| 摘要 |
PURPOSE:To prevent effluent and backflowing impurities from intruding into articles by suitably disposing a trap member which is provided with a capturing surface cooled by a sub-zero refrigerant and has venting parts in a vacuum chamber. CONSTITUTION:After the inside of a vacuum vessle 11 is roughly evacuated with a rough evacuating system 12, the system 12 is shut off, and a high vacuum is developed by a cryogenic pump 13. For example, gaseous Ar is introduced from a gaseous source 15 and an article 16 to be treated is subjected to sputtering treatment. At this time, a sub-zero refrigerant is flowed in a trap member 20 so that the surface of a tube 21 forming the coil serves as a capturing surface for condensing and capturing impurities. The clearances between the turns and upper and lower opening parts of the coil form venting parts that permit passage of the gas. Then, effluent impurities, backflowing impurities and other impurities are condensed and captured without hampering the maintenance of a required low pressure atmosphere, and the intrusion of these impurities into the article 16 to be treated is prevented. |
