Method and system for proximity-aware circuit design
View Patent ↗A method for proximity-aware circuit design where a set of layout constraint values that satisfy predetermined performance or yield goals is determined in accordance with a layout effect model. One of the layout constraint values is then selected as a constraint input to layout design, and a design layout is performed with the selected layout constraint value to provide a semiconductor circuit design for the semiconductor circuit. The set of layout constraint values can be determined by varying an instance parameter of the layout effect model to determine a set of instance parameters that satisfy the at least one predetermined performance or yield goal in accordance with the layout effect model, and determining layout constraints associated with each instance parameter of the set of instance parameters, thus providing a number of candidates in a design space that can be evaluated according to performance and/or yield tradeoffs.
1. A computer-implemented method of proximity-aware circuit design for a selected circuit topology for a semiconductor circuit having at least one predetermined performance or yield goal, comprising:
for each device in the selected circuit topology, determining a set of layout constraint values that satisfy the at least one predetermined performance or yield goal in accordance with a layout effect model;
selecting one of the set of layout constraint values as a constraint input to layout a design for said each device; and
performing a design layout in accordance with the selected one of the set of layout constraint values for said each device to provide a semiconductor circuit design for the semiconductor circuit.
2. The method as claimed in claim 1 further comprising:
placing and routing each of devices in the selected circuit topology in accordance with its respective selected one of the set of layout constraint values to optimize the semiconductor circuit design in accordance with circuit specifications; and
verifying the semiconductor circuit design.
3. The method as claimed in claim 1 wherein the selecting one of the set of layout constraint values as a constraint input to layout a design comprises:
selecting the one of the set of layout constraint values in view of trade-offs between performance and yield goals.
4. The method as claimed in claim 1 wherein the layout effect model comprises at least one of a well proximity effect model, and a shallow trench isolation (STI) stress model.
5. The method as claimed in claim 1 wherein the determining a set of layout constraint values that satisfy the at least one predetermined performance or yield goal in accordance with a layout effect model comprises:
varying an instance parameter of the layout effect model to determine a set of instance parameters that satisfy the at least one predetermined performance or yield goal in accordance with the layout effect model; and
determining layout constraints associated with each instance parameter of the set of instance parameters to provide the set of layout constraint values.
6. The method as claimed in claim 1 wherein the determining a set of layout constraint values that satisfy the at least one predetermined performance or yield goal in accordance with a layout effect model comprises:
determining a set of minimum well distance values that satisfy the at least one predetermined performance or yield goal in accordance with a well proximity effect model.
7. The method as claimed in claim 6 wherein the determining a set of minimum well distance values that satisfy the at least one predetermined performance or yield goal in accordance with a well proximity effect model comprises:
varying an instance parameter (SCA) representing an integral of a first distribution function for scattered well dopants to determine a set of instance parameters that satisfy the at least one predetermined performance or yield goal in accordance with the well proximity effect model; and
determining well keep-out constraints associated with each instance parameter of the set of instance parameters to provide the set of minimum well distance values.
8. The method as claimed in claim 7 wherein the selecting one of the set of layout constraint values as a constraint input to layout a design comprises:
selecting one of the set of instance parameters in view of trade-offs between performance and yield goals; and
inputting minimum well distances corresponding to the selected one of the set of instance parameters as the constraint input.
9. The method as claimed in claim 7 wherein the well proximity effect model models at least one of threshold voltage (V th ), a second-order body bias coefficient (K2) and effective mobility (μ eff ) as a function of SCA.
10. The method as claimed in claim 1 wherein sizing devices in the selected circuit topology and the determining a set of layout constraint values that satisfy the at least one predetermined performance or yield goal in accordance with a layout effect model are performed together.
11. A non-transitory computer-readable medium storing instructions, which, when executed by a processor, cause the processor to execute a method of proximity-aware circuit design for a selected circuit topology for a semiconductor circuit having at least one predetermined performance or yield goal, the method comprising:
for each device in the selected circuit topology, determining a set of layout constraint values that satisfy the at least one predetermined performance or yield goal in accordance with a layout effect model;
selecting one of the set of layout constraint values as a constraint input to layout a design for said each device; and
performing a design layout in accordance with the selected one of the set of layout constraint values for said each device to provide the semiconductor circuit design for a semiconductor circuit.
12. The non-transitory computer-readable medium as claimed in claim 11 wherein the method further comprises:
placing and routing each of devices in the selected circuit topology in accordance with its respective selected one of the set of layout constraint values to optimize the semiconductor circuit design in accordance with circuit specifications; and
verifying the semiconductor circuit design.
13. The non-transitory computer-readable medium as claimed in claim 11 wherein the selecting one of the set of layout constraint values as a constraint input to layout a design comprises:
selecting the one of the set of layout constraint values in view of trade-offs between performance and yield goals.
14. The non-transitory computer-readable medium as claimed in claim 11 wherein the layout effect model comprises at least one of a well proximity effect model, and a shallow trench isolation (STI) stress model.
15. The non-transitory computer-readable medium as claimed in claim 11 wherein the determining a set of layout constraint values that satisfy the at least one predetermined performance or yield goal in accordance with a layout effect model comprises:
varying an instance parameter of the layout effect model to determine a set of instance parameters that satisfy the at least one predetermined performance or yield goal in accordance with the layout effect model; and
determining layout constraints associated with each instance parameter of the set of instance parameters to provide the set of layout constraint values.
16. The non-transitory computer-readable medium as claimed in claim 11 wherein the determining a set of layout constraint values that satisfy the at least one predetermined performance or yield goal in accordance with a layout effect model comprises:
determining a set of minimum well distance values that satisfy the at least one predetermined performance or yield goal in accordance with a well proximity effect model.
17. The non-transitory computer-readable medium as claimed in claim 16 wherein the determining a set of minimum well distance values that satisfy the at least one predetermined performance or yield goal in accordance with a well proximity effect model comprises:
varying an instance parameter (SCA) representing an integral of a first distribution function for scattered well dopants to determine a set of instance parameters that satisfy the at least one predetermined performance or yield goal in accordance with the well proximity effect model; and
determining well keep-out constraints associated with each instance parameter of the set of instance parameters to provide the set of minimum well distance values.
18. The non-transitory computer-readable medium as claimed in claim 17 wherein the selecting one of the set of layout constraint values as a constraint input to layout a design comprises:
selecting one of the set of instance parameters in view of trade-offs between performance and yield goals; and
inputting minimum well distances corresponding to the selected one of the set of instance parameters as the constraint input.
19. The non-transitory computer-readable medium as claimed in claim 17 wherein the well proximity effect model models at least one of threshold voltage (V th ), a second-order body bias coefficient (K2) and effective mobility (μ eff ) as a function of SCA.
20. The non-transitory computer-readable medium as claimed in claim 11 wherein the determining a set of layout constraint values that satisfy the at least one predetermined performance or yield goal in accordance with a layout effect model is performed at the same time as sizing devices in the selected circuit topology.