US4473436A
Expired / Lapsed
US
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Method of producing structures from double layers of metal silicide and polysilicon on integrated circuit substrates by RIE utilizing SF6 and Cl2
Assignee: Infineon Technologies AG
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Filing: 1983-05-02
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Granted: 1984-09-25
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Expires: 2003-05-02
Abstract
Abstract The invention provides a method of producing structures from double layers composed of a metal silicide (4) and polysilicon (3) on a silicon substrate (1) containing integrated semiconductor circuits in an operational plate reactor by reactive ion etching and with the use of a photosensitive resist mask (5) on the double layer to define desired structures. The plate reactor is provided with a controlled reactive gas mixture which contains fluorine and chlorine. The double layer (3, 4) in preferred embodiments is composed of a tantalum silicide layer and a polysilicon layer. An insulating layer (2) can be provided between the substrate and the double layer. The invention is useful for providing low-resistant interconnects in VLSI circuits.
Inventors
- 👤 Willy Beinvogl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:46
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/066
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
84 words
In a method of producing structures from double layers consisting of metal silicide/polysilicon on a silicon substrate containing integrated semiconductor circuits by a reactive ion etching in an operational plate reactor with the use of a reactive gas mixture and a photosensitive resist mask to define desired structures, wherein the improvement comprises: utilizing as said reactive gas mixture a mixture of sulfur hexafluoride and chlorine, and carrying out reactive ion etching of the double layers in said plate reactor to obtain the desired structures.
Claim 2
Dependent Claim
84 words
In a method of producing structures from double layers consisting of metal silicide/polysilicon on a silicon substrate containing integrated semiconductor circuits by a reactive ion etching in an operational plate reactor with the use of a reactive gas mixture and a photosensitive resist mask to define desired structures, wherein the improvement comprises: utilizing as said reactive gas mixture a mixture of sulfur hexafluoride and chlorine, and carrying out reactive ion etching of the double layers in said plate reactor to obtain the desired structures.
Claim 3
Dependent Claim
86 words
In a method of producing structures from tantalum silicide-polysilicon double layers on silicon substrates containing integrated semiconductor circuits by reactive ion etching in an operational plate reactor with a reactive gas mixture, the improvement which comprises: producing an underetching effect by using a reactive gas mixture of sulfur hexafluoride and chlorine at a mixing ratio of about 2:1, a gas pressure in said reactor of about 6 to 9 Pa, and a power input to the reactor of from about 0.1 to 0.14 W/cm 2 .
Claim 4
Dependent Claim
86 words
In a method of producing structures from tantalum silicide-polysilicon double layers on silicon substrates containing integrated semiconductor circuits by reactive ion etching in an operational plate reactor with a reactive gas mixture, the improvement which comprises: producing an underetching effect by using a reactive gas mixture of sulfur hexafluoride and chlorine at a mixing ratio of about 2:1, a gas pressure in said reactor of about 6 to 9 Pa, and a power input to the reactor of from about 0.1 to 0.14 W/cm 2 .
Claim 5
Dependent Claim
98 words
In a method of producing structures from tantalum silicide-polysilicon double layers on silicon substrates containing integrated semiconductor circuits by reactive ion etching in an operational plate reactor with a reactive gas mixture, the improvement which comprises: producing an anisotropic etching effect by using a reactive gas mixture of sulfur hexafluoride and chlorine, the etching process being carried out in two steps with the layer of tantalum silicide being etched first with a ratio of SF 6 :Cl 2 in the gas mixture of greater than 3:1 and thereafter etching the layer of polysilicon with substantially pure chlorine gas.
Claim 6
Dependent Claim
98 words
In a method of producing structures from tantalum silicide-polysilicon double layers on silicon substrates containing integrated semiconductor circuits by reactive ion etching in an operational plate reactor with a reactive gas mixture, the improvement which comprises: producing an anisotropic etching effect by using a reactive gas mixture of sulfur hexafluoride and chlorine, the etching process being carried out in two steps with the layer of tantalum silicide being etched first with a ratio of SF 6 :Cl 2 in the gas mixture of greater than 3:1 and thereafter etching the layer of polysilicon with substantially pure chlorine gas.
Claim 7
Dependent Claim
77 words
In a method of producing structures from tantalum silicide-polysilicon double layers on silicon substrates containing integrated semiconductor circuits by reactive ion etching in an apertured plate reactor with a reactive gas mixture, the improvement which comprises: producing an underetching in the polysilicon layer by using a ratio of active reactive gas volume in said reactor to overall reactor volume of less than about 1:20, and employing a mixing ratio of SF 6 :Cl 2 of about 1:1.
Claim 8
Dependent Claim
77 words
In a method of producing structures from tantalum silicide-polysilicon double layers on silicon substrates containing integrated semiconductor circuits by reactive ion etching in an apertured plate reactor with a reactive gas mixture, the improvement which comprises: producing an underetching in the polysilicon layer by using a ratio of active reactive gas volume in said reactor to overall reactor volume of less than about 1:20, and employing a mixing ratio of SF 6 :Cl 2 of about 1:1.
Claim 9
Dependent Claim
33 words
A method according to claim 4 wherein underetching in the layer of tantalum silicide is achieved using a ratio of reactive gas volume in said reactor to overall reactor volume of about 1:2.
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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) | 1987-09-25 | 1988-03-26 | 1988-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-25 | 1992-03-26 | 1992-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-25 | 1996-03-26 | 1996-09-25 | $7700.00 | Window Closed / Lapsed |