Abstract: In a method of forming a silicon oxide film, the silicon oxide film is formed on a substrate by the use of a plasma CVD method. A plasma-generating region is separated from a deposition region which includes excitation oxygen molecules and excitation oxygen atoms. Plasma of first gas containing oxygen atoms is formed in the plasma-generating region while second gas containing silicon atoms is supplied into the deposition region. First quantity of the excitation oxygen molecules and second quantity of the excitation oxygen atoms are controlled intentionally.

Abstract: A thin film deposition method consists of depositing a thin film on a wafer by supplying a reactant gas molecules toward and onto the wafer within a vacuum vessel or chamber. The pressure within the vacuum vessel is set to the pressure under which the mean free path (d) of the molecules contained in the supplied reactant gas can be longer than the shortest distance (L) between the wafer and the wall of the vacuum vessel exposed to the vacuum side, or d>L. The temperature of the wafer is set to the temperature (T sub) at which the reactant gas can cause substantially the thermally decomposing reaction. The temperature of the vacuum side-exposed wall of the vacuum vessel (T wall) is set to a temperature range having the lower limit higher than the temperature (T vap) at which the saturated vapor pressure can be maintained to be equal to the partial pressure of the molecules contained in the reactant gas, and having the upper limit lower than the temperature of the wafer (T sub), or T vap<T wall<T sub.