Use of Convergent Beam Electron Diffraction for Identification of Antiphase Boundaries in GaAs Grown on Si

摘要

This study shows that dynamical coupling effcts in CBED patterns can be unambiguously used to detect APBs. A high density of APBs can be present in GaAs grown by MOCVD (metal organic chemical vapor deposition) on Si (100) surfaces. APB formation is promoted by surface contamination and irregularities. APBs act as natural obstacles for the propagation of twins and stacking faults into the growing epitaxial layer. Faceting of APBs is probably connected with anisotropy of the interfacial energy of APBs. In most cases extended surface areas of APBs were observed to lie on the energetically favorable (110) planes. This observation is in agreement with earlier theoretical calculations. 17 refs, 6 figs.,. (ERA citation 13:030660)