US5435772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of polishing a semiconductor substrate
Assignee: Motorola Solutions Inc
•
Filing: 1993-04-30
•
Granted: 1995-07-25
•
Expires: 2013-04-30
Abstract
Abstract The present invention includes a polishing pad to improve polishing uniformity across a semiconductor substrate and a method using the polishing pad. The polishing pad has a first region that is closer to the edge of the polishing pad and a second region adjacent to the first region and further from the edge of the polishing pad. The polishing pad is configured, so that the second region is thicker or less compressible compared to the first region. The polishing pad should not require significantly changing any of the equipment. Oscillating range and possibly polishing pressure may need to be changed when one of the polishing pads of the present invention is used. Other operational parameters are not expected to be substantially different from a conventional polishing pad, although slight optimization of the other operating parameters may be needed.
Inventors
- 👤 Chris C. Yu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:53
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/11; B24B37/20; B24B37/22; B24B37/24; Y; Y10; Y10S; Y10S451/00; Y10S451/921
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
168 words
A method of polishing a semiconductor substrate having a center point, an edge point, and a primary surface having a primary surface dimension, wherein the method comprises the steps of: placing the semiconductor substrate in a polisher; and polishing the semiconductor substrate with a polishing pad, wherein: the polishing pad includes: an edge; a first region that has a first thickness and is adjacent to the edge; a second region that has a second thickness, wherein: the second region is adjacent to the first region, the second region is further from the edge compared to the first region; and the second thickness is thicker than the first thickness; the steps of polishing further comprising: rotating the polishing pad; and rotating the substrate about its center point so that portions of the substrate come into contact with both the first and second regions of the pad while the center point of the substrate overlies the second region of the polishing pad to improve the polishing uniformity across the substrate.
Claim 2
Independent Claim
168 words
A method of polishing a semiconductor substrate having a center point, an edge point, and a primary surface having a primary surface dimension, wherein the method comprises the steps of: placing the semiconductor substrate in a polisher; and polishing the semiconductor substrate with a polishing pad, wherein: the polishing pad includes: an edge; a first region that has a first thickness and is adjacent to the edge; a second region that has a second thickness, wherein: the second region is adjacent to the first region, the second region is further from the edge compared to the first region; and the second thickness is thicker than the first thickness; the steps of polishing further comprising: rotating the polishing pad; and rotating the substrate about its center point so that portions of the substrate come into contact with both the first and second regions of the pad while the center point of the substrate overlies the second region of the polishing pad to improve the polishing uniformity across the substrate.
Claim 3
Dependent Claim
62 words
The method of claim 1, wherein the polishing step includes oscillating the semiconductor substrate across a portion of the polishing pad, wherein the oscillating: covers an oscillating range that is a distance in a range of about 5-50 percent of the primary surface dimension; and is performed at an oscillating velocity that is in a range of about 1-10 millimeters per second.
Claim 4
Dependent Claim
25 words
The method of claim 1, wherein the polishing step is performed using a polishing pressure in a range of about 7.5-12.0 pounds per square inch.
Claim 5
Independent Claim
163 words
A method of polishing a semiconductor substrate having a center point, an edge point, and a primary surface having a primary surface dimension, wherein the method comprises the steps of: placing the semiconductor substrate in a polisher; and polishing the semiconductor substrate with a polishing pad, wherein: the polishing pad includes: an edge; a first region having a first compressibility and that is adjacent to the edge; a second region: that is adjacent to the first region; that is further from the edge compared to the first region; and has a second compressibility, wherein the second compressibility is less than the first compressibility; the steps of polishing further comprising: rotating the polishing pad; and rotating the substrate about its center point so that portions of the substrate come into contact with both the first and second regions of the pad while the center point of the substrate overlies the second region of the polishing pad to improve the polishing uniformity across the substrate.
Claim 6
Independent Claim
163 words
A method of polishing a semiconductor substrate having a center point, an edge point, and a primary surface having a primary surface dimension, wherein the method comprises the steps of: placing the semiconductor substrate in a polisher; and polishing the semiconductor substrate with a polishing pad, wherein: the polishing pad includes: an edge; a first region having a first compressibility and that is adjacent to the edge; a second region: that is adjacent to the first region; that is further from the edge compared to the first region; and has a second compressibility, wherein the second compressibility is less than the first compressibility; the steps of polishing further comprising: rotating the polishing pad; and rotating the substrate about its center point so that portions of the substrate come into contact with both the first and second regions of the pad while the center point of the substrate overlies the second region of the polishing pad to improve the polishing uniformity across the substrate.
Claim 7
Dependent Claim
62 words
The method of claim 4, wherein the polishing step includes oscillating the semiconductor substrate across a portion of the polishing pad, wherein the oscillating: covers an oscillating range that is a distance in a range of about 5-50 percent of the primary surface dimension; and is performed at an oscillating velocity that is in a range of about 1-10 millimeters per second.
Claim 8
Dependent Claim
25 words
The method of claim 4, wherein the polishing step is performed using a polishing pressure in a range of about 7.5-12.0 pounds per square inch.
References Cited (Backward Citations)
US3857123A
Cited
US4313284A
Cited
US4511605A
Cited
US4450652A
Cited
US4613345A
Cited
US4927432A
Cited
US4841680A
Cited
US5020283A
Cited
US5036630A
Cited
US5081051A
Cited
US5173441A
Cited
US5216843A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-07-24 | 1999-01-23 | 1999-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-24 | 2003-01-23 | 2003-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-24 | 2007-01-23 | 2007-07-25 | $7700.00 | Window Closed / Lapsed |