Patent ID: 7615163

Claim:
A method of using a film formation apparatus for a semiconductor process, the method comprising: processing by a cleaning gas a by-product film deposited on an inner surface of a reaction chamber of the film formation apparatus, while supplying the cleaning gas into the reaction chamber; setting an interior of the reaction chamber at a first temperature and a first pressure, wherein the by-product film mainly contains metal silicate having a dielectric constant of 7 or more, the cleaning gas contains a mixture gas of hydrogen chloride gas or chlorine gas with an inactive dilution gas without containing fluorine, and the first temperature and the first pressure are set to be within a range of 800 to 1,000° C. and within a range of 6,650 Pa (50 Torr) to atmospheric pressure, respectively, so as to activate chlorine in the cleaning gas and to remove a metal component from the by-product film while leaving a silicate component therein; and performing dry cleaning to etch the by-product film, from which the metal component has been removed, while supplying a second cleaning gas containing fluorine into the reaction chamber.