US 5,398,459 AGranted

Method and apparatus for polishing a workpiece

AssigneesKabushiki Kaisha Toshiba, Ebara Corporation

InventorsKatsuya Okumura, Tohru Watanabe, Riichirou Aoki, Hiroyuki Yano, Masako Kodera, Atsushi Shigeta, You Ishii, Norio Kimura, Masayoshi Hirose, Yukio Ikeda

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Abstract

A workpiece such as a semiconductor wafer is positioned between a turntable and a top ring and polished by an abrasive cloth on the turntable while the top ring is being pressed against the turntable. The top ring has a retaining ring for preventing the workpiece from deviating from the lower surface of the top ring, and the retaining ring has an inside diameter larger than an outside diameter of the workpiece. The rotation of the turntable imparts a pressing force in a direction parallel to the upper surface of the turntable to the workpiece so that an outer periphery of the workpiece contacts an inner periphery of the retaining ring, and the rotation of the retaining ring imparts a rotational force to the workpiece so that the workpiece performs a planetary motion relative to the top ring in the retaining ring.

Claims15

Dependent claims

A polishing apparatus for polishing a surface of a workpiece having a substantially circular shape, comprising:

a turntable with an abrasive cloth mounted on an upper surface thereof;
a top ring positioned above said turntable for supporting the workpiece to be polished and pressing the workpiece against said abrasive cloth, said top ring having a planarized lower surface which contacts an upper surface of the workpiece which is a backside of the workpiece;
first actuating means for rotating said turntable;
second actuating means for rotating said top ring;
and
a retaining ring provided on said lower surface of said top ring for preventing the workpiece from deviating from said lower surface of said top ring, said retaining ring having an inside diameter larger than an outside diameter of the workpiece;
wherein the rotation of said turntable imparts a pressing force in a direction parallel to said upper surface of said turntable to the workpiece so that an outer periphery of the workpiece contacts an inner periphery of said retaining ring, and the rotation of said retaining ring imparts a rotational force to the workpiece so that the workpiece performs planetary motion relative to said top ring within said retaining ring.

4 more elements

A method of polishing a surface of a workpiece having a substantially circular shape, comprising the steps of:

positioning the workpiece between a turntable with an abrasive cloth mounted on an upper surface thereof and a top ring positioned above said turntable, said top ring having a planarized lower surface and a retaining ring provided on said lower surface, said retaining ring preventing the workpiece from deviating from said lower surface of said top ring, said retaining ring having an inside diameter larger than an outside diameter of the workpiece;
rotating said turntable and said top ring;
and
pressing the workpiece against said abrasive cloth by said top ring;
wherein the rotation of said turntable imparts a pressing force in a direction parallel to said upper surface of said turntable to the workpiece so that an outer periphery of the workpiece contacts an inner periphery of said retaining ring, and the rotation of said retaining ring imparts a rotational force to the workpiece so that the workpiece performs a planetary motion relative to said top ring within said retaining ring.

2 more elements

Dependencies are inferred from the claim text.