MOLECULAR-BEAM EPITAXY-GROWN ZNSE STUDIED BY REFLECTANCE ANISOTROPY SPECTROSCOPY AND REFLECTION HIGH-ENERGY ELECTRON-DIFFRACTION

In this work we report on the in situ investigation of MBE grown ZnSe surfaces performed simultaneously by reflectance anisotropy spectrosco py (RAS) and reflection high-energy electron diffraction (RHEED). Reco nstructions and anisotropic reflectance of the ZnSe(001) surface are s tudied in the temperature range from 50 degrees C to 380 degrees C. Wi th increasing temperature the ZnSe surface evolves from a Se-rich c(2x 2)(Se) via a Se-rich (2x1) to a Zn-rich c(2x2)(Zn) surface reconstruct ion with the transition temperatures depending on whether the surface is Se stabilized or not. Each surface reconstruction as verified by RH EED is accompanied by a characteristic RAS spectrum. Time resolved mea surements of the RAS signal at fixed photon energies allowed to determ ine the activation energy (0.7 eV) for the Se desorption from the (2x1 ) reconstructed ZnSe(001) surface. (C) 1996 American Vacuum Society.