Growth of epitaxial films by chemical vapor deposition utilizing a surface cleaning step immediately before deposition
AssigneeMassachusetts Institute of Technology
InventorsL. Rafael Reif, Thomas J. Donahue, Wayne R. Burger
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Abstract
A method and apparatus for low temperature deposition of epitaxial films using low pressure chemical vapor deposition (CVD) with and without plasma enhancement. More specifically, the process enables CVD of epitaxial silicon at temperatures below 800.degree. C. by use of an in situ argon plasma sputter cleaning treatment of the silicon substrate prior to deposition.
Claims12
A chemical vapor deposition process for forming epitaxial films on a substrate at relatively low temperatures comprising the steps of:
- (a) cleaning the surface of the substrate in a reaction chamber to remove material which impedes epitaxial growth, while concurrently maintaining the substrate at a predetermined temperature near the deposition temperature of less than 800.degree. C.;
- and
- (b) terminating said cleaning step (a) and immediately introducing a gaseous reactant into said reaction chamber at relatively low chamber pressure of about 10.sup.-1 Torr or less, said reactant containing an element of the film to be deposited while maintaining the substrate at the desired deposition temperature to promptly form on said surface an epitaxial film of said element.
An epitaxy process for depositing an epitaxial Si film comprising:
- (a) cleaning the surface of silicon substrate disposed in a reaction chamber to remove epitaxially growth impeding substances found on the substrate surface while keeping the substrate temperature near the deposition temperature of less than 800.degree. C. and
- (b) introducing a gas reactant containing Si into the chamber at a relatively low chamber pressure of 10.sup.-1 Torr or less to form an epitaxial film of Si from said reactant gas on said surface by chemical vapor deposition upon terminating the cleaning step (a).
A method of growing epitaxial films on a surface of substrate comprising the steps of:
- (a) disposing the substrate in a reaction chamber;
- (b) while in the reaction chamber, subjecting the surface of the substrate to a cleaning process to remove for a period of time epitaxial growth impeding substances found on the surface;
- (c) during a portion of the cleaning time in step (b), including just prior to termination of said cleaning, heating the substrate to bring it to a temperature at or near the deposition temperature;
- (d) immediately thereafter step (c) bringing the substrate to a deposition temperature of about 800.degree. C. or less in the presence of a gas having molecules to be deposited on said surface and at a chamber pressure in the order of about 10.sup.-1 to 10.sup.-3 Torr to decomposed said gas and cause said decomposed elements to deposite on said surface without plasma enhancement and form an epitaxial film.
Dependencies are inferred from the claim text.