METHOD AND APPARATUS FOR PRODUCING PROTECTIVE FILM

摘要

Disclosed is an apparatus for producing a protective film, which comprises a film formation chamber (32), a gas feed port (47) for introducing at least a gas into the film formation chamber (32), an exhaust pump (43) for exhausting the film formation chamber (32), a cryotrap for controlling the exhaust rate of water independently from the exhaust pump (43), and a temperature control unit for controlling the cooling temperature of the cryotrap. By controlling the exhaust rate of water through control of the cooling temperature of the cryotrap, a protective film which is likely to be affected by the partial pressure of water can be stably produced under the same conditions all the time. Consequently, there can be obtained a protective film having sputtering resistance, which is excellent in secondary electron emission characteristics.