X-RAY-SCATTERING FROM SURFACES AND INTERFACES AND ITS APPLICATION TO THE CHARACTERIZATION OF CAF2 SI(111) INTERFACES/

A survey of X-ray scattering techniques developed so far is presented keeping in mind that the appearance of the next generation of synchrot ron radiation sources makes such techniques one of the promising probe s for ex situ and in situ characterization of the surface and the inte rface of an epitaxially grown crystal. On the basis of the intensity f ormula given by one of the present authors [J. Harada, Ultramicroscopy 52 (1993) 233], it is shown that diffuse scattering associated with t he crystal truncation rod is closely related to the local atomic arran gement on a surface. Our current X-ray scattering studies on CaF2/Si(1 11) films grown by the MBE method are presented and the growth conditi on of the four types of interface structure found in CaF2/Si(111)is di scussed. A hydrogen-terminated Si(111) surface was found to be a promi sing substrate for the low-temperature growth of CaF2 films.