ATOMIC-STRUCTURE OF THE METASTABLE SI(111)2X2-IN SURFACE PHASE

Low energy electron diffraction (LEED), Auger electron spectroscopy (A ES) and scanning tunnelling microscopy (STM) have been used to study t he evolution of the surface structure upon room temperature deposition of In onto In-predeposited Si(lll)root 3x root 3-In surface. The sequ ential formation of the Si(111)2x2 and Si(lll) root 7x root 3 surface phases has been detected and coverage ranges of their existence have b een determined. STM observations have revealed that the Si(111)2x2-In phase has a honeycomb-like atomic structure with depressions in T-4 po sitions. The structural model built of In trimers has been proposed.