Microstructural characteristics of (110) InGaAs layers grown by OMVPE

InGaAs layers grown by organometallic vapor phase epitaxy (OMVPE) on vicinal (110) InP substrates have been studied using transmission electron microscopy. The formation of a phase separated microstructure is found to be limited by surface thermodynamics opposed to surface diffusion. CuAu-I-type ordering is not observed in the present study. An attempt has been made to rationalize this observation by considering the driving force for ordering on the (110) surface. Also, the nucleation of an epitaxial layer on the (110) surface is difficult and the dislocation density is found to decrease at high growth rates. It could be that the point defects formed due to the short residence time of adatoms on the (110) growth surface cannot coalesce into dislocation loops when high growth rates are used.