International Business Machines Corporation

Stuart D Cheney

Eric Jeffrey White

Gary L Milo

Paul A Manfredi

Yutong Wu

Scott R Cline

Kenneth A Bandy

Charles A McKinney

Kent R Becker

Harman S Garvatt

David P Bachand

The present invention comprises a chemical mechanical polishing tool comprising a polishing platen and a removable, replaceable platen top mounted on a top surface of the platen. Preferably, the platen top comprises a material substantially impervious to the slurries used when planarizing an object. Most preferably, the platen top comprises aluminum alloy or glass. The platen top may be tailored to provide enhanced polishing conditions by acting as an insulator, a conductor or machined to be concave or convex. The invention may further include endpoint sensors attached to the platen top.

Removable/disposable platen top

The present invention is intended for use on BiCMOS technology where the BJTs are formed after the FETs. A thin FET protection layer is deposited on the raised and recessed regions of the semiconductor substrate A selectively removable filler layer is then deposited on the FET protection layer with a thickness to over-fill the recessed regions of the gates of the FETs. The selectively removable filler layer is then planarized until the FET protection layer on top of the gates is exposed. The recessed regions between the gates are left substantially filled with selectively removable filler layer The selectively removable filler layer in the region where the BJT is formed is patterned and an opening is made to allow for the depositing of layers of different materials used in the construction of the BJT. The layer of different materials are processed by methods known in the art to form polysilicon emitter of the BJT. Due to selectively removable filler layer creating a substantially planar surface in the recessed regions of the FETs, little to none of the layers of different materials that are used in the construction of the BJT are deposited within the recessed regions Thus, removal of the layers of different materials ( &prime;), from the FET region is simplified. After removal of the layers of different materials ( &prime;), from the FET region, the selectively removable filler layer is removed selectively to the FET protection layer The FET protection layer is then removed. The recessed regions between the gates of the FETs are free from residual films.

Selectively removable filler layer for BiCMOS process

In a chemical mechanical polishing process for planarization of semiconductor wafers, a pair of opposed grippers are used to move the wafer from one station to another. During this movement, the wafer is rotated and brushes along the periphery are placed in contact with the edge of the wafer to remove foreign material and residue which builds up along the edge of the wafer. Cleaning fluid may be introduced to flush away and/or breakup the residue buildup.

Wafer edge cleaning

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Essex Junction, VT, United States of America

Stuart D Cheney