The present disclosure relates generally to a cell architecture, and more particularly, to a cell architecture with an additional oxide diffusion (OD) region.
A cell device is an integrated circuit (IC) that implements digital logic. Such 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 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. There is a need for improved cells devices.
In an aspect of the disclosure, a metal oxide semiconductor (MOS) device on an IC includes a set of p-type MOS (pMOS) transistors on a first side of the IC. The set of pMOS transistors is adjacent to each other in a second direction. The MOS device further includes a set of n-type MOS (nMOS) transistors on a second side of the IC. The set of nMOS transistors is adjacent to each other in the second direction. The second side is opposite the first side in a first direction. The first direction is orthogonal to the second direction. The MOS device further includes an oxide diffusion (OD) region between the set of pMOS transistors and the set of nMOS transistors. The OD region may form in part a first set of transistors that is configured to be dummy transistors or decoupling capacitors.
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.
While an IC is illustrated with GAAFETs in
The MOS device may further include a first set of gate interconnects 326 that extend in the first direction over the OD region 324. The gate interconnects 326 are separated from the pMOS gate interconnects 306 and the nMOS gate interconnects 316 through the gate interconnect cuts 330 (sometimes referred to as POLY cuts). The gate interconnects 326 may form transistor gates (see 102, 202 in
In a first configuration, the first set of transistors 322 are configured to be dummy transistors. In such a configuration, the source, drain, and gate of each of the dummy transistors 322a, 322b, 322c, 322d are configured to be floating and isolated from a voltage source. In a second configuration, the first set of transistors 322 are configured to be decoupling capacitors. In such a configuration, the set of contacts 328 coupled to the sources and the drains of the first set of transistors 322 may be configured to be coupled to a power supply voltage (e.g., Vcc), and the gates 326 of the first set of transistors 322 may be configured to be coupled to a ground voltage (e.g., Vss). Alternatively, the set of contacts 328 coupled to the sources and the drains of the first set of transistors 322 may be configured to be coupled to the ground voltage, and the gates 326 of the first set of transistors 322 may be configured to be coupled to the power supply voltage.
The MOS device may further include a second set of gate interconnects 306 extending in the first direction, where at least a subset of the second set of gate interconnects 306 form gates 306 of the pMOS transistors 302. For example, the set of pMOS transistors 302 may include eight (e.g., 2 rows×4 columns) pMOS transistors, and each of the gate interconnects 306 may form a corresponding gate 306 of one of the pMOS transistors 302. Gate contacts 360 (see 108, 208 of
The MOS device may further include a third set of gate interconnects 316 extending in the first direction, where at least a subset of the third set of gate interconnects 316 form gates 316 of the nMOS transistors 312. For example, the set of nMOS transistors 312 may include eight (e.g., 2 rows×4 columns) nMOS transistors, and each of the gate interconnects 316 may form a corresponding gate 316 of one of the nMOS transistors 312. Gate contacts 362 (see 108, 208 of
Additional gate interconnect cuts 332 are located towards the top and the bottom of the cell 390 so that the gate interconnects 306, 316 are separated from gate interconnects of adjacent cells that are adjacent to the top and bottom of the cell 390. The gate interconnect cuts 330, 332 may reduce the metal boundary effect (MBE) that can occur if the gate interconnects for the pMOS gates/nMOS gates are too close together.
As illustrated in
The MOS device may further include a set of M1 layer interconnects 340 (illustrated with one M1 layer interconnect) coupling at least one of the pMOS transistors 302 to at least one of the nMOS transistors 312. As discussed supra, the set of M1 layer interconnects 340 may be unidirectional, and in particular, may be unidirectional in the first direction. The MOS device may further include a set of M2 layer interconnects 342 (illustrated with one M2 layer interconnect) coupled to at least one M1 layer interconnect 340 of the set of M1 layer interconnects 340. As discussed supra, the set of M2 layer interconnects 342 may also be unidirectional in the first direction.
The MOS device may further include a set of power interconnects 350 extending in the second direction across the IC adjacent an edge at the first side of the IC. The set of power interconnects 350 may be configured to provide a power supply voltage (e.g., Vcc) to the set of pMOS transistors 302. At the set of power interconnects 350, an n-tap (i.e., a p-side tap) may be located to tie the n-well 380 to the power supply voltage. The MOS device may further include a set of ground interconnects 352 extending in the second direction across the IC adjacent an edge at the second side of the IC. The set of ground interconnects 352 may be configured to provide a ground voltage (e.g., Vss) to the set of nMOS transistors 312. At the set of ground interconnects 352, a p-tap (i.e., an n-side tap) may be located to tie the p-type substrate 132, 232 (see
As discussed infra with respect to
Referring now to
An example with numbers may make the discussion clearer. Assume the cell 390 is designed with D equal to 393 nm and a nanosheet width WNS of 25 nm. Such a design would fail a DRC that has an MBC to MBC spacing limitation of 189 nm (i.e., TMBCtoMBC=189 nm) when the nanosheet width WNS equals 25 nm. With the addition of the OD region 324 (e.g., dummy transistors or decoupling capacitors), the design would pass the DRC as long as Dp and Dn meet the DRC. If the OD region 324 is located in the center between the pMOS transistors 302 and the nMOS transistors 312, then the design would pass the DRC as long as (D−WNS)/2=Dn=Dp≤TMBCtoMBC. In this case, Dn and Dp would equal 184 nm (i.e., (393 nm−25 nm)/2), which is just less than the TMBCtoMBC of 189 nm, and therefore the design would pass the DRC.
In the cell 390, in order to pass the DRC, the distance Dp between the set of pMOS transistors 302 and the first set of transistors 322 (e.g., dummy transistors or decoupling capacitors) is designed and manufactured to be less than the threshold distance TMBCtoMBC, and the distance Dn between the set of nMOS transistors 312 and the first set of transistors 322 is designed and manufactured to be less than the threshold distance TMBCtoMBC. To optimize the performance of the pMOS/nMOS transistors 302, 312, the pMOS/nMOS transistors 302, 312 are designed and manufactured to have a distance D larger than the threshold distance TMBCtoMBC. That is, the distance D between the set of pMOS transistors 302 and the set of nMOS transistors 312 is designed and manufactured to be greater than the threshold distance TMBCtoMBC. As such, without the additional OD region 324 (e.g., dummy transistors or decoupling capacitors), the cell 390 would fail the DRC. The additional OD region 324 (e.g., dummy transistors or decoupling capacitors) allows for the distance D to be greater than threshold distance TMBCtoMBC. In one example, the pMOS/nMOS transistors 302, 312 are designed and manufactured to have a distance D larger than twice the threshold distance TMBCtoMBC. In such example, the distance D between the set of pMOS transistors 302 and the set of nMOS transistors 312 is greater than twice the threshold distance TMBCtoMBC (2*TMBCtoMBC) and less than twice the threshold distance TMBCtoMBC plus a nanosheet width WNS (2*TMBCtoMBC+WNS) associated with the transistors of the first set of transistors 322. The constraint D≤2*TMBCtoMBC+WNS is a constraint of the DRC, and the constraint 2*TMBCtoMBC<D is a design choice in order to further space apart the pMOS transistors 302 and nMOS transistors 312 so that their performance is not compromised in this high speed IC. As such, in the one example, assuming TMBCtoMBC=189 nm, WNS=25 nm, and D=393 nm, then the distance D would be greater than 378 nm (2*TMBCtoMBC) and less than 403 nm (2*TMBCtoMBC+WNS), which represents the max distance D possible that still satisfies the DRC.
In the example provided with respect to
Referring again to
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.
Aspect 1 is a MOS device on an IC including a set of pMOS transistors on a first side of the IC, the set of pMOS transistors being adjacent to each other in a second direction; a set of nMOS transistors on a second side of the IC, the set of nMOS transistors being adjacent to each other in the second direction, the second side being opposite the first side in a first direction, the first direction being orthogonal to the second direction; and an OD region between the set of pMOS transistors and the set of nMOS transistors.
Aspect 2 is the MOS device of aspect 1, further including a first set of gate interconnects extending in the first direction over the OD region.
Aspect 3 is the MOS device of aspect 2, further including a set of contacts contacting the OD region adjacent each of the first set of gate interconnects and extending in the first direction.
Aspect 4 is the MOS device of aspect 3, wherein the OD region, the first set of gate interconnects, and the set of contacts form a first set of transistors between the set of pMOS transistors and the set of nMOS transistors, the first set of transistors being adjacent to each other in the second direction, each of the transistors of the first set of transistors including a source corresponding to one contact of the set of contacts, a drain corresponding to one contact of the set of contacts, and a gate corresponding to one gate interconnect of the first set of gate interconnects.
Aspect 5 is the MOS device of aspect 4, wherein the first set of transistors is configured to be dummy transistors.
Aspect 6 is the MOS device of aspect 5, wherein the source, drain, and gate of each of the dummy transistors are configured to be floating and isolated from a voltage source.
Aspect 7 is the MOS device of aspect 4, wherein the first set of transistors is configured to be decoupling capacitors.
Aspect 8 is the MOS device of aspect 7, wherein the set of contacts coupled to the sources and the drains of the first set of transistors are configured to be coupled to a power supply voltage, and the gates of the first set of transistors are configured to be coupled to a ground voltage.
Aspect 9 is the MOS device of aspect 7, wherein the set of contacts coupled to the sources and the drains of the first set of transistors are configured to be coupled to a ground voltage, and the gates of the first set of transistors are configured to be coupled to a power supply voltage.
Aspect 10 is the MOS device of any of aspects 4 to 9, further including a second set of gate interconnects extending in the first direction, at least a subset of the second set of gate interconnects forming gates of the pMOS transistors; and a third set of gate interconnects extending in the first direction, at least a subset of the third set of gate interconnects forming gates of the nMOS transistors; wherein the first set of gate interconnects, the second set of gate interconnects, and the third set of gate interconnects are isolated from and collinear with each other.
Aspect 11 is the MOS device of aspect 10, wherein: the second set of gate interconnects and the first set of gate interconnects are disconnected from each other in a first region adjacent to the first set of transistors, corresponding gate interconnects of the second set of gate interconnects and the first set of gate interconnects being collinear with each other; and the third set of gate interconnects and the first set of gate interconnects are disconnected from each other in a second region adjacent to the first set of transistors, corresponding gate interconnects of the third set of gate interconnects and the first set of gate interconnects being collinear with each other.
Aspect 12 is the MOS device of any of aspects 4 to 11, further including a set of M1 layer interconnects coupling at least one of the pMOS transistors to at least one of the nMOS transistors, the set of M1 layer interconnects being unidirectional.
Aspect 13 is the MOS device of aspect 12, wherein the set of M1 layer interconnects is unidirectional in the first direction.
Aspect 14 is the MOS device of aspect 13, further including a set of M2 layer interconnects coupled to at least one M1 layer interconnect of the set of M1 layer interconnects, the set of M2 layer interconnects being unidirectional in the first direction.
Aspect 15 is the MOS device of any of aspects 4 to 14, further including a set of power interconnects extending in the second direction across the IC adjacent an edge at the first side of the IC, the set of power interconnects being configured to provide a power supply voltage to the set of pMOS transistors; and a set of ground interconnects extending in the second direction across the IC adjacent an edge at the second side of the IC, the set of ground interconnects being configured to provide a ground voltage to the set of nMOS transistors, wherein the first set of transistors are in a center region between the set of power interconnects and the set of ground interconnects.
Aspect 16 is the MOS device of any of aspects 4 to 15, wherein a distance between the set of pMOS transistors and the first set of transistors is less than a threshold distance, and a distance between the set of nMOS transistors and the first set of transistors is less than the threshold distance.
Aspect 17 is the MOS device of aspect 16, wherein a distance between the set of pMOS transistors and the set of nMOS transistors is greater than the threshold distance.
Aspect 18 is the MOS device of aspect 17, wherein the distance between the set of pMOS transistors and the set of nMOS transistors is greater than twice the threshold distance and less than twice the threshold distance plus a nanosheet width WNS associated with the transistors of the first set of transistors.
Aspect 19 is the MOS device of any of aspects 1 to 18, wherein the MOS device is a cell on the IC.
Aspect 20 is the MOS device of any of aspects 1 to 19, wherein the OD region between the set of pMOS transistors and the set of nMOS transistors is continuous in the second direction across the IC.
Aspect 21 is the MOS device of any of aspects 1 to 19, wherein the OD region between the set of pMOS transistors and the set of nMOS transistors is discontinuous in the second direction across the IC.