Method of forming silicon oxide containing films

A method of forming a silicon oxide film, comprising the steps of: -providing a treatment substrate within a reaction chamber; -purging the gas within the reaction chamber by feeding an inert gas into the chamber under reduced pressure at a substrate temperature of 50 to 400 C, -adsorbing, at the same temperatures and under reduced pressure, a silicon compound on the treatment substrate by pulsewise introduction of a gaseous silicon compound into the reaction chamber, -purging, at the same temperatures and under reduced pressure, the unadsorbed silicon compound in the reaction chamber with an inert gas, -at the same temperatures and under reduced pressure, introducing a pulse of ozone-containing mixed gas into the reaction chamber and producing silicon oxide by an oxidation reaction with the silicon compound adsorbed on the treatment substrate; and-repeating steps 1) to 4) if necessary to obtain the desired thickness on the substrate.