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US4249960A
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Laser rounding a sharp semiconductor projection
Assignee: RCA Corp
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Filing: 1979-06-18
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Granted: 1981-02-10
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Expires: 1999-06-18
Abstract
Abstract A method of rounding a sharp semiconductor projection jutting out from a principal body of semiconductor material comprises the step of irradiating the projection with a laser pulse having an energy density of less than about 1.5 joules/cm 2 .
Inventors
- 👤 George L. Schnable
- 👤 Chung P. Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:38
CPC Classifications
H; H10; H10D; H10D86/00; H10D86/01; H10D86/03; H10P; H10P34/00; H10P34/40; H10P34/42; Y; Y10; Y10S; Y10S148/00; Y10S148/093; Y10S438/00; Y10S438/974; Y10S438/978
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
38 words
A method of rounding a sharp semiconductor projection on a principal body of semiconductor material comprising the step of irradiating said projection with a laser pulse having an energy density of less than about 1.5 joules/cm 2 .
Claim 2
Independent Claim
38 words
A method of rounding a sharp semiconductor projection on a principal body of semiconductor material comprising the step of irradiating said projection with a laser pulse having an energy density of less than about 1.5 joules/cm 2 .
Claim 3
Dependent Claim
25 words
A method as recited in claim 1 wherein said sharp semiconductor projection comprises a spike or hillock protruding from a surface of said semiconductor body.
Claim 4
Dependent Claim
25 words
A method as recited in claim 2 wherein said laser beam strikes said projection at an angle acute to the plane of said semiconductor surface.
Claim 5
Dependent Claim
21 words
A method as recited in claim 3 wherein said semiconductor surface comprises a surface of an epitaxially deposited layer of silicon.
Claim 6
Dependent Claim
26 words
A method as recited in claim 1 wherein said sharp semiconductor projection comprises an edge or corner of a semiconductor island disposed on an insulating substrate.
Claim 7
Dependent Claim
20 words
A method as recited in claim 5 wherein said semiconductor island comprises silicon and wherein said insulating substrate comprises sapphire.
Claim 8
Dependent Claim
24 words
A method as recited in claim 1 wherein said laser pulse has a pulse duration time of between about 10 and about 50 nanoseconds.
Claim 9
Dependent Claim
38 words
A method as recited in claim 7 wherein said laser is a Q-switched ruby laser having a pulse energy density of between about 0.2 and 0.8 joule/cm 2 , and a pulse duration time of about 30 nanoseconds.
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) | 1984-02-10 | 1984-08-11 | 1985-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-10 | 1988-08-11 | 1989-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-10 | 1992-08-11 | 1993-02-10 | $7700.00 | Window Closed / Lapsed |