A film deposition system comprises a chamber having an internal space, a support
part provided in the internal space of the chamber for supporting a substrate,
a gas supply part supplying gas to the internal space and a heating part heating
the substrate. After an oxide film is formed on the substrate, the gas supply part
supplies oxygen or a gas mixture of oxygen and ozone to the internal space while
the heating part heats the substrate. Thus provided is a film deposition system
capable of flattening an oxide film.