Patent US5792710A successfully refreshed from Google Patents.
US5792710A
Expired / Lapsed
US
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Method for selectively etching polycide layer
Assignee: NEC Corp
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Filing: 1997-03-11
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Granted: 1998-08-11
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Expires: 2017-03-11
Abstract
Abstract Disclosed herein is a method of manufacturing a semiconductor device, the method including a step of anisotropic-etching of a high-melting-point (or refractory) metal silicide layer by use of a halogen-containing gas using. This halogen-containing gas has a boron trichloride gas as a main component gas and either one of a chlorine gas or a hydrogen bromide gas as an auxiliary or a sub-component gas.
Inventors
- 👤 Kazuyoshi Yoshida
- 👤 Hidenobu Miyamoto
- 👤 Eiji Ikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:32
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
76 words
A method of etching selectively a refractory metal-silicide layer laminated on a polysilicon layer formed on a silicon substrate, said method comprising the step of anisotropically etching said refractory metal silicide layer by an etching gas that consists of a boron trichloride gas as a main component and a hydrogen bromide gas as an auxiliary component, said etching gas comprising more than 25% boron trichloride gas so that residues are not formed on said polysilicon layer.
Claim 2
Independent Claim
76 words
A method of etching selectively a refractory metal-silicide layer laminated on a polysilicon layer formed on a silicon substrate, said method comprising the step of anisotropically etching said refractory metal silicide layer by an etching gas that consists of a boron trichloride gas as a main component and a hydrogen bromide gas as an auxiliary component, said etching gas comprising more than 25% boron trichloride gas so that residues are not formed on said polysilicon layer.
Claim 3
Dependent Claim
16 words
The method as claimed in claim 1, wherein said etching gas further contains a rare gas.
Claim 4
Dependent Claim
18 words
The method as claimed in claim 1, wherein said refractory metal silicide film is a titanium silicide film.
Claim 5
Dependent Claim
18 words
The method as claimed in claim 3, wherein said titanium silicide film is formed on a polysilicon film.
Claim 6
Independent Claim
95 words
A method of manufacturing a semiconductor device comprising the steps of: forming a silicon oxide film on a semiconductor substrate, forming a polysilscon layer on said silicon oxide film, forming a titanium silicide film on said polysilicon layer, selectively etching said titanium silicide film over said polysilicon layer by use of an etching gas that contains a boron trichloride gas and a hydrogen bromide gas, said boron trichloride gas having a flow rate set to be more than 25% of a total gas flow rate so that residue are not formed on said polysilicon layer.
Claim 7
Independent Claim
95 words
A method of manufacturing a semiconductor device comprising the steps of: forming a silicon oxide film on a semiconductor substrate, forming a polysilscon layer on said silicon oxide film, forming a titanium silicide film on said polysilicon layer, selectively etching said titanium silicide film over said polysilicon layer by use of an etching gas that contains a boron trichloride gas and a hydrogen bromide gas, said boron trichloride gas having a flow rate set to be more than 25% of a total gas flow rate so that residue are not formed on said polysilicon layer.
Claim 8
Dependent Claim
16 words
The method as claimed in claim 5, wherein said etching gas further contains a rare gas.
Claim 9
Dependent Claim
15 words
The method as claimed in claim 6, wherein said rare gas includes a helium gas.
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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) | 2001-08-10 | 2002-02-09 | 2002-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-10 | 2006-02-09 | 2006-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-10 | 2010-02-09 | 2010-08-11 | $7700.00 | Window Closed / Lapsed |