US5234867A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for planarizing semiconductor wafers with a non-circular polishing pad
Assignee: Micron Technology Inc
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Filing: 1992-05-27
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Granted: 1993-08-10
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Expires: 2012-05-27
Abstract
Abstract An apparatus for planarizing semiconductor wafers in its preferred form includes a rotatable platen for polishing a surface of the semiconductor wafer and a motor for rotating the platen. A non-circular pad is mounted atop the platen to engage and polish the surface of the semiconductor wafer. A polishing head holds the surface of the semiconductor wafer in juxtaposition relative to the non-circular pad. A polishing head displacement mechanism moves the polishing head and semiconductor wafer across and past a peripheral edge of the non-circular pad to effectuate a uniform polish of the semiconductor wafer surface. Also disclosed is a method for planarizing a semiconductor surface using a non-circular polishing pad.
Inventors
- 👤 Laurence D. Schultz
- 👤 Mark E. Tuttle
- 👤 Trung T. Doan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:34
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/04; B24B37/11; B24B37/20; B24B37/26; B24B7/00; B24B7/20; B24B7/22; B24B7/228; B24D; B24D11/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
64 words
A process for planarizing semiconductor wafers comprising the steps of: rotating a non-circular pad having a non-circular peripheral edge; holding a surface of a semiconductor wafer in juxtaposition relative to the non-circular pad; rotating the wafer and moving the wafer across the non-circular pad; and moving at least a portion of the wafer to a location beyond the peripheral edge of the non-circular pad.
Claim 2
Dependent Claim
64 words
A process for planarizing semiconductor wafers comprising the steps of: rotating a non-circular pad having a non-circular peripheral edge; holding a surface of a semiconductor wafer in juxtaposition relative to the non-circular pad; rotating the wafer and moving the wafer across the non-circular pad; and moving at least a portion of the wafer to a location beyond the peripheral edge of the non-circular pad.
Claim 3
Dependent Claim
101 words
A process for planarizing semiconductor wafers comprising the steps of: rotating a platen about a center axis, the platen having a non-circular pad mounted thereon, the non-circular pad having a non-circular peripheral edge; holding a surface of a semiconductor wafer in juxtaposition relative to the non-circular pad; rotating the wafer about a wafer center and moving the wafer across the non-circular pad; and maintaining the wafer center within a circumscribed boundary around the non-circular pad, the boundary being defined by a circle about the center axis and tangential to an outermost portion of the non-circular peripheral edge of the non-circular pad.
Claim 4
Dependent Claim
101 words
A process for planarizing semiconductor wafers comprising the steps of: rotating a platen about a center axis, the platen having a non-circular pad mounted thereon, the non-circular pad having a non-circular peripheral edge; holding a surface of a semiconductor wafer in juxtaposition relative to the non-circular pad; rotating the wafer about a wafer center and moving the wafer across the non-circular pad; and maintaining the wafer center within a circumscribed boundary around the non-circular pad, the boundary being defined by a circle about the center axis and tangential to an outermost portion of the non-circular peripheral edge of the non-circular pad.
Claim 5
Dependent Claim
115 words
A process for planarizing semiconductor wafers comprising the steps of: rotating a platen at a preselected velocity about a center axis, the platen having a non-circular pad mounted thereon, the non-circular pad having a non-circular peripheral edge; rotating a semiconductor wafer about a wafer center in the same direction that the platen is rotating; holding a surface of the semiconductor wafer in juxtaposition relative to the non-circular pad to polish the surface of the semiconductor wafer; moving the wafer across the non-circular pad; and moving at least a portion of the wafer to a location beyond the peripheral edge of the non-circular pad to facilitate a uniform polish of the surface of the semiconductor wafer.
Claim 6
Dependent Claim
115 words
A process for planarizing semiconductor wafers comprising the steps of: rotating a platen at a preselected velocity about a center axis, the platen having a non-circular pad mounted thereon, the non-circular pad having a non-circular peripheral edge; rotating a semiconductor wafer about a wafer center in the same direction that the platen is rotating; holding a surface of the semiconductor wafer in juxtaposition relative to the non-circular pad to polish the surface of the semiconductor wafer; moving the wafer across the non-circular pad; and moving at least a portion of the wafer to a location beyond the peripheral edge of the non-circular pad to facilitate a uniform polish of the surface of the semiconductor wafer.
Claim 7
Dependent Claim
46 words
A process according to claim 3 further comprising maintaining the wafer center within a circumscribed boundary around the non-circular pad, the boundary being defined by a circle about the center axis and tangential to an outermost portion of the non-circular peripheral edge of the non-circular pad.
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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) | 1996-08-09 | 1997-02-08 | 1997-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-09 | 2001-02-08 | 2001-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-09 | 2005-02-08 | 2005-08-10 | $7700.00 | Window Closed / Lapsed |