ZnSe epitaxial growth on Si(100) and Ge(100) by H-radical assisted MOCVD

Epitaxial ZnSe is a polar material grown on non-polar substrates such as Si(100) and Ge(100) by metal organic chemical vapor deposition methods. Epitaxial growth of ZnSe on non-polar materials is more difficult than on polar materials, for example, on GaAs. For the growth of ZnSe on non-polar substrates, a polarization of substrate surface at the initial step is of importance. The FWHM of XRD peak obtained for ZnSe(100) grown on Ge is wider than that obtained for ZnSe(100) grown on GaAs, in spite of both Ge and GaAs having nearly the same lattice constant. Further, the surface morphology of ZnSe films grown on Ge and GaAs substrates is observed to be different. It is considered that the surface polarization of Ge substrate at the initial stage is not uniform. This results in a lower number of growth sites on Ge substrate compared with that on GaAs substrate.