CRYSTALLINE QUALITY AND INTERFACE SHARPNESS OF ZNSE ZNSXSE1-X SUPERLATTICES ON GAAS - ANALYSIS BY RAMAN-SPECTROSCOPY AND X-RAY-DIFFRACTOMETRY/

ZnSe/ZnSxSe1-x strained layer superlattices were grown by atmospheric- pressure metalorganic vapour phase epitaxy (MOVPE) on GaAs substrates. As group VI precursors for ZnSxSe1-x the combination of diethyl-selen ium (DESe) with either diethyl-sulphur (DES) or with H2S was applied, while we used diethyl-zinc (DEZn) for group II. We investigated the in fluence of sulphur stabilization during growth interruptions. For the analysis of the structural superlattice properties a combination of Ra man spectroscopy and X-ray diffractometry was employed. DES-grown stru ctures with 120 periods, grown at 480 degrees C, show a very good late ral homogeneity of the composition, a high crystal quality and very re gular periodicity, which leads in the DCXD profiles to narrow satellit e peaks and even pendellosung fringes from the total stack thickness, while in the Raman spectrum the regular modulated structure results in narrow folded acoustical phonon peaks. These results demonstrate the capability of MOVPE to grow high quality ZnSe/ZnSxSe1-x superlattices.