公开(公告)号：US20240353318A1

公开(公告)日：2024-10-24

申请号：US18419244

申请日：2024-01-22

Applicant: KLA Corporation

Inventor： Yun Xie ,  Rui-Fang Shi ,  Xin Ye ,  Heng Zhang

IPC: G01N21/21 ,  G01N21/956

CPC classification number: G01N21/21 ,  G01N21/956 ,  G01N2021/95676 ,  G01N2201/061 ,  G01N2201/0683

Abstract: Methods and systems for inspecting a photomask are provided. One system includes an illumination subsystem configured to direct light to the photomask. The system also includes a pupil filter positioned in a path of only the light from the photomask and configured for controlling a polarization of the light in the path by mixing four elements in a Jones matrix for the photomask in a coherent manner. In addition, the system includes a detector configured for detecting the light from the pupil filter and generating output responsive to the detected light. The system further includes a computer subsystem configured for detecting defects on the photomask based on the output.