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US4990464A
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Method of forming improved encapsulation layer
Assignee: Philips North America LLC
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Filing: 1988-12-30
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Granted: 1991-02-05
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Expires: 2008-12-30
Abstract
Abstract An improved technique for forming silicon-on insulator films for use in integrated circuits. The technique provides an improved encapsulation layer to enable in a reproducible way the zone melt recrystallization of such films. The encapsulation layer consists of a first layer of a doped SiO 2 (silicate glass) on which a further layer of Si 3 N 4 is deposited. The doped SiO 2 forms a fusible glassy material which is rendered semi-liquid and flows at the temperatures used in recrystallization. The softening of the encapsulation material accommodates volume expansion and eliminates the biaxial stresses in the layered structure. The Si 3 N 4 layer adds mechanical strength to the SiO 2 layer and improves the wetting angle.
Inventors
- 👤 Helmut Baumgart
- 👤 Andre Martinez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:20
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/38; H10P14/3802; H10P14/3808; H10P14/3814; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/2921; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/3451; H10P14/3452; H10P14/3458; H10P14/3818; H10P14/382; H10P14/60; H10P14/69; H10P14/692; H10P14/6921; H10P14/6922; H10P14/6923; Y; Y10; Y10S; Y10S117/00; Y10S117/903; Y10S117/904; Y10S148/00; Y10S148/152; Y10S148/154
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
73 words
A method of manufacturing a silicon-on-insulator (SOI) semiconductor device comprising the steps of forming a layer of SiO 2 on a substrate forming a relatively thin poly-silicon or α-Si film on said layer of SiO 2 encapsulating said poly-silicon film with a composite structure of a doped layer of SiO 2 deposited on said poly-silicon film and a layer of Si 3 N 4 deposited on said doped layer of SiO 2 .
Claim 2
Independent Claim
73 words
A method of manufacturing a silicon-on-insulator (SOI) semiconductor device comprising the steps of forming a layer of SiO 2 on a substrate forming a relatively thin poly-silicon or α-Si film on said layer of SiO 2 encapsulating said poly-silicon film with a composite structure of a doped layer of SiO 2 deposited on said poly-silicon film and a layer of Si 3 N 4 deposited on said doped layer of SiO 2 .
Claim 3
Dependent Claim
26 words
The method as claimed in claim 1, wherein said SiO 2 is doped with a dopant selected from the group consisting of phosphorus, boron and arsenic.
Claim 4
Dependent Claim
20 words
The method as claimed in claim 1, wherein said SiO 2 is doped with a dopant comprising boron and phosphorous.
Claim 5
Dependent Claim
27 words
The method as claimed in claim 1, further including the step of zone-melting said poly-silicon film or α-silicon through said composite structure to recrystallize said poly-silicon film.
Claim 6
Dependent Claim
22 words
The method as claimed in claim 4, wherein said zone melting is accomplished with the use of radiation emitted by a laser.
Claim 7
Dependent Claim
21 words
The method as claimed in claim 1, wherein said poly-silicon film (or α-Si) is formed by low pressure chemical vapor deposition.
Claim 8
Dependent Claim
23 words
The method as claimed in claim 1, wherein said layer of Si 3 N 4 is deposited by means of low-pressure chemical deposition.
Claim 9
Independent Claim
86 words
A method of manufacturing a single crystalline silicon-on-insulator (SOI) semiconductor structure comprising the steps of forming a layer of SiO 2 on a substrate forming a thin poly-silicon film or α-silicon on said layer of SiO 2 encapsulating said poly-silicon film with a composite structure of a doped layer of SiO 2 deposited on said poly-silicon film and a layer of Si 3 N 4 deposited on said doped layer of SiO 2 zone-melting said poly-silicon film through said composite structure to recrystallize said poly-silicon film.
Claim 10
Independent Claim
86 words
A method of manufacturing a single crystalline silicon-on-insulator (SOI) semiconductor structure comprising the steps of forming a layer of SiO 2 on a substrate forming a thin poly-silicon film or α-silicon on said layer of SiO 2 encapsulating said poly-silicon film with a composite structure of a doped layer of SiO 2 deposited on said poly-silicon film and a layer of Si 3 N 4 deposited on said doped layer of SiO 2 zone-melting said poly-silicon film through said composite structure to recrystallize said poly-silicon film.
Claim 11
Dependent Claim
26 words
The method as claimed in claim 8, wherein said SiO 2 is doped with a dopant selected from the group consisting of phosphorus, boron and arsenic.
Claim 12
Dependent Claim
20 words
The method as claimed in claim 8, wherein said SiO 2 is doped with a dopant comprising boron and phosphorous.
Claim 13
Dependent Claim
25 words
The method as claimed in claim 8, further including the step of zone-melting said poly-silicon film through said composite structure to recrystallize said poly-silicon film.
Claim 14
Dependent Claim
22 words
The method as claimed in claim 8, wherein said zone melting is accomplished with the use of radiation emitted by a laser.
Claim 15
Dependent Claim
19 words
The method as claimed in claim 8, wherein said poly-silicon film is formed by low pressure chemical vapor deposition.
Claim 16
Dependent Claim
23 words
The method as claimed in claim 8, wherein said layer of Si 3 N 4 is deposited by means of low-pressure chemical deposition.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-02-04 | 1994-08-06 | 1995-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-04 | 1998-08-06 | 1999-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-04 | 2002-08-06 | 2003-02-05 | $7700.00 | Window Closed / Lapsed |