Plasma processing apparatus, plasma processing method, method for cleaning plasma processing apparatus and pressure control valve for plasma processing apparatus

Abstract

A plasma processing apparatus is provided with a first exhaust path which extends downward from an exhaust hole; a second exhaust path which is connected to a downstream end portion of the first exhaust path in the exhausting direction and extends in a direction perpendicular to a direction in which the first exhaust path extends, and whose cross-section, which orthogonally intersects with the exhausting direction, is horizontally long such that a widthwise length is greater than a vertical length in the cross-section; a third exhaust path which is connected to a downstream end portion of the second exhaust path in the exhausting direction and extends in a direction perpendicular to the direction in which the second exhaust path extends; a pump which is connected to a downstream end portion of the third exhaust path in the exhausting direction and depressurizes an inside of a processing container; a pressure control valve which is provided in the second exhaust path, and comprises a pressure control valve plate which is capable of closing the second exhaust path and controls a pressure at upstream and downstream sides in the exhausting direction; and a shut-off valve which is provided in the third exhaust path and comprises a shut-off valve plate which opens and closes the third exhaust path.