Optical Rule Checking for Proximity corrected mask shapes

Optical Rule Checking (ORC) is an important vehicle to predict the failure of wafer shapes due to the process proximity effects. Optical Proximity Correction (OPC) if not aided by ORC may cause severe failures affecting the yield in manufacturing. However, it is fairly complicated to do ORC on mask shapes that are pre-corrected either by rules-based or by model-based OPC. ORC is also a good tool to capture the problems that may occur at multi-layer interactions. We present a methodology to use both geometric directives and limited optical simulation to detect potential failures using ORC. We extend our methodology to multi-layer interactions. In case of multi-layer ORC, we present several approaches that deal with how to judiciously mix the geometric directives and the optical simulations for different layers. We show the ORC can help us design better rules for OPC.