US4922320A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated circuit metallization with reduced electromigration
Assignee: Texas Instruments Inc
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Filing: 1988-02-16
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Granted: 1990-05-01
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Expires: 2008-02-16
Abstract
Abstract The specification discloses a method and a device wherein circuit elements (10) are formed on the surface of a semiconductor body (12). A layer of oxide (22) is applied over the circuit element (10). An aperture (32) is opened through the oxide layer (22). The surface of oxide layer (22) is nonuniformly substantially roughened. A layer of metal (24) such as aluminum is formed over the oxide layer (22) and extends into the aperture (32) for contact with a portion of the device (10). The layer of metal (24) has increased granular structure and a roughened exterior surface to provide enhanced electromigration properties.
Inventors
- 👤 James M. McDavid
- 👤 Dirk N. Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:20
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/069; H10W20/071; H10W20/081; H10W20/082; H10W20/40; H10W20/41; H10W20/44; H10W20/4403; H10W20/4405
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
108 words
A semiconductor integrated circuit with reduced electromigration in lead metallization, comprising: A. a body of semiconductor material having a circuit element formed on a face thereof; B. an insulating layer formed on said face over said circuit element, said insulating layer including an aperture formed therethrough to provide access to said underlying circuit element, and said insulating layer having a roughened surface; and C. a conductive metal strip formed over said insulating layer and into said aperture to contact said circuit element, said roughened surface of said insulating layer causing said metal strip to have increased interior grain structure and a roughened surface, which provide improved electromigration characteristics.
Claim 2
Dependent Claim
108 words
A semiconductor integrated circuit with reduced electromigration in lead metallization, comprising: A. a body of semiconductor material having a circuit element formed on a face thereof; B. an insulating layer formed on said face over said circuit element, said insulating layer including an aperture formed therethrough to provide access to said underlying circuit element, and said insulating layer having a roughened surface; and C. a conductive metal strip formed over said insulating layer and into said aperture to contact said circuit element, said roughened surface of said insulating layer causing said metal strip to have increased interior grain structure and a roughened surface, which provide improved electromigration characteristics.
Claim 3
Dependent Claim
24 words
The semiconductor device of claim 1 wherein said insulating layer has a roughened surface nonuniformly varying in thickness between 300 Å and 3000 Å.
Claim 4
Dependent Claim
18 words
The device of claim 1 wherein said semiconductor material is silicon and said insulating layer is silicon oxide.
Claim 5
Dependent Claim
19 words
The semiconductor device of claim 1 wherein said insulating layer comprises a plurality of layers of doped silicon oxide.
Claim 6
Dependent Claim
19 words
The semiconductor device of claim 1 wherein said insulating layer is phosphorus doped at a plurality of different levels.
Claim 7
Dependent Claim
27 words
The semiconductor device of claim 1 wherein said insulating layer has a roughened surface nonuniformly varying in its lateral feature size between 3000 Å and 10,000 Å.
Claim 8
Dependent Claim
15 words
The device of claim 1 in which said conductive metal strip is formed of aluminum.
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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) | 1993-04-30 | 1993-10-30 | 1994-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-30 | 1997-10-30 | 1998-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-30 | 2001-10-30 | 2002-05-01 | $7700.00 | Window Closed / Lapsed |