Texas Instruments Corporation

Lisa A Lester

Lawrence D Dyer

Timothy J Hogan

Mike Brenner

Sean Christopher O'Brien

Joseph G Harden

A method of fabricating a monolithic device, preferably a micromechanical device, from a wafer (20) by carefully selecting the composition of two or more layers of photoresist (52,54). The present invention uses a superhard protective layer such as DLC or TiW deposited over the partially fabricated device prior to a partial-saw. This superhard protective layer reduces the generation of defects in the underlying photoresist layers, and allows a wet chemical HF acid to etch away particles and damage of the underlying oxide edges. A 6% BHF solution can be utilized. The present invention substantially improves the yield of micromechanical devices.

Method of reducing wafer particles after partial saw using a superhard

A method of fabricating a monolithic device, preferably a micromechanical device, from a wafer (20) by carefully selecting the composition of two or more layers of photoresist (52,54). The present invention comprises choosing compatible photoresist layers to avoid generating defects in the layers of photoresist which could allow a wet chemical HF acid etch process to damage an underlying micromechanical device. The present invention allows a very strong solution of hydrofluoric acid to be utilized to remove particles and debris after a partial-saw process, and to remove a damaged portion of an underlying CMOS layer (22) at a region (68) proximate a kerf (62). Using an HF solution having a concentration of about 6% is desired. The present invention substantially improves the yield of micromechanical devices.

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Richardson, TX, United States of America

Lisa A Lester