Elemental diffusion at the GaAs/ZnSe interface

ZnSe epilayers were grown on GaAs using MBE. The native contamination (oxide and carbon) was removed from the substrate surfaces by conventional thermal cleaning and by exposure to atomic hydrogen. A maximum substrate temperature of 600°C was required for the thermal cleaning process, while a substrate temperature of 450°C was sufficient to clean the substrate using the hydrogen. ZnSe epilayers were also grown on As capped GaAs epilayers, which were decapped at a maximum temperature of 350°C. SIMS profiles confirmed that elemental interdiffusion across the interface is minimal for smooth substrates, which has been prepared by exposure to atomic hydrogen flux or using As capped GaAs buffer layer.