US4535220A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated circuits
Assignee: UK Secretary of State for Defence
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Filing: 1982-09-30
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Granted: 1985-08-13
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Expires: 2002-09-30
Abstract
Abstract An integrated circuit comprises a substrate having a plurality of components electrically isolated by regions of amorphous material formed by laser irradiation. Typically the laser radiation has a wavelength less than 400 nm a pulse length between 0.1 and 10 μsec, and a power density between 0.1 and 0.8 J/cm 2 . The substrate material may be Si, Ge, GaAs, GaAlAs, InAs, InP, InAlP.
Inventors
- 👤 Anthony G. Cullis
- 👤 Hugh C. Webber
- 👤 Nigel G. Chew
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:09
CPC Classifications
H; H10; H10P; H10P34/00; H10P34/40; H10P34/42; H10W; H10W10/00; H10W10/01
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
97 words
A method of providing electrical separation between electrical components on a single crystalline silicon substrate, the method comprising the steps of forming amorphous regions in the crystalline silicon substrate by selectively irradiating the silicon substrate with laser radiation of a wavelength less than 400 nanometers and a pulse length less than 10 nanoseconds so that most of the radiation is absorbed in the top 3,000 Å of the irradiated regions of the substrate which rapidly melts and rapidly freezes into an amorphous state, the amorphous regions forming electrically insulating regions adjacent single crystalline silicon regions of substrate.
Claim 2
Independent Claim
97 words
A method of providing electrical separation between electrical components on a single crystalline silicon substrate, the method comprising the steps of forming amorphous regions in the crystalline silicon substrate by selectively irradiating the silicon substrate with laser radiation of a wavelength less than 400 nanometers and a pulse length less than 10 nanoseconds so that most of the radiation is absorbed in the top 3,000 Å of the irradiated regions of the substrate which rapidly melts and rapidly freezes into an amorphous state, the amorphous regions forming electrically insulating regions adjacent single crystalline silicon regions of substrate.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein the pulse length is between 0.1 and 10 nanoseconds.
Claim 4
Dependent Claim
21 words
The method of claim 1 wherein the energy density of radiation is in the range 0.1 to 0.8 J/cm 2 .
References Cited (Backward Citations)
US3615317A
Cited
GB1410896A
Cited
GB1520595A
Cited
US4058699A
Cited
US4240843A
Cited
GB2044980A
Cited
US4370175A
Cited
US4338616A
Cited
US4322253A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-08-12 | 1989-02-11 | 1989-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-12 | 1993-02-11 | 1993-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-12 | 1997-02-11 | 1997-08-13 | $7700.00 | Window Closed / Lapsed |