INTERFACE FORMATION OF GE ZNSE(100) AND GE/ZNS(111) HETEROJUNCTIONS STUDIED BY SYNCHROTRON-RADIATION PHOTOEMISSION/

The microscopic evolution of interface formation between Ge and II-VI compounds such as ZnSe and ZnS single crystals has been studied by syn chrotron radiation photoemission spectroscopy and low energy electron diffraction. Core level intensity measurements from the substrate as w ell as from the overlayer show a nearly ideal two-dimensional growth m ode for the deposition of Ge on ZnSe(100) surface. However, there is a certain deviation from the ideal two-dimensional mode in the case of Ge/ZnS(111) due to the diffusion of substrate atoms into Ge overlayer. Surface sensitive core level spectra indicate that the reaction of Ge with S atoms at Ge/ZnS(111) interfaces is much stronger than that of Ge with Se atoms at Ge/ZnSe(100) interfaces.