Today’s Patent – Optical Proximity Correction and Photomasks

The said invention (US12265334B2) was invented by Dong-Yo Jheng, Ken-Hsien Hsieh, Shih-Ming Chang, Chih-Jie LeeShuo-Yen Chou, Ru-Gun Liu, and patented by USPTO on July 30^th, 2023. Currently, it stands assigned to the Taiwan Semiconductor Manufacturing Co TSMC Ltd.

This invention relates to methods for optimizing photomask layouts used in semiconductor manufacturing by evaluating potential layout modifications against variations in lithographic process conditions.

A layout is first received and associated with multiple target contours, each corresponding to different sets of lithographic conditions (e.g., focus, dose, or mask errors). Candidate modifications to the layout are then simulated under these varied conditions to generate simulated contours. The deviations (e.g., edge placement errors) between the simulated and target contours are assessed and used to compute a cost function.

Based on the computed cost—potentially incorporating fabrication penalties or rule checks—the layout modification with the lowest cost within a defined threshold is selected and provided for mask fabrication. This approach ensures that the final mask design is robust against lithographic variability and produces consistent, manufacturable features under a range of real-world process conditions, improving yield and device performance.