Plasma processing device and method of monitoring plasma discharge state in plasma processing device

Abstract

An object is to provide a plasma processing device capable of rightly monitoring existence of plasma discharge and also rightly monitoring existence of abnormal discharge. Another object of the present invention is to provide a method of monitoring a state of plasma discharge in the plasma processing device. A discharge detection sensor, in which a dielectric memberand a probe electrode unitare combined with each other, is attached to an opening portionprovided in a lid portioncomposing a vacuum chamber. A change in the electric potential induced in the probe electrodeaccording to a change in plasma discharge is received, electric potential change wave-forms of specific patterns are respectively detected by an N-type wave-form detecting portionand V-type wave-form detecting, and a discharge state judgment including a judgment of whether the electric discharge exists or does not exist and whether the electric discharge is normal or abnormal is made according to a counted value of counting the number of times of appearance of these electric potential change wave forms for each type of wave-form by a discharge ON wave-form counter, a discharge OFF wave-form counter, an abnormal discharge wave-form counterand a leak discharge wave-form counter