Low pressure chemical vapor deposition of tungsten silicide
AssigneeInternational Business Machines Corporation
InventorsJoseph M. Jasinski, Bernard S. Meyerson, Bruce A. Scott
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Abstract
A process for preparing tungsten silicide films using low pressure, low temperature chemical vapor deposition to deposit silicon-rich tungsten silicide films. As a source of silicon, higher order silanes, such as disilane and trisilane, are used. The gaseous tungsten source is WF.sub.6. The substrate temperature range is less than about 370.degree. C., while the total pressure range is in the range 0.05-1 Torr. WF.sub.6 flow rates are generally less than 25 sccm, while the higher order silane flow rates are generally less than about 400 sccm.
Claims8
A method for depositing silicon-rich tungsten silicide films on a substrate, said method including the steps of:
- introducing WF.sub.6 gas and a higher order silane gas given by the formula
- Si.sub.n H.sub.2n+2,
- where n=2, 3, . . . into a cold wall, hot susceptor CVD reactor with the substrate located on said susceptor,
- establishing a substrate temperature less than about 370.degree. C. and a total system pressure less than 1 Torr, the flow rate of said WF.sub.6 being less than about 25 sccm while the flow rate of said higher order silane is less than about 500 sccm, and
- reacting said higher order silane and said WF.sub.6 at said substrate to deposit a silicon-rich film of tungsten silicide on said substrate.
A method for the formation of WSi.sub.2 on a substrate including a semiconductor device, including the steps of:
- placing said substrate in a cold wall, hot susceptor CVD apparatus,
- introducing WF.sub.6 gas and a higher order silane gas into said apparatus, said higher order silane gas being given by the formula
- Si.sub.n H.sub.2n+2
- where n=2, 3, . . . ,
- establishing a substrate temperature in the range of about 200.degree.-300.degree. C. and a total system pressure less than about 500 mTorr, the flow rate of said WF.sub.6 being less than about 25 sccm and the flow rate of said higher order silane being less than about 400 sccm,
- reacting said higher order silane and said WF.sub.6 at said substrate to deposit a silicon-rich tungsten silicide film thereon, and
- annealing said tungsten silicide film to crystallize said film to WSi.sub.2.
Dependencies are inferred from the claim text.