Efficient provably good OPC modeling and its applications to interconnect optimization

Abstract

Optical Proximity Correction (OPC) is the most popular technique to handle design shape distortions arising from subwavelength lithography. Existing OPC models are typically very computationally expensive and thus not efficient to be incorporated for layout optimization. In this paper, we present an efficient, yet sufficiently accurate OPC cost model which can predict the optimal location of a wire segment for OPC optimization and give an upper bound of the interference amount, guaranteeing that the interference amount is never underestimated. Based on this cost model, we propose an OPC-aware wire perturbation algorithm for post-layout interconnect optimization. We show that the effects of wire perturbation have the concavity or monotonicity property which can dramatically reduce the search space for finding the optimal location of each wire for OPC optimization. Further, we can incrementally update the OPC cost of a wire by recomputing only the affected wires because of the property of superposition of our model. Experimental results show that our algorithm can efficiently obtain much better OPC results than a state-of-the-art OPC-friendly router, based on a leading commercial OPC tool.