Kla-Tencor Technologies Corporation

Advanced Ion Beam Technology, Inc.

Gongyuan Qu

Amir Azordegan

Gian Francesco Lorusso

Hedong Yang

Peter Mok

Jason Hong

Steven Fong

Terry Sheng

A method and an apparatus for dechucking an electrostatic chuck are disclosed. The gas escapes through an opening between a wafer and a chuck in each stage of a multi-stages process. In each stage, during at least a portion of the stage, the chucking voltage is reduced to a value less than the least threshold voltage needed for holding the wafer, so that the wafer is pushed away from the chuck by the gas. Hence, the gas can escape from an opening between the wafer and the chuck, thereby increasing the dechucking rate. By controlling the decrement and/or the duration of the reduced voltage, any potential damages due to the pushed-away wafer can be minimized.

Step down dechucking

One embodiment relates to a method of automated microalignment using off-axis beam tilting. Image data is collected from a region of interest on a substrate at multiple beam tilts. Potential edges of a feature to be identified in the region are determined, and computational analysis of edge-related data is performed to positively identify the feature(s). Another embodiment relates to a method of automated detection of undercut on a feature using off-axis beam tilting. For each beam tilt, a determination is made of difference data between the edge measurement of one side and the edge measurement of the other side. An undercut on the feature is detected from the difference data. Other embodiments are also disclosed.

Automated feature analysis with off-axis tilting

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San Jose, CA, United States of America

Gongyuan Qu