Microstructures of GaAsN grown on (001) GaAs by metalorganic molecular beam epitaxy

Abstract

Metalorganic molecular beam epitaxial GaAsN layers grown on (001) GaAs substrates have been investigated by TEM and TED. TEM results show that lateral composition modulation occurs in the GaAs1-xNx layer (x < 6.75%). It is shown that increasing N composition leads to poor crystallinity. AFM results show that the surfaces of the samples experience a morphological change from faceting to islanding, as the N composition increases. Based on the TEM and AFM results, a simple model is given to explain the formation mechanism for the lateral composition modulation.