EP0157052A1
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EP
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Low resistivity tungsten silicon composite film
Assignee: Genus Inc
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Filing: 1984-12-17
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Granted: —
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Expires: 2004-12-17
Abstract
Abstract @ A composite film is provided which has a first layer of WSi x , where x is greater than 2, over which is disposed a second layer of a tungsten complex consisting substantially of tungsten with a small amount of silicon therein, typically less than 5%. Both layers are deposited in situ in a cold wall chemical vapor deposition chamber at a substrate temperature of between 500 and 550°C. Before initiating the deposition process for these first and second layers, the substrate onto which they are to be deposited is first plasma etched with NF 3 as the reactant gas, then with H 2 as the reactant gas, both steps being performed at approximately 100 to 200 volts self-bias. WSi x is then deposited onto the surface of the substrate using a gas flow rate for silane which is 20 to 80 times the flow rate of tungsten silicide, followed by deposition of a tungsten complex as the second layer, using a gas flow rate for tungsten hexaflouride which is 1 to 3 times the flow rate of silane, and a gas flow rate of hydrogen which is about 10 times the flow rate of silane. Similarly, in another embodiment, the tungsten complex without the silicide layer is deposited directly onto a silicon surface using the same process as for the tungsten complex in the second layer of the first embodiment.
Inventors
- 👤 Daniel L. Brors
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 09:17
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/02; C23C16/0227; C23C16/0245; C23C16/0272; C23C16/44; H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0112; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/056; H10W20/057; H10W20/064; H10W20/066; H10W20/40; H10W20/41; H10W20/44; H10W20/4403; H10W20/4437; H10W20/4441; Y; Y10; Y10S; Y10S438/00; Y10S438/906
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
65 words
A composite film on a substrate, comprising: a first layer of a material having the chemical formula WSi x , where x is greater than or equal to 2, which is deposited by chemical vapor deposition over said substrate; a second layer substantially of tungsten having a small percentage of silicon therein, with said second layer deposited by chemical vapor deposition over said first layer.
Claim 2
Dependent Claim
65 words
A composite film on a substrate, comprising: a first layer of a material having the chemical formula WSi x , where x is greater than or equal to 2, which is deposited by chemical vapor deposition over said substrate; a second layer substantially of tungsten having a small percentage of silicon therein, with said second layer deposited by chemical vapor deposition over said first layer.
Claim 3
Dependent Claim
11 words
A film as in claim 1, wherein said substrate comprises silicon.
Claim 4
Dependent Claim
14 words
A film as in claim 2, wherein said substrate also comprises Si0 2 .
Claim 5
Dependent Claim
54 words
A process for treating a substrate to increase its receptivity to the deposition of films having both tungsten and silicon as constituants, comprising the steps of: a. plasma etching said substrate using NF 3 as a reactant gas; and b. plasma etching said substrate using H 2 as a reactant gas after step a.
Claim 6
Dependent Claim
54 words
A process for treating a substrate to increase its receptivity to the deposition of films having both tungsten and silicon as constituants, comprising the steps of: a. plasma etching said substrate using NF 3 as a reactant gas; and b. plasma etching said substrate using H 2 as a reactant gas after step a.
Claim 7
Dependent Claim
22 words
A process as in claim 4 including: c. operating at a self-bias of 100 to 200 volts during steps a. and b.
Claim 8
Dependent Claim
21 words
A process as in claim 5 including: d. applying an r.f. power level of 3 to 5 watts per square inch.
Claim 9
Dependent Claim
76 words
In a chemical vapor deposition reactor having a vacuum housing, a process for depositing a composite film on a substrate comprising the steps of: a. plasma etching the substrate; b. after step a., depositing a first layer of WSi over the substrate, with x being greater than or equal to 2; and c. depositing over the first layer a second layer of a tungsten and silicon complex having a percentage of silicon of less than 5%.
Claim 10
Dependent Claim
76 words
In a chemical vapor deposition reactor having a vacuum housing, a process for depositing a composite film on a substrate comprising the steps of: a. plasma etching the substrate; b. after step a., depositing a first layer of WSi over the substrate, with x being greater than or equal to 2; and c. depositing over the first layer a second layer of a tungsten and silicon complex having a percentage of silicon of less than 5%.
Claim 11
Dependent Claim
37 words
A process as in claim 7 wherein step a. includes: d. plasma etching the substrate using NF 3 as an etchant gas; and e. after step d. plasma etching the substrate using H2 as an etchant gas.
Claim 12
Dependent Claim
103 words
A process as in claim 8 wherein step b. includes: f. providing a flow of silane and tungsten hexaflouride into the vacuum housing, with the rate of flow of silane being 20 to 80 times the flow rate of tungsten hexaflouride; g. during step f., heating the substrate to a temperature T 1 which is high enough to cause deposition of WSi x on the substrate, where x is greater than or equal to 2; h. during step g., actively cooling the vacuum housing to a temperature T 2 below which deposition on the vacuum housing of the WSi x is substantially eliminated.
Claim 13
Dependent Claim
102 words
A process as in claim 9 wherein step c. includes: i. providing a flow of silane, tungsten hexaflouride, and hydrogen into the vacuum housing, with the ratio of the flow rate of tungsten hexaflouride being in the range of 1 to 3 times the flow rate of silane, and the flow rate of hydrogen being approximately 10 times the flow rate of silane: j. during step i., heating the substrate to a temperature T 3 which is high enough to cause deposition of a complex of tungsten and silicon over the first layer, with the percentage of silicon being less than 5%.
Claim 14
Dependent Claim
17 words
A process as in claim 10 wherein T 3 is in the range of 500°C to 550°C.
Claim 15
Dependent Claim
103 words
A process as in claim 7 wherein step c. includes: k. providing a flow of silane, tungsten hexaflouride, and hydrogren into the vacuum housing, with the ratio of the flow rate of tungsten hexaflouride being in the range of 1 to 3 times the flow rate of silane, and the flow rate of hydrogen being approximately 10 times the flow rate of silane; and 1. during step k., heating the substrate to a temperature T 3 which is high enough to cause deposition of a complex of tungsten and silicon over the first layer, with the percentage of silicon being less than 5%.
Claim 16
Dependent Claim
137 words
A tungsten and silicon complex deposited by low pressure chemical vapor deposition on a silicon substrate, produced by heating the substrate to a temperature in the range of 500 to 550°C, in an atmosphere of reactant gasses of SiH 4 , WF 6 and H 2 the ratio of the flow rates of these gasses being 1 to 3 for the ratio of the flow rate of WF to the flow rate of SiH 4 , and about 10 for the ratio of the flow rate of H 2 to the flow rate of SiH 4 , the complex being substantially tungsten and having less than 5% silicon by weight, having a bulk resistance in the range of 8 to 10 micro-ohm cm without annealing, and exhibitng step coverage of greater than 95% on an 80° step.
Claim 17
Dependent Claim
137 words
A tungsten and silicon complex deposited by low pressure chemical vapor deposition on a silicon substrate, produced by heating the substrate to a temperature in the range of 500 to 550°C, in an atmosphere of reactant gasses of SiH 4 , WF 6 and H 2 the ratio of the flow rates of these gasses being 1 to 3 for the ratio of the flow rate of WF to the flow rate of SiH 4 , and about 10 for the ratio of the flow rate of H 2 to the flow rate of SiH 4 , the complex being substantially tungsten and having less than 5% silicon by weight, having a bulk resistance in the range of 8 to 10 micro-ohm cm without annealing, and exhibitng step coverage of greater than 95% on an 80° step.
References Cited (Backward Citations)
EP0070751A1
Cited
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