V/III Ratio Dependence of Polarity of GaN Grown on GaAs (111)A-Ga and (111)B-As Surfaces by MOMBE

Abstract

In order to investigate the influence of the substrate polarity and growth conditions on the polarity, GaN was grown on GaAs (111)A-Ga and B-As surfaces with different V/III ratios by metalorganic molecular beam epitaxy (MOMBE). It was found that for GaN grown on GaAs (111)A-Ga surface polarity was dominant independent of the V/III ratio, but the polarity of GaN grown on GaAs (111)B depends on the V/III ratio; N polarity was dominant for high V/III ratios (N rich) and Ga polarity was dominant for low V/III ratios (Ga rich).