US5238871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing a semiconductor device
Assignee: Seiko Epson Corp
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Filing: 1991-11-25
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Granted: 1993-08-24
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Expires: 2011-11-25
Abstract
Abstract A method of manufacturing a semiconductor device including a MOS-type field effect transistor includes cleansing a surface of a substrate; forming, next to the cleansing step, a gate oxide film on the cleansed surface of the substrate; wherein the cleansing step includes dry-etching the surface of the substrate in an atmosphere in which hydrogen fluoride and a substance containing at least a chlorine atom coexist in gaseous state and removing an oxide film and metal impurities on the surface of the substrate. Preferably, the dry-etching is performed under heat and decompression.
Inventors
- 👤 Masato Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:54
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/20; H10P70/23; H10P70/10; H10P70/18; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10P70/12; H10D64/01346; Y; Y10; Y10S; Y10S148/00; Y10S148/017; Y10S148/053; Y10S438/00; Y10S438/906; Y10S438/909; Y10S438/974
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
133 words
A method of manufacturing a semiconductor device including a MOS-type field effect transistor, comprising the steps of: cleansing a surface of a substrate; forming, after said cleansing step, a gate oxide film on the cleansed surface of the substrate; wherein said cleansing step includes: wet-etching the surface of said substrate to remove a natural oxide film therefrom; dry etching the surface of the substrate, after said wet-etching in an atmosphere in which hydrogen fluoride and a substance containing at least a chlorine atom coexist in a gaseous state under decompression, said dry-etching forming metal chlorides with metal impurities on the surface of said substrate; and removing an oxide film and said metal impurities from the surface of the substrate, said metal impurities being removed by removing said metal chlorides in a volatilized state.
Claim 2
Independent Claim
133 words
A method of manufacturing a semiconductor device including a MOS-type field effect transistor, comprising the steps of: cleansing a surface of a substrate; forming, after said cleansing step, a gate oxide film on the cleansed surface of the substrate; wherein said cleansing step includes: wet-etching the surface of said substrate to remove a natural oxide film therefrom; dry etching the surface of the substrate, after said wet-etching in an atmosphere in which hydrogen fluoride and a substance containing at least a chlorine atom coexist in a gaseous state under decompression, said dry-etching forming metal chlorides with metal impurities on the surface of said substrate; and removing an oxide film and said metal impurities from the surface of the substrate, said metal impurities being removed by removing said metal chlorides in a volatilized state.
Claim 3
Dependent Claim
15 words
A method according to claim 1, wherein said dry-etching is performed under heat and decompression.
Claim 4
Dependent Claim
26 words
A method according to claim 1, wherein said substance containing at least a chlorine atom is selected from the group consisting of chlorine and hydrochloric acid.
Claim 5
Dependent Claim
18 words
A method according to claim 1, wherein during said cleansing step, RCA cleaning is performed before said dry-etching.
Claim 6
Dependent Claim
22 words
A method according to claim 1, wherein said wet-etching is accomplished by using a cleaning solution containing nitric acid and hydrogen fluoride.
Claim 7
Dependent Claim
22 words
A method according to claim 1, wherein said dry-etching is performed at a pressure in the range from 0.1 to 0.5 Torr.
Claim 8
Dependent Claim
19 words
A method according to claim 2, wherein said dry-etching is performed at a temperature from 10° to 100° C.
Claim 9
Dependent Claim
22 words
A method according to claim 7, wherein said dry-etching is performed at a pressure in the range from 0.1 to 0.5 Torr.
Claim 10
Dependent Claim
34 words
A method according to claim 1, wherein said substance containing at least a chlorine atom flows through a chamber containing said substrate during said dry-etching at a rate of from 0.1 to 0.5 SCC/minute.
Claim 11
Dependent Claim
29 words
A method according to claim 1, wherein said hydrogen fluoride flows through a chamber containing said substrate during said dry-etching at a rate of from 50 to 100 SCC/minute.
Claim 12
Dependent Claim
34 words
A method according to claim 10, wherein said substance containing at least a chlorine atom flows through said chamber containing said substrate during said dry-etching at a rate of from 0.1 to 0.5 SCC/minute.
Claim 13
Independent Claim
114 words
A method of manufacturing a semiconductor device including a MOS-type field effect transistor, comprising the steps of: cleansing a surface of a substrate; forming, after said cleansing step, a gate oxide film on the cleansed surface of the substrate; wherein said cleansing step includes: wet-etching the surface of said substrate to remove a natural oxide film therefrom; dry-etching the surface of the substrate, after said wet-etching in an atmosphere in which hydrogen fluoride and a substance containing at least a chlorine atom coexist in a gaseous state under decompression at a pressure in the range from 0.1 to 0.5 Torr.; and removing an oxide film and metal impurities from the surface of the substrate.
Claim 14
Independent Claim
114 words
A method of manufacturing a semiconductor device including a MOS-type field effect transistor, comprising the steps of: cleansing a surface of a substrate; forming, after said cleansing step, a gate oxide film on the cleansed surface of the substrate; wherein said cleansing step includes: wet-etching the surface of said substrate to remove a natural oxide film therefrom; dry-etching the surface of the substrate, after said wet-etching in an atmosphere in which hydrogen fluoride and a substance containing at least a chlorine atom coexist in a gaseous state under decompression at a pressure in the range from 0.1 to 0.5 Torr.; and removing an oxide film and metal impurities from the surface of the substrate.
Claim 15
Dependent Claim
26 words
A method according to claim 12, wherein said substance containing at least a chlorine atom is selected from the group consisting of chlorine and hydrochloric acid.
Claim 16
Dependent Claim
22 words
A method according to claim 12, wherein said wet-etching is accomplished by using a cleaning solution containing nitric acid and hydrogen fluoride.
Claim 17
Dependent Claim
19 words
A method according to claim 12, wherein said dry-etching is performed at a temperature from 10° to 100° C.
Claim 18
Dependent Claim
34 words
A method according to claim 12, wherein said substance containing at least a chlorine atom flows through a chamber containing said substrate during said dry-etching at a rate of from 0.1 to 0.5 SCC/minute.
Claim 19
Dependent Claim
29 words
A method according to claim 12, wherein said hydrogen fluoride flows through a chamber containing said substrate during said dry-etching at a rate of from 50 to 100 SCC/minute.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-23 | 1997-02-22 | 1997-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-23 | 2001-02-22 | 2001-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-23 | 2005-02-22 | 2005-08-24 | $7700.00 | Window Closed / Lapsed |