PRODUCTION OF THIN SOLID FILM BY PHOTO CVD METHOD

摘要

PURPOSE:To prevent the decrease in the efficiency of forming a thin SiO2 film owing to a decrease in the quantity of the light transmitted through the glass of a window for allowing passage of light for excitation with a device for forming the thin SiO2 film by a photo CVD method by providing a nozzle for gaseous O2 for SiO2 near said window and blowing said gas to the glass of the window. CONSTITUTION:A thin SiO2 film is formed on a substrate 4 such as an Si wafer or the like in a reaction vessel 1 by a photo CVD method. The short wavelength light as light for excitation by a deuterium lamp is introduced through the window 2 in the upper part of the vessel 1 into the vessel. The gaseous CO2 as the gas for forming SiO2 is passed through a nozzle 8 from a pipeline 7 and likewise a gaseous mixture composed of gaseous SiH4 and gaseous N2 for dilution is supplied through a nozzle 6 from a pipeline 5 into said chamber. The gaseous SiH4 and the gaseous O2 are irradiated by the short wavelength light to excite reaction, by which the thin SiO2 film is formed on the substrate 4. The nozzle 8 for the gaseous O2 is placed near the window 2 and the gaseous O2 is blown uniformly to the glass of the window 2 to prevent formation of the thin SiO2 film on the glass and to prevent the decrease in the efficiency in forming SiO2 by the photo CVD reaction arising from the decrease in the quantity of the light transmitted through the window 2.