Suppression of HBO2 and Sb adsorption on thin-oxide-covered, H-terminated, or Sb-terminated Si(100) surfaces

Solid dopant sources, HBO2 and Sb, are shown to have a higher adsorption selectivity on a Si(100) surface than on surfaces covered with thin oxide, hydrogen atoms, or Sb atoms, by using conventional techniques in Si molecular beam epitaxy and wet chemical treatment. HBO2 adsorption on Si(100) surfaces is reduced by terminating dangling bonds on Si(100) surfaces with thin oxide or an Sb monolayer. The reduction ratios are about 1/30 at temperatures higher than 600°C. More significantly, Sb adsorption is reduced below 1/100 even at room temperature by H-termination as well as by covering with thin-oxide. These selective adsorption phenomena can be applied to selective atomic-molecular-layer doping (ALD/MLD) for achieving ultra-shallow source/drain junctions of 0.1 μm Si-MOSFETs.