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

Antiphase boundaries occur in GaAs epilayers grown on (001) Ge substrates by organometallic vapor-phase epitaxy methods. The formation and structural characteristics of these boundaries were investigated by transmission electron microscopy (TEM). Steps with particular heights at the surface of substrates nucleate antiphase boundaries. The observed faceting behavior of these boundaries indicates that energy associated with the presence of antiphase boundaries is strongly related with the boundary planes, and preservation of the stoichiometry of GaAs appears to play an important role in achieving a lower energy state at antiphase boundaries.