Conformal oxides on Si surfaces

The characteristics of the Si–vacuum interface were compared with the characteristics of the oxide–air interface formed following room temperature oxidation for a variety of samples. Scanning tunneling microscopy was used to measure the surface structure following vacuum preparation, and atomic force microscopy was used to measure the oxide surface on the same samples following exposure to air. Samples investigated included nominally flat Si(111) with equilibrated and quenched surface configurations, Si(111) miscut by 1.25° toward the [211] and equilibrated to yield the faceted structure, and nominally flat Si(001) wafers. In all cases, the step morphology of the clean surfaces was duplicated on the surface of the oxide.