US5398459A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for polishing a workpiece
Assignee: Ebara Corp
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Filing: 1993-11-24
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Granted: 1995-03-21
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Expires: 2013-11-24
Abstract
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.
Inventors
- 👤 Katsuya Okumura
- 👤 Tohru Watanabe
- 👤 Riichirou Aoki
- 👤 Hiroyuki Yano
- 👤 Masako Kodera
- 👤 Atsushi Shigeta
- 👤 You Ishii
- 👤 Norio Kimura
- 👤 Masayoshi Hirose
- 👤 Yukio Ikeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:05
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/04; B24B37/07; B24B37/10; B24B37/102; B24B39/00; B24B37/27; B24B37/30
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
200 words
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.
Claim 2
Dependent Claim
200 words
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.
Claim 3
Dependent Claim
17 words
The polishing apparatus according to claim 1, wherein said retaining ring is made of a resin material.
Claim 4
Dependent Claim
42 words
The polishing apparatus according to claim 1, wherein said top ring has a plurality of suction holes connected to a vacuum source for holding the workpiece on said lower surface of said top ring under a vacuum developed by said vacuum source.
Claim 5
Dependent Claim
23 words
The polishing apparatus according to claim 1, wherein an abrasive slurry nozzle is provided to supply an abrasive slurry onto said abrasive cloth.
Claim 6
Dependent Claim
39 words
The polishing apparatus according to claim 1, wherein the clearance defined by the difference between said inside diameter of said retaining ring and said outside diameter of the workpiece is in the range of approximately 0.5 to 3 mm.
Claim 7
Dependent Claim
36 words
The polishing apparatus according to claim 1, wherein the workpiece comprises a semiconductor wafer having a substrate and a dielectric layer formed over said substrate, and a surface of the dielectric layer is planarized during polishing.
Claim 8
Dependent Claim
35 words
The polishing apparatus according to claim 1, wherein the workpiece comprises a semiconductor wafer having a substrate and a conductive layer formed over said substrate, a surface of the conductive layer is planarized during polishing.
Claim 9
Dependent Claim
33 words
The polishing apparatus according to claim 1, wherein said retaining ring has a tapered inner surface inclined radially inwardly in a downward direction thereof to lift an outer end portion of the workpiece.
Claim 10
Independent Claim
180 words
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.
Claim 11
Independent Claim
180 words
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.
Claim 12
Dependent Claim
60 words
The method of polishing a surface of workpiece according to claim 9, wherein when the outside diameter of the workpiece is D(mm), the difference between the inside diameter of said retaining ring and the outside diameter of the workpiece is d(mm), the rotational speed of said top ring r(r.p.m.) and polishing time t(sec) are selected so as to satisfy (d/D)·r·t≧60.
Claim 13
Dependent Claim
81 words
The method of polishing a surface of workpiece according to claim 9, further comprising the steps of: attracting the workpiece placed at a standby section to said lower surface of said top ring under a vacuum and moving said top ring to said turntable to position the workpiece on said abrasive cloth, said standby section being located adjacent to said table; and releasing the workpiece from said top ring so that said workpiece can be freely moved in said retaining ring.
Claim 14
Dependent Claim
50 words
The method of polishing a surface of workpiece according to claim 11, further comprising the steps of: attracting the workpiece on said abrasive cloth to said lower surface of said top ring under a vacuum after polishing; and moving said top ring to convey the workpiece to a next process.
Claim 15
Dependent Claim
41 words
The method of polishing a surface of workpiece according to claim 9, wherein the workpiece comprises a semiconductor wafer having a substrate and a dielectric layer formed over said substrate, and a surface of the dielectric layer is planarized during polishing.
Claim 16
Dependent Claim
41 words
The method of polishing a surface of workpiece according to claim 9, wherein the workpiece comprises a semiconductor wafer having a substrate and a conductive layer formed over said substrate, and a surface of the conductive layer is planarized during polishing.
Claim 17
Dependent Claim
38 words
The method of polishing a surface of workpiece according to claim 9, wherein said retaining ring has a tapered inner surface inclined radially inwardly in a downward direction thereof to lift an outer end portion of the workpiece.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-03-20 | 1998-09-19 | 1999-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-03-20 | 2002-09-19 | 2003-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-03-20 | 2006-09-19 | 2007-03-21 | $7700.00 | Window Closed / Lapsed |