Ultrathin Silicon Dioxide Formation By Ozone On Ultraflat Si Surface

Abstract

ABSTRACTWe prepared an atomically flat silicon substrate which had a step-terrace structure and observed the topography of the ozone-oxidized surface to clarify whether homogeneous oxidation occurs with ozone. The oxide was formed with high-concentration ozone gas with a thickness of 2.5nm at a temperature of 350°C. The oxide surface still maintained the same step-terrace structure as observed before oxidation, which revealed that ozone-oxidation occurs layer-by-layer and produces an atomically flat oxide. XPS and MEIS analyses show that the stoichiometry of ozone oxide grown at 350°C is the same as that of an oxide grown thermally at 750°C.