Abstract
Thermal stability of ZnSe epilayers grown at the low growth temperatures of 250–300°C by MOVPE depends heavily on growth conditions, particularly the reactor pressure. The high density of deep centers is generated from the surface and diffuses into the epilayer by treating the epilayer at a temperature above 600°C under H2 atmosphere only. However, the increase of deep centers is effectively prevented by mixing dimethylzinc (DMZ) in the atmosphere even at the high temperature of 700°C. Probably, the partial pressure of Zn vapor in the ambience would suppress the generation of Zn vacancies at the high temperature.