Plasma processing apparatus, and plasma processing method

A plasma processing apparatus for cleaning a peripheral portion of a substrate by plasma, comprising:

• a depressurizable processing container accommodating a substrate;
• a phase adjuster;
• and
• a controller,
• wherein the depressurizable processing container includes therein:
• a substrate support configured to support a substrate and including a central electrode facing a central portion of the substrate supported by the substrate support;
• a lower ring electrode formed in a ring shape to face a lower surface of a peripheral portion of the substrate supported by the substrate support;
• and
• an upper ring electrode disposed to face an upper surface of the peripheral portion of the substrate supported by the substrate support,
• wherein the central electrode is grounded,
• a radio frequency (RF) power is supplied to each of the upper ring electrode and the lower ring electrode,
• the RF power is supplied to at least one of the upper ring electrode and the lower ring electrode via the phase adjuster configured to adjust the phase of the RF power, and
• the controller is configured to control the RF power supplied to the upper ring electrode and the RF power supplied to the lower ring electrode between in phase and anti- phase by controlling the phase adjuster.