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US4985371A
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Process for making integrated-circuit device metallization
Assignee: Nokia Bell Labs
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Filing: 1988-12-09
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Granted: 1991-01-15
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Expires: 2008-12-09
Abstract
Abstract In the manufacture of an integrated-circuit device, periodic interruption of grain growth during chemical vapor deposition of a metal film results in enhanced surface smoothness and ease of patterning. Interruption of grain growth is by deposition of an auxiliary material which, in the interest of high conductivity of the film, may be conductive, may form a conductive compound or alloy, or may be eliminated upon additional metal deposition. When the metal is tungsten, silicon is a preferred grain-growth interrupting material.
Inventors
- 👤 Virendra V. S. Rana
- 👤 Nun-Sian Tsai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:43
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0113; H10P; H10P14/00; H10P14/40; H10P14/412; H10D84/00; H10D84/80; H10P14/416; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/052; H10W20/0526
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
165 words
A method for making an integrated-circuit device which includes a dielectric, comprising forming a metallization on said dielectric, and forming said metallization comprising the steps of: depositing a first metal layer, forming on said first metal layer a grain-growth interrupting layer which is selected to cause renucleation of metal upon further metal deposition, and which is selected from the group consisting of conductive materials, materials which form intermetallic compounds with said metal, materials which form conductive alloys with said metal, and materials which are essentially eliminated upon subsequent metal deposition, and depositing a second metal layer on said grain-growth interrupting layer, said second metal layer consisting essentially of the same metal as said first metal layer, second metal layer forming a renucleated metal layer, at least two grain-growth interrupting layers being deposited, whereby the resistivity of said metallization is less than or equal three times the resistivity of a comparison metallization consisting essentially of the same metallization material and having been deposited without grain-growth interruption.
Claim 2
Independent Claim
165 words
A method for making an integrated-circuit device which includes a dielectric, comprising forming a metallization on said dielectric, and forming said metallization comprising the steps of: depositing a first metal layer, forming on said first metal layer a grain-growth interrupting layer which is selected to cause renucleation of metal upon further metal deposition, and which is selected from the group consisting of conductive materials, materials which form intermetallic compounds with said metal, materials which form conductive alloys with said metal, and materials which are essentially eliminated upon subsequent metal deposition, and depositing a second metal layer on said grain-growth interrupting layer, said second metal layer consisting essentially of the same metal as said first metal layer, second metal layer forming a renucleated metal layer, at least two grain-growth interrupting layers being deposited, whereby the resistivity of said metallization is less than or equal three times the resistivity of a comparison metallization consisting essentially of the same metallization material and having been deposited without grain-growth interruption.
Claim 3
Dependent Claim
13 words
The method of claim 1 in which said material is a conductive material.
Claim 4
Dependent Claim
12 words
The method of claim 2 in which said material is a metal.
Claim 5
Dependent Claim
17 words
The method of claim 1 in which said material forms a conductive intermetallic compound with said metal.
Claim 6
Dependent Claim
16 words
The method of claim 1 in which said material forms a conductive alloy with said metal.
Claim 7
Dependent Claim
16 words
The method of claim 1 in which said material is essentially eliminated upon subsequent metal deposition.
Claim 8
Dependent Claim
16 words
The method of claim 6 in which elimination of said material comprises volatilization of said material.
Claim 9
Dependent Claim
17 words
The method of claim 6 in which elimination of said material comprises formation of a volatile compound.
Claim 10
Dependent Claim
26 words
The method of claim 6 in which at least 95 percent of deposited grain-growth interrupting layer material is eliminated upon deposition of said second metal layer.
Claim 11
Dependent Claim
16 words
The method of claim 1 in which grain-growth interrupting layer material is deposited on said dielectric.
Claim 12
Dependent Claim
13 words
The method of claim 1 in which said metallization consists essentially of tungsten.
Claim 13
Dependent Claim
15 words
The method of claim 11 in which tungsten deposition involves reacting tungsten hexafluoride with hydrogen.
Claim 14
Dependent Claim
20 words
The method of claim 11 in which said metallization has grain size in the range from 50 to 200 nanometers.
Claim 15
Dependent Claim
11 words
The method of claim 11 in which said material comprises silicon.
Claim 16
Dependent Claim
12 words
The method of claim 14 in which said material comprises amorphous silicon.
Claim 17
Dependent Claim
12 words
The method of claim 14 in which said material comprises polycrystalline silicon.
Claim 18
Dependent Claim
27 words
The method of claim 14 in which silicon is deposited by low-pressure chemical vapor deposition at a temperature in the range from 400 to 600 degrees C.
Claim 19
Dependent Claim
28 words
The method of claim 14 in which silicon is deposited by plasma-assisted low-pressure chemical vapor deposition at a temperature in the range from 200 to 500 degrees C.
Claim 20
Dependent Claim
23 words
The method of claim 14 in which said grain-growth interrupting layer has a thickness which is greater than or equal to 5 nanometers.
Claim 21
Dependent Claim
32 words
The method of claim 19 in which deposition is in a hot-wall reactor and in which said grain-growth interrupting layer has a thickness which is less than or equal to 50 nanometers.
Claim 22
Dependent Claim
18 words
The method of claim 1 in which said metal is essentially tungsten and said material is essentially copper.
Claim 23
Dependent Claim
18 words
The method of claim 1 in which said metal is essentially aluminum and said material is essentially silicon.
Claim 24
Dependent Claim
18 words
The method of claim 1 in which said metal is essentially aluminum and said material is essentially carbon.
Claim 25
Dependent Claim
18 words
The method of claim 1 in which said metal is essentially aluminum and said material is essentially copper.
Claim 26
Dependent Claim
19 words
The method of claim 1 in which said dielectric has been patterned to expose selected portions of semiconductor material.
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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) | 1994-01-14 | 1994-07-16 | 1995-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-14 | 1998-07-16 | 1999-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-14 | 2002-07-16 | 2003-01-15 | $7700.00 | Window Closed / Lapsed |