Morphology of Silicon Oxide Film on Silicon Wafer Surface during Its Removal Process in a Hydrogen Ambient

Abstract

In order to develop the low-temperature silicon epitaxial growth process, the change in the surface morphology of the silicon dioxide film and the silicon surface is studied in a transient state, for the first time, at 1223 K at a pressure of 40–101 kPa in a hydrogen ambient. A very smooth and clear silicon substrate surface is achieved using a uniform silicon dioxide film formed using ozonated ultrapure water and a very low flow rate of hydrogen gas. The surface morphology of the silicon substrate finally becomes smooth and the pit formation is suppressed, although the surface shows a nonuniform island appearance during the removal of the silicon dioxide film. The microroughness of the silicon substrate surface is improved by heating in a hydrogen ambient and by the silicon epitaxial film growth after complete removal of the ozone oxide film.