Patent US4522656A successfully refreshed from Google Patents.
US4522656A
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US
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Method of making reference surface markings on semiconductor wafers by laser beam
Assignee: Lumonics Corp
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Filing: 1984-04-26
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Granted: 1985-06-11
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Expires: 2004-04-26
Abstract
Abstract A method for producing contrast rich, permanent and slag-free characterizations, particularly on polished semiconductor disks is described, in which the surface for generating the surface pattern is partially melted by laser radiation. According to the invention, a surface segment corresponding to 1.5 to 6.5 times the surface area of the desired surface pattern is irradiated, and the semiconductor material is caused to melt and partially vaporize only in the center thereof.
Inventors
- 👤 Franz Kuhn-Kuhnenfeld
- 👤 Josef Kramler
- 👤 Hans-Adolf Gerber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:54
CPC Classifications
H; H10; H10W; H10W46/00; B; B41; B41M; B41M5/00; B41M5/24; B44; B44C; B44C1/00; B44C1/02; H10P; H10P34/00; H10P34/40; H10P34/42; H10W46/101; H10W46/103; H10W46/201; Y; Y10; Y10S; Y10S438/00; Y10S438/94
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
111 words
In a method for the characterization of semiconductor surfaces by means of surface patterns, which are each generated by melting and partial vaporization of a surface segment by means of a laser pulse, the improvement comprising the steps of: irradiating by means of a laser pulse a surface segment of the semiconductor surface whose surface area corresponds to 1.5 to 6.5 times the surface area of the desired surface pattern; and adjusting the energy of the laser pulse so that melting and partial vaporization of the semiconductor material takes place only in the center of said surface segment on a surface of the semiconductor material corresponding to the desired surface pattern.
Claim 2
Dependent Claim
111 words
In a method for the characterization of semiconductor surfaces by means of surface patterns, which are each generated by melting and partial vaporization of a surface segment by means of a laser pulse, the improvement comprising the steps of: irradiating by means of a laser pulse a surface segment of the semiconductor surface whose surface area corresponds to 1.5 to 6.5 times the surface area of the desired surface pattern; and adjusting the energy of the laser pulse so that melting and partial vaporization of the semiconductor material takes place only in the center of said surface segment on a surface of the semiconductor material corresponding to the desired surface pattern.
Claim 3
Dependent Claim
24 words
The method of claim 1, wherein the irradiated semiconductor surfaces having an average roughness value, according to DIN 4768, of at most 0.4 μm.
Claim 4
Dependent Claim
31 words
The method of claim 1 wherein said irradiating and adjusting steps result in the generation of circular recesses as said surface patterns having a diameter ranging from 50 to 150 μm.
Claim 5
Dependent Claim
25 words
The method of claim 1, wherein said circular recesses each have, relative to the original semiconductor surface, a raised annular rim and a recessed center.
Claim 6
Dependent Claim
27 words
The method of claim 1, wherein said surface segment of said semiconductor material is melted and partially vaporized to a depth of from 1 to 5 μm.
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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) | 1988-06-10 | 1988-12-10 | 1989-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-10 | 1992-12-10 | 1993-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-10 | 1996-12-10 | 1997-06-11 | $7700.00 | Window Closed / Lapsed |