Off-target Model-based OPC And OPC-relative Verifications

OPC (Optical Proximity Correction) has developed to be a part of EDA framework, which is primarily used to increase the achievable resolution and pattern transfer fidelity. And now it also serves to make contributions for DFM (Design for Manufacturability).This Dissertation aims to improve the accuracy of model-based OPC (MOPC) and OPC-relative verifications. The process information of conventional MOPC focuses on optimal conditions, so the model can not predict accurately when the process conditions are changed, and should be built again. A major contribution of this dissertation is the development of process-window-based OPC model, off-target MOPC (OTMOPC). OTMOPC provides robust correction through the variations of process parameters. OTMOPC can cover the variations of process conditions within the process window, saving much time of data preparation before mask tape-out. Thus the cycle time of model construction is greatly shortened.Another contribution of this dissertation is the insertion lithographic rule checking (LRC) into the design flow next to design rule checking (DRC). LRC is used to identify the weak points in the design layout for optimizing the design rules and avoiding the OPC non-friendly features and optimizing the mask shapes based on the process window information.As for mask quality control, a scientific sampling plan is provided and mask CDSEM images are used to monitor the performance of OPCed structures. In the phase of OPC mask inspection, the methods to fine-tuning inspection program are also introduced.