US5376234A
Expired / Lapsed
US
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Dry etching method
Assignee: Sony Corp
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Filing: 1993-06-21
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Granted: 1994-12-27
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Expires: 2013-06-21
Abstract
Abstract A dry etching method wherein one compound selected from mercaptan, thioether and disulfide each having a fluorocarbon side chain is used as a main component of an etching gas. These compounds may form CF x + and S on dissociation due to electric discharges, and contribute to high-rate etching and surface protection of a wafer. If a halogen compound such as CO, SOF 2 or NOF is added to the etching gas, a high-rate etching reaction due to extraction of O atoms from SiO 2 and structural reinforcement of carbonaceous polymer become possible. Also, S 2 F 2 may be added for reinforcing deposition of S. These effects lead to a reduction of the deposit amount of polymer necessary for highly selective processing, and contribute greatly to low pollution in a process.
Inventors
- 👤 Toshiharu Yanagida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:07
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10P50/73
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
77 words
A plasma etching method for etching a silicon compound layer, comprising the steps of: providing a patterned masking material over the silicon compound layer to expose the areas of the silicon compound layer to be etched; and etching the exposed silicon compound layer using an etching gas comprising at least one sulfur-containing compound selected from the group consisting of mercaptan having a fluorocarbon side chain, thioether having a fluorocarbon side chain, and disulfide having fluorocarbon side chain.
Claim 2
Dependent Claim
77 words
A plasma etching method for etching a silicon compound layer, comprising the steps of: providing a patterned masking material over the silicon compound layer to expose the areas of the silicon compound layer to be etched; and etching the exposed silicon compound layer using an etching gas comprising at least one sulfur-containing compound selected from the group consisting of mercaptan having a fluorocarbon side chain, thioether having a fluorocarbon side chain, and disulfide having fluorocarbon side chain.
Claim 3
Dependent Claim
34 words
The plasma etching method as claimed in claim 1, wherein said silicon compound layer is selected from the group consisting of a silicon oxide based material layer and a silicon nitride based material layer.
Claim 4
Dependent Claim
54 words
The plasma etching method as claimed in claim 1, wherein said silicon compound layer is formed on a base layer which is selected from the group consisting of an impurity diffused region in a single crystal Si substrate, a polysilicon layer, a polycide film, an Al based material layer, and a refractory metal layer.
Claim 5
Dependent Claim
51 words
The plasma etching method as claimed in claim 1, wherein said etching gas comprises at least one kind of sulfur fluoride selected from the group consisting of S 2 F 2 , SF 2 , SF 4 and S 2 F 10 , for supplying depositable S during the etching step.
Claim 6
Dependent Claim
16 words
The plasma etching method as claimed in claim 1, wherein said disulfide is bis (trifluoromethyl) disulfide.
Claim 7
Dependent Claim
30 words
The plasma etching method as claimed in claim 1, wherein said etching gas comprises at least one compound selected from a second group consisting of carbon monoxide and carbonyl sulfide.
Claim 8
Dependent Claim
34 words
The dry etching method as claimed in claim 6, wherein said silicon compound layer is selected from the group consisting of a silicon oxide based material layer and a silicon nitride based material layer.
Claim 9
Dependent Claim
54 words
The plasma etching method as claimed in claim 6, wherein said silicon compound layer is formed on a base layer which is selected from the group consisting of an impurity diffused region in a single crystal Si substrate, a polysilicon layer, a polycide film, an Al based material layer, and a refractory metal layer.
Claim 10
Dependent Claim
27 words
The plasma etching method as claimed in claim 6, wherein said halogen compound is selected from the group consisting of carbonyl fluoride, thionyl fluoride and nitrosyl fluoride.
Claim 11
Dependent Claim
51 words
The plasma etching method as claimed in claim 6, wherein said etching gas comprises at least one kind of sulfur fluoride selected from the group consisting of S 2 F 2 , SF 2 , SF 4 and S 2 F 10 , for supplying depositable S during the etching step.
Claim 12
Dependent Claim
16 words
The dry etching method as claimed in claim 6, wherein said disulfide is bis (trifluoromethyl) disulfide,
Claim 13
Dependent Claim
44 words
A plasma etching method as claimed in claim 1, wherein said etching gas comprises a halogen compound having in a molecule a halogen atom and at least one functional group selected from the group consisting of carbonyl, thionyl, sulfuryl, nitryl and nitrosyl functional groups.
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) | 1997-12-26 | 1998-06-27 | 1998-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-26 | 2002-06-27 | 2002-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-26 | 2006-06-27 | 2006-12-27 | $7700.00 | Window Closed / Lapsed |