Mask Optimization based on artificial desired pattern

Abstract

As one of the most effective methods to compensate image distortion, inverse lithography technology (ILT) has been widely used in the computational lithography. However, the compensation capability of ILT to wafer image is restricted by the effect of low-pass filtering, and difficult to resolve high frequency signals. In this paper, a new optimization algorithm is investigated and applied to ILT. The high frequency points on the target pattern are characterized, and additional low frequency signals are added at these points to form an artificial desired pattern. The artificial desired pattern will replace the target pattern in the optimization, which is proposed to resolve the impact of high frequency signals. Simulation results demonstrate the superiority of the proposed method, which effectively improves the fidelity of the target pattern.