OPC flow for non-conventional layouts: specific application to optical diffusers

Some specific applications, such as optical devices, require non-conventional layouts. In this context, the known OPC solutions developed during decades and optimized for CMOS planar applications are facing significant challenges. Standard design files format as well as OPC algorithms are indeed suitable for 0-45-90° edges (also called Manhattan layouts) and other angle edges can lead to bad OPC results, huge run time, large file size, and even run crashes. While innovative developments are on going from OPC suppliers’ side, we have to use smartly the conventional OPC platforms to achieve accurate, fast and cost-effective solutions. Taking the example of optical diffusers application, we will discuss the implementation of such an OPC flow, including rule-based correction, SRAF insertion, model-based correction, and mask sign-off strategy.