International Business Machines Corporation

James E Currie

Adam D Ticknor

Ronald N Schulz

Ahmet Bindal

A wafer polishing fixture is disclosed containing a first liquid film confined by a non-porous but flexible enclosure for distributing evenly the applied polishing forces across the surface of a wafer supported by the confined liquid. The fixture comprises a flexible, non-porous template with a pocket for receiving a wafer to be polished. A washer is placed between a carrier and the template pocket. A film of water fills the bottom of the pocket and is confined with the aid of the washer and by an overlying porous pad extending across the pocket and having a non-porous sheath facing the liquid. A second liquid film saturates and covers the upper surface of the pad. The wafer to be polished floats upon the second liquid film within the pocket.

Confined water fixture for holding wafers undergoing chemical-mechanical

A method of forming a SOI integrated circuit includes defining thin silicon mesas by wet etching a device layer having the &lt;100&gt; orientation down to the underlying insulator so that the (111) crystal planes control the lateral etching, forming a nitride bottom polish stop in the bottom of the apertures by a low temperature CVD process, with nitride sidewalls on the (111) planes of the silicon mesas being susceptible to easy removal, so that no hard material is present during a chemical-mechanical polishing step to thin the device layer down to less than 1000 .ANG., and filling the apertures with a temporary layer of polysilicon to provide mechanical support to the edges of the device layer during the polishing operation.

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Washington, NY, United States of America

James E Currie