US3661637A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for epitactic precipitation of silicon at low temperatures
Assignee: Siemens AG
•
Filing: 1969-12-22
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Granted: 1972-05-09
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Expires: 1989-12-22
Abstract
Abstract A method for producing highly pure, monocrystalline silicon layers, with or without dopant additions, upon a wafer shaped substrate body, which comprises thermal dissociating a gaseous silane compound, and by precipitating silicon upon a heated substrate body located in a reaction chamber. The crystalline structure of the silicon body is exposed e.g. by etching and its surface is flooded by the reaction gas. The silane compound is a dihalogen silane of formula SiH2X2, wherein X is chlorine, bromine, or iodine. The thermal dissociation is effected by heating the substrate body at low temperatures, preferably within a temperature range between 600* and 1,000* C.
Inventors
- 👤 Erhard Sirtl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:26
CPC Classifications
C; C30; C30B; C30B29/00; C30B29/02; C30B29/06; C01; C01B; C01B33/00; C01B33/02; C23; C23C; C23C16/00; C23C16/44; C23C16/48; C23C16/481; C23C16/482; C30B25/00; C30B25/02; Y; Y10; Y10S; Y10S117/00; Y10S117/903; Y10S117/904; Y10S148/00; Y10S148/007; Y10S148/017; Y10S148/027; Y10S148/049; Y10S148/051; Y10S148/071
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
20 words
The method of claim 1, wherein the thermal dissociation of the silane compound is effected in a noble gas atmosphere.
Claim 2
Dependent Claim
15 words
The method of claim 1, wherein the gaseous silane is mixed with a carrier gas.
Claim 3
Dependent Claim
13 words
The method of claim 3, wherein hydrogen is used as the carrier gas.
Claim 4
Dependent Claim
25 words
The method of claim 3 wherein the IR radiation for regional heating of the substrate body is concentrated upon specific points of the substrate body.
Claim 5
Dependent Claim
24 words
The method of claim 3, wherein the IR heating of specific regions of the surface of the substrate body is effected by laser beams.
Claim 6
Dependent Claim
47 words
The method of claim 1, wherein the substrate body is subjected, prior to thermal dissociation of the silane compound, to a surface treatment through the action of sulphur hexafluoride (SF6) or nitrogen trifluoride (NF3), in a noble gas atmosphere and at temperatures between 500* and 800* C.
Claim 7
Dependent Claim
22 words
The method of claim 1, wherein the thermal dissociation is carried out in a dynamic vacuum of 10 3 to 1 Torr.
References Cited (Backward Citations)
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Cited
GB932418A
Cited
US3047438A
Cited
US3341360A
Cited
US3486933A
Cited
US3458368A
Cited
US3546036A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |