Iterative feedback tuning of optical proximity correction mask in lithography

Abstract

Due to the resolution limits of optical lithography systems, the electronics industry has relied on resolution enhancement techniques (RETs), such as optical proximity correction (OPC), to compensate and minimize mask distortions as they are projected onto semiconductor wafers. A novel performance-based OPC (PB-OPC) methodology which focuses on the circuit performance has been demonstrated to achieve little loss in circuit performance accuracy with a reduced mask size. PB-OPC is performed by iteratively shifting the transistor edges on the mask layout until convergence requirements are achieved. The limitation is the computational time used in generating the required mask. In this paper, we make use of ideas from feedback control to improve on the convergence speed of generating the OPC mask. We also proposed an iterative feedback tuning method and have obtained improvement in convergence time. © 2011 IEEE.