HIGH-PURITY ZNSE EPILAYERS GROWN BY ATMOSPHERIC DOUBLE ZONE METALORGANIC ATOMIC LAYER EPITAXY

ZnSe epilayers were grown on semi-insulating GaAs (100) substrates by metalorganic atomic layer epitaxy (MOALE) using dimethylzinc (DMZn) an d hydrogen selenide (H2Se) source gases with a substrate temperature o f 350 degrees C. The MOALE system is modified from atmospheric metalor ganic vapor phase epitaxy (MOVPE) by rotating susceptor to allow succe ssive exposure to streams of gases. Also long gas inlets were introduc ed in the pre-heating zone of the reactor for purifying the source gas es. The photoluminescence spectra of the ZnSe epilayers show dominant heavy-hole and light-hole exciton emissions for thicknesses below and above a critical thickness. The epilayer thickness was examined for th e different operating cycles and was found to depend only on the numbe r of substrate rotation cycles. These results reflect that the growth of high purity ZnSe epilayers are achieved by MOALE.