EP0451471A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and apparatus for polishing a semiconductor wafer
Assignee: International Business Machines Corp
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Filing: 1991-02-23
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Granted: —
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Expires: 2011-02-23
Abstract
Abstract Disclosed is an improved method of polishing a semiconductor wafer (1), which involves mounting the wafer (1) to a wafer carrier (2) comprising at least two materials (12, 13) having different coefficients of thermal expansion and regulating the temperature of the carrier (2), to thereby impart a convex (or concave) bias to the wafer (1). This provides an increased polishing action at the wafer center (or edges), so as to compensate for otherwise non-uniform radial polishing action across the wafer surface. Also disclosed, is an apparatus which incorporates the unique wafer carrier (2) and temperature regulating means for achieving the desired degree of radial curvature of the wafer carrier (2).
Inventors
- 👤 Carter W. Kaanta
- 👤 Howard S. Landis
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 14:34
CPC Classifications
B; B24; B24B; B24B55/00; B24B55/02; B24B37/00; B24B37/005; B24B37/015; B24B37/27; B24B37/30
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
93 words
A method of polishing a surface on a workpiece, employing a polishing apparatus wherein said workpiece (1) is mounted to a carrier (2) and rotatably contacted with a plishing pad (9) to effect a polishing action across said workpiece (1), which method comprises mounting said workpiece (1) to a carrier (2) comprising at least two materials (12, 13) having different coefficients of thermal expansion, and regulating the temperature of said carrier (2) to control the radial curvature of said carrier, to impart a concave or convex bias to said workpiece (1) during polishing.
Claim 2
Dependent Claim
40 words
The method of claim 1, wherein said carrier (2) comprises a lower metal portion (13) which mounts said workpiece (1) and an upper metal portion (12), said lower metal portion comprising said material having the higher coefficient of thermal expansion.
Claim 3
Dependent Claim
25 words
The method of claim 2, wherein said lower metal portion (13) comprises a stainless steel and said upper metal portion (12) comprises a nickel-based alloy.
Claim 4
Independent Claim
42 words
The method of anyone of the claims 1 to 3, wherein the temperature of said carrier is regulated so as to impart a convex bias to said workpiece to increase the polishing action near the center of said workpiece (1) during polishing.
Claim 5
Independent Claim
18 words
The method of anyone of the claims 1 to 4, wherein said workpiece (1) is a semiconductor wafer.
Claim 6
Independent Claim
115 words
An apparatus for polishing a surface on a workpiece, comprising: a rotatable turntable assembly (7); a plishing pad (9) supported on said assembly; a rotatable carrier (2), located above said assembly (7) and adapted to hold a workpiece (1) during polishing, with said workpiece (1) positioned between said carrier (2) and said plishing pad (9), said carrier (2) comprising at least two materials (12, 13) having different coefficients of thermal expansion; and temperature regulating means (15, 16, 17) communicating with said carrier (2) for regulating the temperature of said carrier to control the radial curvature of said carrier, to impart a concave or convex bias to a workpiece (1) mounted to said carrier during polishing.
Claim 7
Dependent Claim
34 words
The apparatus of claim 6, wherein said temperature regulating means comprises a fluid chamber (15) within said carrier (2), and means (16, 17) for introducing and withdrawing fluid to and from said fluid chamber.
Claim 8
Dependent Claim
14 words
The apparatus of claim 7, wherein said fluid chamber is a serpentine channel (15).
Claim 9
Independent Claim
50 words
The apparatus of anyone of the claims 6 to 8, wherein said carrier (2) comprises a lower metal portion (13) which is adapted to mount a workpiece (1) being polished and an upper metal portion (12), said lower portion (13) comprising said material having the higher coefficient of thermal expansion.
Claim 10
Dependent Claim
25 words
The apparatus of claim 9, wherein said lower metal portion (13) comprises a stainless steel and said upper metal portion (12) comprises a nickel-based alloy.
References Cited (Backward Citations)
No citation records indexed.
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