SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE PROCESSING METHOD

摘要

Occurrence of microarcs is detected so as to effectively suppress the microarcs that would otherwise cause damage to devices and substrates. A substrate processing apparatus is adapted to apply a high frequency electric power from a high frequency power supply part (100) through a matching unit (300) to an electrode (210) provided in a processing room (200) to generate a plasma (P). A directivity coupler (121) is provided between a high frequency power supply source (111) and the matching unit (300) to couple both a reflective wave reflected from the electrode (210) and a progressive wave progressing to the electrode (210) to a detector (122). The detector (122) outputs a detection signal when the level of the reflective wave (Pr) and its differential level exceed their respective prescribed values. In order for the beginning stage of discharging to be outside the detection interval, the detector (122) also outputs a delayed progressive wave obtained by delaying the progressive wave. Upon coincidence of three detection signals outputted from the detector (122), control means (130) regards it as occurrence of deleterious microarcs, and then applies an RF cut signal to a CPU (116), thereby temporally stopping or temporally reducing the high frequency electric power from the high frequency power supply source (111).