IDEAL UNRECONSTRUCTED HYDROGEN TERMINATION OF THE SI(111) SURFACE OBTAINED BY HYDROGEN EXPOSURE OF THE SQUARE-ROOT-3 X SQUARE-ROOT-3-IN SURFACE

Hydrogen exposure of the Si(111)square-root 3 x square-root 3-In surface resulted in a replacement of the Si-In bonds by Si-H bonds as evidenced by core-level and angle-resolved photoelectron spectroscopy. Saturation of the Si dangling bonds by hydrogen atoms led to the formation of an unreconstructed Si(111)1 x 1-H surface. Besides a peak due to Si-H bonds, a sharp peak, due to Si-Si backbonds, appeared in the valence-band spectra. The experimental dispersions of these states showed excellent agreement with calculated surface bands. The In atoms formed metallic islands on a small part of the surface (approximately 5%).