Setting MRC Rules: Balancing Inspection Capabilities, Defect Sensitivity and OPC

One of the challenges associated with shrinking design dimensions is finding photomask inspection settings which achieve sufficient defect detection capabilities while supporting aggressive Optical Proximity Correction (OPC). The most recent technology nodes require very aggressive and advanced Resolution Enhancement Techniques (RETs) which involve printing small features that are challenging for mask inspection tools. We examine the problems associated with constraining Models-Based OPC with mask inspection driven rules. We give examples of a 45nm technology node contact layer design which will receive sub-optimal OPC treatment due to mask inspection constraints.