Surface reaction mechanism in MOVPE growth of ZnSe revealed using radicals produced by photolysis of alkyl azide

Epitaxial growth mechanism of ZnSe under alternate supply of diethylzinc DEZn.and dimethylselenium DMSe.was studied by in situ optical monitoring of the growing surface. When H2 was used as carrier gas, the time-dependent optical reflectance was found to exhibit a sawtooth pattern under DEZn supply. The sawtooth reflection signal was also observed in growth experiments using N2 carrier gas when DEZn was provided after supply of neutral free radicals produced by laser photolysis of alkyl azide. Based on these experimental results, microscopic mechanism of growth enhancement by coexistent H2 is discussed in terms of ab initio quantum chemistry. q2000 Elsevier Science B.V. All rights reserved.