Patent US3881884A successfully refreshed from Google Patents.
US3881884A
Expired / Lapsed
US
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Method for the formation of corrosion resistant electronic interconnections
Assignee: International Business Machines Corp
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Filing: 1973-10-12
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Granted: 1975-05-06
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Expires: 1993-10-12
Abstract
Abstract Disclosed is a method for the manufacture of composite thin films useful among other applications as electronic microcircuit interconnections, fuses, and contacts, terminal pads and voltage distribution ring metallurgy comprising in carrying out an integral circuit fabrication process the steps of first depositing a barrier layer of antidiffusion material, such as chromium, followed by superimposing thereon a film of highly conductive metals susceptible to corrosion and followed by the deposition of a highly corrosive resistant metal film. A subtractive etch pattern is formed in the composite metal film followed by heating the structure to an elevated temperature for a predetermined period of time so that the uppermost layer of the composite flows by diffusion over the edge section to protect the conductive metal film from corrosive effects.
Inventors
- 👤 Herbert Carl Cook
- 👤 Paul Alden Farrar
- 👤 Robert Lee Hallen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:42
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/24; H05K3/244; H01; H01B; H01B1/00; H05K3/38; H05K3/388; H10; H10P; H10P95/00; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/425; H10W20/44; H10W20/4403; H10W20/4432; H10W72/00; H10W72/01; H10W72/012; H05K2203/00; H05K2203/11; H05K2203/1105; H10W72/20; H10W72/251; H10W72/90; H10W72/921; H10W72/923; H10W72/951; H10W72/952
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
118 words
IN AN INTEGRATED CIRCUIT FABRICATION PROCESS THE STEPS OF DEPOSITION ON A PARTIALLY FABRICATED INTEGRATED CIRCUIT SUBSTRATE A COMPOSITE CONDUCTIVE FILM STRUCTURE BY SEQUENTIALLY FORMING A FIRST CONDUCTIVE FILM AND SUPERIMPOSING THEREON A SECOND CONDUCTIVE FILM THROUGH A TRANSISTORY LAYER MADE OF MATERIAL OF BOTH OF SAID FIRST AND SECOND FILMS AND FORMING THEREON A THIRD NOBLE METAL CONDUCTIVE METAL FILM FOLLOWED BY SUBSTRACTIVELY ETCHING A PORTION OF SAID COMPOSITE FILM TO FORM A GIVEN PATTERN HAVING EXPOSED EDGES OF SAID SECOND FILM TO FORM A GIVEN THE ETCHED SURFACE TO AN ELEVATED TEMPERATURE IN A SELECTED ATMOSPHERE TO FLOW BY SURFACE DIFFUSION A PORTION OF SAID NOBLE METAL FILM OVER THE EXPOSED EDGES OF SAID SECOND FILM.
Claim 2
Dependent Claim
118 words
IN AN INTEGRATED CIRCUIT FABRICATION PROCESS THE STEPS OF DEPOSITION ON A PARTIALLY FABRICATED INTEGRATED CIRCUIT SUBSTRATE A COMPOSITE CONDUCTIVE FILM STRUCTURE BY SEQUENTIALLY FORMING A FIRST CONDUCTIVE FILM AND SUPERIMPOSING THEREON A SECOND CONDUCTIVE FILM THROUGH A TRANSISTORY LAYER MADE OF MATERIAL OF BOTH OF SAID FIRST AND SECOND FILMS AND FORMING THEREON A THIRD NOBLE METAL CONDUCTIVE METAL FILM FOLLOWED BY SUBSTRACTIVELY ETCHING A PORTION OF SAID COMPOSITE FILM TO FORM A GIVEN PATTERN HAVING EXPOSED EDGES OF SAID SECOND FILM TO FORM A GIVEN THE ETCHED SURFACE TO AN ELEVATED TEMPERATURE IN A SELECTED ATMOSPHERE TO FLOW BY SURFACE DIFFUSION A PORTION OF SAID NOBLE METAL FILM OVER THE EXPOSED EDGES OF SAID SECOND FILM.
Claim 3
Dependent Claim
20 words
A method in accordance with claim 1 wherein said composite film is a sequential deposition of chromium, copper and gold.
Claim 4
Dependent Claim
18 words
A method in accordance with claim 1 wherein said composite film is formed on a quartz covered substrate.
Claim 5
Dependent Claim
19 words
A method in accordance with claim 1 wherein said composite film is formed on an organic polymeric covered substrate.
Claim 6
Dependent Claim
18 words
A method in accordance with claim 1 wherein said composite film is formed on a polyimide covered substrate.
Claim 7
Dependent Claim
18 words
A method in accordance with claim 1 wherein said heat treatment is carried out in a reducing atmosphere.
Claim 8
Dependent Claim
18 words
A method in accordance with claim 1 wherein said heat treatment is carried out in a hydrogen atmosphere.
Claim 9
Dependent Claim
19 words
A method in accordance with claim 1 wherein said heat treatment is carried out in an inert gas atmosphere.
Claim 10
Dependent Claim
14 words
A method in accordance with claim 1 wherein said noble metal film is gold.
Claim 11
Dependent Claim
33 words
A method in accordance with claim 1 wherein said substrate is quartz covered And the composite film is sequentially chromium-copper-gold heat treated in a hydrogen atmosphere to a temperature between 345*C and 355*C.
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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |