Patent US4975389A successfully refreshed from Google Patents.
US4975389A
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Aluminum metallization for semiconductor devices
Assignee: Nokia Bell Labs
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Filing: 1989-10-25
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Granted: 1990-12-04
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Expires: 2009-10-25
Abstract
Abstract Stress induced grain boundary movement in aluminum lines used as connections in integrated circuits is substantially avoided by doping the aluminum with iron. Through this expedient not only is grain boundary movemenmt avoided but electromigration problems are also decreased.
Inventors
- 👤 Vivian W. Ryan
- 👤 Ronald J. Schutz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:28
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/44; H10W20/4403; H10W20/4405; H10W20/4407; Y; Y10; Y10S; Y10S438/00; Y10S438/927
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
93 words
A process for fabricating a semiconductor integrated circuit device comprising the steps of forming active device regions of said integrated circuit in a substrate comprising a semiconductor material and electrically interconnecting said active regions within said integrated circuit with a region of metal characterized in that at least a portion of said region of metal is formed from a material comprising iron doped aluminum whereby the tensile yield strength of said iron doped aluminum material is increased at least 15 percent relative to that obtained for aluminum doped with 0.5 atomic percent copper.
Claim 2
Dependent Claim
93 words
A process for fabricating a semiconductor integrated circuit device comprising the steps of forming active device regions of said integrated circuit in a substrate comprising a semiconductor material and electrically interconnecting said active regions within said integrated circuit with a region of metal characterized in that at least a portion of said region of metal is formed from a material comprising iron doped aluminum whereby the tensile yield strength of said iron doped aluminum material is increased at least 15 percent relative to that obtained for aluminum doped with 0.5 atomic percent copper.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein said iron doped aluminum material comprises aluminum doped with up to 5 atomic percent iron.
Claim 4
Dependent Claim
10 words
The process of claim 1 wherein said aluminum includes silicon.
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) | 1993-12-03 | 1994-06-04 | 1994-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-03 | 1998-06-04 | 1998-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-03 | 2002-06-04 | 2002-12-04 | $7700.00 | Window Closed / Lapsed |