Suppression of HBO 2 and Sb adsorption on thin-oxide-covered, H-terminated, or Sb-terminated Si(100) surfaces

Abstract

Solid dopant sources, HBO 2 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. HBO 2 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.