SURFACE SEGREGATION OF INDIUM DURING GROWTH OF INGAAS IN CHEMICAL BEAM EPITAXY

An initial growth stage of InGaAs on (100) GaAs using gaseous sources of triethylgallium (TEG), trimethylindium (TMI), and arsine has been studied through reflection high-energy electron diffraction intensity oscillations. The growth rate of InGaAs gradually decreased with proceeding growth. The decreasing growth rate had strong dependencies on the growth temperature and the AsH3 flow rate. At a growth temperature of 570° C, a 50% reduction of the growth rate was observed after the growth of eight monolayers of InGaAs. These phenomena are attributed to indium surface segregation, by which the decomposition and /or desorption kinetics of gallium compound gases (diethylgallium, TEG, etc.) are strongly affected. © 1990.