Abstract: Fluorine is deposited on a semiconductor substrate surface according to a novel process. A semiconductor substrate is placed in a reaction chamber and the substrate surface is wetted with water and/or alcohol. A compound containing fluorine is led to the substrate surface, so that a cleaned semiconductor surface covered with fluorine is produced, and the compound containing fluorine is removed from the reaction chamber. The cleaned semiconductor surface covered with fluorine is then wetted with a mixture containing at least 10% by volume of water and at least 10% by volume of alcohol, for producing a cleaned semiconductor surface covered with a predetermined amount of fluorine. The predetermined amount of fluorine is lower the higher a proportion of water in the mixture is chosen to be. Then, the water and the alcohol are removed from the semiconductor surface.

Abstract: A method is disclosed for depositing silicon with high deposition rates and good step coverage. The process is performed at high pressures, including close to atmospheric pressures, at temperatures of greater than about 650° C. Silane and hydrogen are flowed over a substrate in a single-wafer chamber. Advantageously, the process maintains good step coverage and high deposition rates (e.g., greater that 50 nn/min) even when dopant gases are added to the process, resulting in commercially practicable rates of deposition for conductive silicon. Despite the high deposition rates, step coverage is sufficient to deposit polysilicon into extremely deep trenches and vias with aspect ratios as high as 40:1, filling such structures without forming voids or keyholes.