US4494303A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making dielectrically isolated silicon devices
Assignee: Nokia Bell Labs
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Filing: 1983-03-31
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Granted: 1985-01-22
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Expires: 2003-03-31
Abstract
Abstract Structures useful for dielectrically isolated high voltage devices are produced utilizing a melting technique. In this technique a cavity is produced in a silicon wafer, the surface of the cavity is, for example, oxidized to form a dielectric material, and silicon is deposited onto the dielectric material so that it extends to a region where it is in contact with single crystal silicon, e.g., a portion of the wafer. The entire region of polycrystalline silicon is then melted. Upon termination of the melting energy, the polycrystalline silicon is converted into a thick region of dielectrically isolated single crystal silicon. This thick region is useful for the formation of high voltage devices.
Inventors
- 👤 George K. Celler
- 👤 David J. Lischner
- 👤 McDonald Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:04
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/019; H10W10/10; Y; Y10; Y10S; Y10S438/00; Y10S438/977
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
114 words
A process for producing dielectrically isolated electronic devices in a semiconductor body comprising single crystal silicon, comprising the steps of depositing a layer of silicon on a dielectric material and converting said deposited silicon layer into a single crystal silicon region, CHARACTERIZED IN THAT said dielectric material is at least 1 μm thick and is formed on the surfaces of a cavity in said semiconductor body, said deposited silicon extends continuously to a single crystal silicon nucleation region and said conversion to said single crystal silicon region is effected by first melting all of said deposited silicon layer to form a molten region extending to said single crystal nucleation region and then inducing recrystallization.
Claim 2
Dependent Claim
114 words
A process for producing dielectrically isolated electronic devices in a semiconductor body comprising single crystal silicon, comprising the steps of depositing a layer of silicon on a dielectric material and converting said deposited silicon layer into a single crystal silicon region, CHARACTERIZED IN THAT said dielectric material is at least 1 μm thick and is formed on the surfaces of a cavity in said semiconductor body, said deposited silicon extends continuously to a single crystal silicon nucleation region and said conversion to said single crystal silicon region is effected by first melting all of said deposited silicon layer to form a molten region extending to said single crystal nucleation region and then inducing recrystallization.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein said dielectric material comprises silicon dioxide.
Claim 4
Dependent Claim
14 words
The process of claim 2 wherein said silicon dioxide is formed by thermal oxidation.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein said melting is performed with radiant energy.
Claim 6
Dependent Claim
14 words
The process of claim 1 wherein said cavity is formed utilizing a crystallographic etchant.
Claim 7
Dependent Claim
18 words
The process of claim 1 wherein said single crystal nucleation region is a portion of said semiconductor body.
Claim 8
Dependent Claim
22 words
The process of claim 1 wherein said melting is performed in the presence of a capping layer on said deposited silicon layer.
Claim 9
Dependent Claim
12 words
The process of claim 7 wherein said capping layer comprises silicon dioxide.
Claim 10
Dependent Claim
11 words
The process of claim 1 wherein said converted region is polished.
References Cited (Backward Citations)
US4381201A
Cited
US4404735A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-22 | 1988-07-23 | 1989-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-22 | 1992-07-23 | 1993-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-22 | 1996-07-23 | 1997-01-22 | $7700.00 | Window Closed / Lapsed |