Photolithography is the bottleneck for quality improvement in semiconductor manufacturing processes. The decreasing critical dimensions of the semiconductor product requires more effective run-to-run control technology. Currently, Exponential Weighted Moving Average (EWMA) control scheme is widely used in the overlay control of lithography processes. In this article, we address three shortcomings of the current EWMA run-to-run control scheme: (i) the weight parameter $\lambda $ used in the EWMA control scheme is set as a fixed value instead of adjusted adaptively according to the process changes; (ii) the conventional EWMA control scheme fails to take the model and parameter uncertainties into consideration; and (iii) the adjustable range of the control variables is not considered in the conventional EWMA control scheme. To meet tighter overlay specifications, we propose a new adaptive run-to-run control scheme to address these three limitations. The effectiveness of the new controller is validated through simulation studies.

中文翻译：

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用于光刻工艺的自适应谨慎正则化运行间控制器

光刻是半导体制造工艺质量提升的瓶颈。半导体产品的临界尺寸不断减小，需要更有效的连续运行控制技术。目前，指数加权移动平均（EWMA）控制方案广泛用于光刻工艺的叠加控制。在本文中，我们解决了当前 EWMA 逐次运行控制方案的三个缺点：(i) 权重参数 $\lambda $ EWMA控制方案中使用的设置为固定值，而不是根据工艺变化自适应调整；(ii) 常规 EWMA 控制方案没有考虑模型和参数的不确定性；(iii) 在传统的 EWMA 控制方案中没有考虑控制变量的可调范围。为了满足更严格的覆盖规范，我们提出了一种新的自适应运行到运行控制方案来解决这三个限制。通过仿真研究验证了新控制器的有效性。