US 11,874,597 B2
Stochastic optical proximity corrections
Zachary Levinson, Mountain View, CA (US); and Yunqiang Zhang, Mountain View, CA (US)
Assigned to Synopsys, Inc., Sunnyvale, CA (US)
Filed by Synopsys, Inc., Mountain View, CA (US)
Filed on Feb. 24, 2021, as Appl. No. 17/184,460.
Claims priority of provisional application 62/981,444, filed on Feb. 25, 2020.
Prior Publication US 2021/0263407 A1, Aug. 26, 2021
Int. Cl. G03F 1/72 (2012.01); G03F 1/84 (2012.01); H01L 21/033 (2006.01); H01L 21/311 (2006.01)
CPC G03F 1/72 (2013.01) [G03F 1/84 (2013.01); H01L 21/0337 (2013.01); H01L 21/31144 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of improving mask data used in fabrication of a semiconductor device, the method comprising:
setting a threshold value associated with a defect based on stochastic failure rate of the defect;
performing a first optimal proximity correction (OPC) of the mask data using nominal values of mask pattern contours;
identifying locations within the first OPC mask data where stochastically determined mask pattern contours correspond to a potential defect;
placing check figures on the identified locations to enable measurement of distances between the stochastically determined mask pattern contours; and
performing, by a processor, a second OPC of the first OPC mask data so as to cause the measured distances to be greater than the threshold value.