Memc Electronic Materials, Inc.

Plasmasil, LLC

AnKur Desai

Roland R Vandamme

Milind S Kulkarni

Dale A Witte

Yun-Biao Xin

A method of processing a semiconductor wafer sliced from a single-crystal ingot and having front and back surfaces and a peripheral edge comprises the step of plasma jet etching the wafer to reduce the sub-surface wafer damage. The method further comprises high-gloss etching the wafer by subjecting the wafer to a high-gloss etchant that smooths the wafer such that surface roughness and nonspecularly reflected light are reduced. Plasma assisted chemical etching (PACE) is performed on the wafer to improve the flatness and the thickness uniformity of the wafer. The wafer is final polished to further reduce surface roughness and nonspecularly reflected light.

Silicon wafering process flow

A process for reducing the waviness of a semiconductor wafer utilizing plasma assisted chemical etching is disclosed. The process includes measuring the surface profile at discrete points on one surface of the wafer independent from the apposing surface, computing a dwell time versus position map based on the measured surface profiles, and selectively removing material from each surface of the wafer by plasma assisted chemical etching to reduce the waviness of the wafer.

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St. Peters, MO, United States of America

AnKur Desai