Abstract: A method is described for cleaning a silicon surface of a semiconductor wafer in a vacuum chamber while radiantly heating said silicon surface to maintain it within a first temperature range in the presence of hydrogen gas; then quickly cooling the wafer down to a second temperature range by reducing the radiant heat; and then forming a layer of either polysilicon or oxide over the cleaned surface within this second temperature range without removing the cleaned wafer from the chamber. By cleaning the wafer and then depositing polysilicon or growing oxide over the cleaned silicon surface in the same vacuum chamber, formation of oxides and other contaminants on the cleaned silicon surface between the cleaning step and the deposition or growth step is inhibited, resulting in a higher quality polysilicon or oxide layer formed over the cleaned silicon surface.