Quantitative characterization of absorber and phase defects on EUV reticles using coherent diffraction imaging
Quantitative characterization of absorber and phase defects on EUV reticles using coherent diffraction imaging
复制标题
使用相干衍射成像对 EUV 掩模版上的吸收体和相位缺陷进行定量表征
DOI：
10.1117/1.jmm.19.1.014002
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Y. Ekinci
中科院分区：
文献类型：
--
作者：
I. Mochi;Sara Fernández;R. Nebling;U. Locans;R. Rajeev;A. Dejkameh;D. Kazazis;L. Tseng;S. Danylyuk;L. Juschkin;Y. Ekinci
摘要。背景：可靠的光掩膜计量是降低半导体制造过程中良率损失风险以及吸收材料研究的必要条件。用传统的方法检测EUV光斑是一个具有挑战性的问题。为此，我们开发了RESCAN，一个基于相干衍射成像的API平台。目的：验证该平台对吸收剂和相缺陷的灵敏度。方法：我们设计并制造了两个具有吸收器和相位缺陷的EUV掩模样品，并使用RESCAN在模到数据库模式下对其进行了检测。结果：我们重建了一个阵列的程序吸收缺陷的图像，我们创建了我们的样品缺陷图。我们检测了两个具有3.5和7.8 nm高度的埋藏结构的程序化相缺陷样品。结论：我们验证了RESCAN，在其当前配置下，可以检测随机模式的吸收器缺陷和埋藏（相位）缺陷，小至50 × 50 nm2。
Abstract. Background: Reliable photomask metrology is required to reduce the risk of yield loss in the semiconductor manufacturing process as well as for the research on absorber materials. Actinic pattern inspection (API) of EUV reticles is a challenging problem to tackle with a conventional approach. For this reason, we developed RESCAN, an API platform based on coherent diffraction imaging. Aim: We want to verify the sensitivity of our platform to absorber and phase defects. Approach: We designed and manufactured two EUV mask samples with absorber and phase defects, and we inspected them with RESCAN in die-to-database mode. Results: We reconstructed an image of an array of programmed absorber defects, and we created a defect map of our sample. We inspected two programmed phase defect samples with buried structures of 3.5 and 7.8 nm height. Conclusions: We verified that RESCAN, in its current configuration, can detect absorber defects in random patterns and buried (phase) defects down to 50 × 50 nm2.