US5314576A
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Dry etching method using (SN)x protective layer
Assignee: Sony Corp
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Filing: 1992-06-09
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Granted: 1994-05-24
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Expires: 2012-06-09
Abstract
Abstract A dry etching method whereby high anisotropy can be achieved while providing sidewall protection effects by using an appropriate alternative substance to a carbonaceous polymer. A target material layer is etched by using etching gas containing a nitrogen based compound and a sulfur based compound capable of forming free sulfur (S) in a plasma when dissociated by electric discharges while a pattern sidewall is protected by a sulfur nitride based compound occurring from the gaseous phase. The sulfur nitride based compound is composed mainly of polythiazyl (SN) x , which causes no particle pollution because it will be removed from a wafer through sublimation or decomposition when the wafer is heated to temperatures above 130° C. For instance, a polysilicon layer or an Al based material layer can be etched into an anisotropic shape by using S 2 Cl 2 /N 2 mixed gas. Particularly, a silicon based compound layer can be etched while preventing chloroflurocarbon (CFC) gas effectively. The sidewall protection film composed of (SN) x has such excellent resistance to attacks by radicals or incident ions that a pattern formed into an anisotropic shape will not be deformed even when over-etched with radicals.
Inventors
- 👤 Shingo Kadomura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:53
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
68 words
A dry etching method comprising plasma etching a target material layer selected from the group consisting of silicon based materials and aluminum based materials deposited on a substrate by using etching gas containing a nitrogen based compound and a sulfur based compound capable of forming free nitrogen and sulfur, respectively, in a plasma when dissociated by electric discharges to form a side wall protection compound of sulfur nitride.
Claim 2
Dependent Claim
68 words
A dry etching method comprising plasma etching a target material layer selected from the group consisting of silicon based materials and aluminum based materials deposited on a substrate by using etching gas containing a nitrogen based compound and a sulfur based compound capable of forming free nitrogen and sulfur, respectively, in a plasma when dissociated by electric discharges to form a side wall protection compound of sulfur nitride.
Claim 3
Dependent Claim
46 words
A dry etching method as claimed in claim 1 wherein said nitrogen based compound is at least one compound selected from the group consisting of N 2 , N 2 H 2 , NF 3 , NCl 3 , NBr 3 , and NO 2 .
Claim 4
Dependent Claim
77 words
A dry etching method as claimed in claim 1 wherein said sulfur based compound is at least one compound selected from the group consisting of S 2 F 2 , SF 2 , SF 4 , S 2 F 10 , S 3 Cl 2 , S 2 Cl 2 , SCl 2 , S 3 Br 2 , S 2 Br 2 , SBr 2 , SOF 2 , SOCl 2 , and SOBr 2 .
Claim 5
Dependent Claim
43 words
A dry etching method as claimed in claim 1 wherein said target material layer is any material selected from the group consisting of a single-crystal silicon layer, a polysilicon layer, an amorphous silicon layer, a refractory metal silicide layer, and a polycide film.
Claim 6
Dependent Claim
38 words
A dry etching method as claimed in claim 1 wherein said substrate is a single-crystal silicon substrate coated on the surface thereof with a gate oxide film, said target material layer being a polysilicon layer or polycide film.
Claim 7
Dependent Claim
36 words
A dry etching method as claimed in claim 1 wherein said substrate is coated on the surface thereof with an inter-layer insulation film, said target material layer being a polycide film or Al based material layer.
Claim 8
Dependent Claim
98 words
A dry etching method comprising plasma etching a target material layer selected from the group consisting of silicon based materials and aluminum based materials deposited on a substrate by using etching gas containing a nitrogen based compound, a sulfur based compound, and at least one halogen radical consuming compound selected from the group consisting of H 2 , H 2 S, and silane based compounds, said sulfur based compound and said nitrogen based compound forming free sulfur and nitrogen, respectively, in a plasma when dissociated by electric discharges to form a side wall protection compound of sulfur nitride.
Claim 9
Dependent Claim
98 words
A dry etching method comprising plasma etching a target material layer selected from the group consisting of silicon based materials and aluminum based materials deposited on a substrate by using etching gas containing a nitrogen based compound, a sulfur based compound, and at least one halogen radical consuming compound selected from the group consisting of H 2 , H 2 S, and silane based compounds, said sulfur based compound and said nitrogen based compound forming free sulfur and nitrogen, respectively, in a plasma when dissociated by electric discharges to form a side wall protection compound of sulfur nitride.
Claim 10
Dependent Claim
46 words
A dry etching method as claimed in claim 7 wherein said nitrogen based compound is at least one compound selected from the group consisting of N 2 , N 2 H 2 , NF 3 , NCl 3 , NBr 3 , and NO 2 .
Claim 11
Dependent Claim
77 words
A dry etching method as claimed in claim 7 wherein said sulfur based compound is at least one compound selected from the group consisting of S 2 F 2 , SF 2 , SF 4 , S 2 F 10 , S 3 Cl 2 , S 2 Cl 2 , SCl 2 , S 3 Br 2 , S 2 Br 2 , SBr 2 , SOF 2 , SOCl 2 , and SOBr 2 .
Claim 12
Dependent Claim
43 words
A dry etching method as claimed in claim 7 wherein said silicon based material is any material selected from the group consisting of a single-crystal silicon layer, a polysilicon layer, an amorphous silicon layer, a refractory metal silicide layer and, a polycide film.
Claim 13
Dependent Claim
38 words
A dry etching method as claimed in claim 7 wherein said substrate is a single-crystal silicon substrate coated on the surface thereof with a gate oxide film, said target material layer being a polysilicon layer or polycide film.
Claim 14
Dependent Claim
36 words
A dry etching method as claimed in claim 7 wherein said substrate is coated on the surface thereof with an inter-layer insulation film, said target material layer being a polycide film or Al based material layer.
Claim 15
Dependent Claim
27 words
A dry etching method as claimed in claim 7 wherein said target material layer is etched in such a manner that it has a tapered sectional shape.
Claim 16
Dependent Claim
104 words
A dry etching method comprising a step of plasma etching a target material layer selected from the group consisting of silicon based materials and aluminum based materials deposited on a substrate having a surface with grooves and steps by using etching gas containing a nitrogen based compound and s sulfur based compound capable of forming free nitrogen and sulfur, respectively, in a plasma when dissociated by electric discharges to form a side wall protection compound of sulfur nitride, and a subsequent step of removing etching residues of said target material layer form the bottoms of said steps and grooves mainly by etching with radicals.
Claim 17
Dependent Claim
104 words
A dry etching method comprising a step of plasma etching a target material layer selected from the group consisting of silicon based materials and aluminum based materials deposited on a substrate having a surface with grooves and steps by using etching gas containing a nitrogen based compound and s sulfur based compound capable of forming free nitrogen and sulfur, respectively, in a plasma when dissociated by electric discharges to form a side wall protection compound of sulfur nitride, and a subsequent step of removing etching residues of said target material layer form the bottoms of said steps and grooves mainly by etching with radicals.
Claim 18
Dependent Claim
46 words
A dry etching method as claimed in claim 14 wherein said nitrogen based compound is at least one compound selected from the group consisting of N 2 , N 2 H 2 , NF 3 , NCl 3 , NBr 3 , and NO 2 .
Claim 19
Dependent Claim
77 words
A dry etching method as claimed in claim 14 wherein said sulfur based compound is at least one compound selected from the group consisting of S 2 F 2 , SF 2 , SF 4 , S 2 F 10 , S 3 Cl 2 , S 2 Cl 2 , SCl 2 , S 3 Br 2 , S 2 Br 2 , SBr 2 , SOF 2 , SOCl 2 , and SOBr 2 .
Claim 20
Dependent Claim
43 words
A dry etching method as claimed in claim 14 wherein said silicon based material is any material selected from the group consisting of a single-crystal silicon layer, a polysilicon layer, an amorphous silicon layer, a refractory metal silicide layer and, a polycide film.
Claim 21
Dependent Claim
38 words
A dry etching method as claimed in claim 14 wherein said substrate is a single-crystal silicon substrate coated on the surface thereof with a gate oxide film, said target material layer being a polysilicon layer or polycide film.
Claim 22
Dependent Claim
36 words
A dry etching method as claimed in claim 14 wherein said substrate is coated on the surface thereof with an inter-layer insulation film, said target material layer being a polycide film or Al based material layer.
Claim 23
Dependent Claim
135 words
A dry etching method comprising: a step of plasma etching a target material layer selected from the group consisting of silicon based materials and aluminum based materials deposited on a substrate having grooves on the surface thereof by using an etching gas containing a nitrogen based compound, a sulfur based compound, which sulfur based compound and nitrogen based compound are capable of forming free sulfur and nitrogen, respectively, in a plasma when dissociated by electric discharges to form a sulfur nitride sidewall protection compound, and said gas having at least one halogen radical consuming compound selected from the group consisting of H 2 , H 2 S, and silane based compounds, and a subsequent step of removing etching residues of said target material layer from the bottoms of said grooves mainly by etching with radicals.
Claim 24
Dependent Claim
135 words
A dry etching method comprising: a step of plasma etching a target material layer selected from the group consisting of silicon based materials and aluminum based materials deposited on a substrate having grooves on the surface thereof by using an etching gas containing a nitrogen based compound, a sulfur based compound, which sulfur based compound and nitrogen based compound are capable of forming free sulfur and nitrogen, respectively, in a plasma when dissociated by electric discharges to form a sulfur nitride sidewall protection compound, and said gas having at least one halogen radical consuming compound selected from the group consisting of H 2 , H 2 S, and silane based compounds, and a subsequent step of removing etching residues of said target material layer from the bottoms of said grooves mainly by etching with radicals.
Claim 25
Dependent Claim
46 words
A dry etching method as claimed in claim 20 wherein said nitrogen based compound is at least one compound selected from the group consisting of N 2 , N 2 H 2 , NF 3 , NCl 3 , NBr 3 , and NO 2 .
Claim 26
Dependent Claim
77 words
A dry etching method as claimed in claim 20 wherein said sulfur based compound is at least one compound selected from the group consisting of S 2 F 2 , SF 2 , SF 4 , S 2 F 10 , S 3 Cl 2 , S 2 Cl 2 , SCl 2 , S 3 Br 2 , S 2 Br 2 , SBr 2 , SOF 2 , SOCl 2 , and SOBr 2 .
Claim 27
Dependent Claim
39 words
A dry etching method as claimed in claim 20 wherein said target material layer is any material selected from the group consisting of a single-crystal silicon layer, polysilicon layer, amorphous silicon layer, refractory metal silicide layer and, polycide film.
Claim 28
Dependent Claim
38 words
A dry etching method as claimed in claim 20 wherein said substrate is a single-crystal silicon substrate coated on the surface thereof with a gate oxide film, said target material layer being a polysilicon layer or polycide film.
Claim 29
Dependent Claim
36 words
A dry etching method as claimed in claim 20 wherein said substrate is coated on the surface thereof with an inter-layer insulation film, said target material layer being a polycide film or Al based material layer.
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| 3.5 Years (Year 4) | 1997-05-23 | 1997-11-22 | 1998-05-24 | $2000.00 | Window Closed / Lapsed |
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