EVIDENCE OF ELECTRON CONFINEMENT IN THE SINGLE-DOMAIN, (4X1)-IN SUPERSTRUCTURE ON VICINAL SI(111)

Reflectance anisotropy spectroscopy is applied to submonolayer growth of In on the vicinal silicon (111) surface. Deposition in the region o f 1 monolayer onto a clean stepped Si(111) surface at elevated tempera ture produces a single-domain In-induced (4x1) superstructure consisti ng of quasi-one-dimensional chains aligned parallel to the vicinal sur face step edges. A significant optical anisotropy (1.65% uncharacteris tic of semiconductor systems, develops in the region of 1.9 eV which s aturates upon completion of the (4x1) superstructure. We relate this f eature to an optical transition involving a flat, highly populated fil led surface state observed previously. We argue that the intensity and direction of this peak are indicative of electronic confinement withi n this system perpendicular to the In-induced chain length. (C) 1998 A merican Institute of Physics. [S0003-6951(98)01741-0].