Patent US5298449A successfully refreshed from Google Patents.
US5298449A
Expired / Lapsed
US
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Semiconductor substrate having a silicon-on-insulator structure and method of fabricating the same
Assignee: NEC Electronics Corp
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Filing: 1993-03-08
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Granted: 1994-03-29
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Expires: 2013-03-08
Abstract
Abstract The invention provides a silicon-on-insulator semiconductor substrate structure and a method of fabricating the same. The structure includes a base silicon substrate, a mono-crystalline silicon film formed on the base silicon substrate in a predetermined region, a poly-crystalline silicon film formed on the base silicon substrate in opposite region to the predetermined region, an insulator film formed on the polycrystalline silicon film, and a mono-crystalline silicon layer overlaying both the insulator film and the mono-crystalline silicon film so that the mono-crystalline silicon layer is electrically connected to the base silicon substrate through the mono-crystalline silicon film. The mono-crystalline silicon film permits not the mono-crystalline silicon layer only but also the base silicon substrate to serve as active regions.
Inventors
- 👤 Hiroaki Kikuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:45
CPC Classifications
H; H10; H10P; H10P36/00; H10P36/03; H10P36/07; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; H10W; H10W10/00; H10W10/01; H10W10/021; H10W10/10; H10W10/181; H10W10/20; H10W20/00; H10W20/01; H10W20/021; Y; Y10; Y10S; Y10S148/00; Y10S148/012; Y10S148/135
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
161 words
A method of fabricating a semiconductor substrate having a silicon-on-insulator structure comprising the steps of: forming selectively an insulation film on one surface of a first silicon substrate so as to expose said one surface in a predetermined region of said first silicon substrate; forming an amorphous silicon film so as to cover both said insulation film and said exposed surface of said first silicon substrate; contacting said first silicon substrate with a second silicon substrate through said amorphous silicon film; subjecting said first and second silicon substrates to a heat treatment so that said amorphous silicon film becomes both a mono-crystalline silicon film in contact with said exposed surface of said first silicon substrate and a polycrystalline silicon film in contact with said insulator film, thereby electrically connecting between said first and second silicon substrates through said mono-crystalline silicon film; and subjecting said first silicon substrate to a polishing treatment at opposite surface so as to have a predetermined thickness.
Claim 2
Independent Claim
161 words
A method of fabricating a semiconductor substrate having a silicon-on-insulator structure comprising the steps of: forming selectively an insulation film on one surface of a first silicon substrate so as to expose said one surface in a predetermined region of said first silicon substrate; forming an amorphous silicon film so as to cover both said insulation film and said exposed surface of said first silicon substrate; contacting said first silicon substrate with a second silicon substrate through said amorphous silicon film; subjecting said first and second silicon substrates to a heat treatment so that said amorphous silicon film becomes both a mono-crystalline silicon film in contact with said exposed surface of said first silicon substrate and a polycrystalline silicon film in contact with said insulator film, thereby electrically connecting between said first and second silicon substrates through said mono-crystalline silicon film; and subjecting said first silicon substrate to a polishing treatment at opposite surface so as to have a predetermined thickness.
Claim 3
Dependent Claim
17 words
The fabrication method as claimed in claim 1, wherein said insulator film is a dioxide silicon film.
Claim 4
Dependent Claim
26 words
The fabrication method as claimed in claim 2, wherein said dioxide silicon film is formed by a thermal oxidation, a dry etching and a wet etching.
Claim 5
Dependent Claim
30 words
The fabrication method as claimed in claim 1, wherein said second step of forming said amorphous silicon film comprises the step of accomplishing a chemical vapor deposition of amorphous silicon.
Claim 6
Dependent Claim
67 words
The fabrication method as claimed in claim 1, wherein said second step of forming said amorphous silicon film comprises the steps of: forming a polycrystalline silicon film on the device so as to cover both said insulation film and said exposed surface of said first silicon substrate; and accomplishing an ion-implantation of silicon to said polycrystalline silicon film so that said polycrystalline silicon becomes an amorphous silicon.
Claim 7
Dependent Claim
31 words
The fabrication process as claimed in claim 5, wherein said ion-implantation of silicon is accomplished at an energy of 300 kV and at a dose of 1×10 16 atoms/cm 2 .
Claim 8
Dependent Claim
20 words
The fabrication method as claimed in claim 5, wherein said polycrystalline silicon film is formed by a chemical vapor deposition.
Claim 9
Dependent Claim
32 words
The fabrication method as claimed in claim 1, further comprising the step of subjecting a surface of said amorphous silicon film to a mirror polishing treatment prior to said third contacting step.
Claim 10
Dependent Claim
27 words
The fabrication method as claimed in claim 1, wherein said heat treatment is accomplished at a temperature of 1100° C. for an hour in a nitrogen atmosphere.
Claim 11
Dependent Claim
22 words
The fabrication method as claimed in claim 1, wherein said polishing treatment to said second silicon substrate is a mirror polishing treatment.
Claim 12
Dependent Claim
21 words
The fabrication method as claimed in claim 1, wherein said first and second silicon substrate are doped with a p-type dopant.
Claim 13
Dependent Claim
21 words
The fabrication method as claimed in claim 1, wherein said first and second silicon substrate are doped with an n-type dopant.
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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) | 1997-03-28 | 1997-09-27 | 1998-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-28 | 2001-09-27 | 2002-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-28 | 2005-09-27 | 2006-03-29 | $7700.00 | Window Closed / Lapsed |