US4337476A
Expired / Lapsed
US
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Silicon rich refractory silicides as gate metal
Assignee: AT&T Inc
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Filing: 1980-08-18
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Granted: 1982-06-29
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Expires: 2000-08-18
Abstract
Abstract Silicon-rich silicides of titanium and tantalum have been found to be suitable for use as the gate metal in semiconductor integrated circuits replacing polysilicon altogether. Such silicon-rich silicides, formed by sintering a cosputtered alloy with silicon to metal ratio of three as in deposited film, are stable even on gate oxide. The use of these compounds leads to stable, low resistivity gates and eliminates the need for the high resistivity polysilicon gate.
Inventors
- 👤 David B. Fraser
- 👤 Shyam P. Murarka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:37
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/60; H10D64/66; H10D64/667; H10D64/668; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01318; H10D64/0132; Y; Y10; Y10S; Y10S148/00; Y10S148/14
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
88 words
An arrangement including a semiconductor chip comprising a single crystal semiconductor layer, a first electrically-insulating SiO 2 layer overlying said semiconductor layer, a first layer of electrically-conducting material overlying said SiO 2 layer, said electrically-conducting material comprising a silicon-rich silicide taken from a group of metals comprising titanium and tantalium and having an atomic ratio of the silicon to metal in the as-deposited film equal to or greater than 2 and less than or equal to 3, and a second layer of SiO 2 overlying said first layer.
Claim 2
Dependent Claim
88 words
An arrangement including a semiconductor chip comprising a single crystal semiconductor layer, a first electrically-insulating SiO 2 layer overlying said semiconductor layer, a first layer of electrically-conducting material overlying said SiO 2 layer, said electrically-conducting material comprising a silicon-rich silicide taken from a group of metals comprising titanium and tantalium and having an atomic ratio of the silicon to metal in the as-deposited film equal to or greater than 2 and less than or equal to 3, and a second layer of SiO 2 overlying said first layer.
Claim 3
Dependent Claim
18 words
An arrangement in accordance with claim 1 wherein said semiconductor layer comprises an epitaxially grown layer of silicon.
Claim 4
Dependent Claim
27 words
An arrangement in accordance with claim 2 wherein said second electrically-insulating SiO 2 layer overlying said first layer of electrically-conducting material has a pattern of apertures therein.
Claim 5
Dependent Claim
37 words
An arrangement in accordance with claim 3 wherein said chip also comprises a second layer of electrically-conducting material overlying said patterned second layer of SiO 2 and forming through connections to said first layer of electrically-conducting material.
Claim 6
Dependent Claim
16 words
An arrangement in accordance with claim 4 wherein said second layer of electrically-conducting material comprises aluminum.
Claim 7
Dependent Claim
26 words
An arrangement in accordance with claim 2 wherein said silicon-rich silicide is formed by sintering in hydrogen at a temperature not less than 800 degrees C.
Claim 8
Dependent Claim
23 words
An arrangement in accordance with claim 6 wherein said silicon and metal are cosputtered in an atomic ratio of silicon/metal equal to three.
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) | 1985-06-28 | 1985-12-28 | 1986-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-28 | 1989-12-28 | 1990-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-28 | 1993-12-28 | 1994-06-29 | $7700.00 | Window Closed / Lapsed |