US4888302A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of reduced stress recrystallization
Assignee: Philips North America LLC
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Filing: 1989-03-29
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Granted: 1989-12-19
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Expires: 2009-03-29
Abstract
Abstract A defect free monocrystalline layer of silicon on an insulator is produced by forming a thin layer of silicon dioxide on a monocrystalline silicon substrate, forming a thin layer of polycrystalline or amorphous silicon on the silicon dioxide layer and focussing two beams from lamps on the thin silicon layer to form a line image providing a melt zone surrounded by two narrow heated zones having temperatures lower than the melt zone and having a temperature differential of from 2°-10° C./mm decreasing form the melt zone while heating the substrate to a temperature below that of the zones heated by the lamps and scanning the structure.
Inventors
- 👤 Subramanian Ramesh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:26
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/29; H10P14/2901; H10P14/2922; H10P14/2902; H10P14/2905; H10P14/32; H10P14/3202; H10P14/3238; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/3451; H10P14/3452; H10P14/3458; H10P14/38; H10P14/3802; H10P14/382; Y; Y10; Y10S; Y10S148/00; Y10S148/004; Y10S148/048; Y10S148/071; Y10S148/152
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
169 words
A method of forming a thin, defect free, monocrystalline layer of a semiconductor material on an insulator, said method comprising: (a) depositing a thin polycrystalline or amorphous layer of a semiconductor material on an insulating substrate to form a layered structure; (b) focusing beams from an arc lamp and a filament lamp on the layer of semiconductor material in such a manner that the center of said beams coincide to form a line image on said line image, the power distribution on said layer being such as to provide a narrow melt zone in said layer of semiconductor material at the center of the line image surrounded by two narrow heated zones, the temperature of said narrow heated zones being below the temperature of said melt zone and said narrow heated zone having a temperature differential of from 2°-10° C./mm decreasing from said melt zone while scanning said layered structure relative to said line image and heating said substrate to a temperature below the temperature of said heated zone.
Claim 2
Independent Claim
169 words
A method of forming a thin, defect free, monocrystalline layer of a semiconductor material on an insulator, said method comprising: (a) depositing a thin polycrystalline or amorphous layer of a semiconductor material on an insulating substrate to form a layered structure; (b) focusing beams from an arc lamp and a filament lamp on the layer of semiconductor material in such a manner that the center of said beams coincide to form a line image on said line image, the power distribution on said layer being such as to provide a narrow melt zone in said layer of semiconductor material at the center of the line image surrounded by two narrow heated zones, the temperature of said narrow heated zones being below the temperature of said melt zone and said narrow heated zone having a temperature differential of from 2°-10° C./mm decreasing from said melt zone while scanning said layered structure relative to said line image and heating said substrate to a temperature below the temperature of said heated zone.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein the semiconductor material is silicon.
Claim 4
Dependent Claim
10 words
The method of claim 2 wherein the substrate is glass.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein the substrate is heated to a temperature of 1000° C.-1250° C.
Claim 6
Dependent Claim
32 words
The method of claim 2 wherein the melt zone is less than about 200-800 μm in width and the width of each of the narrow heated zones is about 2 mm wide.
Claim 7
Dependent Claim
11 words
The method of claim 2 wherein the substrate is oxidized silicon.
Claim 8
Independent Claim
202 words
A method of forming a thin, defect free, monocrystalline layer of silicon on an insulator, said method comprising: (a) depositing a thin layer of silicon dioxide on a substrate of monocrystalline silicon; (b) depositing a thin layer of polycrystalline or amorphous silicon on said layer of silicon dioxide to form thereby a layered structure; (c) focusing beams from an arc lamp and a filament lamp on said layer of polycrystalline or amorphous silicon in such a manner that the beams from both lamps impinge on said layer of polycrystalline or amorphous silicon prior to infringing on said substrate and the centers of said beams coincide to form a line image on said layer, the power distribution on said layer being such as to provide a narrow melt zone in said layer of at the center of the line image surrounded by two narrow heated zones, the temperature of said narrow heated zones being below the temperature of said melt zone and said narrow heated zone having a temperature differential of from 2°-10° C./mm decreasing from said melt zone while scanning said layered structure relative to said line image and heating said substrate to a temperature below the temperature of said heated zone.
Claim 9
Independent Claim
202 words
A method of forming a thin, defect free, monocrystalline layer of silicon on an insulator, said method comprising: (a) depositing a thin layer of silicon dioxide on a substrate of monocrystalline silicon; (b) depositing a thin layer of polycrystalline or amorphous silicon on said layer of silicon dioxide to form thereby a layered structure; (c) focusing beams from an arc lamp and a filament lamp on said layer of polycrystalline or amorphous silicon in such a manner that the beams from both lamps impinge on said layer of polycrystalline or amorphous silicon prior to infringing on said substrate and the centers of said beams coincide to form a line image on said layer, the power distribution on said layer being such as to provide a narrow melt zone in said layer of at the center of the line image surrounded by two narrow heated zones, the temperature of said narrow heated zones being below the temperature of said melt zone and said narrow heated zone having a temperature differential of from 2°-10° C./mm decreasing from said melt zone while scanning said layered structure relative to said line image and heating said substrate to a temperature below the temperature of said heated zone.
Claim 10
Dependent Claim
14 words
The method of claim 7 wherein the substrate is heated to about 1100° C.
Claim 11
Dependent Claim
17 words
The method of claim 8 wherein the width of the melt zone is from about 400-500 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) | 1992-12-18 | 1993-06-19 | 1993-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-18 | 1997-06-19 | 1997-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-18 | 2001-06-19 | 2001-12-19 | $7700.00 | Window Closed / Lapsed |