This paper deals with the modeling and control of thermo-mechanical deformations of a wafer, resulting from absorbed exposure power, in EUV lithography. To achieve correction of the induced deformations, an active wafer clamp concept is proposed. In this concept, between 1,000 and 30,000 actuators are incorporated into the electrostatic wafer clamp, such that forces can be applied directly onto the wafer. Due to dimensionality of the control problem, a distributed feedforward control approach is proposed which acts locally around the exposure slit, and reduces the number of design inputs by approximately 80%. The results obtained with this controller show an average reduction of a factor 10, of the thermo-mechanical deformations at the edge of the wafer as well as more towards the center of the wafer.

中文翻译：

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使用有源晶片夹具控制 EUV 光刻中的热机械晶片变形

本文涉及在 EUV 光刻中对由吸收的曝光功率引起的晶片热机械变形的建模和控制。为了实现对诱发变形的校正，提出了主动晶片夹具概念。在这个概念中，静电晶片夹具中包含 1,000 到 30,000 个致动器，以便可以将力直接施加到晶片上。由于控制问题的维度，提出了一种分布式前馈控制方法，它在曝光狭缝周围局部起作用，并将设计输入的数量减少了大约 80%。使用该控制器获得的结果表明，晶片边缘处的热机械变形以及朝向晶片中心的热机械变形平均减少了 10 倍。