THE ROLE OF OXYGEN IN INCREASING THE CARRIER CONCENTRATION OF N-TYPE SILICON-GERMANIUM GALLIUM-PHOSPHIDE ALLOYS

The role of oxygen in increasing the carrier concentraction of n-type silicon germanium-gallium phosphide alloys was investigated. It was fo und that silicon germanium-gallium phosphide alloy without additional dopant prepared by mechanical alloying and cold pressing is p-type if heat treated in argon or hydrogen, but is n-type if heat treated in ai r. The results indicate that carrier enhancement probably relates to t he dissociation of gallium phosphide followed by oxidation of the diss ociated gallium and phosphorus. A possible mechanism for carrier enhan cement in n-type silicon germanium-gallium phosphide alloys is propose d.