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 epitax y were studied using temperature programmed desorption and high resolu tion electron energy loss spectroscopy. DEZ and DESe adsorbed molecula rly and did not decompose on clean ZnSe(100). Thermal cracking of the DESe reactant prior to adsorption was necessary in order to achieve fi lm growth. Adsorption of DEZ on Se-covered surfaces resulted in transf er of the ethyl groups from the DEZ to the Se forming adsorbed monoeth ylselenium. This species underwent disproportionation at 600 K forming gaseous DESe and adsorbed Se atoms. beta-Hydride elimination from sur face ethyl groups to form gaseous ethylene was also observed. The impl ications of these results for chemical beam epitaxy of ZnSe thin films are discussed.