Formation, faceting, and interaction behaviors of antiphase boundaries in GaAs thin films

Antiphase boundaries occur in GaAs epilayers grown on (001) Ge substrates b y organometallic vapor-phase epitaxy methods. The formation and structural characteristics of these boundaries were investigated by transmission elect ron microscopy (TEM). Steps with particular heights at the surface of subst rates nucleate antiphase boundaries. The observed faceting behavior of thes e boundaries indicates that energy associated with the presence of antiphas e boundaries is strongly related with the boundary planes, and preservation of the stoichiometry of GaAs appears to play an important role in achievin g a lower energy state at antiphase boundaries. (C) 2001 Kluwer Academic Pu blishers.