THE REACTIONS OF DIETHYLSELENIUM AND DIETHYLZINC ON THE SURFACES OF ZNSE THIN-FILMS

The reactivity of diethylselenium (DESe) and diethylzinc (DEZ) on the surfaces of ZnSe thin films grown on GaAs(100) by chemical beam epitaxy were studied using temperature programmed desorption and high resolution electron energy loss spectroscopy. DEZ and DESe adsorbed molecularly and did not decompose on clean ZnSe(100). Thermal cracking of the DESe reactant prior to adsorption was necessary in order to achieve film growth. Adsorption of DEZ on Se-covered surfaces resulted in transfer of the ethyl groups from the DEZ to the Se forming adsorbed monoethylselenium. This species underwent disproportionation at 600 K forming gaseous DESe and adsorbed Se atoms. beta-Hydride elimination from surface ethyl groups to form gaseous ethylene was also observed. The implications of these results for chemical beam epitaxy of ZnSe thin films are discussed.