width of less than or equal to about 45 nanometers and is positioned to extend lengthwise along a corresponding gate gridline. Each gate gridline has at least one gate structure positioned thereon. A first-metal layer is formed above top surfaces of the gate structures within the region and includes first-metal structures positioned in accordance with a first-metal vertical grid that includes at least eight first-metal gridlines. Each first-metal structure has a substantially rectangular shape and is positioned to extend along a corresponding first-metal gridline. At least six contact structures of substantially rectangular shape contact the at least six gate structures.

## Background
CLAIM OF PRIORITY
This application is a continuation application under 35 U.S.C. 120 of prior U.S. application Ser. No. 15/263,282, filed on Sep. 12, 2016, which is a continuation application under 35 U.S.C. 120 of prior U.S. application Ser. No. 14/711,731, filed on May 13, 2015, issued as U.S. Pat. No. 9,443,947, on Sep. 13, 2016, which is a continuation application under 35 U.S.C. 120 of prior U.S. application Ser. No. 13/774,919, filed on Feb. 22, 2013, which is a continuation application under 35 U.S.C. 120 of prior U.S. application Ser. No. 12/572,225, filed on Oct. 1, 2009, issued as U.S. Pat. No. 8,436,400, on May 7, 2013, which is a continuation application under 35 U.S.C. 120 of prior U.S. application Ser. No. 12/212,562, filed Sep. 17, 2008, issued as U.S. Pat. No. 7,842,975, on Nov. 30, 2010, which is a continuation application under 35 U.S.C. 120 of prior U.S. application Ser. No. 11/683,402, filed Mar. 7, 2007, issued as U.S. Pat. No. 7,446,352, on Nov. 4, 2008, which claims priority under 35 U.S.C. 119(e) to U.S. Provisional Patent Application No. 60/781,288, filed Mar. 9, 2006. Each of the above-identified applications is incorporated herein by reference in its entirety for all purposes.


CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to each application identified in the table below. The disclosure of each application identified in the table below is incorporated herein by reference in its entirety.














Application No.
Filing Date









12/561,207
Sep. 16, 2009



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BACKGROUND
A push for higher performance and smaller die size drives the semiconductor industry to reduce circuit chip area by approximately 50% every two years. The chip area reduction provides an economic benefit for migrating to newer technologies. The 50% chip area reduction is achieved by reducing the feature sizes between 25% and 30%. The reduction in feature size is enabled by improvements in manufacturing equipment and materials. For example, improvement in the lithographic process has enabled smaller feature sizes to be achieved, while improvement in chemical mechanical polishing (CMP) has in-part enabled a higher number of interconnect layers.
In the evolution of lithography, as the minimum feature size approached the wavelength of the light source used to expose the feature shapes, unintended interactions occurred between neighboring features. Today minimum feature sizes are approaching 45 nm (nanometers), while the wavelength of the light source used in the photolithography process remains at 193 nm. The difference between the minimum feature size and the wavelength of light used in the photolithography process is defined as the lithographic gap. As the lithographic gap grows, the resolution capability of the lithographic process decreases.
An interference pattern occurs as each shape on the mask interacts with the light. The interference patterns from neighboring shapes can create constructive or destructive interference. In the case of constructive interference, unwanted shapes may be inadvertently created. In the case of destructive interference, desired shapes may be inadvertently removed. In either case, a particular shape is printed in a different manner than intended, possibly causing a device failure. Correction methodologies, such as optical proximity correction (OPC), attempt to predict the impact from neighboring shapes and modify the mask such that the printed shape is fabricated as desired. The quality of the light interaction prediction is declining as process geometries shrink and as the light interactions become more complex.
In view of the foregoing, a solution is needed for managing lithographic gap issues as technology continues to progress toward smaller semiconductor device features sizes.
SUMMARY
In one embodiment, an integrated circuit is disclosed to include a first gate electrode feature of a first gate electrode track. The first gate electrode feature of the first gate electrode track forms a first n-channel transistor as it crosses an n-diffusion region. The integrated circuit also includes a second gate electrode feature of the first gate electrode track. The second gate electrode feature of the first gate electrode track forms a first p-channel transistor as it crosses a p-diffusion region. The first and second gate electrode features of the first gate electrode track are separated by a first end-to-end spacing. The integrated circuit also includes a first gate electrode feature of a second gate electrode track. The first gate electrode feature of the second gate electrode track forms a second n-channel transistor as it crosses the n-diffusion region. The integrated circuit also includes a second gate electrode feature of the second gate electrode track. The second gate electrode feature of the second gate electrode track forms a second p-channel transistor as it crosses the p-diffusion region. The first and second gate electrode features of the second gate electrode track are separated by a second end-to-end spacing that is offset from the first end-to-end spacing such that a line of sight perpendicular to the first and second gate electrode tracks does not exist through the first and second end-to-end spacings.
In another embodiment, a cell of a semiconductor device is disclosed. The cell includes a substrate portion formed to include a plurality of diffusion regions. The plurality of diffusion regions respectively correspond to active areas of the substrate portion within which one or more processes are applied to modify one or more electrical characteristics of the active areas of the substrate portion. The plurality of diffusion regions are separated from each other by one or more non-active regions of the substrate portion.
Also in this embodiment, the cell includes a gate electrode level of the cell formed above the substrate portion. The gate electrode level includes a number of conductive features defined to extend in only a first parallel direction. Adjacent ones of the number of conductive features that share a common line of extent in the first parallel direction are fabricated from respective originating layout features that are separated from each other by an end-to-end spacing having a size measured in the first parallel direction. The size of each end-to-end spacing between originating layout features corresponding to adjacent ones of the number of conductive features within the gate electrode level of the cell is substantially equal and is minimized to an extent allowed by a semiconductor device manufacturing capability. The number of conductive features within the gate electrode level of the cell includes conductive features defined along at least four different virtual lines of extent in the first parallel direction across the gate electrode level of the cell.
A width size of the conductive features within the gate electrode level is measured perpendicular to the first parallel direction. The width size of the conductive features within a photolithographic interaction radius within the gate electrode level is less than a wavelength of light used in a photolithography process to fabricate the conductive features within the gate electrode level. The wavelength of light used in the photolithography process is less than or equal to 193 nanometers. The photolithographic interaction radius is five wavelengths of light used in the photolithography process.
Some of the number of conductive features within the gate electrode level of the cell are defined to include one or more gate electrode portions which extend over one or more of the active areas of the substrate portion corresponding to the plurality of diffusion regions. Each gate electrode portion and a corresponding active area of the substrate portion over which it extends together define a respective transistor device.
Also in this embodiment, the cell includes a number of interconnect levels formed above the gate electrode level of the cell. The substrate portion, the gate electrode level of the cell, and the number of interconnect levels are spatially aligned such that structures fabricated within each of the substrate portion, the gate electrode level of the cell, and the number of interconnect levels spatially relate to connect as required to form functional electronic devices within the semiconductor device.
In one embodiment, a semiconductor chip includes a region including a plurality of transistors. Each of the plurality of transistors in the region forms part of circuitry associated with execution of one or more logic functions. The region includes at least ten conductive structures formed within the semiconductor chip. Some of the at least ten conductive structures form at least one transistor gate electrode. Each of the at least ten conductive structures respectively has a corresponding top surface. An entirety of a periphery of the corresponding top surface is defined by a corresponding first end, a corresponding second end, a corresponding first edge, and a corresponding second edge, such that a total distance along the entirety of the periphery of the corresponding top surface is equal to a sum of a total distance along the corresponding first edge and a total distance along the corresponding second edge and a total distance along the corresponding first end and a total distance along the corresponding second end. The total distance along the corresponding first edge is greater than two times the total distance along the corresponding first end. The total distance along the corresponding first edge is greater than two times the total distance along the corresponding second end. The total distance along the corresponding second edge is greater than two times the total distance along the corresponding first end. The total distance along the corresponding second edge is greater than two times the total distance along the corresponding second end. The corresponding first end extends from the corresponding first edge to the corresponding second edge and is located principally within a space between the corresponding first and second edges. The corresponding second end extends from the corresponding first edge to the corresponding second edge and is located principally within the space between the corresponding first and second edges. The top surfaces of the at least ten conductive structures are co-planar with each other. Each of the at least ten conductive structures has a corresponding lengthwise centerline oriented in a first direction along its top surface and extending from its first end to its second end. Each of the at least ten conductive structures has a length as measured along its lengthwise centerline from its first end to its second end. The first edge of each of the at least ten conductive structures is substantially straight. The second edge of each of the at least ten conductive structures is substantially straight. Each of the at least ten conductive structures has both its first edge and its second edge oriented substantially parallel to its lengthwise centerline. Each of the at least ten conductive structures has a width measured in a second direction perpendicular to the first direction at a midpoint of its lengthwise centerline. Each of the first direction and the second direction is oriented substantially parallel to the co-planar top surfaces of the at least ten conductive structures. The at least ten conductive structures are positioned in a side-by-side manner such that each of the at least ten conductive structures is positioned to have at least a portion of its length beside at least a portion of the length of another of the at least ten conductive structures. The width of each of the at least ten conductive structures is less than 45 nanometers. The region has a size of about 965 nanometers as measured in the second direction. Each of the at least ten conductive structures is positioned such that a distance as measured in the second direction between its lengthwise centerline and the lengthwise centerline of at least one other of the at least ten conductive structures is substantially equal to a first pitch that is less than or equal to about 193 nanometers. The region includes a first transistor of a first transistor type, a second transistor of the first transistor type, a first transistor of a second transistor type, and a second transistor of the second transistor type. Each transistor of the first transistor type that has its gate electrode formed by any of the at least ten conductive structures is included in a first collection of transistors, and each transistor of the second transistor type that has its gate electrode formed by any of the at least ten conductive structures is included in a second collection of transistors. The first and second collections of transistors are separated from each other by an inner sub-region of the region, wherein the inner sub-region does not include a source or a drain of any transistor. The first transistor of the first transistor type has a gate electrode formed by a portion of a first conductive structure of the at least ten conductive structures. Any transistor having its gate electrode formed by the first conductive structure is of the first transistor type. The second transistor of the first transistor type has a gate electrode formed by a portion of a second conductive structure of the at least ten conductive structures. The first transistor of the second transistor type has a gate electrode formed by another portion of the second conductive structure. The second conductive structure is positioned such that its lengthwise centerline is separated from the lengthwise centerline of the first conductive structure by the first pitch as measured in the second direction. The second transistor of the second transistor type has a gate electrode formed by one of the at least ten conductive structures. The conductive structure that forms the gate electrode of the second transistor of the second transistor type is positioned such that its lengthwise centerline is separated from the lengthwise centerline of the second conductive structure by the first pitch as measured in the second direction. Any transistor having its gate electrode formed by the conductive structure that forms the gate electrode of the second transistor of the second transistor type is of the second transistor type. The first conductive structure has a total length as measured in the first direction that is greater than one-half of a total length of the second conductive structure as measured in the first direction. The second conductive structure has at least one end substantially positioned at a first reference line oriented in the second direction. And, the conductive structure that forms the gate electrode of the second transistor of the second transistor type also has at least one end substantially positioned at the first reference line.
Other aspects and advantages of the invention will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the present invention.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration showing a number of neighboring layout features and a representation of light intensity used to render each of the layout features, in accordance with one embodiment of the present invention;
FIG. 2 is an illustration showing a generalized stack of layers used to define a dynamic array architecture, in accordance with one embodiment of the present invention;
FIG. 3A is an illustration showing an exemplary base grid to be projected onto the dynamic array to facilitate definition of the restricted topology, in accordance with one embodiment of the present invention;
FIG. 3B is an illustration showing separate base grids projected across separate regions of the die, in accordance with an exemplary embodiment of the present invention;
FIG. 3C is an illustration showing an exemplary linear-shaped feature defined to be compatible with the dynamic array, in accordance with one embodiment of the present invention;
FIG. 3D is an illustration showing another exemplary linear-shaped feature defined to be compatible with the dynamic array, in accordance with one embodiment of the present invention;
FIG. 4 is an illustration showing a diffusion layer layout of an exemplary dynamic array, in accordance with one embodiment of the present invention;
FIG. 5 is an illustration showing a gate electrode layer and a diffusion contact layer above and adjacent to the diffusion layer of FIG. 4, in accordance with one embodiment of the present invention;
FIG. 6 is an illustration showing a gate electrode contact layer defined above and adjacent to the gate electrode layer of FIG. 5, in accordance with one embodiment of the present invention;
FIGS. 6A-6E show annotated versions of FIG. 6;
FIG. 7A is an illustration showing a traditional approach for making contact to the gate electrode;
FIG. 7B is an illustration showing a gate electrode contact defined in accordance with one embodiment of the present invention;
FIG. 8A is an illustration showing a metal 1 layer defined above and adjacent to the gate electrode contact layer of FIG. 6, in accordance with one embodiment of the present invention;
FIG. 8B is an illustration showing the metal 1 layer of FIG. 8A with larger track widths for the metal 1 ground and power tracks, relative to the other metal 1 tracks;
FIG. 9 is an illustration showing a via 1 layer defined above and adjacent to the metal 1 layer of FIG. 8A, in accordance with one embodiment of the present invention;
FIG. 10 is an illustration showing a metal 2 layer defined above and adjacent to the via 1 layer of FIG. 9, in accordance with one embodiment of the present invention;
FIG. 11 is an illustration showing conductor tracks traversing the dynamic array in a first diagonal direction relative to the first and second reference directions (x) and (y), in accordance with one embodiment of the present invention;
FIG. 12 is an illustration showing conductor tracks traversing the dynamic array in a second diagonal direction relative to the first and second reference directions (x) and (y), in accordance with one embodiment of the present invention;
FIG. 13A is an illustration showing an example of a sub-resolution contact layout used to lithographically reinforce diffusion contacts and gate electrode contacts, in accordance with one embodiment of the present invention;
FIG. 13B is an illustration showing the sub-resolution contact layout of FIG. 13A with sub-resolution contacts defined to fill the grid to the extent possible, in accordance with one embodiment of the present invention;
FIG. 13C is an illustration showing an example of a sub-resolution contact layout utilizing various shaped sub-resolution contacts, in accordance with one embodiment of the present invention;
FIG. 13D is an illustration showing an exemplary implementation of alternate phase shift masking (APSM) with sub-resolution contacts, in accordance with one embodiment of the present invention;
FIG. 14 is an illustration showing a semiconductor chip structure, in accordance with one embodiment of the present invention;
FIG. 14A shows an annotated version of FIG. 14;
FIG. 15 shows an example layout architecture defined in accordance with one embodiment of the present invention; and
FIG. 15A shows an annotated version of FIG. 15.



DETAILED DESCRIPTION
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention.
Generally speaking, a dynamic array architecture is provided to address semiconductor manufacturing process variability associated with a continually increasing lithographic gap. In the area of semiconductor manufacturing, lithographic gap is defined as the difference between the minimum size of a feature to be defined and the wavelength of light used to render the feature in the lithographic process, wherein the feature size is less than the wavelength of the light. Current lithographic processes utilize a light wavelength of 193 nm. However, current feature sizes are as small as 65 nm and are expected to soon approach sizes as small as 45 nm. With a size of 65 nm, the shapes are three times smaller than the wavelength of the light used to define the shapes. Also, considering that the interaction radius of light is about five light wavelengths, it should be appreciated that shapes exposed with a 193 nm light source will influence the exposure of shapes approximately 5*193 nm (965 nm) away. When considering the 65 nm sized features with respect to 90 nm sized features, it should be appreciated that approximately two times as many 65 nm sizes features may be within the 965 nm interaction radius of the 193 nm light source as compared to the 90 nm sized features.
Due to the increased number of features within the interaction radius of the light source, the extent and complexity of light interference contributing to exposure of a given feature is significant. Additionally, the particular shapes associated with the features within the interaction radius of the light source weighs heavily on the type of light interactions that occur. Traditionally, designers were allowed to define essentially any two-dimensional topology of feature shapes so long as a set of design rules were satisfied. For example, in a given layer of the chip, i.e., in a given mask, the designer may have defined two-dimensionally varying features having bends that wrap around each other. When such two-dimensionally varying features are located in neighboring proximity to each other, the light used to expose the features will interact in a complex and generally unpredictable manner. The light interaction becomes increasingly more complex and unpredictable as the feature sizes and relative spacing become smaller.
Traditionally, if a designer follows the established set of design rules, the resulting product will be manufacturable with a specified probability associated with the set of design rules. Otherwise, for a design that violates the set of design rules, the probability of successful manufacture of the resulting product is unknown. To address the complex light interaction between neighboring two-dimensionally varying features, in the interest of successful product manufacturing, the set of design rules is expanded significantly to adequately address the possible combinations of two-dimensionally varying features. This expanded set of design rules quickly becomes so complicated and unwieldy that application of the expanded set of design rules becomes prohibitively time consuming, expensive, and prone to error. For example, the expanded set of design rules requires complex verification. Also, the expanded set of design rules may not be universally applied. Furthermore, manufacturing yield is not guaranteed even if all design rules are satisfied.
It should be appreciated that accurate prediction of all possible light interactions when rendering arbitrarily-shaped two-dimensional features is generally not feasible. Moreover, as an alternative to or in combination with expansion of the set of design rules, the set of design rules may also be modified to include increased margin to account for unpredictable light interaction between the neighboring two-dimensionally varying features. Because the design rules are established in an attempt to cover the random two-dimensional feature topology, the design rules may incorporate a significant amount of margin. While addition of margin in the set of design rules assists with the layout portions that include the neighboring two-dimensionally varying features, such global addition of margin causes other portions of the layout that do not include the neighboring two-dimensionally varying features to be overdesigned, thus leading to decreased optimization of chip area utilization and electrical performance.
In view of the foregoing, it should be appreciated that semiconductor product yield is reduced as a result of parametric failures that stem from variability introduced by design-dependent unconstrained feature topologies, i.e., arbitrary two-dimensionally varying features disposed in proximity to each other. By way of example, these parametric failures may result from failure to accurately print contacts and vias and from variability in fabrication processes. The variability in fabrication processes may include CMP dishing, layout feature shape distortion due to photolithography, gate distortion, oxide thickness variability, implant variability, and other fabrication related phenomena. The dynamic array architecture of the present invention is defined to address the above-mentioned semiconductor manufacturing process variability.
FIG. 1 is an illustration showing a number of neighboring layout features and a representation of light intensity used to render each of the layout features, in accordance with one embodiment of the present invention. Specifically, three neighboring linear-shaped layout features (101A-101C) are depicted as being disposed in a substantially parallel relationship within a given mask layer. The distribution of light intensity from a layout feature shape is represented by a sinc function. The sinc functions (103A-103C) represent the distribution of light intensity from each of the layout features (101A-101C, respectively). The neighboring linear-shaped layout features (101A-101C) are spaced apart at locations corresponding to peaks of the sinc functions (103A-103C). Thus, constructive interference between the light energy associated with the neighboring layout features (101A-101C), i.e., at the peaks of the sinc functions (103A-103C), serves to reinforce the exposure of the neighboring shapes (101A-101C) for the layout feature spacing illustrated. In accordance with the foregoing, the light interaction represented in FIG. 1 represents a synchronous case.
As illustrated in FIG. 1, when linear-shaped layout features are defined in a regular repeating pattern at an appropriate spacing, constructive interference of the light energy associated with the various layout features serves to enhance the exposure of each layout feature. The enhanced exposure of the layout features provided by the constructive light interference can dramatically reduce or even eliminate a need to utilize optical proximity correction (OPC) and/or reticle enhancement technology (RET) to obtain sufficient rendering of the layout features.
A forbidden pitch, i.e., forbidden layout feature spacing, occurs when the neighboring layout features (101A-101C) are spaced such that peaks of the sinc function associated with one layout feature align with valleys of the sinc function associated with another layout feature, thus causing destructive interference of the light energy. The destructive interference of the light energy causes the light energy focused at a given location to be reduced. Therefore, to realize the beneficial constructive light interference associated with neighboring layout features, it is necessary to predict the layout feature spacing at which the constructive overlap of the sinc function peaks will occur. Predictable constructive overlap of the sinc function peaks and corresponding layout feature shape enhancement can be realized if the layout feature shapes are rectangular, near the same size, and are oriented in the same direction, as illustrated by the layout features (101A-101C) in FIG. 1. In this manner, resonant light energy from neighboring layout feature shapes is used to enhance the exposure of a particular layout feature shape.
FIG. 2 is an illustration showing a generalized stack of layers used to define a dynamic array architecture, in accordance with one embodiment of the present invention. It should be appreciated that the generalized stack of layers used to define the dynamic array architecture, as described with respect to FIG. 2, is not intended to represent an exhaustive description of the CMOS manufacturing process. However, the dynamic array is to be built in accordance with standard CMOS manufacturing processes. Generally speaking, the dynamic array architecture includes both the definition of the underlying structure of the dynamic array and the techniques for assembling the dynamic array for optimization of area utilization and manufacturability. Thus, the dynamic array is designed to optimize semiconductor manufacturing capabilities.
With regard to the definition of the underlying structure of the dynamic array, the dynamic array is built-up in a layered manner upon a base substrate 201, e.g., upon a silicon substrate, or silicon-on-insulator (SOI) substrate. Diffusion regions 203 are defined in the base substrate 201. The diffusion regions 203 represent selected regions of the base substrate 201 within which impurities are introduced for the purpose of modifying the electrical properties of the base substrate 201. Above the diffusion regions 203, diffusion contacts 205 are defined to enable connection between the diffusion regions 203 and conductor lines. For example, the diffusion contacts 205 are defined to enable connection between source and drain diffusion regions 203 and their respective conductor nets. Also, gate electrode features 207 are defined above the diffusion regions 203 to form transistor gates. Gate electrode contacts 209 are defined to enable connection between the gate electrode features 207 and conductor lines. For example, the gate electrode contacts 209 are defined to enable connection between transistor gates and their respective conductor nets.
Interconnect layers are defined above the diffusion contact 205 layer and the gate electrode contact layer 209. The interconnect layers include a first metal (metal 1) layer 211, a first via (via 1) layer 213, a second metal (metal 2) layer 215, a second via (via 2) layer 217, a third metal (metal 3) layer 219, a third via (via 3) layer 221, and a fourth metal (metal 4) layer 223. The metal and via layers enable definition of the desired circuit connectivity. For example, the metal and via layers enable electrical connection of the various diffusion contacts 205 and gate electrode contacts 209 such that the logic function of the circuitry is realized. It should be appreciated that the dynamic array architecture is not limited to a specific number of interconnect layers, i.e., metal and via layers. In one embodiment, the dynamic array may include additional interconnect layers 225, beyond the fourth metal (metal 4) layer 223. Alternatively, in another embodiment, the dynamic array may include less than four metal layers.
The dynamic array is defined such that layers (other than the diffusion region layer 203) are restricted with regard to layout feature shapes that can be defined therein. Specifically, in each layer other than the diffusion region layer 203, only linear-shaped layout features are allowed. A linear-shaped layout feature in a given layer is characterized as having a consistent vertical cross-section shape and extending in a single direction over the substrate. Thus, the linear-shaped layout features define structures that are one-dimensionally varying. The diffusion regions 203 are not required to be one-dimensionally varying, although they are allowed to be if necessary. Specifically, the diffusion regions 203 within the substrate can be defined to have any two-dimensionally varying shape with respect to a plane coincident with a top surface of the substrate. In one embodiment, the number of diffusion bend topologies is limited such that the interaction between the bend in diffusion and the conductive material, e.g., polysilicon, that forms the gate electrode of the transistor is predictable and can be accurately modeled. The linear-shaped layout features in a given layer are positioned to be parallel with respect to each other. Thus, the linear-shaped layout features in a given layer extend in a common direction over the substrate and parallel with the substrate.
The underlying layout methodology of the dynamic array uses constructive light interference of light waves in the lithographic process to reinforce exposure of neighboring shapes in a given layer. Therefore, the spacing of the parallel, linear-shaped layout features in a given layer is designed around the constructive light interference of the standing light waves such that lithographic correction (e.g., OPC/RET) is minimized or eliminated. Thus, in contrast to conventional OPC/RET-based lithographic processes, the dynamic array defined herein exploits the light interaction between neighboring features, rather than attempting to compensate for the light interaction between neighboring features.
Because the standing light wave for a given linear-shaped layout feature can be accurately modeled, it is possible to predict how the standing light waves associated with the neighboring linear-shaped layout features disposed in parallel in a given layer will interact. Therefore, it is possible to predict how the standing light wave used to expose one linear-shaped feature will contribute to the exposure of its neighboring linear-shaped features. Prediction of the light interaction between neighboring linear-shaped features enables the identification of an optimum feature-to-feature spacing such that light used to render a given shape will reinforce its neighboring shapes. The feature-to-feature spacing in a given layer is defined as the feature pitch, wherein the pitch is the center-to-center separation distance between adjacent linear-shaped features in a given layer.
To provide the desired exposure reinforcement between neighboring features, the linear-shaped layout features in a given layer are spaced such that constructive and destructive interference of the light from neighboring features will be optimized to produce the best rendering of all features in the neighborhood. The feature-to-feature spacing in a given layer is proportional to the wavelength of the light used to expose the features. The light used to expose each feature within about a five light wavelength distance from a given feature will serve to enhance the exposure of the given feature to some extent. The exploitation of constructive interference of the standing light waves used to expose neighboring features enables the manufacturing equipment capability to be maximized and not be limited by concerns regarding light interactions during the lithography process.
As discussed above, the dynamic array incorporates a restricted topology in which the features within each layer (other than diffusion) are required to be linear-shaped features that are oriented in a parallel manner to traverse over the substrate in a common direction. With the restricted topology of the dynamic array, the light interaction in the photolithography process can be optimized such that the printed image on the mask is essentially identical to the drawn shape in the layout, i.e., essentially a 100% accurate transfer of the layout onto the resist is achieved.
FIG. 3A is an illustration showing an exemplary base grid to be projected onto the dynamic array to facilitate definition of the restricted topology, in accordance with one embodiment of the present invention. The base grid can be used to facilitate parallel placement of the linear-shaped features in each layer of the dynamic array at the appropriate optimized pitch. Although not physically defined as part of the dynamic array, the base grid can be considered as a projection on each layer of the dynamic array. Also, it should be understood that the base grid is projected in a substantially consistent manner with respect to position on each layer of the dynamic array, thus facilitating accurate feature stacking and alignment.
In the exemplary embodiment of FIG. 3A, the base grid is defined as a rectangular grid, i.e., Cartesian grid, in accordance with a first reference direction (x) and a second reference direction (y). The gridpoint-to-gridpoint spacing in the first and second reference directions can be defined as necessary to enable definition of the linear-shaped features at the optimized feature-to-feature spacing. Also, the gridpoint spacing in the first reference direction (x) can be different than the gridpoint spacing in the second reference direction (y). In one embodiment, a single base grid is projected across the entire die to enable location of the various linear-shaped features in each layer across the entire die. However, in other embodiments, separate base grids can be projected across separate regions of the die to support different feature-to-feature spacing requirements within the separate regions of the die. FIG. 3B is an illustration showing separate base grids projected across separate regions of the die, in accordance with an exemplary embodiment of the present invention.
The base grid is defined with consideration for the light interaction function, i.e., the sinc function, and the manufacturing capability, wherein the manufacturing capability is defined by the manufacturing equipment and processes to be utilized in fabricating the dynamic array. With regard to the light interaction function, the base grid is defined such that the spacing between gridpoints enables alignment of peaks in the sinc functions describing the light energy projected upon neighboring gridpoints. Therefore, linear-shaped features optimized for lithographic reinforcement can be specified by drawing a line from a first gridpoint to a second gridpoint, wherein the line represents a rectangular structure of a given width. It should be appreciated that the various linear-shaped features in each layer can be specified according to their endpoint locations on the base grid and their width.
FIG. 3C is an illustration showing an exemplary linear-shaped feature 301 defined to be compatible with the dynamic array, in accordance with one embodiment of the present invention. The linear-shaped feature 301 has a substantially rectangular cross-section defined by a width 303 and a height 307. The linear-shaped feature 301 extends in a linear direction to a length 305. In one embodiment, a cross-section of the linear-shaped feature, as defined by its width 303 and height 307, is substantially uniform along its length 305. It should be understood, however, that lithographic effects may cause a rounding of the ends of the linear-shaped feature 301. The first and second reference directions (x) and (y), respectively, of FIG. 3A are shown to illustrate an exemplary orientation of the linear-shaped feature on the dynamic array. It should be appreciated that the linear-shaped feature may be oriented to have its length 305 extend in either the first reference direction (x), the second reference direction (y), or in diagonal direction defined relative to the first and second reference directions (x) and (y). Regardless of the linear-shaped features' particular orientation with respect to the first and second reference directions (x) and (y), it should be understood that the linear-shaped feature is defined in a plane that is substantially parallel to a top surface of the substrate upon which the dynamic array is built. Also, it should be understood that the linear-shaped feature is free of bends, i.e., change in direction, in the plane defined by the first and second reference directions.
FIG. 3D is an illustration showing another exemplary linear-shaped feature 317 defined to be compatible with the dynamic array, in accordance with one embodiment of the present invention. The linear-shaped feature 317 has a trapezoidal cross-section defined by a lower width 313, an upper width 315, and a height 309. The linear-shaped feature 317 extends in a linear direction to a length 311. In one embodiment, the cross-section of the linear-shaped feature 317 is substantially uniform along its length 311. It should be understood, however, that lithographic effects may cause a rounding of the ends of the linear-shaped feature 317. The first and second reference directions (x) and (y), respectively, of FIG. 3A are shown to illustrate an exemplary orientation of the linear-shaped feature on the dynamic array. It should be appreciated that the linear-shaped feature 317 may be oriented to have its length 311 extend in either the first reference direction (x), the second reference direction (y), or in diagonal direction defined relative to the first and second reference directions (x) and (y). Regardless of the particular orientation of the linear-shaped feature 317 with regard to the first and second reference directions (x) and (y), it should be understood that the linear-shaped feature 317 is defined in a plane that is substantially parallel to a top surface of the substrate upon which the dynamic array is built. Also, it should be understood that the linear-shaped feature 317 is free of bends, i.e., change in direction, in the plane defined by the first and second reference directions.
Although FIGS. 3C and 3D explicitly discuss linear shaped features having rectangular and trapezoidal cross-sections, respectively, it should be understood that the linear shaped features having other types of cross-sections can be defined within the dynamic array. Therefore, essentially any suitable cross-sectional shape of the linear-shaped feature can be utilized so long as the linear-shaped feature is defined to have a length that extends in one direction, and is oriented to have its length extend in either the first reference direction (x), the second reference direction (y), or in diagonal direction defined relative to the first and second reference directions (x) and (y).
The layout architecture of the dynamic array follows the base grid pattern. Thus, it is possible to use grid points to represent where changes in direction occur in diffusion, wherein gate electrode and metal linear-shaped features are placed, where contacts are placed, where opens are in the linear-shaped gate electrode and metal features, etc. The pitch of the gridpoints, i.e., the gridpoint-to-gridpoint spacing, should be set for a given feature line width, e.g., width 303 in FIG. 3C, such that exposure of neighboring linear-shaped features of the given feature line width will reinforce each other, wherein the linear-shaped features are centered on gridpoints. With reference to the dynamic array stack of FIG. 2 and the exemplary base grid of FIG. 3A, in one embodiment, the gridpoint spacing in the first reference direction (x) is set by the required gate electrode gate pitch. In this same embodiment, the gridpoint pitch in the second reference direction (y) is set by the metal 1 and metal 3 pitch. For example, in a 90 nm process technology, i.e., minimum feature size equal to 90 nm, the gridpoint pitch in the second reference direction (y) is about 0.24 micron. In one embodiment, metal 1 and metal 2 layers will have a common spacing and pitch. A different spacing and pitch may be used above the metal 2 layer.
The various layers of the dynamic array are defined such that the linear-shaped features in adjacent layers extend in a crosswise manner with respect to each other. For example, the linear-shaped features of adjacent layers may extend orthogonally, i.e., perpendicularly with respect to each other. Also, the linear-shaped features of one layer may extend across the linear-shaped features of an adjacent layer at an angle, e.g., at about 45 degrees. For example, in one embodiment the linear-shaped feature of one layer extend in the first reference direction (x) and the linear-shaped features of the adjacent layer extend diagonally with respect to the first (x) and second (y) reference directions. It should be appreciated that to route a design in the dynamic array having the linear-shaped features positioned in the crosswise manner in adjacent layers, opens can be defined in the linear-shaped features, and contacts and vias can be defined as necessary.
The dynamic array minimizes the use of bends in layout shapes to eliminate unpredictable lithographic interactions. Specifically, prior to OPC or other RET processing, the dynamic array allows bends in the diffusion layer to enable control of device sizes, but does not allow bends in layers above the diffusion layer. The layout features in each layer above the diffusion layer are linear in shape, e.g., FIG. 3C, and disposed in a parallel relationship with respect to each other. The linear shapes and parallel positioning of layout features are implemented in each stack layer of the dynamic array where predictability of constructive light interference is necessary to ensure manufacturability. In one embodiment, the linear shapes and parallel positioning of layout features are implemented in the dynamic array in each layer above diffusion through metal 2. Above metal 2, the layout features may be of sufficient size and shape that constructive light interference is not required to ensure manufacturability. However, the presence of constructive light interference in patterning layout features above metal 2 may be beneficial.
An exemplary buildup of dynamic array layers from diffusion through metal 2 are described with respect to FIGS. 4 through 14. It should be appreciated that the dynamic array described with respect to FIGS. 4 through 14 is provided by way of example only, and is not intended to convey limitations of the dynamic array architecture. The dynamic array can be used in accordance with the principles presented herein to define essentially any integrated circuit design.
FIG. 4 is an illustration showing a diffusion layer layout of an exemplary dynamic array, in accordance with one embodiment of the present invention. The diffusion layer of FIG. 4 shows a p-diffusion region 401 and an n-diffusion region 403. While the diffusion regions are defined according to the underlying base grid, the diffusion regions are not subject to the linear-shaped feature restrictions associated with the layers above the diffusion layer. The diffusion regions 401 and 403 include diffusion squares 405 defined where diffusion contacts will be located. The diffusion regions 401 and 403 do not include extraneous jogs or corners, thus improving the use of lithographic resolution and enabling more accurate device extraction. Additionally, n+ mask regions (412 and 416) and p+ mask regions (410 and 414) are defined as rectangles on the (x), (y) grid with no extraneous jogs or notches. This style permits use of larger diffusion regions, eliminates need for OPC/RET, and enables use of lower resolution and lower cost lithographic systems, e.g., i-line illumination at 365 nm. It should be appreciated that the n+ mask region 416 and the p+ mask region 410, as depicted in FIG. 4, are for an embodiment that does not employ well-biasing. In an alternative embodiment where well-biasing is to be used, the n+ mask region 416 shown in FIG. 4 will actually be defined as a p+ mask region. Also, in this alternative embodiment, the p+ mask region 410 shown in FIG. 4 will actually be defined as a n+ mask region.
FIG. 5 is an illustration showing a gate electrode layer and a diffusion contact layer above and adjacent to the diffusion layer of FIG. 4, in accordance with one embodiment of the present invention. As those skilled in the CMOS arts will appreciate, the gate electrode features 501 define the transistor gates. The gate electrode features 501 are defined as linear shaped features extending in a parallel relationship across the dynamic array in the second reference direction (y). In one embodiment, the gate electrode features 501 are defined to have a common width. However, in another embodiment, one or more of the gate electrode features can be defined to have a different width. For example, FIG. 5 shows a gate electrode features 501A that has a larger width relative to the other gate electrode features 501. The pitch (center-to-center spacing) of the gate electrode features 501 is minimized while ensuring optimization of lithographic reinforcement, i.e., resonant imaging, provided by neighboring gate electrode features 501. For discussion purposes, gate electrode features 501 extending across the dynamic array in a given line are referred to as a gate electrode track.
The gate electrode features 501 form n-channel and p-channel transistors as they cross the diffusion regions 403 and 401, respectively. Optimal gate electrode feature 501 printing is achieved by drawing gate electrode features 501 at every grid location, even though no diffusion region may be present at some grid locations. Also, long continuous gate electrode features 501 tend to improve line end shortening effects at the ends of gate electrode features within the interior of the dynamic array. Additionally, gate electrode printing is significantly improved when all bends are removed from the gate electrode features 501.
Each of the gate electrode tracks may be interrupted, i.e., broken, any number of times in linearly traversing across the dynamic array in order to provide required electrical connectivity for a particular logic function to be implemented. When a given gate electrode track is required to be interrupted, the separation between ends of the gate electrode track segments at the point of interruption is minimized to the extent possible taking into consideration the manufacturing capability and electrical effects. In one embodiment, optimal manufacturability is achieved when a common end-to-end spacing is used between features within a particular layer.
Minimizing the separation between ends of the gate electrode track segments at the points of interruption serves to maximize the lithographic reinforcement, and uniformity thereof, provided from neighboring gate electrode tracks. Also, in one embodiment, if adjacent gate electrode tracks need to be interrupted, the interruptions of the adjacent gate electrode tracks are made such that the respective points of interruption are offset from each other so as to avoid, to the extent possible, an occurrence of neighboring points of interruption. More specifically, points of interruption within adjacent gate electrode tracks are respectively positioned such that a line of sight does not exist through the points of interruption, wherein the line of sight is considered to extend perpendicularly to the direction in which the gate electrode tracks extend over the substrate. Additionally, in one embodiment, the gate electrodes may extend through the boundaries at the top and bottom of the cells, i.e., the PMOS or NMOS cells. This embodiment would enable bridging of neighboring cells.
With further regard to FIG. 5, diffusion contacts 503 are defined at each diffusion square 405 to enhance the printing of diffusion contacts via resonant imaging. The diffusion squares 405 are present around every diffusion contact 503 to enhance the printing of the power and ground connection polygons at the diffusion contacts 503.
The gate electrode features 501 and diffusion contacts 503 share a common grid spacing. More specifically, the gate electrode feature 501 placement is offset by one-half the grid spacing relative to the diffusion contacts 503. For example, if the gate electrode features 501 and diffusion contact 503 grid spacing is 0.36 μm, then the diffusion contacts are placed such that the x-coordinate of their center falls on an integer multiple of 0.36 μm, while the x-coordinate of the center of each gate electrode feature 501 minus 0.18 μm should be an integer multiple of 0.36 μm. In the present example, the x-coordinates are represented by the following:

Diffusion contact center x-coordinate=I*0.36 μm, where I is the grid number;

Gate electrode feature center x-coordinate=0.18 μm+I*0.36 μm, where I is the grid number.

The grid based system of the dynamic array ensures that all contacts (diffusion and gate electrode) will land on a horizontal grid that is equal to a multiple of one-half of the diffusion contact grid and a vertical grid that is set by the metal 1 pitch. In the example above, the gate electrode feature and diffusion contact grid is 0.36 μm. The diffusion contacts and gate electrode contacts will land on a horizontal grid that is a multiple of 0.18 μm. Also, the vertical grid for 90 nm process technologies is about 0.24 μm.
FIG. 6 is an illustration showing a gate electrode contact layer defined above and adjacent to the gate electrode layer of FIG. 5, in accordance with one embodiment of the present invention. In the gate electrode contact layer, gate electrode contacts 601 are drawn to enable connection of the gate electrode features 501 to the overlying metal conduction lines. In general, design rules will dictate the optimum placement of the gate electrode contacts 601. In one embodiment, the gate electrode contacts are drawn on top of the transistor endcap regions. This embodiment minimizes white space in the dynamic array when design rules specify long transistor endcaps. In some process technologies white space may be minimized by placing a number of gate electrode contacts for a cell in the center of the cell. Also, it should be appreciated that in the present invention, the gate electrode contact 601 is oversized in the direction perpendicular to the gate electrode feature 501 to ensure overlap between the gate electrode contact 601 and the gate electrode feature 501.
FIG. 6A shows an annotated version of FIG. 6. The features depicted in FIG. 6A are exactly the same as the features depicted in FIG. 6. FIG. 6A shows a first conductive gate level structure 501a having a lengthwise centerline 6a01. FIG. 6A shows a second conductive gate level structure 501b and a third conductive gate level structure 501c having a lengthwise centerline 6a03. FIG. 6A shows a fourth conductive gate level structure 501d and a fifth conductive gate level structure 501e having the lengthwise centerline 6a05. FIG. 6A shows a sixth conductive gate level structure 501f having a lengthwise centerline 6a07. FIG. 6A shows a seventh conductive gate level structure 501g having a lengthwise centerline 6a09. FIG. 6A shows an eighth conductive gate level structure 501h having a lengthwise centerline 6a11.
FIG. 6A shows the first conductive gate level structure 501a separated from each of the second conductive gate level structure 501b and third conductive gate level structure 501c by a centerline-to-centerline spacing 6a13 as measured in a direction perpendicular to the parallel direction of the gate level structures. FIG. 6A shows the second conductive gate level structure 501b separated from the fourth conductive gate level structure 501d by a centerline-to-centerline spacing 6a15 as measured in the direction perpendicular to the parallel direction of the gate level structures. FIG. 6A shows the third conductive gate level structure 501c separated from the fifth conductive gate level structure 501e by a centerline-to-centerline spacing 6a15 as measured in the direction perpendicular to the parallel direction of the gate level structures. FIG. 6A shows the sixth conductive gate level structure 501f separated from each of the fourth conductive gate level structure 501d and fifth conductive gate level structure 501e by a centerline-to-centerline spacing 6a17 as measured in the direction perpendicular to the parallel direction of the gate level structures. FIG. 6A shows the sixth conductive gate level structure 501f separated from the seventh conductive gate level structure 501g by a centerline-to-centerline spacing 6a19 as measured in the direction perpendicular to the parallel direction of the gate level structures. FIG. 6A shows the seventh conductive gate level structure 501g separated from the eighth conductive gate level structure 501h by a centerline-to-centerline spacing 6a21 as measured in the direction perpendicular to the parallel direction of the gate level structures.
FIG. 6A shows the first conductive gate level structure 501a forming a gate electrode of a transistor 6a47 of a first transistor type and a gate electrode of a transistor 6a37 of a second transistor type. FIG. 6A shows the second conductive gate level structure 501b forming a gate electrode of a transistor 6a49 of the first transistor type. FIG. 6A shows the third conductive gate level structure 501c forming a gate electrode of a transistor 6a39 of the second transistor type. FIG. 6A shows the fourth conductive gate level structure 501d forming a gate electrode of a transistor 6a51 of the first transistor type. FIG. 6A shows the fifth conductive gate level structure 501e forming a gate electrode of a transistor 6a41 of the second transistor type. FIG. 6A shows the sixth conductive gate level structure 501f forming a gate electrode of a transistor 6a53 of the first transistor type and a gate electrode of a transistor 6a43 of the second transistor type. FIG. 6A shows the seventh conductive gate level structure 501g not forming a gate electrode of a transistor. FIG. 6A shows the eighth conductive gate level structure 501h forming a gate electrode of a transistor 6a55 of the first transistor type and a gate electrode of a transistor 6a45 of the second transistor type.
FIG. 6A shows the contact 601a connected to the first conductive gate level structure 501a. FIG. 6A shows the contact 601b connected to the second conductive gate level structure 501b. FIG. 6A shows the contact 601c connected to the third conductive gate level structure 501c. FIG. 6A shows the contact 601d connected to the fourth conductive gate level structure 501d. FIG. 6A shows the contact 601e connected to the fifth conductive gate level structure 501e. FIG. 6A shows the contact 601f connected to the sixth conductive gate level structure 501f. 
FIG. 6A shows the contact 601b positioned to contact the second conductive gate level structure 501b at a contact-to-gate distance 6a25 from a gate electrode of the transistor 6a49. FIG. 6A shows the contact 601c positioned to contact the third conductive gate level structure 501c at a contact-to-gate distance 6a27 from a gate electrode of the transistor 6a39. FIG. 6A shows the contact 601d positioned to contact the fourth conductive gate level structure 501d at a contact-to-gate distance 6a23 from a gate electrode of the transistor 6a51. FIG. 6A shows the contact 601e positioned to contact the fifth conductive gate level structure 501e at a contact-to-gate distance 6a29 from a gate electrode of the transistor 6a41.
FIG. 6B shows an annotated version of FIG. 6. The features depicted in FIG. 6B are exactly the same as the features depicted in FIG. 6. FIG. 6B shows the contact 601b located at a contact position 6a31 in the parallel direction of the conductive gate level structures, i.e., in the y direction. FIG. 6B shows the contact 601c and the contact 601d located at a contact position 6a33 in the parallel direction of the conductive gate level structures. FIG. 6B shows the contact 601e located at a contact position 6a35 in the parallel direction of the conductive gate level structures. FIG. 6B shows the contacts 601b and 601e positioned outside the diffusion regions 401 and 403 of different diffusion region types. FIG. 6B shows the contacts 601c and 601d positioned between the diffusion regions 401 and 403 of different diffusion region types, i.e., positioned over the inner non-diffusion region between the diffusion regions 401 and 403 of different diffusion region types.
FIG. 6C shows an annotated version of FIG. 6. The features depicted in FIG. 6C are exactly the same as the features depicted in FIG. 6. FIG. 6C shows the second conductive gate level structure 501b extending a distance 6a57 beyond the contact 601b in the parallel direction (y-direction) away from the gate electrode of the transistor 6a49. FIG. 6C shows the third conductive gate level structure 501c extending a distance 6a59 beyond the contact 601c in the parallel direction (y-direction) away from the gate electrode of the transistor 6a39. FIG. 6C shows the fourth conductive gate level structure 501d extending a distance 6a61 beyond the contact 601d in the parallel direction (y-direction) away from the gate electrode of the transistor 6a51. FIG. 6C shows the fifth conductive gate level structure 501e extending a distance 6a63 beyond the contact 601e in the parallel direction (y-direction) away from the gate electrode of the transistor 6a41.
FIG. 6D shows an annotated version of FIG. 6. The features depicted in FIG. 6D are exactly the same as the features depicted in FIG. 6. FIG. 6D shows the first conductive gate level structure 501a defined to have a length 6a89 as measured in the parallel direction (y-direction). FIG. 6D shows the second conductive gate level structure 501b defined to have a length 6a93 as measured in the parallel direction (y-direction). FIG. 6D shows the third conductive gate level structure 501c defined to have a length 6a91 as measured in the parallel direction (y-direction). FIG. 6D shows the fourth conductive gate level structure 501d defined to have a length 6a97 as measured in the parallel direction (y-direction). FIG. 6D shows the fifth conductive gate level structure 501e defined to have a length 6a95 as measured in the parallel direction (y-direction). FIG. 6D shows the sixth conductive gate level structure 501f defined to have a length 6a99 as measured in the parallel direction (y-direction). FIG. 6D shows the seventh conductive gate level structure 501g defined to have a length 6a101 as measured in the parallel direction (y-direction). FIG. 6D shows the eighth conductive gate level structure 501h defined to have a length 6a103 as measured in the parallel direction (y-direction).
FIG. 6D shows the second conductive gate level structure 501b positioned in a spaced apart end-to-end manner with the third conductive gate level structure 501c. FIG. 6D shows the second conductive gate level structure 501b separated from the third conductive gate level structure 501c by a first end-to-end spacing 6a85 as measured in the parallel direction (y-direction). FIG. 6D shows the fourth conductive gate level structure 501d positioned in a spaced apart end-to-end manner with the fifth conductive gate level structure 501e. FIG. 6D shows the fourth conductive gate level structure 501d separated from the fifth conductive gate level structure 501e by a second end-to-end spacing 6a87 as measured in the parallel direction (y-direction). FIG. 6D shows the first end-to-end spacing 6a85 positioned over the inner non-diffusion region between the two diffusion regions 401 and 403 of different diffusion types. FIG. 6D shows the second end-to-end spacing 6a87 positioned over the inner non-diffusion region between the two diffusion regions 401 and 403 of different diffusion types. FIG. 6D shows the first end-to-end spacing 6a85 offset in the parallel direction (y-direction) from the second end-to-end spacing 6a87.
FIG. 6D shows the first, second, fourth, sixth, seventh, and eighth conductive gate level structures 501a, 501b, 501d, 501f, 501g, 501h, respectively, each having an end aligned with a first common position 6a81 in the parallel direction (y-direction). FIG. 6D shows the first, third, fifth, sixth, seventh, and eighth conductive gate level structures 501a, 501c, 501e, 501f, 501g, 501h, respectively, each having an end aligned with a second common position 6a83 in the parallel direction (y-direction).
FIG. 6E shows an annotated version of FIG. 6. The features depicted in FIG. 6E are exactly the same as the features depicted in FIG. 6. FIG. 6E shows the second conductive gate level feature 501b having an outer extension distance 6a105 as measured in the parallel direction (y-direction) away from the gate electrode of the transistor 6a49 and away from the transistor 6a39. FIG. 6E shows the second conductive gate level feature 501b having an inner extension distance 6a107 as measured in the parallel direction (y-direction) away from the gate electrode of the transistor 6a49 and toward the transistor 6a39. FIG. 6E shows the third conductive gate level feature 501c having an outer extension distance 6a111 as measured in the parallel direction (y-direction) away from the gate electrode of the transistor 6a39 and away from the transistor 6a49. FIG. 6E shows the third conductive gate level feature 501c having an inner extension distance 6a109 as measured in the parallel direction (y-direction) away from the gate electrode of the transistor 6a39 and toward the transistor 6a49.
FIG. 6E shows the fourth conductive gate level feature 501d having an outer extension distance 6a113 as measured in the parallel direction (y-direction) away from the gate electrode of the transistor 6a51 and away from the transistor 6a41. FIG. 6E shows the fourth conductive gate level feature 501d having an inner extension distance 6a115 as measured in the parallel direction (y-direction) away from the gate electrode of the transistor 6a51 and toward the transistor 6a41. FIG. 6E shows the fifth conductive gate level feature 501e having an outer extension distance 6a119 as measured in the parallel direction (y-direction) away from the gate electrode of the transistor 6a41 and away from the transistor 6a51. FIG. 6E shows the fifth conductive gate level feature 501e having an inner extension distance 6a117 as measured in the parallel direction (y-direction) away from the gate electrode of the transistor 6a41 and toward the transistor 6a51. FIG. 7A is an illustration showing a traditional approach for making contact to a gate electrode, e.g., polysilicon feature. In the traditional configuration of FIG. 7A, an enlarged rectangular gate electrode region 707 is defined where a gate electrode contact 709 is to be located. The enlarged rectangular gate electrode region 707 introduces a bend of distance 705 in the gate electrode. The bend associated with the enlarged rectangular gate electrode region 707 sets up undesirable light interactions and distorts the gate electrode line 711. Distortion of the gate electrode line 711 is especially problematic when the gate electrode width is about the same as a transistor length.
FIG. 7B is an illustration showing a gate electrode contact 601, e.g., polysilicon contact, defined in accordance with one embodiment of the present invention. The gate electrode contact 601 is drawn to overlap the edges of the gate electrode feature 501, and extend in a direction substantially perpendicular to the gate electrode feature 501. In one embodiment, the gate electrode contact 601 is drawn such that the vertical dimension 703 is same as the vertical dimension used for the diffusion contacts 503. For example, if the diffusion contact 503 opening is specified to be 0.12 μm square then the vertical dimension of the gate electrode contact 601 is drawn at 0.12 μm. However, in other embodiments, the gate electrode contact 601 can be drawn such that the vertical dimension 703 is different from the vertical dimension used for the diffusion contacts 503.
In one embodiment, the gate electrode contact 601 extension 701 beyond the gate electrode feature 501 is set such that maximum overlap is achieved between the gate electrode contact 601 and the gate electrode feature 501. The extension 701 is defined to accommodate line end shortening of the gate electrode contact 601, and misalignment between the gate electrode contact layer and gate electrode feature layer. The length of the gate electrode contact 601 is defined to ensure maximum surface area contact between the gate electrode contact 601 and the gate electrode feature 501, wherein the maximum surface area contact is defined by the width of the gate electrode feature 501.
FIG. 8A is an illustration showing a metal 1 layer defined above the gate electrode contact layer of FIG. 6, in accordance with one embodiment of the present invention. The metal 1 layer includes a number of metal 1 tracks 801-821 defined to include linear shaped features extending in a parallel relationship across the dynamic array. The metal 1 tracks 801-821 extend in a direction substantially perpendicular to the gate electrode features 501 in the underlying gate electrode layer of FIG. 5. Thus, in the present example, the metal 1 tracks 801-821 extend linearly across the dynamic array in the first reference direction (x). The pitch (center-to-center spacing) of the metal 1 tracks 801-821 is minimized while ensuring optimization of lithographic reinforcement, i.e., resonant imaging, provided by neighboring metal 1 tracks 801-821. For example, in one embodiment, the metal 1 tracks 801-821 are centered on a vertical grid of about 0.24 μm for a 90 nm process technology.
Each of the metal 1 tracks 801-821 may be interrupted, i.e., broken, any number of times in linearly traversing across the dynamic array in order to provide required electrical connectivity for a particular logic function to be implemented. When a given metal 1 track 801-821 is required to be interrupted, the separation between ends of the metal 1 track segments at the point of interruption is minimized to the extent possible taking into consideration manufacturing capability and electrical effects. Minimizing the separation between ends of the metal 1 track segments at the points of interruption serves to maximize the lithographic reinforcement, and uniformity thereof, provided from neighboring metal 1 tracks. Also, in one embodiment, if adjacent metal 1 tracks need to be interrupted, the interruptions of the adjacent metal 1 tracks are made such that the respective points of interruption are offset from each other so as to avoid, to the extent possible, an occurrence of neighboring points of interruption. More specifically, points of interruption within adjacent metal 1 tracks are respectively positioned such that a line of sight does not exist through the points of interruption, wherein the line of sight is considered to extend perpendicularly to the direction in which the metal 1 tracks extend over the substrate.
In the example of FIG. 8A, the metal 1 track 801 is connected to the ground supply, and the metal 1 track 821 is connected to the power supply voltage. In the embodiment of FIG. 8A, the widths of the metal 1 tracks 801 and 821 are the same as the other metal 1 tracks 803-819. However, in another embodiment, the widths of metal 1 tracks 801 and 821 are larger than the widths of the other metal 1 tracks 803-819. FIG. 8B is an illustration showing the metal 1 layer of FIG. 8A with larger track widths for the metal 1 ground and power tracks (801A and 821A), relative to the other metal 1 tracks 803-819.
The metal 1 track pattern is optimally configured to optimize the use of “white space” (space not occupied by transistors). The example of FIG. 8A includes the two shared metal 1 power tracks 801 and 821, and nine metal 1 signal tracks 803-819. Metal 1 tracks 803, 809, 811, and 819 are defined as gate electrode contact tracks in order to minimize white space. Metal 1 tracks 805 and 807 are defined to connect to n-channel transistor source and drains. Metal 1 tracks 813, 815, and 817 are defined to connect to p-channel source and drains. Also, any of the nine metal 1 signal tracks 803-819 can be used as a feed through if no connection is required. For example, metal 1 tracks 813 and 815 are configured as feed through connections.
FIG. 9 is an illustration showing a via 1 layer defined above and adjacent to the metal 1 layer of FIG. 8A, in accordance with one embodiment of the present invention. Vias 901 are defined in the via 1 layer to enable connection of the metal 1 tracks 801-821 to higher level conduction lines.
FIG. 10 is an illustration showing a metal 2 layer defined above and adjacent to the via 1 layer of FIG. 9, in accordance with one embodiment of the present invention. The metal 2 layer includes a number of metal 2 tracks 1001 defined as linear shaped features extending in a parallel relationship across the dynamic array. The metal 2 tracks 1001 extend in a direction substantially perpendicular to the metal 1 tracks 801-821 in the underlying metal 1 layer of FIG. 8A, and in a direction substantially parallel to the gate electrode tracks 501 in the underlying gate electrode layer of FIG. 5. Thus, in the present example, the metal 2 tracks 1001 extend linearly across the dynamic array in the second reference direction (y).
The pitch (center-to-center spacing) of the metal 2 tracks 1001 is minimized while ensuring optimization of lithographic reinforcement, i.e., resonant imaging, provided by neighboring metal 2 tracks. It should be appreciated that regularity can be maintained on higher level interconnect layers in the same manner as implemented in the gate electrode and metal 1 layers. In one embodiment, the gate electrode feature 501 pitch and the metal 2 track pitch is the same. In another embodiment, the contacted gate electrode pitch (e.g., polysilicon-to-polysilicon space with a diffusion contact in between) is greater than the metal 2 track pitch. In this embodiment, the metal 2 track pitch is optimally set to be 2⁄3 or 3⁄4 of the contacted gate electrode pitch. Thus, in this embodiment, the gate electrode track and metal 2 track align at every two gate electrode track pitches and every three metal 2 track pitches. For example, in a 90 nm process technology, the optimum contacted gate electrode track pitch is 0.36 μm, and the optimum metal 2 track pitch is 0.24 μm. In another embodiment, the gate electrode track and the metal 2 track align at every three gate electrode pitches and every four metal 2 pitches. For example, in a 90 nm process technology, the optimum contacted gate electrode track pitch is 0.36 μm, and the optimum metal 2 track pitch is 0.27 μm.
Each of the metal 2 tracks 1001 may be interrupted, i.e., broken, any number of times in linearly traversing across the dynamic array in order to provide required electrical connectivity for a particular logic function to be implemented. When a given metal 2 track 1001 is required to be interrupted, the separation between ends of the metal 2 track segments at the point of interruption is minimized to the extent possible taking into consideration manufacturing and electrical effects. Minimizing the separation between ends of the metal 2 track segments at the points of interruption serves to maximize the lithographic reinforcement, and uniformity thereof, provided from neighboring metal 2 tracks. Also, in one embodiment, if adjacent metal 2 tracks need to be interrupted, the interruptions of the adjacent metal 2 tracks are made such that the respective points of interruption are offset from each other so as to avoid, to the extent possible, an occurrence of neighboring points of interruption. More specifically, points of interruption within adjacent metal 2 tracks are respectively positioned such that a line of sight does not exist through the points of interruption, wherein the line of sight is considered to extend perpendicularly to the direction in which the metal 2 tracks extend over the substrate.
As discussed above, the conduction lines in a given metal layer above the gate electrode layer may traverse the dynamic array in a direction coincident with either the first reference direction (x) or the second reference direction (y). It should be further appreciated that the conduction lines in a given metal layer above the gate electrode layer may traverse the dynamic array in a diagonal direction relative to the first and second reference directions (x) and (y). FIG. 11 is an illustration showing conductor tracks 1101 traversing the dynamic array in a first diagonal direction relative to the first and second reference directions (x) and (y), in accordance with one embodiment of the present invention. FIG. 12 is an illustration showing conductor tracks 1201 traversing the dynamic array in a second diagonal direction relative to the first and second reference directions (x) and (y), in accordance with one embodiment of the present invention.
As with the metal 1 and metal 2 tracks discussed above, the diagonal traversing conductor tracks 1101 and 1201 of FIGS. 11 and 12 may be interrupted, i.e., broken, any number of times in linearly traversing across the dynamic array in order to provide required electrical connectivity for a particular logic function to be implemented. When a given diagonal traversing conductor track is required to be interrupted, the separation between ends of the diagonal conductor track at the point of interruption is minimized to the extent possible taking into consideration manufacturing and electrical effects. Minimizing the separation between ends of the diagonal conductor track at the points of interruption serves to maximize the lithographic reinforcement, and uniformity thereof, provided from neighboring diagonal conductor tracks.
An optimal layout density within the dynamic array is achieved by implementing the following design rules:
at least two metal 1 tracks be provided across the n-channel device area;
at least two metal 1 tracks be provided across the p-channel device area;
at least two gate electrode tracks be provided for the n-channel device; and
at least two gate electrode tracks be provided for the p-channel device.
Contacts and vias are becoming the most difficult mask from a lithographic point of view. This is because the contacts and vias are getting smaller, more closely spaced, and are randomly distributed. The spacing and density of the cuts (contact or vias) makes it extremely difficult to reliably print the shapes. For example, cut shapes may be printed improperly due to destructive interference patterns from neighboring shapes or lack of energy on lone shapes. If a cut is properly printed, the manufacturing yield of the associated contact or via is extremely high. Sub-resolution contacts can be provided to reinforce the exposure of the actual contacts, so long as the sub-resolution contacts do not resolve. Also, the sub-resolution contacts can be of any shape so long as they are smaller than the resolution capability of the lithographic process.
FIG. 13A is an illustration showing an example of a sub-resolution contact layout used to lithographically reinforce diffusion contacts and gate electrode contacts, in accordance with one embodiment of the present invention. Sub-resolution contacts 1301 are drawn such that they are below the resolution of the lithographic system and will not be printed. The function of the sub-resolution contacts 1301 is to increase the light energy at the desired contact locations, e.g., 503, 601, through resonant imaging. In one embodiment, sub-resolution contacts 1301 are placed on a grid such that both gate electrode contacts 601 and diffusion contacts 503 are lithographically reinforced. For example, sub-resolution contacts 1301 are placed on a grid that is equal to one-half the diffusion contact 503 grid spacing to positively impact both gate electrode contacts 601 and diffusion contacts 503. In one embodiment, a vertical spacing of the sub-resolution contacts 1301 follows the vertical spacing of the gate electrode contacts 601 and diffusion contacts 503.
Grid location 1303 in FIG. 13A denotes a location between adjacent gate electrode contacts 601. Depending upon the lithographic parameters in the manufacturing process, it is possible that a sub-resolution contact 1301 at this grid location would create an undesirable bridge between the two adjacent gate electrode contacts 601. If bridging is likely to occur, a sub-resolution contact 1301 at location 1303 can be omitted. Although FIG. 13A shows an embodiment where sub-resolution contacts are placed adjacent to actual features to be resolved and not elsewhere, it should be understood that another embodiment may place a sub-resolution contact at each available grid location so as to fill the grid.
FIG. 13B is an illustration showing the sub-resolution contact layout of FIG. 13A with sub-resolution contacts defined to fill the grid to the extent possible, in accordance with one embodiment of the present invention. It should be appreciated that while the embodiment of FIG. 13B fills the grid to the extent possible with sub-resolution contacts, placement of sub-resolution contacts is avoided at locations that would potentially cause undesirable bridging between adjacent fully resolved features.
FIG. 13C is an illustration showing an example of a sub-resolution contact layout utilizing various shaped sub-resolution contacts, in accordance with one embodiment of the present invention. Alternative sub-resolution contact shapes can be utilized so long as the sub-resolution contacts are below the resolution capability of the manufacturing process. FIG. 13C shows the use of “X-shaped” sub-resolution contacts 1305 to focus light energy at the corners of the adjacent contacts. In one embodiment, the ends of the X-shaped sub-resolution contact 1305 are extended to further enhance the deposition of light energy at the corners of the adjacent contacts.
FIG. 13D is an illustration showing an exemplary implementation of alternate phase shift masking (APSM) with sub-resolution contacts, in accordance with one embodiment of the present invention. As in FIG. 13A, sub-resolution contacts are utilized to lithographically reinforce diffusion contacts 503 and gate electrode contacts 601. APSM is used to improve resolution when neighboring shapes create destructive interference patterns. The APSM technique modifies the mask so that the phase of light traveling through the mask on neighboring shapes is 180 degrees out of phase. This phase shift serves to remove destructive interference and allowing for greater contact density. By way of example, contacts in FIG. 13D marked with a plus “+” sign represent contacts exposed with light waves of a first phase while contacts marked with a minus sign “−” represent contacts exposed with light waves that are shifted in phase by 180 degrees relative to the first phase used for the “+” sign contacts. It should be appreciated that the APSM technique is utilized to ensure that adjacent contacts are separated from each other.
As feature sizes decrease, semiconductor dies are capable of including more gates. As more gates are included, however, the density of the interconnect layers begins to dictate the die size. This increasing demand on the interconnect layers drives higher levels of interconnect layers. However, the stacking of interconnect layers is limited in part by the topology of the underlying layers. For example, as interconnect layers are built up, islands, ridges, and troughs can occur. These islands, ridges, and troughs can cause breaks in the interconnect lines that cross them.
To mitigate these islands and troughs, the semiconductor manufacturing process utilizes a chemical mechanical polishing (CMP) procedure to mechanically and chemically polish the surface of the semiconductor wafer such that each subsequent interconnect layer is deposited on a substantially flat surface. Like the photolithography process the quality of the CMP process is layout pattern dependent. Specifically, an uneven distribution of a layout features across a die or a wafer can cause too much material to be removed in some places and not enough material to be removed in other places, thus causing variations in the interconnect thickness and unacceptable variations in the capacitance and resistance of the interconnect layer. The capacitance and resistance variation within the interconnect layer may alter the timing of a critical net causing design failure.
The CMP process requires that dummy fill be added in the areas without interconnect shapes so that a substantially uniform wafer topology is provided to avoid dishing and improve center-to-edge uniformity. Traditionally, dummy fill is placed post-design. Thus, in the traditional approach the designer is not aware of the dummy fill characteristics. Consequently, the dummy fill placed post-design may adversely influence the design performance in a manner that has not been evaluated by the designer. Also, because the conventional topology prior to the dummy fill is unconstrained, i.e., non-uniform, the post-design dummy fill will not be uniform and predictable. Therefore, in the conventional process, the capacitive coupling between the dummy fill regions and the neighboring active nets cannot be predicted by the designer.
As previously discussed, the dynamic array disclosed herein provides optimal regularity by maximally filling all interconnect tracks from gate electrode layer upward. If multiple nets are required in a single interconnect track, the interconnect track is split with a minimally spaced gap. For example, track 809 representing the metal 1 conduction line in FIG. 8A represents three separate nets in the same track, where each net corresponds to a particular track segment. More specifically, there are two poly contact nets and a floating net to fill the track with minimal spacing between the track segments. The substantially complete filling of tracks maintains the regular pattern that creates resonant images across the dynamic array. Also, the regular architecture of the dynamic array with maximally filled interconnect tracks ensures that the dummy fill is placed in a uniform manner across the die. Therefore, the regular architecture of the dynamic array assists the CMP process to produce substantially uniform results across the die/wafer. Also, the regular gate pattern of the dynamic array assists with gate etching uniformity (microloading). Additionally, the regular architecture of the dynamic array combined with the maximally filled interconnect tracks allows the designer to analyze the capacitive coupling effects associated with the maximally filled tracks during the design phase and prior to fabrication.
Because the dynamic array sets the size and spacing of the linearly shaped features, i.e., tracks and contacts, in each mask layer, the design of the dynamic array can be optimized for the maximum capability of the manufacturing equipment and processes. That is to say, because the dynamic array is restricted to the regular architecture for each layer above diffusion, the manufacturer is capable of optimizing the manufacturing process for the specific characteristics of the regular architecture. It should be appreciated that with the dynamic array, the manufacturer does not have to be concerned with accommodating the manufacture of a widely varying set of arbitrarily-shaped layout features as is present in conventional unconstrained layouts.
An example of how the capability of manufacturing equipment can be optimized is provided as follows. Consider that a 90 nm process has a metal 2 pitch of 280 nm. This metal 2 pitch of 280 nm is not set by the maximum capability of equipment. Rather, this metal 2 pitch of 280 nm is set by the lithography of the vias. With the via lithography issues removed, the maximum capability of the equipment allows for a metal 2 pitch of about 220 nm. Thus, the design rules for metal 2 pitch include about 25% margin to account for the light interaction unpredictability in the via lithography.
The regular architecture implemented within the dynamic array allows the light interaction unpredictability in the via lithography to be removed, thus allowing for a reduction in the metal 2 pitch margin. Such a reduction in the metal 2 pitch margin allows for a more dense design, i.e., allows for optimization of chip area utilization. Additionally, with the restricted, i.e., regular, topology afforded by the dynamic array, the margin in the design rules can be reduced. Moreover, not only can the excess margin beyond the capability of the process be reduced, the restricted topology afforded by the dynamic array also allows the number of required design rules to be substantially reduced. For example, a typical design rule set for an unconstrained topology could have more than 600 design rules. A design rule set for use with the dynamic array may have about 45 design rules. Therefore, the effort required to analyze and verify the design against the design rules is decreased by more than a factor of ten with the restricted topology of the dynamic array.
When dealing with line end-to-line end gaps (i.e., track segment-to-track segment gaps) in a given track of a mask layer in the dynamic array, a limited number of light interactions exist. This limited number of light interactions can be identified, predicted, and accurately compensated for ahead of time, dramatically reducing or completely eliminating the requirement for OPC/RET. The compensation for light interactions at line end-to-line end gaps represents a lithographic modification of the as-drawn feature, as opposed to a correction based on modeling of interactions, e.g., OPC/RET, associated with the as-drawn feature.
Also, with the dynamic array, changes to the as-drawn layout are only made where needed. In contrast, OPC is performed over an entire layout in a conventional design flow. In one embodiment, a correction model can be implemented as part of the layout generation for the dynamic array. For example, due to the limited number of possible line end gap interactions, a router can be programmed to insert a line break having characteristics defined as a function of its surroundings, i.e., as a function of its particular line end gap light interactions. It should be further appreciated that the regular architecture of the dynamic array allows the line ends to be adjusted by changing vertices rather than by adding vertices. Thus, in contrast with unconstrained topologies that rely on the OPC process, the dynamic array significantly reduces the cost and risk of mask production. Also, because the line end gap interactions in the dynamic array can be accurately predicted in the design phase, compensation for the predicted line end gap interactions during the design phase does not increase risk of design failure.
In conventional unconstrained topologies, designers are required to have knowledge of the physics associated with the manufacturing process due to the presence of design dependent failures. With the grid-based system of the dynamic array as disclosed herein, the logical design can be separated from the physical design. More specifically, with the regular architecture of the dynamic array, the limited number of light interactions to be evaluated within the dynamic array, and the design independent nature of the dynamic array, designs can be represented using a grid point based netlist, as opposed to a physical netlist.
With the dynamic array, the design is not required to be represented in terms of physical information. Rather, the design can be represented as a symbolic layout. Thus, the designer can represent the design from a pure logic perspective without having to represent physical characteristics, e.g., sizes, of the design. It should be understood that the grid-based netlist, when translated to physical, matches the optimum design rules exactly for the dynamic array platform. When the grid-based dynamic array moves to a new technology, e.g., smaller technology, a grid-based netlist can be moved directly to the new technology because there is no physical data in the design representation. In one embodiment, the grid-based dynamic array system includes a rules database, a grid-based (symbolic) netlist, and the dynamic array architecture.
It should be appreciated that the grid-based dynamic array eliminates topology related failures associated with conventional unconstrained architectures. Also, because the manufacturability of the grid-based dynamic array is design independent, the yield of the design implemented on the dynamic array is independent of the design. Therefore, because the validity and yield of the dynamic array is preverified, the grid-based netlist can be implemented on the dynamic array with preverified yield performance.
FIG. 14 is an illustration showing a semiconductor chip structure 1400, in accordance with one embodiment of the present invention. The semiconductor chip structure 1400 represents an exemplary portion of a semiconductor chip, including a diffusion region 1401 having a number of conductive lines 1403A-1403G defined thereover. The diffusion region 1401 is defined in a substrate 1405, to define an active region for at least one transistor device. The diffusion region 1401 can be defined to cover an area of arbitrary shape relative to the substrate 1405 surface.
The conductive lines 1403A-1403G are arranged to extend over the substrate 1405 in a common direction 1407. It should also be appreciated that each of the number of conductive lines 1403A-1403G are restricted to extending over the diffusion region 1401 in the common direction 1407. In one embodiment, the conductive lines 1403A-1403G defined immediately over the substrate 1405 are polysilicon lines. In one embodiment, each of the conductive lines 1403A-1403G is defined to have essentially the same width 1409 in a direction perpendicular to the common direction 1407 of extension. In another embodiment, some of the conductive lines 1403A-1403G are defined to have different widths relative to the other conductive lines. However, regardless of the width of the conductive lines 1403A-1403G, each of the conductive lines 1403A-1403G is spaced apart from adjacent conductive lines according to essentially the same center-to-center pitch 1411.
As shown in FIG. 14, some of the conductive lines (1403B-1403E) extend over the diffusion region 1401, and other conductive lines (1403A, 1403F, 1403G) extend over non-diffusion portions the substrate 1405. It should be appreciated that the conductive lines 1403A-1403G maintain their width 1409 and pitch 1411 regardless of whether they are defined over diffusion region 1401 or not. Also, it should be appreciated that the conductive lines 1403A-1403G maintain essentially the same length 1413 regardless of whether they are defined over diffusion region 1401 or not, thereby maximizing lithographic reinforcement between the conductive lines 1403A-1403G across the substrate. In this manner, some of the conductive lines, e.g., 1403D, defined over the diffusion region 1401 include a necessary active portion 1415, and one or more uniformity extending portions 1417.
It should be appreciated that the semiconductor chip structure 1400 represents a portion of the dynamic array described above with respect to FIGS. 2-13D. Therefore, it should be understood that the uniformity extending portions 1417 of the conductive lines (1403B-1403E) are present to provide lithographic reinforcement of neighboring conductive lines 1403A-1403G. Also, although they may not be required for circuit operation, each of conductive lines 1403A, 1403F, and 1403G are present to provide lithographic reinforcement of neighboring conductive lines 1403A-1403G.
The concept of the necessary active portion 1415 and the uniformity extending portions 1417 also applies to higher level interconnect layers. As previously described with regard to the dynamic array architecture, adjacent interconnect layers traverse over the substrate in transverse directions, e.g., perpendicular or diagonal directions, to enable routing/connectivity required by the logic device implemented within the dynamic array. As with the conductive lines 1403A-1403G, each of the conductive lines within an interconnect layer may include a required portion (necessary active portion) to enable required routing/connectivity, and a non-required portion (uniformity extending portion) to provide lithographic reinforcement to neighboring conductive lines. Also, as with the conductive lines 1403A-1403G, the conductive lines within an interconnect layer extend in a common direction over the substrate, have essentially the same width, and are spaced apart from each other according to an essentially constant pitch.
In one embodiment, conductive lines within an interconnect layer follow essentially the same ratio between line width and line spacing. For example, at 90 nm the metal 4 pitch is 280 nm with a line width and line spacing equal to 140 nm. Larger conductive lines can be printed on a larger line pitch if the line width is equal to the line spacing.
FIG. 14A shows an annotated version of FIG. 14. The features depicted in FIG. 14A are exactly the same as the features depicted in FIG. 14. FIG. 14A shows each of the conductive lines 1403B and 1403C to have a uniformity extending portion 14a01 as measured in the common direction 1407. FIG. 14A shows each of the conductive lines 1403D and 1403E to have a uniformity extending portion 14a03 as measured in the common direction 1407. FIG. 14A shows each of the conductive lines 1403B, 1403C, 1403D, and 1403E to have a uniformity extending portion 14a05 as measured in the common direction 1407. FIG. 15 shows an example layout architecture defined in accordance with one embodiment of the present invention. The layout architecture follows a grid pattern and is based upon a horizontal grid and a vertical grid. The horizontal grid is set by the poly gate pitch. The vertical pitch is set by the metal 1/metal 3 pitch. All of the rectangular shapes should be centered on a grid point. The layout architecture minimizes the use of bends to eliminate unpredictable lithographic interactions. Bends are allowed on the diffusion layer to control transistor device sizes. Other layers should be rectangular in shape and fixed in one dimension.
FIG. 15A shows an annotated version of FIG. 15. The features depicted in FIG. 15A are exactly the same as the features depicted in FIG. 15. FIG. 15A shows a first electrical connection 15a01 (as denoted by the heavy solid black line). FIG. 15A shows a second electrical connection 15a03 (as denoted by the heavy dashed black line).
The invention described herein can be embodied as computer readable code on a computer readable medium. The computer readable medium is any data storage device that can store data which can be thereafter be read by a computer system. Examples of the computer readable medium include hard drives, network attached storage (NAS), read-only memory, random-access memory, CD-ROMs, CD-Rs, CD-RWs, magnetic tapes, and other optical and non-optical data storage devices. The computer readable medium can also be distributed over a network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. Additionally, a graphical user interface (GUI) implemented as computer readable code on a computer readable medium can be developed to provide a user interface for performing any embodiment of the present invention.
While this invention has been described in terms of several embodiments, it will be appreciated that those skilled in the art upon reading the preceding specifications and studying the drawings will realize various alterations, additions, permutations and equivalents thereof. Therefore, it is intended that the present invention includes all such alterations, additions, permutations, and equivalents as fall within the true spirit and scope of the invention.

## Claims

1. A semiconductor chip, comprising:
gate structures formed within a region of the semiconductor chip, the gate structures formed in part based on corresponding gate structure layout shapes used as an input to a lithography process, the gate structure layout shapes positioned in accordance with a gate horizontal grid, the gate horizontal grid including at least seven gate gridlines, wherein adjacent gate gridlines are separated from each other by an as-fabricated gate pitch of less than or equal to about 193 nanometers, each gate structure layout shape in the region having a substantially rectangular shape and having an as-fabricated gate structure width of less than or equal to about 45 nanometers and positioned to extend lengthwise in a y-direction in a substantially centered manner along an associated gate gridline, wherein each gate gridline has at least one gate structure layout shape positioned thereon, wherein each pair of gate structure layout shapes that are positioned in an end-to-end manner are separated from each other by an as-fabricated line end-to-line end gap of less than or equal to about 193 nanometers;
a first-metal layer formed above top surfaces of the gate structures within the region of the semiconductor chip, the first-metal layer positioned first in a stack of metal layers counting upward from top surfaces of the gate structures, the first-metal layer separated from the top surfaces of the gate structures by at least one insulator material, adjacent metal layers in the stack of metal layers separated by at least one insulator material, wherein the first-metal layer includes first-metal structures formed in part based on corresponding first-metal structure layout shapes used as an input to a lithography process, the first-metal structure layout shapes positioned in accordance with a first-metal vertical grid, the first-metal vertical grid including at least eight first-metal gridlines, each first-metal structure layout shape in the region having a substantially rectangular shape and positioned to extend lengthwise in an x-direction in a substantially centered manner on an associated first-metal gridline, each first-metal structure layout shape in the region having at least one adjacent first-metal structure layout shape positioned next to each of its sides at an as-fabricated y-coordinate spacing of less than or equal to 193 nanometers, wherein each pair of first-metal structure layout shapes that are positioned in an end-to-end manner are separated by an as-fabricated line end-to-line end gap of less than or equal to about 193 nanometers;
at least six contact structures formed within the region of the semiconductor chip, the at least six contact structures formed in part utilizing corresponding at least six contact structure layout shapes as an input to a lithography process, the at least six contact structures formed in physical and electrical contact with corresponding ones of at least six of the gate structures, each of the at least six contact structure layout shapes having a substantially rectangular shape and a corresponding length greater than a corresponding width and with the corresponding length oriented in the x-direction, each of the at least six contact structure layout shapes positioned and sized to form its corresponding contact structure to overlap both edges of the top surface of the gate structure to which it is in physical and electrical contact,
wherein at least one gate structure within the region is a first-transistor-type-only gate structure that forms at least one gate electrode of at least one transistor of a first transistor type and does not form a gate electrode of a transistor of a second transistor type, wherein at least one gate structure within the region is a second-transistor-type-only gate structure that forms at least one gate electrode of at least one transistor of the second transistor type and does not form a gate electrode of a transistor of the first transistor type, wherein a total number of first-transistor-type-only gate structures within the region is equal to a total number of second-transistor-type-only gate structures within the region, wherein the region includes at least four transistors of the first transistor type and at least four transistors of the second transistor type that collectively form part of a logic circuit, wherein a portion of the logic circuit includes electrical connections that collectively include first-metal structures positioned on at least five of the at least eight first-metal gridlines.

2. The semiconductor chip as recited in claim 1, wherein the region includes a second-metal layer including second-metal structures formed in part based on corresponding second-metal structure layout shapes used as an input to a lithography process, the second-metal structure layout shapes positioned in accordance with a second-metal horizontal grid, the second-metal horizontal grid including at least eight second-metal gridlines, each second-metal structure layout shape in the region having at least one adjacent second-metal structure layout shape positioned next to each of its sides at an as-fabricated x-coordinate spacing of less than or equal to 193 nanometers, each second-metal structure layout shape in the region having a substantially rectangular shape and positioned to extend lengthwise in the y-direction in a substantially centered manner along an associated second-metal gridline, wherein at least eight of the at least eight second-metal gridlines have at least one second-metal structure layout shape positioned thereon, wherein each pair of second-metal structure layout shapes that are positioned in an end-to-end manner are separated by a line end-to-line end gap, wherein the second-metal layer is positioned second in the stack of metal layers counting upward from the top surfaces of the gate structures.

3. The semiconductor chip as recited in claim 2, wherein each first-metal structure layout shape in the region has a width measured in the y-direction that is either a first width or a second width different than the first width.

4. The semiconductor chip as recited in claim 3, wherein at least one gate structure within the region that forms at least one gate electrode of at least one transistor of a first transistor type and does not form a gate electrode of a transistor of a second transistor type is electrically connected to at least one gate structure within the region that forms at least one gate electrode of at least one transistor of the second transistor type and does not form a gate electrode of a transistor of the first transistor type through an electrical connection that includes at least one first-metal structure and at least one second-metal structure.

5. The semiconductor chip as recited in claim 2, wherein the at least six contact structure layout shapes are positioned in accordance with a contact vertical grid, the contact vertical grid including contact gridlines extending in the x-direction, each of the at least six contact structure layout shapes positioned to extend lengthwise in the x-direction in a substantially centered manner along an associated contact gridline, and at least two of the at least six contact structure layout shapes positioned to also extend lengthwise in the x-direction in a substantially centered manner along an associated first-metal gridline.

6. The semiconductor chip as recited in claim 2, wherein each second-metal structure layout shape in the region is positioned next to at least one other second-metal structure layout shape on a first side in accordance with a second-metal pitch and is positioned next to at least one other second-metal structure layout shape on a second side in accordance with the second-metal pitch, wherein the second-metal pitch is measured in the x-direction and is equal to the gate pitch.

7. The semiconductor chip as recited in claim 6, wherein each second-metal structure layout shape in the region has a substantially equal width as measured in the x-direction.

8. The semiconductor chip as recited in claim 7, wherein each first-metal structure layout shape in the region has a width measured in the y-direction that is either a first width or a second width different than the first width.

9. The semiconductor chip as recited in claim 7, wherein the region has a size of 1930 nanometers as measured in the x-direction and a size of 1930 nanometers as measured in the y-direction.

10. The semiconductor chip as recited in claim 7, wherein the region includes a third-metal layer including third-metal structures formed in part based on corresponding third-metal structure layout shapes used as an input to a lithography process, the third-metal structure layout shapes positioned in accordance with a third-metal vertical grid, the third-metal vertical grid including at least eight third-metal gridlines, each third-metal structure layout shape in the region having at least one adjacent third-metal structure layout shape positioned next to each of its sides at an as-fabricated y-coordinate spacing of less than or equal to 193 nanometers, each third-metal structure layout shape in the region having a substantially rectangular shape and positioned to extend lengthwise in the x-direction in a substantially centered manner along an associated third-metal gridline, wherein at least eight of the at least eight third-metal gridlines have at least one third-metal structure layout shape positioned thereon, wherein each pair of third-metal structure layout shapes that are positioned in an end-to-end manner are separated by a line end-to-line end gap, wherein the third-metal layer is positioned third in the stack of metal layers counting upward from the top surfaces of the gate structures.

11. The semiconductor chip as recited in claim 10, wherein each second-metal structure layout shape in the region is positioned next to at least one other second-metal structure layout shape on a first side in accordance with a second-metal pitch and is positioned next to at least one other second-metal structure layout shape on a second side in accordance with the second-metal pitch, wherein the second-metal pitch is measured in the x-direction and is equal to the gate pitch.

12. The semiconductor chip as recited in claim 10, wherein the region includes a fourth-metal layer including fourth-metal structures formed in part based on corresponding fourth-metal structure layout shapes used as an input to a lithography process, the fourth-metal structure layout shapes positioned in accordance with a fourth-metal horizontal grid, the fourth-metal horizontal grid including at least eight fourth-metal gridlines, each fourth-metal structure layout shape in the region having at least one adjacent fourth-metal structure layout shape positioned next to each of its sides at an as-fabricated x-coordinate spacing of less than or equal to 193 nanometers, each fourth-metal structure layout shape in the region having a substantially rectangular shape and positioned to extend lengthwise in the y-direction in a substantially centered manner along an associated fourth-metal gridline, wherein at least eight of the at least eight fourth-metal gridlines have at least one fourth-metal structure layout shape positioned thereon, wherein each pair of fourth-metal structure layout shapes that are positioned in an end-to-end manner are separated by a line end-to-line end gap, wherein the fourth-metal layer is positioned fourth in the stack of metal layers counting upward from the top surfaces of the gate structures.

13. The semiconductor chip as recited in claim 2, wherein each first-metal structure layout shape in the region is positioned next to at least one other first-metal structure layout shape on a first side in accordance with a first-metal pitch and is positioned next to at least one other first-metal structure layout shape on a second side in accordance with the first-metal pitch.

14. The semiconductor chip as recited in claim 13, wherein the region has a size of 1930 nanometers as measured in the x-direction and a size of 1930 nanometers as measured in the y-direction.

15. The semiconductor chip as recited in claim 1, wherein each transistor within the region of the semiconductor chip is formed in part by a corresponding diffusion region, wherein each diffusion region that forms part of at least one transistor within the region of the semiconductor chip has a substantially rectangular shape.

16. The semiconductor chip as recited in claim 1, wherein the at least four transistors of the first transistor type and the at least four transistors of the second transistor type within the region collectively form part of an inverting two-to-one multiplexer.

17. The semiconductor chip as recited in claim 1, wherein at least one of the at least six contact structures is in physical and electrical contact with, and is substantially centered in the x-direction on, a gate structure within the region that forms at least one gate electrode of at least one transistor of the first transistor type and that does not form a gate electrode of a transistor of the second transistor type.

18. The semiconductor chip as recited in claim 1, wherein each of at least four of the first-metal gridlines has at least two first-metal structure layout shapes positioned thereon within the region, wherein each of the at least two first-metal structure layout shapes positioned on the at least four of the first-metal gridlines is positioned next to and spaced apart from at least one other first-metal structure layout shape in accordance with a fixed pitch.

19. The semiconductor chip as recited in claim 1, wherein each first-metal structure layout shape positioned on any first-metal gridline within the region is positioned next to and spaced apart from at least one other first-metal structure layout shape in accordance with a fixed pitch.

20. The semiconductor chip as recited in claim 1, wherein the region includes a second-metal layer including second-metal structures formed in part based on corresponding second-metal structure layout shapes used as an input to a lithography process, the second-metal structure layout shapes positioned in accordance with a second-metal horizontal grid, the second-metal horizontal grid including at least eight second-metal gridlines, each second-metal structure layout shape in the region having at least one adjacent second-metal structure layout shape positioned next to each of its sides at an as-fabricated x-coordinate spacing of less than or equal to 193 nanometers, each second-metal structure layout shape in the region having a substantially rectangular shape and positioned to extend lengthwise in the y-direction in a substantially centered manner along an associated second-metal gridline, wherein at least eight of the at least eight second-metal gridlines have at least one second-metal structure layout shape positioned thereon, wherein each pair of second-metal structure layout shapes that are positioned in an end-to-end manner are separated by a line end-to-line end gap, wherein the second-metal layer is positioned second in the stack of metal layers counting upward from the top surfaces of the gate structures,
wherein the region includes a third-metal layer including third-metal structures formed in part based on corresponding third-metal structure layout shapes used as an input to a lithography process, the third-metal structure layout shapes positioned in accordance with a third-metal vertical grid, the third-metal vertical grid including at least eight third-metal gridlines, each third-metal structure layout shape in the region having at least one adjacent third-metal structure layout shape positioned next to each of its sides at an as-fabricated y-coordinate spacing of less than or equal to 193 nanometers, each third-metal structure layout shape in the third-metal layer having a substantially rectangular shape and positioned to extend lengthwise in the x-direction in a substantially centered manner along an associated third-metal gridline, wherein at least eight of the at least eight third-metal gridlines have at least one third-metal structure layout shape positioned thereon, wherein each pair of third-metal structure layout shapes that are positioned in an end-to-end manner are separated by a line end-to-line end gap, wherein the third-metal layer is positioned third in the stack of metal layers counting upward from the top surfaces of the gate structures.

21. The semiconductor chip as recited in claim 20, wherein the region includes a fourth-metal layer including fourth-metal structures formed in part based on corresponding fourth-metal structure layout shapes used as an input to a lithography process, the fourth-metal structure layout shapes positioned in accordance with a fourth-metal horizontal grid, the fourth-metal horizontal grid including at least eight fourth-metal gridlines, each fourth-metal structure layout shape in the region having at least one adjacent fourth-metal structure layout shape positioned next to each of its sides at an as-fabricated x-coordinate spacing of less than or equal to 193 nanometers, each fourth-metal structure layout shape in the region having a substantially rectangular shape and positioned to extend lengthwise in the y-direction in a substantially centered manner along an associated fourth-metal gridline, wherein at least eight of the at least eight fourth-metal gridlines have at least one fourth-metal structure layout shape positioned thereon, wherein each pair of fourth-metal structure layout shapes that are positioned in an end-to-end manner are separated by a line end-to-line end gap, wherein the fourth-metal layer is positioned fourth in the stack of metal layers counting upward from the top surfaces of the gate structures.

22. The semiconductor chip as recited in claim 20, wherein the at least four transistors of the first transistor type include a first transistor of the first transistor type, wherein the at least four transistors of the second transistor type include a first transistor of the second transistor type, wherein a gate structure layout shape forming a gate electrode of the first transistor of the first transistor type is positioned on a given gate gridline, wherein a gate structure layout shape forming a gate electrode of the first transistor of the second transistor type is also positioned on the given gate gridline, wherein no other transistor is positioned on the given gate gridline between the gate structure layout shapes that form the gate electrodes of the first transistor of the first transistor type and the first transistor of the second transistor type,
wherein each transistor within the region of the semiconductor chip is formed in part by a corresponding diffusion region, wherein a diffusion region of the first transistor of the first transistor type is electrically connected to a diffusion region of the first transistor of the second transistor type,
wherein the at least six contact structure layout shapes include a contact structure layout shape substantially centered in the x-direction on the given gate gridline at a location between the diffusion regions of the first transistor of the first transistor type and the first transistor of the second transistor type.

23. The semiconductor chip as recited in claim 22, wherein an electrical connection between the diffusion region of the first transistor of the first transistor type and the diffusion region of the first transistor of the second transistor type includes at least one first-metal structure and at least one second-metal structure.

24. The semiconductor chip as recited in claim 23, wherein the gate electrode of the first transistor of the first transistor type is electrically connected to the gate electrode of the first transistor of the second transistor type.

25. The semiconductor chip as recited in claim 1, wherein the at least four transistors of the first transistor type include a first transistor of the first transistor type, wherein the at least four transistors of the second transistor type include a first transistor of the second transistor type, wherein a gate structure layout shape forming a gate electrode of the first transistor of the first transistor type is positioned on a given gate gridline, wherein a gate structure layout shape forming a gate electrode of the first transistor of the second transistor type is also positioned on the given gate gridline, wherein no other transistor is positioned on the given gate gridline between the gate structure layout shapes that form the gate electrodes of the first transistor of the first transistor type and the first transistor of the second transistor type,
wherein each transistor within the region of the semiconductor chip is formed in part by a corresponding diffusion region, wherein a diffusion region of the first transistor of the first transistor type is electrically connected to a diffusion region of the first transistor of the second transistor type,
wherein the at least six contact structure layout shapes include a contact structure layout shape substantially centered in the x-direction on the given gate gridline at a location between the diffusion regions of the first transistor of the first transistor type and the first transistor of the second transistor type.

26. The semiconductor chip as recited in claim 25, wherein an electrical connection between the diffusion region of the first transistor of the first transistor type and the diffusion region of the first transistor of the second transistor type includes at least one first-metal structure and at least one second-metal structure in a second-metal layer within the region, wherein the second-metal layer includes second-metal structures formed in part based on corresponding second-metal structure layout shapes used as an input to a lithography process, the second-metal structure layout shapes positioned in accordance with a second-metal horizontal grid, the second-metal horizontal grid including at least eight second-metal gridlines, each second-metal structure layout shape in the region having at least one adjacent second-metal structure layout shape positioned next to each of its sides at an as-fabricated x-coordinate spacing of less than or equal to 193 nanometers, each second-metal structure layout shape in the region having a substantially rectangular shape and positioned to extend lengthwise in the y-direction in a substantially centered manner along an associated second-metal gridline, wherein at least eight of the at least eight second-metal gridlines have at least one second-metal structure layout shape positioned thereon, wherein each pair of second-metal structure layout shapes that are positioned in an end-to-end manner are separated by a line end-to-line end gap, wherein the second-metal layer is positioned second in the stack of metal layers formed above the gate structures counting upward from the top surfaces of the gate structures.

27. The semiconductor chip as recited in claim 1, wherein the at least four transistors of the first transistor type are collectively separated from the at least four transistors of the second transistor type by an inner region that does not include another transistor.

28. The semiconductor chip as recited in claim 27, wherein at least one of the at least six contact structures is in physical and electrical contact with, and is substantially centered in the x-direction on, a given gate structure within the region that forms at least one gate electrode of at least one transistor, wherein the at least one of the at least six contact structures is positioned over the inner region.

29. A semiconductor chip, comprising:
gate structures formed within a region of the semiconductor chip, the gate structures formed in part based on corresponding gate structure layout shapes used as an input to a lithography process, the gate structure layout shapes positioned in accordance with a gate horizontal grid that includes at least seven gate gridlines, wherein adjacent gate gridlines are separated from each other by an as-fabricated gate pitch of less than or equal to about 193 nanometers, each gate structure layout shape having a substantially rectangular shape and having an as-fabricated gate structure width of less than or equal to about 45 nanometers and positioned to extend lengthwise in a y-direction in a substantially centered manner along an associated gate gridline, wherein each gate gridline has at least one gate structure layout shape positioned thereon, wherein each pair of gate structure layout shapes that are positioned in an end-to-end manner are separated from each other by an as-fabricated line end-to-line end gap of less than or equal to about 193 nanometers, wherein at least one gate structure within the region is a first-transistor-type-only gate structure that forms at least one gate electrode of at least one transistor of a first transistor type and does not form a gate electrode of a transistor of a second transistor type, wherein at least one gate structure within the region is a second-transistor-type-only gate structure that forms at least one gate electrode of at least one transistor of the second transistor type and does not form a gate electrode of a transistor of the first transistor type, wherein a total number of first-transistor-type-only gate structures within the region is equal to a total number of second-transistor-type-only gate structures within the region;
a number of contact structures formed within the region of the semiconductor chip, wherein each gate structure that forms any transistor gate electrode within the region has a respective top surface in physical and electrical contact with a corresponding contact structure formed in part based on a corresponding contact structure layout shape having a substantially rectangular shape, wherein each contact structure that contacts a given gate structure that forms any transistor gate electrode does not contact another gate structure, wherein each contact structure layout shape has a corresponding length greater than or equal to a corresponding width and is oriented to have its corresponding length extend in an x-direction, wherein each contact structure that contacts a corresponding gate structure has its corresponding contact structure layout shape positioned to overlap at least one edge of the gate structure layout shape of the corresponding gate structure,
wherein each transistor within the region is formed in part by a corresponding diffusion region, wherein each diffusion region that forms part of any transistor within the region is formed in part based on a corresponding diffusion region layout shape having a substantially rectangular shape,
wherein the region includes at least four transistors of the first transistor type and at least four transistors of the second transistor type that collectively form a portion of a multiplexer or a portion of a latch, wherein at least one first-transistor-type-only gate structure within the region is included within the portion of the multiplexer or the portion of the latch, wherein at least one second-transistor-type-only gate structure within the region is included within the portion of the multiplexer or the portion of the latch,
wherein the at least four transistors of the first transistor type include a first transistor of the first transistor type, wherein the at least four transistors of the second transistor type include a first transistor of the second transistor type, wherein a first gate structure forms both a gate electrode of the first transistor of the first transistor type and a gate electrode of the first transistor of the second transistor type.

30. A semiconductor chip, comprising:
gate structures formed within a region of the semiconductor chip, the gate structures formed in part based on corresponding gate structure layout shapes used as an input to a lithography process, the gate structure layout shapes positioned in accordance with a gate horizontal grid that includes a number of gate gridlines, wherein adjacent gate gridlines are separated from each other by a gate pitch of less than or equal to about 193 nanometers, each gate structure layout shape in the region having a substantially rectangular shape with a width of less than or equal to about 45 nanometers and positioned to extend lengthwise in a y-direction in a substantially centered manner along an associated gate gridline, wherein each gate gridline has at least one gate structure layout shape positioned thereon, wherein each pair of gate structure layout shapes that are positioned in an end-to-end manner are separated from each other by an as-fabricated line end-to-line end gap of less than or equal to about 193 nanometers, wherein at least one gate structure within the region is a first-transistor-type-only gate structure that forms at least one gate electrode of at least one transistor of a first transistor type and does not form a gate electrode of a transistor of a second transistor type, wherein at least one gate structure within the region is a second-transistor-type-only gate structure that forms at least one gate electrode of at least one transistor of the second transistor type and does not form a gate electrode of a transistor of the first transistor type, wherein a total number of first-transistor-type-only gate structures within the region is equal to a total number of second-transistor-type-only gate structures within the region;
a number of contact structures formed within the region of the semiconductor chip, wherein each of at least six gate structures within the region has a respective top surface in physical and electrical contact with a corresponding contact structure formed in part based on a corresponding contact structure layout shape having a substantially rectangular shape, wherein each contact structure layout shape is centered in an x-direction on the gate structure layout shape of the gate structure with which it physical contacts, wherein each contact structure layout shape has a corresponding length greater than or equal to a corresponding width and is oriented to have its corresponding length extend in an x-direction, wherein each corresponding contact structure is in physical contact with only one gate structure, wherein each corresponding contact structure has its contact structure layout shape positioned to overlap at least one edge of the gate structure layout shape of the gate structure contacted by the corresponding contact structure,
wherein each transistor within the region is formed in part by a corresponding diffusion region, wherein each diffusion region that forms part of any transistor within the region is formed in part based on a corresponding diffusion region layout shape having a substantially rectangular shape,
wherein the region includes at least four transistors of the first transistor type and at least four transistors of the second transistor type that collectively form a portion of a multiplexer or a portion of a latch, wherein at least one first-transistor-type-only gate structure within the region is included within the portion of the multiplexer or the portion of the latch, wherein at least one second-transistor-type-only gate structure within the region is included within the portion of the multiplexer or the portion of the latch,
wherein both a gate electrode of a transistor of a first transistor type and a gate electrode of a transistor of a second transistor type are formed by a same gate structure within the region.