US5310455A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Techniques for assembling polishing pads for chemi-mechanical polishing of silicon wafers
Assignee: LSI Corp
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Filing: 1992-07-10
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Granted: 1994-05-10
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Expires: 2012-07-10
Abstract
Abstract A technique for mounting polishing pads to a platen in chemi-mechanical semiconductor wafer polishing apparatus is disclosed. A lower pad is mounted to the platen, and is trimmed to the size of the platen. An upper pad is mounted to the lower pad, and is sized so that an extreme outer edge portion of the upper pad extends beyond the trimmed outer edge of the lower pad. The outer edge portion of the upper pad is deformed downwardly, towards the lower pad. In this manner, polishing slurry is diverted from the pad-to-pad interface. Additionally, an integral annular lip can be formed on the front face of the upper pad, creating a reservoir for slurry to be retained on the face of the upper pad for enhancing residence time of the polishing slurry prior to the slurry washing over the face of the upper pad.
Inventors
- 👤 Nicholas F. Pasch
- 👤 Thomas G. Mallon
- 👤 Mark A. Franklin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:31
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/11; B24B37/20; B24B37/22; Y; Y10; Y10S; Y10S438/00; Y10S438/959; Y10S451/00; Y10S451/921; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1026; Y10T156/1034; Y10T156/1052
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
148 words
Method of assembling polishing pads to the platen of apparatus for chemi-mechanical polishing of semiconductor wafers, comprising: assembling a first planar polishing pad to a platen of a chemi-mechanical polisher, the platen having an outer edge and a diameter "d"; trimming the first polishing pad so that an outer edge of the first polishing pad is coincident with the outer edge of the platen; assembling a second polishing pad, having a front face for polishing a wafer, to the first polishing pad, the second polishing pad having a diameter "D" greater than the diameter "d" of the platen, so that an edge portion region of the second polishing pad extends beyond the periphery of the first polishing pad about the entire circumference of the first polishing pad, the front face of the second polishing pad being exposed after assembling to the first polishing pad for polishing the wafer.
Claim 2
Dependent Claim
148 words
Method of assembling polishing pads to the platen of apparatus for chemi-mechanical polishing of semiconductor wafers, comprising: assembling a first planar polishing pad to a platen of a chemi-mechanical polisher, the platen having an outer edge and a diameter "d"; trimming the first polishing pad so that an outer edge of the first polishing pad is coincident with the outer edge of the platen; assembling a second polishing pad, having a front face for polishing a wafer, to the first polishing pad, the second polishing pad having a diameter "D" greater than the diameter "d" of the platen, so that an edge portion region of the second polishing pad extends beyond the periphery of the first polishing pad about the entire circumference of the first polishing pad, the front face of the second polishing pad being exposed after assembling to the first polishing pad for polishing the wafer.
Claim 3
Dependent Claim
50 words
Method according to claim 1, wherein: the first polishing pad has a diameter greater than the diameter "d" of the platen, prior to trimming; and further comprising: trimming the first polishing pad so that a circumferential edge of the first polishing pad is coincident with the edge of the platen.
Claim 4
Dependent Claim
41 words
Method according to claim 1, further comprising: bending the extending edge portion of the second polishing pad downward in the direction of the first polishing pad; wherein: during and after bending the second polishing pad, the first polishing pad remains planar.
Claim 5
Dependent Claim
27 words
Method according to claim 3, further comprising: applying a holding force to the front face of the second polishing pad while bending the extending edge portion downwards.
Claim 6
Dependent Claim
26 words
Method according to claim 3, further comprising: bending the extending edge portion of the second polishing pad downward sufficiently to entirely overhang the first polishing pad.
Claim 7
Dependent Claim
35 words
Method according to claim 5, wherein: the first polishing pad had a thickness "t"; the extending edge portion of the second polishing pad extends a distance 2πt/4 beyond the edge of the first polishing pad.
Claim 8
Dependent Claim
46 words
Method according to claim 3, further comprising: while bending the extending edge portion of the second polishing pad downward, causing an annular lip to be formed on the exposed front face of the second polishing pad, said annular lip formed integral with the second polishing pad.
Claim 9
Dependent Claim
27 words
Method according to claim 7, further comprising: applying a holding force to the front face of the second polishing pad while bending the extending edge portion downwards.
Claim 10
Dependent Claim
30 words
Method according to claim 7, wherein: a void is created under the annular lip, between the first and second polishing pads; and further comprising: filling the void with silicon caulk.
References Cited (Backward Citations)
US2768483A
Cited
US3653857A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-05-09 | 1997-11-08 | 1998-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-09 | 2001-11-08 | 2002-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-09 | 2005-11-08 | 2006-05-10 | $7700.00 | Window Closed / Lapsed |