Kla Tencor Corporation

Kla Corporation

Zhengcheng Lin

Rui-Fang Shi

Weston L Sousa

Zefram Marks

Michael J Wright

Daniel L Belin

Dmitry Skvortsov

Wilfred L Ghonsalves

Zhengyu Guo

Nicolas Steven Juliano

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.

Integration of an optical height sensor in mask inspection tools

Disclosed are methods and apparatus for detecting defects in a semiconductor sample having a plurality of identically designed areas. An inspection tool is used to construct an initial focus trajectory for a first swath of the sample. The inspection tool is then used to scan the first swath by following the initial focus trajectory for the first swath while collecting autofocus data. A z offset measurement vector for each identically designed area in the first swath is generated based on the autofocus data. A corrected z offset vector is constructed for inspection of the first swath with the inspection tool. Constructing the corrected z offset vector is based on combining the z offset measurement vectors for two or more of the identically designed areas in the first swath so that the corrected z offset vector specifies a same z offset for each set of same positions in the two or more identically designed areas.

Auto-focus system and methods for die-to-die inspection

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San Jose, CA, United States of America

Zhengcheng Lin