US4847215A
Expired / Lapsed
US
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Method for forming silicon carbide semiconductor film
Assignee: Soken Inc
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Filing: 1988-10-31
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Granted: 1989-07-11
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Expires: 2008-10-31
Abstract
Abstract A method for forming a SiC film having a wide optical energy gap and a high conductivity, which is capable of being stacked on a substrate of a large area uniformly. The SiC film is formed by supplying a material gas composed of monosilane gas, methane gas, diboran gas and hydrogen gas and having a hydrogen dilution ratio of about 144 and carbon mixing ratio of about 0.35, to the substrate, and supplying rf power of 60 to 270W(rf power density=80 to 350mW/cm2) under a gas pressure of 0.2 torr at a substrate temperature of 220 DEG C. The obtained film exhibits high dark-conductivity of 10-6Scm-1 or more, and a Raman spectrum light thereof peaks at around 520 cm-1.
Inventors
- 👤 KenIchi Hanaki
- 👤 Hitomi Kitagawa
- 👤 Takayuki Tominaga
- 👤 Tadashi Hattori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:52
CPC Classifications
H; H10; H10F; H10F10/00; H10F10/10; H10F10/17; C; C23; C23C; C23C16/00; C23C16/22; C23C16/30; C23C16/32; C23C16/325; H10F71/00; H10F71/10; H10F71/103; H10F71/1035; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/548; Y02P; Y02P70/00; Y02P70/50; Y10; Y10S; Y10S148/00; Y10S148/148; Y10S438/00; Y10S438/931
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
141 words
A method for forming a silicon carbide semiconductor film by utilizing radio frequency glow discharge, comprising the steps of preparing a material gas composed of a mixture of a silicon-containing gas, a carbon-containing gas and a hydrogen gas, said material gas having a carbon mixing ratio k(k=[C]/{[S]+[C]} where [C] is the partial pressure of the carbon-containing gas, [S] is the partial pressure of the silicon-containing gas) of 0.5 or less, and a hydrogen dilution ratio γ (γ=[H]/{[S]+[C]} where [H] is the partial pressure of the hydrogen gas) of 60 or more; supplying said material gas to a substrate; generating plasma at a substrate temperature of 180° C. or more under a gas pressure of 0.5 torr or less with radio frequency power density of from 80 to 300 mW/cm 2 whereby the silicon carbide semiconductor film is stacked on said substrate.
Claim 2
Independent Claim
141 words
A method for forming a silicon carbide semiconductor film by utilizing radio frequency glow discharge, comprising the steps of preparing a material gas composed of a mixture of a silicon-containing gas, a carbon-containing gas and a hydrogen gas, said material gas having a carbon mixing ratio k(k=[C]/{[S]+[C]} where [C] is the partial pressure of the carbon-containing gas, [S] is the partial pressure of the silicon-containing gas) of 0.5 or less, and a hydrogen dilution ratio γ (γ=[H]/{[S]+[C]} where [H] is the partial pressure of the hydrogen gas) of 60 or more; supplying said material gas to a substrate; generating plasma at a substrate temperature of 180° C. or more under a gas pressure of 0.5 torr or less with radio frequency power density of from 80 to 300 mW/cm 2 whereby the silicon carbide semiconductor film is stacked on said substrate.
Claim 3
Dependent Claim
40 words
A method according to claim 1, wherein said silicon-containing gas is one of silane gas and a gas obtained by substituting one of methyl group and ethyl group for at least one part of hydrogen atoms of said silane gas.
Claim 4
Dependent Claim
38 words
A method according to claim 1, wherein said silicon-containing gas is one of silane gas and a gas obtained by substituting one of fluorine and chlorine for at least one part of hydrogen atoms of said silane gas.
Claim 5
Dependent Claim
68 words
A method according to claim 1, wherein said material gas is further composed of 0.05 to 4% of a gas containing group IIIa elements to control the valence electron of the silicon carbide semiconductor film to p-type, k is 0.35 or less, γ is 70 or more, the substrate temperature is 200 C. or higher, and the radio frequency power density is 170 to 340 mW/cm 2 .
Claim 6
Dependent Claim
21 words
A method according to claim 4, wherein γ is 70 to 110 and the substrate temperature is 200° to 300° C.
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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) | 1992-07-10 | 1993-01-09 | 1993-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-10 | 1997-01-09 | 1997-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-10 | 2001-01-09 | 2001-07-11 | $7700.00 | Window Closed / Lapsed |