US4313284A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for improving flatness of polished wafers
Assignee: SunEdison Inc
•
Filing: 1980-03-27
•
Granted: 1982-02-02
•
Expires: 2000-03-27
Abstract
Abstract Apparatus for improving polished wafer flatness such as slices of semiconductor materials through mounting of the wafers onto a deformable thin disc carrier which is mounted through a resilient device to a rotable pressure plate, the combined mounting being rotably engageable with a rotable turntable supported polishing surface, the turntable having an axis of rotation to edge bow away from the mounted wafers. The carrier is deformed to a concave shape opening toward the bowed table; thus permitting the mounted wafers to achieve through rotation polishing, uniformly improved flatness.
Inventors
- 👤 Robert J. Walsh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:12
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/27; B24B37/30; H; H10; H10F; H10F99/00; B24B37/005; B24B37/015; B24B55/00; B24B55/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
123 words
Apparatus for improving polished wafer flatness comprising: a thin deformable carrier disc mounted to a resilient ring which is mounted to a rotable pressure plate, said pressure plate, resilient ring, and first carrier surface forming a chamber, said chamber in communication with a vacuum means for deforming said carrier disc into an inwardly convex shape toward the chamber; said deformed carrier having wafers mounted on a second surface which is concave; said wafers rotably engageable with a polishing pad mounted turntable having an internal cooling means for disapating heat from the polishing pad and first surface of the turntable, the turntable second surface being cooler than the first surface during polishing resulting in a thermal bow of the turntable toward the second surface.
Claim 2
Dependent Claim
123 words
Apparatus for improving polished wafer flatness comprising: a thin deformable carrier disc mounted to a resilient ring which is mounted to a rotable pressure plate, said pressure plate, resilient ring, and first carrier surface forming a chamber, said chamber in communication with a vacuum means for deforming said carrier disc into an inwardly convex shape toward the chamber; said deformed carrier having wafers mounted on a second surface which is concave; said wafers rotably engageable with a polishing pad mounted turntable having an internal cooling means for disapating heat from the polishing pad and first surface of the turntable, the turntable second surface being cooler than the first surface during polishing resulting in a thermal bow of the turntable toward the second surface.
Claim 3
Dependent Claim
19 words
The apparatus according to claim 1 wherein the wafers are wax mounted to the concave surface of the carrier.
Claim 4
Dependent Claim
21 words
The apparatus according to claim 1 wherein the rotable turntable provides frictional drive rotation of the wafer mounted carrier, pressure plate.
Claim 5
Dependent Claim
18 words
Apparatus according to claim 1 wherein the wafers are rotated through an independent pressure plate rotation drive means.
Claim 6
Dependent Claim
31 words
Apparatus according to claim 1 wherein multiple pressure plate, carrier apparatus are engageable with the turntable, the multiple apparatus being engageable with the turntable in respective radius dimensions of the turntable.
References Cited (Backward Citations)
US2241478A
Cited
US3170273A
Cited
US3475867A
Cited
US3611654A
Cited
US3693301A
Cited
US3747282A
Cited
US3977130A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-02-01 | 1985-08-03 | 1986-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-01 | 1989-08-03 | 1990-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-01 | 1993-08-03 | 1994-02-02 | $7700.00 | Window Closed / Lapsed |