US4980020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Local interconnect etch technique
Assignee: Texas Instruments Inc
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Filing: 1989-12-22
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Granted: 1990-12-25
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Expires: 2009-12-22
Abstract
Abstract The disclosure relates to a method of forming a local interconnect by using a fluorine-based etchant with selectivity to cobalt and/or titanium silicide for removing unmasked portions of an electrically conductive interconnect pattern which is connected to a region of cobalt or titanium silicide.
Inventors
- 👤 Monte A. Douglas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:38
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10P; H10P50/00; H10P50/60; H10P50/66; H10P50/663; H10P50/667; H10W20/031; H10W20/0698
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
107 words
A method of forming an electrically conductive interconnect comprising the steps of: (a) providing a silicon semiconductor surface having regions of exposed silicon and regions of dielectric thereon; (b) forming a layer taken from the class consisting of cobalt and titanium over said surface; (c) reacting said layer with said exposed silicon to form a silicide therewith; (d) removing the non-silicided portion of said layer; (e) forming a layer of electrically conductive material over said surface; (f) forming a mask over predetermined portions of said layer of electrically conductive material; (g) removing the unmasked portion of said layer of electrically conductive material; and (h) removing said mask.
Claim 2
Independent Claim
107 words
A method of forming an electrically conductive interconnect comprising the steps of: (a) providing a silicon semiconductor surface having regions of exposed silicon and regions of dielectric thereon; (b) forming a layer taken from the class consisting of cobalt and titanium over said surface; (c) reacting said layer with said exposed silicon to form a silicide therewith; (d) removing the non-silicided portion of said layer; (e) forming a layer of electrically conductive material over said surface; (f) forming a mask over predetermined portions of said layer of electrically conductive material; (g) removing the unmasked portion of said layer of electrically conductive material; and (h) removing said mask.
Claim 3
Dependent Claim
30 words
The method according to claim 1 wherein said electrically conductive material is taken from the class consisting of such materials that form volatile fluoride compounds at about 25 degrees C.
Claim 4
Dependent Claim
21 words
The method of claim 1 wherein said mask extends between two electrically isolated ones of the silicided portions of said layer.
Claim 5
Dependent Claim
21 words
The method of claim 2 wherein said mask extends between two electrically isolated ones of the silicided portions of said layer.
Claim 6
Dependent Claim
27 words
The method of claim 1 wherein said mask extends between a said silicide portion of said layer and an electrical conductor electrically isolated from said silicided portion.
Claim 7
Dependent Claim
27 words
The method of claim 2 wherein said mask extends between a said silicide portion of said layer and an electrical conductor electrically isolated from said silicided portion.
Claim 8
Independent Claim
35 words
The method of claim I wherein said step of removing the unmasked portion of said layer of electrically conductive material comprises etching said unmasked portion with a fluorine based etchant with selectivity to said silicide.
Claim 9
Dependent Claim
35 words
The method of claim 2 wherein said step of removing the unmasked portion of said layer of electrically conductive material comprises etching said unmasked portion with a fluorine based etchant with selectivity to said silicide.
Claim 10
Dependent Claim
35 words
The method of claim 3 wherein said step of removing the unmasked portion of said layer of electrically conductive material comprises etching said unmasked portion with a fluorine based etchant with selectivity to said silicide.
Claim 11
Dependent Claim
35 words
The method of claim 4 wherein said step of removing the unmasked portion of said layer of electrically conductive material comprises etching said unmasked portion with a fluorine based etchant with selectivity to said silicide.
Claim 12
Dependent Claim
35 words
The method of claim 5 wherein said step of removing the unmasked portion of said layer of electrically conductive material comprises etching said unmasked portion with a fluorine based etchant with selectivity to said silicide.
Claim 13
Dependent Claim
35 words
The method of claim 6 wherein said step of removing the unmasked portion of said layer of electrically conductive material comprises etching said unmasked portion with a fluorine based etchant with selectivity to said silicide.
References Cited (Backward Citations)
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Cited
US4863559A
Cited
US4863559B1
Cited
US4793896C1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-24 | 1994-06-25 | 1994-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-24 | 1998-06-25 | 1998-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-24 | 2002-06-25 | 2002-12-25 | $7700.00 | Window Closed / Lapsed |