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Patent US4415794A successfully refreshed from Google Patents.
US4415794A
Expired / Lapsed
US
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Laser scanning method for annealing, glass flow and related processes
Assignee: National Semiconductor Corp
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Filing: 1981-03-16
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Granted: 1983-11-15
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Expires: 2001-03-16
Abstract
Abstract A method for scanning the top surface of a semiconductor wafer prevents damage to the wafer (11) by ensuring that the laser beam (13) does not cross over the edge (11a) of the wafer during the scanning process nor approach within one (1) to two (2) millimeters to the edge of the wafer.
Inventors
- 👤 Michelangelo Delfino
- 👤 Timothy Reifsteck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:56
CPC Classifications
H; H10; H10P; H10P34/00; H10P34/40; H10P34/42; H10P95/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
52 words
The method of laser scanning a semiconductor wafer which comprises the steps of: directing the beam from the laser across the top surface of the wafer in a selected pattern while at the same time preventing the laser beam from coming within a selected distance, d, of the edge of the wafer.
Claim 2
Independent Claim
52 words
The method of laser scanning a semiconductor wafer which comprises the steps of: directing the beam from the laser across the top surface of the wafer in a selected pattern while at the same time preventing the laser beam from coming within a selected distance, d, of the edge of the wafer.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein d is about one (1) millimeter.
Claim 4
Dependent Claim
34 words
The method of claim 1 wherein said laser beam covers the top surface of the wafer but comes no closer than about one (1) to two (2) millimeters to the edge of the wafer.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein said laser beam is prevented from coming closer than about one and a half millimeters from the edge of the wafer.
Claim 6
Dependent Claim
13 words
The product produced by the method of claim 1, 2, 3 or 4.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-11-14 | 1987-05-16 | 1987-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-14 | 1991-05-16 | 1991-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-14 | 1995-05-16 | 1995-11-15 | $7700.00 | Window Closed / Lapsed |