Process for low temperature stoichiometric recrystallization of compound semiconductor films
AssigneeHughes Aircraft Company
InventorsLewis M. Fraas, William P. Bleha, Jr.
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Abstract
A new, useful and nonobvious process is disclosed wherein vapor phase controlled stoichiometry is employed to obtain compound semiconductor films having large crystallite textures. The process has been found to be particularly useful in the formation of compound semiconductor films where one of the components is a high vapor pressure element and the substrate material is amorphous.
Claims6
A vapor phase controlled processing method for producing recrystallized MX films with improved photoelectric properties where M is a metal taken from Group II or III Of the periodic table and X is a high vapor pressure element taken from Group V or VI of the periodic table comprising the steps of:
- (a) depositing an MX compound onto an amorphous substrate taken from the group comprised of soda-lime glass, soda-lime glass overcoated with ITO, sapphire, borosilicate glass, and fused silica via physical vapor deposition to form a thin film;
- (b) placing said film into a reaction chamber equipped with a means for introducing alternatively an inert and reactive gaseous atmosphere;
- (c) raising the temperature of said film in said chamber to its recrystallization temperatures while purging said chamber with an inert gas;
- (d) passing a reactive atmosphere of XH.sub.n where n may be 2 or 3 and H.sub.2 through said chamber whereby a vapor pressure ratio is induced and maintained at the MX compound stoichiometric level while maintaining said recrystallization temperature over a period ranging from 5 to 50 minutes;
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- (e) subsequently cooling said film by reintroducing an inert gas until the temperature of said film has returned to room temperature.
Dependencies are inferred from the claim text.