Fast model-based optical proximity correction method for plasmonic lithography

Plasmonic lithography has the characteristic of breaking through the diffraction limit, but it is not a “perfect imaging”, that is, it cannot perfectly restore the information of the “object” (mask pattern), and there is an optical proximity effect similar to that in projection lithography. Therefore, it is necessary to optimize the mask pattern by using plasmonic lithography optical proximity correction (OPC) technology to achieve the purpose of reducing the pattern error (PE) and improving the imaging fidelity. This paper proposes a fast model-based OPC method for plasmonic lithography. This method is based on the imaging model established by the improved rigorous coupled wave analysis (RCWA) method, and the optimization process is based on the movement of edges. Based on the edge placement error (EPE) in the previous iteration, the movement of the edge fragments in the next iteration is determined. This feedback closed loop enables OPC to gradually approach the target, and it can converge quickly in about 7 iterations. The simulation experiments show that about 7 iterations can achieve an average reduction of about 76% in the sum of the absolute values of EPE sum_|EPE| and 71% in PE. And for patterns with different line width sizes, the OPC method proposed in this paper has good compatibility. The above results effectively verify the efficiency and effectiveness of the OPC method proposed in this paper.