On the formation of antiphase domains in the system of GaAs on Ge

The formation of antiphase domains (APDs) in GaAs grown on Ge(001) misoriented towards [110] has been studied as a function of substrate misorientation angle, growth rate, V/III ratio and growth temperature, by DSL (diluted Sirtl-like etchant used with light) and molten KOH defect revealing etch; transmission electron microscopy and optical interference contrast microscopy. Strong dependencies of the formation of APDs on all the parameters investigated have been found, which provides detailed information on the characteristics of polar on nonpolar heteroepitaxy. Insight into the mechanism of APD formation leads to a concept to grow completely APD-free GaAs on Ge, which has been proved by the experimental results of this study.