Substrate processing apparatus and substrate processing method

Abstract

To effectively prevent a micro arc causing damage to an apparatus and a substrate, by detecting a generation of the micro arc. A substrate processing apparatus is constituted so as to generate a plasma P, by applying a high frequency power to an electrodeprovided in a processing chamberfrom a high frequency power supply partthrough a matching unit. A directional coupleris provided between a high frequency power sourceand the matching unit, so that a reflected wave reflected from the electrodeand a traveling wave advancing toward the electrodeare coupled to a detector. The detectoroutputs a detection signal, when a level of a reflected wave Pr and a differential level thereof exceed each set value. In order to place an initial period of discharge out of a detection period, a delay traveling wave, which is a delayed traveling wave, is also outputted. A controllerdetermines the generation of a harmful micro arc, when coincidence of three detection signals outputted from the detectoris obtained, supplies an RF cut signal to a CPU, and temporarily stops or temporarily decreases a high frequency power from the high frequency power source