适用于双工件台光刻机的高精度离焦量解耦算法研究

Defocus-decoupling algorithm in dual-stage lithographic system is studied in the manner of theoretical analysis, analog simulation, and experimental verification. Actual shape of focal plane in Projection lens is recognized by PGFM（phase grating focus monitor）. Defocus algorithm is studied considering of Shape of focal plane in Projection lens and topography of wafer. Pre-diagnosis is carried out for the defocus-point. Defocus-decoupling algorithm is studied, which is used to transferring defocus to controlling quantity for the leveling system. This algorithm assures that there is no shift during focusing and leveling. High frequency filtering is made to making the trajectory much smoother. Theoretical basis is built for the development of defocus-decoupling algorithm. As the dual-stage lithographic system becomes the mainstream, this study will have a bright future.

本项目旨在应用理论分析、仿真模拟、实验验证相结合的方式对适用于双工件台光刻机的离焦量解耦算法进行研究。结合高精度的PGFM（phase grating focus monitor）技术获得投影物镜的真实焦面形状，综合考虑投影物镜焦面形状和硅片形貌，研究一种双工件台光刻机用离焦量计算方法并对离焦点成因进行预诊断；研究一种离焦量解耦算法，该算法将狭缝曝光场的离焦量解耦为三个调平控制器的控制量并保证狭缝曝光场中心在调平调焦运动过程中不发生平移；最后将由离焦量确定的硅片扫描曝光过程中的调平调焦运动轨迹进行高频滤波，以使运动轨迹更加平滑。通过本项目的研究为双工件台光刻机离焦量解耦算法的发展打下坚实的理论基础，伴随着双工件台光刻机市场主流地位的确立，本研究具有光明的应用前景。

本项目对适用于双工件台光刻机的离焦量解耦算法进行了研究：首先，结合高精度的PGFM（phase grating focus monitor）技术获得投影物镜的真实焦面形状，其次，综合考虑投影物镜焦面形状和硅片形貌，研究了一种双工件台光刻机用离焦量计算方法并对离焦点成因进行预诊断；最后，研究了一种离焦量解耦算法，该算法可保证狭缝曝光场中心在调平调焦运动过程中不发生平移，并将由离焦量确定的硅片扫描曝光过程中的调平调焦运动轨迹进行高阶滤波，通过轨迹优化以使运动更加平滑、无冲击。通过本项目的研究为双工件台光刻机离焦量解耦算法的发展打下坚实的理论基础，具有光明的应用前景。