BEATING IN RHEED OSCILLATIONS OBSERVED DURING MEE GROWTH OF ZNSE

We have made the first observations of beating in RHEED oscillations occurring during MEE growth of ZnSe. From measurements of the beat frequency, we have determined the amount of ZnSe deposited per MEE cycle as a function of Zn and Se deposition times and substrate temperature. A unique feature of the ZnSe oscillations is that the amount of ZnSe deposited in each MEE cycle saturates as the Zn and Se deposition times are increased. The saturated amount deposited per MEE cycle depends on the substrate temperature. For example, the saturated deposition amounts are 0.68 monolayers/cycle at 220-degrees-C and 0.39 monolayers/cycle at 340-degrees-C. We have also investigated thermally-induced and electron-beam-induced desorption by examining the effects, on the per-cycle deposition amounts, of varying the electron beam intensity, and of varying the time between Zn and Se depositions.