Epitaxial Growth of ZnTe and ZnSe on GaAs by Pulsed Laser Deposition

Abstract

ABSTRACTWe report the successful growth of ZnTe and ZnSe epitaxial layers on GaAs by pulsed laser deposition. A frequency doubled Nd:YAG laser was used to ablate/evaporate II-VI bulk targets and pressed powder targets in an ultra high vacuum enclosure. For typical growth temperatures in the range 200°-400°C x-ray analysis of the layers revealed sharp <100> peaks with no evidence of growth in other orientations. Polarization dependent Raman spectroscopy was also used to further characterize the epitaxial layers, by verifying the selection rules for backscattering from <100> oriented films. The low temperature photoluminescence spectra show distinct near-band-edge features indicating high crystalline quality. The photoluminescence of the films grown from bulk targets was superior to that of films grown from pressed powder targets, indicating that the use of high purity bulk targets is critical. Our results indicate that pulsed laser deposition is a promising new growth technique for the fabrication of II-VI epitaxial layers with unique advantages.