公开(公告)号：US20220196572A1

公开(公告)日：2022-06-23

申请号：US17352361

申请日：2021-06-21

Applicant: KLA Corporation

Inventor： Zefram Marks ,  Dmitry Skvortsov ,  Zhengyu Guo ,  Zhengcheng Lin ,  Nicolas Steven Juliano ,  Rui-Fang Shi

IPC: G01N21/956 ,  G01N21/45 ,  G01B11/06

Abstract: A photomask-inspection system includes a vacuum chamber and a stage, disposed in the vacuum chamber, to support a photomask and to translate the photomask horizontally and vertically. The system also includes an EUV objective, disposed in the vacuum chamber, to collect EUV light from the photomask to inspect the photomask for defects and an optical height sensor, at least partially disposed in the vacuum chamber, to measure heights on a surface of the photomask. The system further includes a stage controller to translate the stage horizontally and vertically in accordance with a focal map for the photomask produced using the measured heights on the surface of the photomask.