US4720908A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making contacts and interconnects for holes having vertical sidewalls
Assignee: Texas Instruments Inc
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Filing: 1984-07-11
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Granted: 1988-01-26
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Expires: 2004-07-11
Abstract
Abstract A contact and interconnect for an MOS VLSI semiconductor device employs a contact hole in an insulator coating; the contact hole has vertical instead of sloped sidewalls. A first metallization is applied by CVD so that the sidewalls will be coated to a uniform thickness, then this first metal is anisotropically etched to leave metal sidewalls. A second metallization is applied by sputtering or evaporation, which provides a more dense and electromigration-resistant coating. A refractory metal layer may be interposed between the metallization and the silicon substrate, and also between the metal interconnect and the insulator, since the insulator usually contains phosphorus.
Inventors
- 👤 Kendall S. Wills
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:40
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/056; H10W20/057
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
150 words
A method of making a semiconductor device comprising the steps of: applying a coating of an insulator material on a face of a semiconductor body; forming in said coating a contact hole having substantially vertical sidewalls; depositing a first barrier layer of refractory metal over said contact hole so as to cover a bottom surface thereof; depositing a first conductor on said face by an isotropic deposition method whereby said sidewalls are coated, and anisotropically etching said first conductor to leave said first conductor on the sidewalls; depositing a second barrier layer of a refractory metal over said face, and covering said first conductor on the sidewalls of said contact hole; depositing a second conductor coating on said face to substantially fill said contact hole, and patterning said second conductor coating and said second barrier layer concurrently to leave a conductor strip on said face extending into said contact hole.
Claim 2
Independent Claim
150 words
A method of making a semiconductor device comprising the steps of: applying a coating of an insulator material on a face of a semiconductor body; forming in said coating a contact hole having substantially vertical sidewalls; depositing a first barrier layer of refractory metal over said contact hole so as to cover a bottom surface thereof; depositing a first conductor on said face by an isotropic deposition method whereby said sidewalls are coated, and anisotropically etching said first conductor to leave said first conductor on the sidewalls; depositing a second barrier layer of a refractory metal over said face, and covering said first conductor on the sidewalls of said contact hole; depositing a second conductor coating on said face to substantially fill said contact hole, and patterning said second conductor coating and said second barrier layer concurrently to leave a conductor strip on said face extending into said contact hole.
Claim 3
Dependent Claim
27 words
A method according to claim 1 wherein said semiconductor body is silicon, said insulator coating is phosphosilicate glass, and said first and second conductor coatings are metal.
Claim 4
Dependent Claim
23 words
A method according to claim 2, wherein said first barrier layer is selectively deposited only over the bottom surface of said contact opening.
Claim 5
Dependent Claim
20 words
A method according to claim 1 wherein the step of depositing said first conductor is a chemical vapor deposition method.
Claim 6
Dependent Claim
18 words
A method according to claim 4 wherein said step of depositing the second conductor is evaporation or sputtering.
References Cited (Backward Citations)
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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) | 1991-01-25 | 1991-07-27 | 1992-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-25 | 1995-07-27 | 1996-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-25 | 1999-07-27 | 2000-01-26 | $7700.00 | Window Closed / Lapsed |