Strain effects and atomic arrangements of 60 degrees and 90 degrees dislocations near the ZnTe/GaAs heterointerface

Abstract

Auger electron spectroscopy (AES) and secondary ion mass spectroscopy (SIMS) measurements were carried out to characterize the composition of ZnTe films, and transmission electron microscopy (TEM) measurements were performed to investigate the lattice mismatch and the microstructural properties of the ZnTe/GaAs heterostructures. The AES and SIMS results showed that the ZnTe/GaAs heterointerfaces had relatively sharp interfaces. The TEM images and the selected-area electron-diffraction patterns showed a large lattice mismatch between the ZnTe epitaxial layer and the GaAs substrate, 60 degrees and 90 degrees dislocations together with stacking faults, near the ZnTe/GaAs heterointerface. The ZnTe epitaxial film grown on the GaAs substrate receives a compressive strain of -0.61%, and possible atomic arrangements of the 60 degrees and the 90 degrees dislocations are presented on the basis of the high-resolution TEM results. (C) 2001 American Institute of Physics.