The present disclosure relates generally to a standard/logic cell architecture, and more particularly, to a heterogeneous height standard/logic cell architecture.
A standard cell device is an integrated circuit (IC) that implements digital logic. Such standard cell device may be reused multiple times within an application-specific IC (ASIC). An ASIC, such as a system-on-a-chip (SoC) device, may contain thousands to millions of standard cell devices. A typical IC includes a stack of sequentially formed layers. Each layer may be stacked or overlaid on a prior layer and patterned to form the shapes that define transistors (e.g., field effect transistors (FETs), fin FETs (FinFETs), gate-all-around (GAA) FETs (GAAFETs), and/or other multigate FETs) and connect the transistors into circuits.
A taller standard cell architecture for tall standard cells may provide higher performance than a shorter standard cell architecture for short standard cells, whereas a shorter standard cell architecture for short standard cells may provide better area efficiency than a taller standard cell architecture for tall standard cells. Both short and tall standard cell architectures may be utilized separately to achieve both higher performance or area efficiency. There is currently a need for a heterogeneous height standard cell architecture for utilizing both short and tall standard cells.
In an aspect of the disclosure, a metal oxide semiconductor (MOS) IC includes a first set of transistor logic. The first set of transistor logic has a first plurality of gate interconnects extending in a first direction. The first plurality of gate interconnects has a gate pitch. The first set of transistor logic has one or more pairs of power rails providing a power supply voltage and a ground voltage to logic between each corresponding pair of power rails. The first set of transistor logic has a first cell height h1 and has a first number of metal x (Mx) layer tracks that extend unidirectionally in a second direction between each pair of power rails. The second direction is orthogonal to the first direction. The MOS IC further includes a second set of transistor logic. The second set of transistor logic is located adjacent in the first direction to the first set of transistor logic. The second set of transistor logic has a second plurality of gate interconnects extending in the first direction. The second plurality of gate interconnects has the same gate pitch as the first plurality of gate interconnects and each is collinear with a respective one of the first plurality of gate interconnects. The second set of transistor logic has one or more pairs of power rails providing the power supply voltage and the ground voltage to logic between each corresponding pair of power rails. The second set of transistor logic has a second cell height h2 and has a second number of Mx layer tracks that extend unidirectionally in the second direction between each pair of power rails. The second cell height h2 is greater than the first cell height h1. The second number of Mx layer tracks is greater than the first number of Mx layer tracks. At least one of a height ratio hR=h2/h1 is a non-integer value or a subset of the first set of transistor logic and a subset of the second set of transistor logic are within one logic cell.
The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts. Apparatuses and methods will be described in the following detailed description and may be illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, elements, etc.
Standard cells are cells that are standardized in a design. The same standard cell may be utilized thousands of times throughout an IC. Herein, standard cells may be referred to as logic cells. A logic cell has a set of inputs and set of outputs, where the inputs/outputs are interconnected through intra-cell routing within the logic cell (rather than inter-cell routing across different logic cells). Such logic cell may be utilized in an IC hundreds to thousands of times, with the same intra-cell routing configuration. The height of a cell is equal to the distance (in the first direction in
The gate interconnects 360 have the same pitch pg for both the taller height portion 370 and the shorter height portion 380, where the pitch pg is the distance between the centers of adjacent gate interconnects. The pitch p2 of the set of Mx layer tracks 320 may be the same or different than the pitch p1 of the set of Mx layer tracks 340, where the pitches p1, p2 are the distances between the centers of corresponding adjacent Mx layer tracks. In a first configuration, the set of Mx layer tracks 320 and the set of Mx layer tracks 340 have the same pitch (p2=p1). In a second configuration, the set of Mx layer tracks 320 and the set of Mx layer tracks 340 have different pitches (p2≠p1).
The taller height portion 370 may be utilized for complex logic cells (e.g., flip-flops or other complex or higher performance logic), as the taller height portion 370 provides a sufficient number of Mx layer tracks 320 for intra-cell routing of the complex logic cells. The taller height portion 370 also provides for a larger area (i.e., greater number of fins) for the p-type and n-type diffusion regions, and therefore may provide higher performance than the shorter height portion 380. The shorter height portion 380 may be utilized for simple logic cells (e.g., combinational logic cells), as less Mx layer tracks 340 are provided.
Within the taller height portion 370 and the shorter height portion 380, logic cells may be located. A logic cell may span just one of the portions 370, 380 or across both portions 370, 380. Referring again to the height ratio hR=h2/h1, the height ratio hR=h2/h1 may be a non-integer value or an integer value. If the height ratio hR=h2/h1 is a non-integer value, individual logic cells may span one of the portions 370, 380 and/or across both portions 370, 380. Accordingly, individual logic cells of an IC may have a homogeneous-height design and/or a heterogeneous-height design. If the height ratio hR=h2/h1 is an integer value, two configurations are possible. In a first configuration, individual logic cells may span both portions 370, 380. Accordingly, all individual logic cells of an IC may have a heterogeneous-height design. In a second configuration, individual logic cells may span one of the portions 370, 380 and/or both portions 370, 380. Accordingly, individual logic cells of an IC may have a homogeneous-height design and/or a heterogeneous-height design. Example locations of logic cells within the heterogeneous height logic cell architecture are illustrated in
For another example, in the diagram 720, a first set of transistor logic with the smaller height architecture includes n1=M1+1 power rails, and has height M1*h1, and correspondingly, a height of (n1−1)h1. Adjacent the first set of transistor logic is a second set of transistor logic with the taller height architecture. The second set of transistor logic includes n2=M2+1 power rails, and has height M2*h2, and correspondingly, a height of (n2−1)h2. Adjacent the second set of transistor logic is a third set of transistor logic with the smaller height architecture. The third set of transistor logic includes n3=M3+1 power rails, and has height M3*h1, and correspondingly, a height of (n3−1)h1. Adjacent the third set of transistor logic are different sets of different taller and smaller height architectures, leading finally to an Nth set of transistor logic with the taller height architecture. The Nth set of transistor logic includes nN=MN+1 power rails, and has height MN*h2, and correspondingly, a height of (nN−1)h2.
For another example, in the diagram 740, a first set of transistor logic with the taller height architecture includes n1=M1+1 power rails, and has height M1*h2, and correspondingly, a height of (n1−1)h2. Adjacent the first set of transistor logic is a second set of transistor logic with the shorter height architecture. The second set of transistor logic includes n2=M2+1 power rails, and has height M2*h1, and correspondingly, a height of (n2−1)h1. Adjacent the second set of transistor logic is a third set of transistor logic with the taller height architecture. The third set of transistor logic includes n3=M3+1 power rails, and has height M3*h2, and correspondingly, a height of (n3−1)h2. Adjacent the third set of transistor logic are different sets of different taller and smaller height architectures, leading finally to an Nth set of transistor logic with the smaller height architecture. The Nth set of transistor logic includes nN=MN+1 power rails, and has height MN*h1, and correspondingly, a height of (nN−1)h1.
For another example, in the diagram 760, a first set of transistor logic with the taller height architecture includes n1=M1+1 power rails, and has height M1*h2, and correspondingly, a height of (n1−1)h2. Adjacent the first set of transistor logic is a second set of transistor logic with the shorter height architecture. The second set of transistor logic includes n2=M2+1 power rails, and has height M2*h1, and correspondingly, a height of (n2−1)h1. Adjacent the second set of transistor logic is a third set of transistor logic with the taller height architecture. The third set of transistor logic includes n3=M3+1 power rails, and has height M3*h2, and correspondingly, a height of (n3−1)h2. Adjacent the third set of transistor logic are different sets of different taller and smaller height architectures, leading finally to an Nth set of transistor logic with the taller height architecture. The Nth set of transistor logic includes nN=MN+1 power rails, and has height MN*h2, and correspondingly, a height of (nN−1)h2.
Generally, one logic cell may include any combination of sets of logic cells as illustrated in the diagrams 700, 720, 740, 760. For example, if one logic cell includes first, second, and third sets of transistor logic, with combination short-tall-short architectures, a height hm of the one logic cell would be equal to (n1−1)h1+(n2−1)h2+(n3−1)h1, where n1≥2 and is a number of power rail tracks within the first set of transistor logic, n2≥2 and is a number of power rail tracks within the second set of transistor logic, and n3≥2 and is a number of power rail tracks within the third set of transistor logic, and where n1+n2+n3−2 is a total number of power rails within the one logic cell. Further, in another example, if one logic cell includes first, second, and third sets of transistor logic, with combination tall-short-tall architectures, a height hm of the one logic cell would be equal to (n1−1)h2+(n2−1)h1+(n3−1)h2, where n1≥2 and is a number of power rail tracks within the first set of transistor logic, n2≥2 and is a number of power rail tracks within the second set of transistor logic, and n3≥2 and is a number of power rail tracks within the third set of transistor logic, and where n1+n2+n3−2 is a total number of power rails within the one logic cell.
Referring again to
In one configuration, a power rail 330 of the one or more pairs of power rails 350, 330, 310 of the first and second sets of transistor logic 380, 370 extends in the second direction between the first set of transistor logic 380 and the second set of transistor logic 370. The power rail 330 is a shared power rail and is configured to provide one of the power supply voltage or the ground voltage to at least a subset of the first set of transistor logic 380 and to at least a subset of the second set of transistor logic 370.
In one configuration, a pitch p1 of the first number of Mx layer tracks 340 of the first set of transistor logic 380, and a pitch p2 of the second number of Mx layer tracks 320 of the second set of transistor logic 370 are the same. In another configuration, p1≠p2.
In one configuration, the Mx layer is a lowest metal layer that extends unidirectionally in the second direction. For example, the Mx layer may be an M0 layer or an M1 layer.
In one configuration, the height ratio hR=h2/h1 is a non-integer value, and the first set of transistor logic 380 includes a first set of logic cells, and the second set of transistor logic 370 includes a second set of logic cells (for example, see logic cells 402, 404, 408, 410 of
In one configuration, the subset of the first set of transistor logic 380, 604 and the subset of the second set of transistor logic 370, 606 are within one logic cell 602 (for example, see
In one configuration, for a short-tall-short architecture (see for example, diagrams 700, 720 of
The second set of transistor logic is between the first set of transistor logic and the third set of transistor logic. In one configuration, a power rail of the one or more pairs of power rails of the second and third sets of transistor logic extends in the second direction between the second set of transistor logic and the third set of transistor logic. The power rail is a shared power rail and is configured to provide one of the power supply voltage or the ground voltage to at least a subset of the second set of transistor logic and to at least a subset of the third set of transistor logic. In one configuration, a subset of the first set of transistor logic, a subset of the second set of transistor logic, and a subset of the third set of transistor logic are within one logic cell. A height hm of the one logic cell is equal to (n1−1)h1+(n2−1)h2+(n3−1)h1, where n1≥2 and is a number of power rail tracks within the subset of the first set of transistor logic, n2≥2 and is a number of power rail tracks within the subset of the second set of transistor logic, and n3≥2 and is a number of power rail tracks within the subset of the third set of transistor logic, and where n1+n2+n3−2 is a total number of power rails within the one logic cell. In one configuration, the subset of the first set of transistor logic, the subset of the second set of transistor logic, and the subset of the third set of transistor logic are coupled together within the one logic cell.
In one configuration, for a tall-short-tall architecture (see for example, diagrams 740, 760 of
Referring to
As discussed supra, for the provided heterogeneous height logic cell architecture, relatively taller and relatively shorter logic architectures may be located adjacent to each other, both with aligned gate interconnects with the same pitch. The taller logic architecture may provide a greater number of routing tracks than the shorter logic architecture. The taller logic architecture may provide relatively higher performance with a lower area efficiency, whereas the shorter logic architecture may provide relatively lower performance with a higher area efficiency. Logic cells may be located within the taller logic architecture, the shorter logic architecture, or within both the taller and shorter logic architectures. The heterogeneous height logic cell architecture may allow for optimized area/performance, while also allowing for easier process scaling to smaller technology process nodes.
It is understood that the specific order or hierarchy of steps in the processes disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged. Further, some steps may be combined or omitted. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.
The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects.” Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C,” “at least one of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C,” “at least one of A, B, and C,” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.”
The following examples are illustrative only and may be combined with aspects of other embodiments or teachings described herein, without limitation.
Example 1 is a MOS IC including a first set of transistor logic. The first set of transistor logic has a first plurality of gate interconnects extending in a first direction. The first plurality of gate interconnects has a gate pitch. The first set of transistor logic has one or more pairs of power rails providing a power supply voltage and a ground voltage to logic between each corresponding pair of power rails. The first set of transistor logic has a first cell height h1 and has a first number of Mx layer tracks that extend unidirectionally in a second direction between each pair of power rails. The second direction is orthogonal to the first direction. The MOS IC further includes a second set of transistor logic. The second set of transistor logic is located adjacent in the first direction to the first set of transistor logic. The second set of transistor logic has a second plurality of gate interconnects extending in the first direction. The second plurality of gate interconnects has a same gate pitch as the first plurality of gate interconnects and each is collinear with a respective one of the first plurality of gate interconnects. The second set of transistor logic has one or more pairs of power rails providing the power supply voltage and the ground voltage to logic between each corresponding pair of power rails. The second set of transistor logic has a second cell height h2 and has a second number of Mx layer tracks that extend unidirectionally in the second direction between each pair of power rails. The second cell height h2 is greater than the first cell height h1. The second number of Mx layer tracks is greater than the first number of Mx layer tracks. At least one of a height ratio hR=h2/h1 is a non-integer value or a subset of the first set of transistor logic and a subset of the second set of transistor logic are within one logic cell.
Example 2 is the MOS IC of example 1, wherein a power rail of the one or more pairs of power rails of the first and second sets of transistor logic extends in the second direction between the first set of transistor logic and the second set of transistor logic. The power rail is configured to provide one of the power supply voltage or the ground voltage to at least a subset of the first set of transistor logic and to at least a subset of the second set of transistor logic.
Example 3 is the MOS IC of any of examples 1 and 2, wherein a pitch of the first number of Mx layer tracks of the first set of transistor logic, and a pitch of the second number of Mx layer tracks of the second set of transistor logic are the same.
Example 4 is the MOS IC of any of examples 1 to 3, wherein the Mx layer is a lowest metal layer that extends unidirectionally in the second direction.
Example 5 is the MOS IC of any of examples 1 to 4, wherein the height ratio hR=h2/h1 is a non-integer value, and the first set of transistor logic includes a first set of logic cells, and the second set of transistor logic includes a second set of logic cells.
Example 6 is the MOS IC of any of examples 1 to 5, wherein the subset of the first set of transistor logic and the subset of the second set of transistor logic are within one logic cell. A height hm of the one logic cell is equal to (n1−1)h1+(n2−1)h2, where n1≥2 and is a number of power rail tracks within the subset of the first set of transistor logic, and n2≥2 and is a number of power rail tracks within the subset of the second set of transistor logic, and where n1+n2−1 is a total number of power rails within the one logic cell.
Example 7 is the MOS IC of example 6, wherein the subset of the first set of transistor logic and the subset of the second set of transistor logic are coupled together within the one logic cell.
Example 8 is the MOS IC of any of examples 1 to 7, further including a third set of transistor logic. The third set of transistor logic has a third plurality of gate interconnects extending in the first direction. The third plurality of gate interconnects has the same gate pitch as the first plurality of gate interconnects and the second plurality of gate interconnects, and each is collinear with respective ones of the first plurality of gate interconnects and the second plurality of gate interconnects. The third set of transistor logic has one or more pairs of power rails providing the power supply voltage and the ground voltage to logic between each corresponding pair of power rails. The third set of transistor logic has the first cell height h1 and has the first number of Mx layer tracks that extend unidirectionally in the second direction between each pair of power rails. The second set of transistor logic is between the first set of transistor logic and the third set of transistor logic.
Example 9 is the MOS IC of example 8, wherein a power rail of the one or more pairs of power rails of the second and third sets of transistor logic extends in the second direction between the second set of transistor logic and the third set of transistor logic. The power rail is configured to provide one of the power supply voltage or the ground voltage to at least a subset of the second set of transistor logic and to at least a subset of the third set of transistor logic.
Example 10 is the MOS IC of any of examples 8 and 9, wherein a subset of the first set of transistor logic, a subset of the second set of transistor logic, and a subset of the third set of transistor logic are within one logic cell. A height hm of the one logic cell is equal to (n1−1)h1+(n2−1)h2+(n3−1)h1, where n1≥2 and is a number of power rail tracks within the subset of the first set of transistor logic, n2≥2 and is a number of power rail tracks within the subset of the second set of transistor logic, and n3≥2 and is a number of power rail tracks within the subset of the third set of transistor logic, and where n1+n2+n3−2 is a total number of power rails within the one logic cell.
Example 11 is the MOS IC of example 10, wherein the subset of the first set of transistor logic, the subset of the second set of transistor logic, and the subset of the third set of transistor logic are coupled together within the one logic cell.
Example 12 is the MOS IC of any of examples 1 to 11, further including a third set of transistor logic. The third set of transistor logic has a third plurality of gate interconnects extending in the first direction. The third plurality of gate interconnects has the same gate pitch as the first plurality of gate interconnects and the second plurality of gate interconnects, and each is collinear with respective ones of the first plurality of gate interconnects and the second plurality of gate interconnects. The third set of transistor logic has one or more pairs of power rails providing the power supply voltage and the ground voltage to logic between each corresponding pair of power rails. The third set of transistor logic has the second cell height h2 and has the second number of Mx layer tracks that extend unidirectionally in the second direction between each pair of power rails. The first set of transistor logic is between the second set of transistor logic and the third set of transistor logic.
Example 13 is the MOS IC of example 12, wherein a power rail of the one or more pairs of power rails of the first and third sets of transistor logic extends in the second direction between the first set of transistor logic and the third set of transistor logic. The power rail is configured to provide one of the power supply voltage or the ground voltage to at least a subset of the first set of transistor logic and to at least a subset of the third set of transistor logic.
Example 14 is the MOS IC of any of examples 12 and 13, wherein a subset of the first set of transistor logic, a subset of the second set of transistor logic, and a subset of the third set of transistor logic are within one logic cell. A height hm of the one logic cell is equal to (n3−1)h2+(n1−1)h1+(n2−1)h2, where n1≥2 and is a number of power rail tracks within the subset of the first set of transistor logic, n2≥2 and is a number of power rail tracks within the subset of the second set of transistor logic, and n3≥2 and is a number of power rail tracks within the subset of the third set of transistor logic, and where n1+n2+n3−2 is a total number of power rails within the one logic cell.
Example 15 is the MOS IC of example 14, wherein the subset of the first set of transistor logic, the subset of the second set of transistor logic, and the subset of the third set of transistor logic are coupled together within the one logic cell.
Example 16 is the MOS IC of any of examples 1 to 15, further including n sets of transistor logic. The n sets of transistor logic are located adjacent in the first direction to one of the first set of transistor logic or the second set of transistor logic. Each set of the n sets of transistor logic has a same number of gate interconnects extending in the first direction. The gate interconnects have the same gate pitch and each is collinear with respective ones of the first and second plurality of gate interconnects. Each set of then sets of transistor logic has one or more pairs of power rails providing the power supply voltage and the ground voltage to logic between each corresponding pair of power rails. Each set of the n sets of transistor logic has either the first cell height h1 and the first number of Mx layer tracks or the second cell height h2 and the second number of Mx layer tracks.