Uniform tungsten silicide films produced by chemical vapor deposition
AssigneeApplied Materials, Inc.
InventorsSusan G. Telford, Meng C. Tseng, Michio Aruga
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Abstract
A tungsten silicide film is deposited from WF.sub.6 and SiCl.sub.2 H.sub.2 onto a substrate so that the tungsten to silicon ratio is substantially uniform through the thickness of the WSi.sub.x film, and the WSi.sub.x film is substantially free of fluorine. The film can be deposited by a multi-stage process where the pressure in the chamber is varied, or by a high temperature, high pressure deposition process in a plasma cleaned deposition chamber. Preferably the SiCl.sub.2 H.sub.2 and the WF.sub.6 are mixed upstream of the deposition chamber. A seeding gas can be added to the process gases.
Claims11
A chemical vapor deposition process for depositing a substantially uniform, substantially fluorine free layer of WSi.sub.x on a substrate, the process comprising the steps of:
- (a) placing a substrate within a deposition zone;
- (b) during an initial deposition stage, (i) introducing seeding gas, dichlorosilane and tungsten hexa-fluoride into the deposition zone;
- and (ii) maintaining the deposition zone at process conditions suitable for depositing an interfacial layer of WSi.sub.x having a substantially uniform Si:W ratio directly on the substrate;
- and
- (c) during a second deposition stage, (i) stopping flow of the seeding gas, while continuing to flow dichlorosilane and tungsten hexa-fluoride into the deposition zone;
- and (ii) maintaining the deposition zone at process conditions suitable for depositing a substantially uniform WSi.sub.x layer on the interfacial WSi.sub.x layer.
Dependencies are inferred from the claim text.