CVD process for DCS-based tungsten silicide
AssigneeApplied Materials, Inc.
InventorsToshio Itoh, Mei Chang
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Abstract
A multiple step chemical vapor deposition process for depositing a tungsten silicide layer on a substrate. A first step of the deposition process includes a pretreatment step in which WF6 is introduced into a deposition chamber. Next, the introduction of WF6 is stopped and a silicon-containing gas, e.g., SiH4, is introduced into the chamber. Finally, during a third step, the SiH4 flow is stopped and DCS and WF6 are introduced into the chamber to deposit a tungsten silicide layer on the substrate.
Claims37
A process for forming a layer on a substrate, said process comprising:
- (a) forming a polysilicon layer over said substrate;
- (b) thereafter, depositing a tungsten silicide layer on said polysilicon layer in a chemical vapor deposition process by:
- (i) during a first process stage, introducing a tungsten-containing gas into a substrate processing chamber in an amount less than 5 cubic centimeters without flowing a silicon-containing source into said chamber;
- (ii) during a second process stage after said first stage, flowing a silicon-containing gas into said chamber without flowing a tungsten-containing gas;
- and
- (iii) during a third process stage after said second stage, flowing a process gas comprising said tungsten-containing gas and dichlorosilane into the chamber to deposit said tungsten silicide layer, wherein an average bulk ratio of silicon to tungsten in said tungsten silicide layer is between 2.0 to 2.8.
A process for forming a layer on a substrate, said process comprising:
- (a) forming a polysilicon layer over said substrate;
- (b) thereafter, depositing a tungsten silicide layer on said polysilicon layer in a chemical vapor deposition process by:
- (i) during a first process stage, introducing a tungsten-containing gas into a substrate processing chamber without flowing a silicon-containing source into said chamber, wherein said first process stage introduces said tungsten-containing gas by:
- flowing said tungsten-containing gas and an inert gas into a source line that leads to said chamber while diverting said gases away from said chamber into an exhaust line;
- then stopping the flow of said tungsten-containing gas while maintaining said flow of said inert gas into said source line;
- and directing said inert gas into said chamber so that a residual amount of said tungsten-containing source within said source line is directed into said chamber;
- (ii) during a second process stage after said first stage, flowing a silicon-containing gas into said chamber without flowing a tungsten-containing gas;
- and
- (iii) during a third process stage after said second stage, flowing a process gas comprising said tungsten-containing gas and dichlorosilane into the chamber to deposit said tungsten silicide layer, wherein an average bulk ratio of silicon to tungsten in said tungsten silicide layer is between 2.0 to 2.8.
A process for forming a layer on a substrate, said process comprising:
- (a) forming a polysilicon layer over said substrate;
- (b) thereafter, depositing a tungsten silicide layer on said polysilicon layer in a chemical vapor deposition process by:
- (i) during a first process stage, introducing a tungsten-containing gas into a substrate processing chamber in an amount that provides a partial layer of tungsten atoms less than one atom thick at the film surface without flowing a silicon-containing source into said chamber;
- (ii) during a second process stage after said first stage, flowing a silicon-containing gas into said chamber without flowing a tungsten-containing gas;
- and
- (iii) during a third process stage after said second stage, flowing a process gas comprising said tungsten-containing gas and dichlorosilane into the chamber to deposit said tungsten silicide layer, wherein an average bulk ratio of silicon to tungsten in said tungsten silicide layer is between 2.0 to 2.8.
Dependencies are inferred from the claim text.