US5480492A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for removing organic or inorganic contaminant from silicon substrate surface
Assignee: New Energy and Industrial Technology Development Organization
•
Filing: 1993-10-15
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Granted: 1996-01-02
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Expires: 2013-10-15
Abstract
Abstract For removing an unnecessary substance on a silicon substrate surface, a temperature of the unnecessary substance on the silicon substrate surface is not less than 750° C. when the unnecessary substance is exposed to a gas including ozone.
Inventors
- 👤 Masaharu Udagawa
- 👤 Juro Yasui
- 👤 Masaaki Niwa
- 👤 Yoshihiko Hirai
- 👤 Kenji Okada
- 👤 Kiyoshi Morimoto
- 👤 Koichiro Yuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:57
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/10; H10P70/12
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
116 words
A method for removing an organic or inorganic contaminant on a silicon substrate surface, said method comprising: causing a temperature of the organic or inorganic contaminant on the silicon substrate surface to be not less than 7500° C.; and exposing the organic or inorganic contaminant to a gas including ozone while the temperature of the organic or inorganic contaminant is not less than 750° C. and a partial pressure formed by at least one of oxygen atoms (O), oxygen molecules (O 2 ) and ozone molecules (O 3 ) over the organic or inorganic contaminant on the silicon substrate surface is not higher than 10 1 Pa to prevent the silicon substrate surface from being oxidized.
Claim 2
Independent Claim
116 words
A method for removing an organic or inorganic contaminant on a silicon substrate surface, said method comprising: causing a temperature of the organic or inorganic contaminant on the silicon substrate surface to be not less than 7500° C.; and exposing the organic or inorganic contaminant to a gas including ozone while the temperature of the organic or inorganic contaminant is not less than 750° C. and a partial pressure formed by at least one of oxygen atoms (O), oxygen molecules (O 2 ) and ozone molecules (O 3 ) over the organic or inorganic contaminant on the silicon substrate surface is not higher than 10 1 Pa to prevent the silicon substrate surface from being oxidized.
Claim 3
Dependent Claim
33 words
A method according to claim 1, wherein the organic or inorganic contaminant on the silicon substrate surface is heated to the temperature not less than 750° C. after being exposed to the gas.
Claim 4
Dependent Claim
69 words
A method according to claim 1, wherein the organic or inorganic contaminant on the silicon substrate surface is exposed to the gas before at least a part of the organic or inorganic contaminant over the silicon substrate surface is substantially removed in such a degree that an undesirable chemical change of the silicon substrate surface is generated by at least one of the gas and heating of silicon substrate.
Claim 5
Dependent Claim
33 words
A method according to claim 1, wherein the organic or inorganic contaminant on the silicon substrate surface is heated to the temperature not less than 750° C. before being exposed to the gas.
Claim 6
Dependent Claim
35 words
A method according to claim 1, wherein the organic or inorganic contaminant on the silicon substrate surface is heated to the temperature not less than 750° C. substantially simultaneously with being exposed to the gas.
Claim 7
Dependent Claim
16 words
A method according to claim 1, wherein the organic or inorganic contaminant includes a silicon oxide.
Claim 8
Dependent Claim
15 words
A method according to claim 1, wherein the organic or inorganic contaminant includes a hydrocarbon.
Claim 9
Dependent Claim
15 words
A method according to claim 1, wherein the temperature is not larger than 1100° C.
Claim 10
Dependent Claim
31 words
A method according to claim 1, wherein a partial pressure formed by oxygen over the organic or inorganic contaminant on the silicon substrate surface is not higher than 10 -4 Pa.
Claim 11
Dependent Claim
48 words
A method according to claim 1, wherein a partial pressure formed by at least one of oxygen atomics (O), oxygen molecules (O 2 ) and ozone molecules (O 3 ) over the organic or inorganic contaminant on the silicon substrate surface is not higher than 10 -4 Pa.
Claim 12
Dependent Claim
21 words
A method according to claim 1, wherein the gas is substantially prevented from including at least one of carbon and carbide.
Claim 13
Dependent Claim
22 words
A method according to claim 1, wherein the gas further includes at least one of oxygen molecule, hydrogen molecule and inert gas.
Claim 14
Dependent Claim
19 words
A method according to claim 1, wherein the ozone is formed by applying ultraviolet rays to oxygen molecule gas.
Claim 15
Dependent Claim
33 words
A method according to claim 1, wherein the ozone is formed over the organic or inorganic contaminant by supplying both of ultraviolet rays and oxygen molecule gas onto the organic or inorganic contaminant.
Claim 16
Dependent Claim
16 words
A method according to claim 1, wherein the gas flows onto the organic or inorganic contaminant.
Claim 17
Dependent Claim
22 words
A method according to claim 1, wherein the silicon substrate surface is also heated to the temperature not less than 750° C.
Claim 18
Dependent Claim
55 words
A method according to claim 1, wherein the ozone is substantially completely discharged from the silicon substrate surface when the silicon substrate surface is cooled below 750° C., after the organic or inorganic contaminant on the silicon substrate surface is kept at the temperature not less than 750° C. while being exposed to the gas.
Claim 19
Dependent Claim
28 words
A method according to claim 1, wherein the gas flows from the silicon substrate surface toward an area whose gas pressure is not higher than 10 -7 Pa.
Claim 20
Dependent Claim
29 words
A method according to claim 1, wherein a circumferential gas pressure over the organic or inorganic contaminant on the silicon substrate surface is not higher than the atmospheric pressure.
Claim 21
Dependent Claim
20 words
A method according to claim 1, wherein said organic or inorganic contaminant comprises an organic contaminant and a silicon oxide.
Claim 22
Dependent Claim
27 words
A silicon substrate having a silicon substrate surface cleaned by the process of claim 1, wherein the silicon substrate surface has a roughness not exceeding 0.034 nm.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1999-01-01 | 1999-07-03 | 2000-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-01 | 2003-07-03 | 2004-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-01 | 2007-07-03 | 2008-01-02 | $7700.00 | Window Closed / Lapsed |