The latest generation wafer scanners use extreme ultraviolet light to project a pattern of electronic connections onto a silicon wafer. A significant part of the projection light is absorbed by the mirrors in the projection system. This causes the mirrors to heat up and expand, which leads to a significant reduction in the imaging quality of the wafer scanner. The imaging quality can be improved by applying an additional actuation heat load to the mirrors. Because the wafer scanner can be used with a large number of different illumination settings (which lead to different load cases) and the number of thermal actuators is limited, designing an effective actuation heater layout is an important but nontrivial task. To assist this design process, this paper proposes a computational framework to optimize a small number of spatial actuation heat load shapes with their corresponding intensities for a large number of load cases. It is guaranteed that the obtained actuation heat load shapes can keep the steady-state temperature in the optical surface of the mirror sufficiently close to a desired temperature in all considered load cases. The proposed computational framework is applied to a representative three-dimensional finite element model of a mirror. The obtained actuation heat load shapes and their corresponding intensities provide insights for the design of a thermal actuation layout for mirror heating.

最新一代的晶圆扫描仪使用极紫外光将电子连接图案投射到硅晶圆上。投影光的很大一部分被投影系统中的反射镜吸收。这会导致反射镜升温和膨胀，从而导致晶圆扫描仪的成像质量显着降低。可以通过向镜子施加额外的驱动热负载来提高成像质量。由于晶圆扫描仪可以与大量不同的照明设置（导致不同的负载情况）一起使用，并且热致动器的数量有限，因此设计有效的致动加热器布局是一项重要但不平凡的任务。为了协助这个设计过程，本文提出了一种计算框架，可以针对大量载荷情况优化少量空间驱动热载荷形状及其相应的强度。保证获得的致动热负载形状可以在所有考虑的负载情况下保持反射镜光学表面中的稳态温度充分接近所需温度。所提出的计算框架应用于镜子的代表性三维有限元模型。获得的驱动热负载形状及其相应的强度为设计用于镜面加热的热驱动布局提供了见解。保证获得的致动热负载形状可以在所有考虑的负载情况下保持反射镜光学表面中的稳态温度充分接近所需温度。所提出的计算框架应用于镜子的代表性三维有限元模型。获得的驱动热负载形状及其相应的强度为设计用于镜面加热的热驱动布局提供了见解。保证获得的致动热负载形状可以在所有考虑的负载情况下保持反射镜光学表面中的稳态温度充分接近所需温度。所提出的计算框架应用于镜子的代表性三维有限元模型。获得的驱动热负载形状及其相应的强度为设计用于镜面加热的热驱动布局提供了见解。