Features of nanometer scale islands on CdSe/ZnSe surfaces

We examined the early-stage (within a few hours) properties in air of nanom eter scale islands formed on a CdSe/ZnSe surface. When a CdSe/ZnSe surface grown in vacuum was exposed to air, some islands were newly formed. The asp ect ratio of the island was found to increase first and then decrease. A de pletion zone was observed in the perimeter of the island which indicates th e intermixing of ZnSe into the island. Surface analyses using Auger electro n spectroscopy indicated that the island was composed mainly of oxides and the outer shell was Zn enriched and Cd depleted. This letter shows that sur face oxidation plays a key role in the formation of islands on CdSe/ZnSe su rfaces in atmosphere. (C) 2000 American Institute of Physics. [S0003-6951(0 0)04451-X].