Kla Tencor Corporation

Michael J Wright

David Alles

Daniel L Belin

Robert W Walsh

Daniel C Wack

Pradeep Subrahmanyan

Weston L Sousa

Zhengcheng Lin

Wilfred L Ghonsalves

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

Methods and apparatus relating to the inspection of photomasks are described. In an embodiment, an inspection tool may be automatically focused on a reticle utilizing various topographic mapping techniques. Other embodiments are also described.

Auto focus system for reticle inspection

A method for synchronizing sample stage motion with a time delay integration (TDI) charge-couple device (CCD) in a semiconductor inspection tool, including: measuring a lateral position of a stage holding a sample being inspected; measuring a vertical position of the stage; determining a corrected lateral position of an imaged pixel of the sample based on the measured lateral and vertical positions; and synchronizing charge transfer of the TDI CCD with the corrected lateral position of the imaged pixel.

Apparatus and method for synchronizing sample stage motion with a time delay integration charge-couple device in a semiconductor inspection tool

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San Carlos, CA, United States of America

Michael J Wright