METALORGANIC VAPOR-PHASE EPITAXY GROWTH AND NITROGEN-DOPING OF ZNXCD1-XS USING PHOTO-ASSISTANCE

Heteroepitaxial growth of ZnxCd1-xS on (100) GaAs substrates using photo-assistance has been performed. Illumination during the growth was obtained from a 500 W xenon lamp. We will report the effect of growth temperature (340 < T < 430 degrees C) and light intensity on growth kinetics, composition control, crystalline quality and optical properties of epitaxial layers. We used diethylzinc, dimethylcadmium and tertiaributylmercarptan as source materials. Our attention was concentrated on the growth of layers nearly lattice-matched to GaAs. Epilayers grown at 380 degrees C exhibited the best crystalline quality with a full width at half maximum of similar or equal to 70 are sec by X-ray diffraction rocking curve. Concerning optical properties, we observed a strong luminescence peak at about 2.80 eV (4.2 K) for x = 0.40. Furthermore, tertiaributylamine was employed as an acceptor dopant in a first trial of p-type doping. Promising potential of photo-illumination for p-type doping will be also discussed.