US5232873A
Expired / Lapsed
US
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Method of fabricating contacts for semiconductor devices
Assignee: Nokia Bell Labs
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Filing: 1992-10-13
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Granted: 1993-08-03
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Expires: 2012-10-13
Abstract
Abstract A semiconductor device substrate has a major surface on which is located an insulating layer, such as silicon dioxide, having an aperture penetrating through it all the way down to the major surface. An impurity-doped plug, such as tungsten doped with zinc, is spatially selectively deposited in the aperture to a thickness such that the height of the plug is significantly less than the height of the aperture in the insulating layer, by means of a rapid-thermal-cycle low-pressure-metalorganic-chemical vapor deposition (RTC-LP-MOCVD) process. Then another plug, of (pure) conductive barrier metal such as tungsten, is deposited on at least the entire top surface of the impurity-doped plug and on the sidewalls of the insulating layer. The structure being fabricated can then be heated, in order to diffuse the impurity into the underlying semiconductor device substrate. A metallization layer such as titanium/platinum/gold can be deposited on the (pure) conductive barrier metal and patterned, in order to supply a desired access metallization for the device.
Inventors
- 👤 Michael Geva
- 👤 Avishay Katz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:48
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10P; H10P14/00; H10P14/40; H10P14/42; H10D64/0116; H10P32/00; H10P32/10; H10P32/12; H10P32/17; H10P32/174; Y; Y10; Y10S; Y10S148/00; Y10S148/11
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
165 words
In a method of fabricating a semiconductor device, the steps of: (a) providing a semiconductor body having a major surface; (b) forming on at least a portion of the major surface an insulating layer of uniform thickness except for at least one aperture in it; (c) spatially selectively depositing, by rapid-thermal-cycle low-pressure-metalorganic chemical vapor deposition, a first metallic layer selectively in the aperture to a prescribed thickness that is less than that of the thickness of the insulating layer, the first metallic layer comprising a first metal and an impurity, the impurity having a significantly greater tendency than the first metal to diffuse from the thus deposited metallic layer into the semiconductor body; and (d) spatially selectively depositing, by chemical vapor deposition, a second metallic layer at least everywhere on the first metallic layer in the aperture, the second metallic layer comprising a second metal but not the impurity, and the second metallic layer having the property of suppressing diffusion of the impurity through it.
Claim 2
Dependent Claim
165 words
In a method of fabricating a semiconductor device, the steps of: (a) providing a semiconductor body having a major surface; (b) forming on at least a portion of the major surface an insulating layer of uniform thickness except for at least one aperture in it; (c) spatially selectively depositing, by rapid-thermal-cycle low-pressure-metalorganic chemical vapor deposition, a first metallic layer selectively in the aperture to a prescribed thickness that is less than that of the thickness of the insulating layer, the first metallic layer comprising a first metal and an impurity, the impurity having a significantly greater tendency than the first metal to diffuse from the thus deposited metallic layer into the semiconductor body; and (d) spatially selectively depositing, by chemical vapor deposition, a second metallic layer at least everywhere on the first metallic layer in the aperture, the second metallic layer comprising a second metal but not the impurity, and the second metallic layer having the property of suppressing diffusion of the impurity through it.
Claim 3
Dependent Claim
33 words
The method of claim 1 further comprising, following step (d), the step of forming a third metallic layer on at least a part of the insulating layer and on the second metallic layer.
Claim 4
Dependent Claim
16 words
The method of claim 2 in which the first and second metals are the same elements.
Claim 5
Dependent Claim
21 words
The method of claim 3 in which the first and second metals are essentially tungsten and the impurity is essentially zinc.
Claim 6
Dependent Claim
18 words
The method of claim 4 in which steps (c) and (d) are performed in a single deposition chamber.
Claim 7
Dependent Claim
42 words
The method of claim 3 further comprising the step of heating the first metallic layer to a prescribed temperature for a prescribed amount of time whereby at least some of the impurity diffuses from the first metallic layer into the semiconductor body.
Claim 8
Dependent Claim
42 words
The method of claim 2 further comprising the step of heating the first metallic layer to a prescribed temperature for a prescribed amount of time whereby at least some of the impurity diffuses from the first metallic layer into the semiconductor body.
Claim 9
Dependent Claim
21 words
The method of claim 1 in which the first and second metals are essentially tungsten and the impurity is essentially zinc.
Claim 10
Dependent Claim
33 words
The method of claim 8 further in which steps (c) and (d) are performed in-situ in a single deposition chamber without removing the body from the chamber between performing steps (c) and (d).
Claim 11
Dependent Claim
42 words
The method of claim 8 further comprising the step of heating the first metallic layer to a prescribed temperature for a prescribed amount of time whereby at least some of the impurity diffuses from the first metallic layer into the semiconductor body.
Claim 12
Dependent Claim
15 words
The method of claim 1 in which the first and second metals are essentially tungsten.
Claim 13
Dependent Claim
33 words
The method of claim 11 further comprising, following step (d), the step of forming a third metallic layer on at least a part of the insulating layer and on the second metallic layer.
Claim 14
Dependent Claim
42 words
The method of claim 12 further comprising the step of heating the first metallic layer to a prescribed temperature for a prescribed amount of time whereby at least some of the impurity diffuses from the first metallic layer into the semiconductor body.
Claim 15
Dependent Claim
12 words
The method of claim 1 in which the impurity is essentially zinc.
Claim 16
Dependent Claim
33 words
The method of claim 14 further comprising, following step (d), the step of forming a third metallic layer on at least a part of the insulating layer and on the second metallic layer.
Claim 17
Dependent Claim
18 words
The method of claim 15 in which steps (c) and (d) are performed in a single deposition chamber.
Claim 18
Dependent Claim
42 words
The method of claim 15 further comprising the step of heating the first metallic layer to a prescribed temperature for a prescribed amount of time whereby at least some of the impurity diffuses from the first metallic layer into the semiconductor body.
Claim 19
Dependent Claim
18 words
The method of claim 1 in which steps (c) and (d) are performed in a single deposition chamber.
Claim 20
Dependent Claim
42 words
The method of claim 18 further comprising the step of heating the first metallic layer to a prescribed temperature for a prescribed amount of time whereby at least some of the impurity diffuses from the first metallic layer into the semiconductor body.
Claim 21
Dependent Claim
42 words
The method of claim 1 further comprising the step of heating the first metallic layer to a prescribed temperature for a prescribed amount of time whereby at least some of the impurity diffuses from the first metallic layer into the semiconductor body.
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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) | 1996-08-02 | 1997-02-01 | 1997-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-02 | 2001-02-01 | 2001-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-02 | 2005-02-01 | 2005-08-03 | $7700.00 | Window Closed / Lapsed |