US4985372A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming conductive layer including removal of native oxide
Assignee: Tokyo Electron Ltd
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Filing: 1990-02-09
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Granted: 1991-01-15
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Expires: 2010-02-09
Abstract
Abstract A method of forming a conductive layr includes the steps of performing dry etching of a surface of a substrate in a first chamber maintained in a nonoxidizing atmosphere to remove a natural oxide from the surface of the substrate, transferring the substrate from the first chamber to a second chamber while the nonoxidizing atmosphere is maintained, and forming a refractory metal film on the surface of the substrate by low-pressure CVD in the second chamber.
Inventors
- 👤 Tomonori Narita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:23
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/40; H10P14/42; H10P14/43; H10P70/00; H10P70/10; H10P70/12; H10D; H10D62/00; H10D62/10; H10D62/13; H10D62/149; H10D62/151; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/60; H10D64/66; H10D64/661; H10D64/662; H10D64/663; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P70/20; H10P70/23; H10P70/234; H10P70/27; Y; Y10; Y10S; Y10S148/00; Y10S148/006; Y10S148/017; Y10S438/00; Y10S438/906
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
95 words
A method of forming a conductive layer, comprising the steps of: performing dry etching of a surface of a substrate in a first chamber maintained in a nonoxidizing atmosphere, using a gas mixture of an N 2 gas and an NF 3 gas, to remove a natural oxide from said surface of said substrate; transferring said substrate from said first chamber to a second chamber while the nonoxidizing atmosphere is maintained; and forming a conductive layer consisting essentially of a refractory metal on said surface of said substrate by low-pressure CVD in said second chamber.
Claim 2
Independent Claim
95 words
A method of forming a conductive layer, comprising the steps of: performing dry etching of a surface of a substrate in a first chamber maintained in a nonoxidizing atmosphere, using a gas mixture of an N 2 gas and an NF 3 gas, to remove a natural oxide from said surface of said substrate; transferring said substrate from said first chamber to a second chamber while the nonoxidizing atmosphere is maintained; and forming a conductive layer consisting essentially of a refractory metal on said surface of said substrate by low-pressure CVD in said second chamber.
Claim 3
Dependent Claim
17 words
A method according to claim 1, wherein said dry etching is chemical dry etching using a plasma.
Claim 4
Dependent Claim
12 words
A method according to claim 1, wherein said refractory metal is tungsten.
Claim 5
Dependent Claim
32 words
A method according to claim 3, wherein said low-pressure CVD comprises the step of heating said substrate and supplying a WF 6 gas and an SiH 4 gas to said second chamber.
Claim 6
Independent Claim
151 words
A method for forming a gate electrode of a MOS type semiconductor device, comprising the steps of: forming a gate oxide film on a surface of a semiconductor substrate; forming a polycrystalline silicon layer on said gate oxide film; performing dry etching of said surface of said polycrystalline silicon layer in a first chamber maintained in a nonoxidizing atmosphere, using a gas mixture of an N 2 gas and an NF 3 gas, to remove a natural oxide from said surface of said polycrystalline silicon layer; transferring said substrate from said first chamber to a second chamber while the nonoxidizing atmosphere is maintained; forming a refractory metal layer on said surface of said polycrystalline silicon layer by low-pressure CVD in said second chamber; and patterning said polycrystalline silicon layer and said refractory metal layer to form a gate electrode consisting essentially of said polycrystalline silicon layer and said refractory metal layer.
Claim 7
Independent Claim
151 words
A method for forming a gate electrode of a MOS type semiconductor device, comprising the steps of: forming a gate oxide film on a surface of a semiconductor substrate; forming a polycrystalline silicon layer on said gate oxide film; performing dry etching of said surface of said polycrystalline silicon layer in a first chamber maintained in a nonoxidizing atmosphere, using a gas mixture of an N 2 gas and an NF 3 gas, to remove a natural oxide from said surface of said polycrystalline silicon layer; transferring said substrate from said first chamber to a second chamber while the nonoxidizing atmosphere is maintained; forming a refractory metal layer on said surface of said polycrystalline silicon layer by low-pressure CVD in said second chamber; and patterning said polycrystalline silicon layer and said refractory metal layer to form a gate electrode consisting essentially of said polycrystalline silicon layer and said refractory metal layer.
Claim 8
Dependent Claim
17 words
A method according to claim 5, wherein said dry etching is chemical dry etching using a plasma.
Claim 9
Dependent Claim
32 words
A method according to claim 5, wherein said low-pressure CVD comprises the step of heating said substrate and supplying a WF 6 gas and an SiH 4 gas to said second chamber.
Claim 10
Independent Claim
133 words
A method for forming source and drain electrodes of a MOS type semiconductor device, comprising the steps of: forming a gate oxide film and a gate electrode on a surface of a semiconductor substrate; forming source and drain regions by doping an impurity in said semiconductor substrate; performing dry etching of surfaces of said source and drain regions in a first chamber maintained in a nonoxidizing atmosphere, using a gas mixture of an N 2 gas and an NF 3 gas, to remove a natural oxide from said surfaces of said source and drain regions; transferring said substrate from said first chamber to a second chamber while the nonoxidizing atmosphere is maintained; and depositing a refractory metal on said surfaces of said source and drain regions by low-pressure CVD in said second chamber.
Claim 11
Independent Claim
133 words
A method for forming source and drain electrodes of a MOS type semiconductor device, comprising the steps of: forming a gate oxide film and a gate electrode on a surface of a semiconductor substrate; forming source and drain regions by doping an impurity in said semiconductor substrate; performing dry etching of surfaces of said source and drain regions in a first chamber maintained in a nonoxidizing atmosphere, using a gas mixture of an N 2 gas and an NF 3 gas, to remove a natural oxide from said surfaces of said source and drain regions; transferring said substrate from said first chamber to a second chamber while the nonoxidizing atmosphere is maintained; and depositing a refractory metal on said surfaces of said source and drain regions by low-pressure CVD in said second chamber.
Claim 12
Dependent Claim
17 words
A method according to claim 8, wherein said dry etching is chemical dry etching using a plasma.
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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) | 1994-01-14 | 1994-07-16 | 1995-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-14 | 1998-07-16 | 1999-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-14 | 2002-07-16 | 2003-01-15 | $7700.00 | Window Closed / Lapsed |