Carbosilane precursors for low temperature film deposition
Provided are processes for the low temperature deposition of silicon-containing films using carbosilane precursors containing a carbon atom bridging at least two silicon atoms. Certain methods comprise providing a substrate; in a PECVD process, exposing the substrate surface to a carbosilane precursor containing at least one carbon atom bridging at least two silicon atoms; exposing the carbosilane precursor to a low-powered energy sourcedirect plasma to provide a carbosilane at the substrate surface; and densifying the carbosilanestripping away at least some of the hydrogen atoms to provide a film comprising SiC. The SiC film may be exposed to the carbosilane surface to a nitrogen source to provide a film comprising SiCN.
1. A method of forming a layer on a substrate surface, the method comprising:
providing a substrate;
in a PECVD process exposing the substrate surface to a carbosilane precursor containing at least one methylene bridging two silicon atoms;
exposing the carbosilane precursor to a direct plasma to provide a carbosilane at the substrate surface;
stripping away at least some of the hydrogen atoms; and
exposing the carbosilane surface to a nitrogen source to provide a film comprising SiCN suitable as a low k dielectric film.
2. The method of claim 1 wherein the direct plasma has a value of about 10 W to about 200 W.
3. The method of claim 1 , wherein the carbosilane precursor is exposed to the direct plasma for between 0.10 seconds and 5.0 seconds.
4. The method of claim 1 , wherein the carbosilane precursor is one or more of 1,3,5-trisilapentane, 1,3-disilabutane, 1,3-disilacyclobutane and 1,3,5-trisilacyclohexane.
5. The method of claim 4 , wherein the carbosilane precursor is 1,3,5-trisilapentane.
6. The method of claim 1 , wherein exposing the carbosilane to a nitrogen source comprises exposing the carbosilane to a plasma containing nitrogen.
7. The method of 6 , wherein exposing the carbosilane to a plasma containing nitrogen results in the formation of N—H bonds that promote irreversible attachment of a monolayer of the carbosilane to the substrate surface.
8. The method of claim 1 , wherein exposing the carbosilane to a nitrogen source comprises flowing ammonia or nitrogen gas.