Process for the formation of an amorphous silicon deposited film with intermittent irradiation of inert gas plasma

A process for forming a silicon-containing amorphous film on a substrate which comprises (a) a step of depositing a silicon-containing amorphous film on said substrate and (b) a step of irradiating a plasma of inert gas to said silicon-containing amorphous film deposited on the substrate in said step (a), wherein said step (a) and said step (b) are alternately repeated while (i) controlling the thickness of said silicon-containing amorphous film deposited on each repetition of said step (a) to a thickness of at least 10 .ANG. and (ii) maintaining the temperature of the substrate when irradiating a plasma of inert gas in step (b) to at least a transition temperature at which a marked reduction is caused in the content of hydrogen atoms contained in the silicon-containing amorphous film formed on the substrate.