INITIAL STAGES OF EPITAXY OF METALS ON Si(lll)-7x7 STUDIED BY UHV ELECTRON MICROSCOPY

Abstract

AbstractInitial condensations of Cu, Ag and Au on Si(lll)-7x7 surface are seen continuously by video tape recording and intermittently by photographic films using an UHV electron microscope in reflection electron microscopy (REM). The growths of initial superlattice structures are found to relate with the steps of the 7x7 surface and the superlattice structures of a for Cu, for Ag and 5x2 for Au are nucleated at the upper side of the stepsand grow over the lower side terrace accompanied by the step movement. The growth of Au on Si(lll)-7x7 surface is seen in transmission electron microscopy (TEM) to supplement geometric information. It is found that the 5x2 domain of Au grows in the <llO>Si direction preferentially. The superlattice structures formed at submonolayer range are seen for the first time in TED pattern, which is useful to judge the previously proposed models from intensity distribution. REM-RHEED and TEM-TED allow us to study dynamic process of the initial growth stages of metals on Si(lll)-7x7 in real space and to analyse the geometrical structures of the superlattice structures at submonolayer.