EFFECT OF OPERATING-CONDITIONS AND PRECURSORS ON OPTOELECTRONIC PROPERTIES OF OMVPE GROWN ZNSE

The growth of ZnSe on (100)GaAs substrates by low pressure organometallic vapor phase epitaxy (OMVPE) has been investigated in a vertical reactor. Dimethylzinc (DMZn) was used as the Zn precursor, while three selenium sources were employed: diethylselenide (DESe), methylallylselenide (MASe) and hydrogen selenide (H2Se). Films grown at the optimal conditions, corresponding to each source combination, contain different impurities. The optically active impurities are analyzed by comparing photoluminescence spectra of as-grown films. The source combination H2Se/DMZn produces the best quality ZnSe epilayers. The effect of operating conditions on the electrical and photoluminescence properties of films grown from H2Se/DMZn is examined. Chlorine is determined to be the major shallow donor impurity of these films and an increase in the growth temperature is demonstrated to be a simple way to control the residual chlorine impurities. Finally, a relationship between electrical properties and photoluminescence characteristics is proposed and examined in view of data from this study as well as from previously reported OMVPE and molecular beam epitaxy (MBE) studies. © 1989.