Semiconductor manufacturing is continuously ramping up the yield of technology processes with transistor dimensions well below the exposure wave length. Light diffraction effects limit the resolution of pattern with ever smaller dimension in ArF lithography using a fixed exposure wave length of 193nm and prevent printing wafer patterns identical to the shapes drawn on the exposure mask. Resolution enhancement techniques such as Optical Proximity Correction (OPC) enable new technologies to be realized in wafer manufacturing. Sub-resolution assist features (SRAF), or scatter bars (SB), provide critical process window enhancements in the lithography process. Traditionally, SRAF generation is based on geometric rules, which are extracted from a large amount of simulation and empirical wafer data from printing test masks.

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