Growth of Hg1−x(Cd1−yZny)xTe epilayers on (100) Cd1−yZnyTe/GaAs substrates by ISOVPE

Hg1−xCdxTe (MCT) and Hg1−x(Cd1−yZny)xTe (MCZT) epilayers were grown by isothermal vapor phase epitaxy (ISOVPE) using CdTe and lattice matched Cd1−yZnyTe (y≈0.045, CZT) layers, respectively, of various thickness on (100) GaAs as substrate. The problems of void formation and Ga outdiffusion can be overcome by using a sufficiently thick substrate layer. The ISOVPE epilayers show improved quality compared with substrate and their quality was found to be independent of substrate. It was found that FWHM values for MCZT epilayers grown on lattice matched CZT/GaAs were 70–90 arcsec, smaller than those reported here for MCT/CdTe/GaAs. Despite the broader FWHM for CZT/GaAs, a significant improvement in the quality of ISOVPE MCZT epilayers grown on these substrates was observed. This result is mainly attributed to the smaller lattice mismatch and the effect of Zn addition compared with MCT/CdTe.