As extreme ultraviolet (EUV) lithography enters high volume manufacturing (HVM) to enable the sub-7nm scaling roadmap, characterizing and monitoring defects that print at wafer level are of critical importance to yield. This is especially true for defects coming from the EUV mask, due to multi-layer defects or added particles or growth on mask during its use, and for defects coming from the pattern formation process itself, which are known as stochastic printing defects or simply stochastic defects. In this paper we focus on developing inspection solutions for stochastic defects, which essentially are random local variations that occur between structures that should, in principle, print identically. These defects occur at significant frequencies with current state-of-the-art processes. Specifically, we discuss the importance of detecting these defects using KLA broadband plasma (BBP) optical inspection systems and the development of useful analysis methodologies. In addition, we describe use of traditional focus-dose process window discovery methodology developed on these optical inspection systems, for a foundry N5 equivalent M2 layer with both hybrid EUV and direct EUV patterning schemes. We highlight the impact of EUV stochastics to the overall process window.

中文翻译：

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使用用于极紫外 (EUV) 光刻的宽带等离子体光学系统检测随机缺陷

随着极紫外 (EUV) 光刻进入大批量制造 (HVM) 以实现亚 7 纳米缩放路线图，表征和监控晶圆级印刷缺陷对良率至关重要。对于来自 EUV 掩模的缺陷（由于使用过程中掩模上的多层缺陷或添加的颗粒或生长引起的缺陷，以及来自图案形成过程本身的缺陷（称为随机印刷缺陷或简称为随机））尤其如此缺陷。在本文中，我们专注于开发随机缺陷的检测解决方案，这些缺陷本质上是发生在结构之间的随机局部变化，原则上应该打印相同。这些缺陷在当前最先进的工艺中以显着的频率发生。具体来说，我们讨论了使用 KLA 宽带等离子体 (BBP) 光学检测系统检测这些缺陷的重要性以及开发有用的分析方法。此外，我们描述了在这些光学检测系统上开发的传统聚焦剂量工艺窗口发现方法的使用，用于具有混合 EUV 和直接 EUV 图案化方案的代工厂 N5 等效 M2 层。我们强调了 EUV 随机性对整个工艺窗口的影响。