The edge-based OPC has been serving the industry for more than 20 years with few changes in the way to alter the mask. In the past 10 years, ILT pioneers in the creation of the curvilinear mask using alternate algorithms. The two approaches differ so much that the experiences in conventional OPC do not easily translate to the use of ILT and vice versa. In this paper, we report a new system for curvilinear OPC built on top of the conventional OPC workflow without being limited to moving edges. It creates and manipulates the curvilinear shapes by generalizing the edge-based OPC to vertices. Conventional OPC techniques, including dissection, classification, target point placement, etc., keep playing central roles. Full-chip correction results demonstrate the good performance of the curvilinear mask for both contact and line/space patterns. The runtime cost of adoption is reported.
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