US5023201A
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Selective deposition of tungsten on TiSi2
Assignee: Cornell Research Foundation Inc
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Filing: 1990-08-30
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Granted: 1991-06-11
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Expires: 2010-08-30
Abstract
Abstract An improved process for preparing selective deposition of conductive metals on disilicide encroachment barriers allows the construction of integrated circuit components wherein the metal/disilicide interface is substantially free of O and/or F contamination. The level of interfacial oxygen and/or fluorine contamination in the selective W deposition on the TiSi 2 was substantially reduced or eliminated by first forming a C49 TiSi 2 phase on a substrate, selectively depositing W on the C49 TiSi 2 phase and thereafter annealing at a (minimum) temperature sufficient to convert the high resistivity phase C49 TiSi 2 to the low resistivity phase C54 TiSi 2 .
Inventors
- 👤 David Stanasolovich
- 👤 Leslie H. Allen
- 👤 James W. Mayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:16
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/40; H10P14/42; H10P14/43; H10P14/432; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/056; H10W20/057; Y; Y10; Y10S; Y10S438/00; Y10S438/934
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
142 words
A process for the selective deposition of tungsten on a titanium disilicide surface which comprises: 1) first forming a metastable titanium disilicide layer on a substrate wherein said disilicide is characterized as a metastable C49 titanium disilicide (TiSi 2 ); 2) selectively depositing tungsten (W) on said C49 TiSi 2 to give a product having a W/C49 TiSi 2 interface which is substantially free of oxygen and/or fluorine contamination; and 3) annealing the product of step 2 at a temperature and time sufficient to convert the C49 TiSi 2 to C54 TiSi 2 ; wherein the C49 TiSi 2 layer of step 2 is characterized by a resistivity of from about 80 to about 120 μohm-cm and is converted by annealing to a C54 TiSi 2 characterized by a resistivity in the range of from about 5 μohm-cm to about 50 μohm-centimeter.
Claim 2
Dependent Claim
142 words
A process for the selective deposition of tungsten on a titanium disilicide surface which comprises: 1) first forming a metastable titanium disilicide layer on a substrate wherein said disilicide is characterized as a metastable C49 titanium disilicide (TiSi 2 ); 2) selectively depositing tungsten (W) on said C49 TiSi 2 to give a product having a W/C49 TiSi 2 interface which is substantially free of oxygen and/or fluorine contamination; and 3) annealing the product of step 2 at a temperature and time sufficient to convert the C49 TiSi 2 to C54 TiSi 2 ; wherein the C49 TiSi 2 layer of step 2 is characterized by a resistivity of from about 80 to about 120 μohm-cm and is converted by annealing to a C54 TiSi 2 characterized by a resistivity in the range of from about 5 μohm-cm to about 50 μohm-centimeter.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein the tungsten deposition on C49 TiSi 2 is carried out by chemical vapor deposition.
Claim 4
Dependent Claim
40 words
The process of claim 2 wherein the C49 TiSi 2 is formed by a rapid Thermal Anneal under protecting atmosphere using an anneal time of from about 10-35 seconds and anneal temperature of from about 575° C. to 700° C.
Claim 5
Dependent Claim
24 words
The process of claim 3 wherein the thermal anneal is conducted for 10-20 seconds at a temperature from about 575° C. to 675° C.
Claim 6
Dependent Claim
21 words
The process of claim 3 wherein the thermal anneal is conducted for 15-30 seconds at a temperature of about 700° C.
Claim 7
Dependent Claim
42 words
The process of claim 1 wherein the selective tungsten deposition is carried out by contacting the said C49 TiSi 2 layer with a mixture of WF 6 and hydrogen, a mixture of WF 6 with a silicon hydride or a mixture thereof.
Claim 8
Dependent Claim
23 words
The process of claim 5 wherein the selective tungsten deposition is carried out with a mixture of WF 6 and SiH 4 .
Claim 9
Dependent Claim
21 words
The process of claim 5 wherein the selective tungsten deposition is carried out with a mixture of WF 6 and hydrogen.
Claim 10
Dependent Claim
65 words
A process to substantially reduce or eliminate interfacial oxygen and/or fluorine contamination in the selective deposition on TiSi 2 which comprises first selectively depositing tungsten on the surface of a metastable C49 TiSi 2 to give a product having a W-C49 TiSi 2 interface substantially free of oxygen and/or fluorine and then converting the C49 TiSi 2 in said product to C54 TiSi 2 .
Claim 11
Dependent Claim
65 words
A process to substantially reduce or eliminate interfacial oxygen and/or fluorine contamination in the selective deposition on TiSi 2 which comprises first selectively depositing tungsten on the surface of a metastable C49 TiSi 2 to give a product having a W-C49 TiSi 2 interface substantially free of oxygen and/or fluorine and then converting the C49 TiSi 2 in said product to C54 TiSi 2 .
Claim 12
Dependent Claim
39 words
The process of claim 9 wherein the selective W deposition is carried out by contacting the C49 TiSi 2 with a mixture of WF 6 and hydrogen a reducing gas selected from the group consisting of hydrogen and silane.
Claim 13
Dependent Claim
33 words
The process of claim 10 wherein the C49 TiSi 2 on which the tungsten is selectively deposited is a silicon-rich TiSi 2 having a silicon content in excess of the stoichiometric formula amount.
Claim 14
Dependent Claim
22 words
The process of claim 11 wherein the silicon-rich TiSi 2 contains at least about 3.0 percent excess silicon over the stoichiometric amount.
Claim 15
Dependent Claim
166 words
A process for the selective deposition of a metal or metal compound on a (M) titanium disilicide encroachment barrier which comprises: 1) first forming a titanium disilicide layer on a substrate wherein said disilicide is characterized as a C49 titanium disilicide (TiSi 2 ); 2) selectively depositing said metal (M) on said C49 TiSi 2 to give a product having a M-C49 TiSi 2 interface which is substantially free of oxygen and/or fluorine contamination; and 3) annealing the product of step 2 at a temperature and time sufficient to convert the C49 TiSi 2 to C54 TiSi 2 ; wherein the C49 TiSi 2 layer of step 2 is characterized by a resistivity of from about 80 to about 120 μohm-cm and is converted by annealing to a C54 TiSi 2 characterized by a resistivity in the range of from about 5 to about 50 μohm-cm; wherein M is selected from the group consisting of: platinum, molybdenum, titanium, titanium nitride, tungsten, tantalum, copper, silver and aluminum.
Claim 16
Dependent Claim
166 words
A process for the selective deposition of a metal or metal compound on a (M) titanium disilicide encroachment barrier which comprises: 1) first forming a titanium disilicide layer on a substrate wherein said disilicide is characterized as a C49 titanium disilicide (TiSi 2 ); 2) selectively depositing said metal (M) on said C49 TiSi 2 to give a product having a M-C49 TiSi 2 interface which is substantially free of oxygen and/or fluorine contamination; and 3) annealing the product of step 2 at a temperature and time sufficient to convert the C49 TiSi 2 to C54 TiSi 2 ; wherein the C49 TiSi 2 layer of step 2 is characterized by a resistivity of from about 80 to about 120 μohm-cm and is converted by annealing to a C54 TiSi 2 characterized by a resistivity in the range of from about 5 to about 50 μohm-cm; wherein M is selected from the group consisting of: platinum, molybdenum, titanium, titanium nitride, tungsten, tantalum, copper, silver and aluminum.
Claim 17
Dependent Claim
19 words
The process of claim 13 wherein the metal deposition on C49 TiSi 2 is effected by chemical vapor deposition.
Claim 18
Dependent Claim
146 words
A process for the selective deposition of tungsten on a metal disilicide encroachment barrier which comprises: 1) first forming a metal disilicide MSi 2 layer on a substrate wherein said disilicide layer is characterized as having, at least on the surface thereof, an amount of silicon from about 2.5 to about 3.5 mole percent in excess of the calculated formula MSi 2 ; and 2) selectively depositing tungsten (W) on said MSi 2 layer to give a product having a W-MSi 2 interface which is substantially free of oxygen and/or fluorine contamination; and wherein said metal disilicide is selected from the group consisting of titanium disilicide, tungsten disilicide (WSi 2 ), molybdenum disilicide (MoSi 2 ), tantalum disilicide (TaSi 2 ), vanadium disilicide (VSi 2 ), platinum silicide (ptSi), nickel silicide (NiSi; Ni 2 Si), chromium disilicide (CrSi 2 ) and niobium disilicide (NbSi 2 ).
Claim 19
Dependent Claim
146 words
A process for the selective deposition of tungsten on a metal disilicide encroachment barrier which comprises: 1) first forming a metal disilicide MSi 2 layer on a substrate wherein said disilicide layer is characterized as having, at least on the surface thereof, an amount of silicon from about 2.5 to about 3.5 mole percent in excess of the calculated formula MSi 2 ; and 2) selectively depositing tungsten (W) on said MSi 2 layer to give a product having a W-MSi 2 interface which is substantially free of oxygen and/or fluorine contamination; and wherein said metal disilicide is selected from the group consisting of titanium disilicide, tungsten disilicide (WSi 2 ), molybdenum disilicide (MoSi 2 ), tantalum disilicide (TaSi 2 ), vanadium disilicide (VSi 2 ), platinum silicide (ptSi), nickel silicide (NiSi; Ni 2 Si), chromium disilicide (CrSi 2 ) and niobium disilicide (NbSi 2 ).
Claim 20
Dependent Claim
14 words
The process of claim 15 wherein the metal disilicide is C54 TiSi 2 .
References Cited (Backward Citations)
US4940509A
Cited
US4957777A
Cited
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