As the EUV lithography is extending beyond 7nm technology, design to mask strategy becomes more complex. New challenges including advanced OPC and ILT in mask optimization, curvilinear masks, shrinking Mask Rule Checking (MRC), Sub-Resolution Assist Features (SRAF) generation and formation, and other complex mask geometries drive the needs to study this synergy from different stages of the flow from Optical Proximity Correction (OPC), Mask Process Correction (MPC), fracturing, to mask writing and inspection. In this study, different OPC and SRAF mask formations including curvilinear masks, controlled Manhattanized approximations of curvilinear masks, and conventional masks are generated. We illustrate whether curvilinear masks have any demonstrable lithographic benefits. A quantitative comparison of how the Manhattanization impacts mask formation. The image quality metrics such as Image Log Slope (ILS), Process Viability (PV) Band, and Depth of Focus (DOF) from various OPC mask flavors including different MRC settings and different mask forms are compared and discussed. The mask manufacturability study is conducted to identify any major challenges and approaches to minimize, including assessing the value and need for native curvilinear write tool support on a MultiBeam Mask Writer (MBMW) or a single beam Vector Shaped Beam (VSB) mask writer.
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