Wafer polishing method and apparatus

Abstract

A wafer polishing apparatus includes a wafer polishing assembly having a plurality of wafer carriers for substantially simultaneously polishing a plurality of wafers against a rotating polishing surface. A plurality of wafers to be polished are substantially simultaneously loaded into the plurality of wafer carriers by wafer holding apparatus of an index table. Similarly, a plurality of wafer carriers are substantially simultaneously unloaded into wafer holding apparatus of the index table. The wafer carriers are individually computer controlled for exact polishing and different polishing requirements can be met at the same time by different wafer carriers.

Description

BACKGROUND OF THE INVENTIONThis invention relates to polishing methods and apparatus and more particularly, to such methods and apparatus for accurately polishing wafers of semiconductor material with high throughput and in a manner compatible with semiconductor processing clean room environments.The production of integrated circuits begins with the creation of high quality semiconductor wafers. Each wafer is of relatively high cost due to the detailed processing needed to produce it. During the integrated circuit production process, an extremely flat surface is desired on at least one face of the wafer. Wafer polishing to achieve such a flat surface is a known technique.Such polishing generally includes attaching one side of the wafer to a flat surface of a wafer carrier or chuck and pressing the wafer against a flat polishing surface. The polishing surface is moved under the wafer, and the wafer may also be rotated about its vertical axis and oscillated back and forth to improve p...

AI Technical Summary

Benefits of technology

Wafer polishing apparatus in accordance with the present invention comprises a polishing assembly having a plurality of wafer carriers for substantially simultaneously engaging a plurality of wafers of material with a polishing surface. The apparatus includes an index table for holding wafers to be polished, and positioning apparatus to move the polishing assembly between the polishing surface and the index table. At the index table, all wafer carriers of the polishing assembly are substantially simultaneously loaded with wafers. After loading the carriers, the polishing assembly is positioned in polishing engagement with the polishing surface. By incorporating an index table into the apparatus, unpolished wafers can be loaded onto the index table in preparation for loading them simultaneously onto the wafer carriers, providing throughput advantages.

The alignment of polish assembly, index table and polishing surface is maintained by providing a stable framework in the apparatus. To this end, a linear track for moving the polishing assembly extends between the polishing surface and the index table. The linear track provides a stable, rugged frame while permitting controlled movement of the polishing assembly between the index table and the polishing surface.

Problems solved by technology

Each wafer is of relatively high cost due to the detailed processing needed to produce it.

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