针对透射式投影物镜中由于不均匀照明产生的像散, 提出了采用平面透镜作为主动光学元件以补偿像散的方法。本文对直径为 Φ140 mm, 通光孔径为 Φ120 mm 的平面透镜的支撑结构进行设计和有限元分析, 分析了支撑结构的各个关键参数、镜片厚度和驱动力大小对面形的影响, 得到了支撑结构的关键参数和驱动力对面形的影响规律为线性曲线, 镜片厚度对面形的影响规律为指数下降曲线和不同驱动力导致的面形图。结果表明, 本支撑结构在补偿像散时, 面形补偿分辨率约为 2 nm, 引入的高阶像差可以忽略, 设计分析结果为投影物镜中主动光学镜片的选择和支撑结构的设计及实验提供依据。

A method which adopted plane-parallel plate as active optics element is proposed to compensate the astigmatism because of non-uniformed illumination in projection objective. The supporting structure is designed and analyzed for the plane-parallel plate with Φ140 mm diameter. The key parameters of supporting structure, the thickness of lens and the driving force are analyzed to receive the influence rules to the surface quality. The results indicate that the influence of the key parameter and driving force on the surface quality seems to be linearity, and the influence of lens thickness on the surface quality seems to be exponential. The figure is received by changing the value of driving force. The results indicate that high order aberration which the supporting structure brings is negligible when compensating. The resolution of astigmatism compensation is 2 nm. The designed and analyzed results provide reference for selecting of active optics lens, designing of supporting structure and experiment.