Patent US5243221A successfully refreshed from Google Patents.
US5243221A
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Aluminum metallization doped with iron and copper to prevent electromigration
Assignee: Nokia Bell Labs
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Filing: 1993-01-05
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Granted: 1993-09-07
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Expires: 2013-01-05
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 movement 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 17:17
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/44; H10W20/4403; H10W20/4405; H10W20/4407; H10W20/45; H10W20/48
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
82 words
A semiconductor device comprising a substrate comprising a silicon semiconductor material including active regions with electrical interconnects between said active regions wherein at least a portion of said interconnects are made with a material comprising iron doped aluminum whereby the tensile 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 and wherein contact to said active regions is between said material and a second electrical conductor.
Claim 2
Dependent Claim
82 words
A semiconductor device comprising a substrate comprising a silicon semiconductor material including active regions with electrical interconnects between said active regions wherein at least a portion of said interconnects are made with a material comprising iron doped aluminum whereby the tensile 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 and wherein contact to said active regions is between said material and a second electrical conductor.
Claim 3
Dependent Claim
20 words
The device of claim 1 wherein said iron doped aluminum comprises aluminum doped with up to 0.5 atomic percent copper.
Claim 4
Dependent Claim
10 words
The device 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) | 1996-09-06 | 1997-03-08 | 1997-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-09-06 | 2001-03-08 | 2001-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-09-06 | 2005-03-08 | 2005-09-07 | $7700.00 | Window Closed / Lapsed |