Plasma processing apparatus and potential control method

A potential control method in a plasma processing apparatus comprising:

• providing the plasma processing apparatus comprising:
• a chamber including a stage,
• a plurality of electrodes provided in a portion facing the ring assembly inside the stage;
• a power supply;
• a switch;
• and
• controller circuitry, the method comprising:
• by the controller circuitry:
• controlling the switch to supply bias power to a first electrode, among the plurality of electrodes, having a largest capacitance with the ring assembly when increasing a potential of the ring assembly, and
• controlling the switch to supply the bias power to a second electrode, among the plurality of electrodes, having a smallest capacitance with the ring assembly when decreasing the potential of the ring assembly.

A plasma processing apparatus comprising:

• a chamber to generate plasma therein;
• a stage disposed in the chamber, formed of a dielectric material, and receiving a substrate thereon and the stage receiving a ring assembly thereon around the substrate;
• a plurality of electrodes provided in a portion facing the ring assembly inside the stage,
• wherein an annular region of the stage is divided into a plurality of zones, and the plurality of electrodes are provided for each zone;
• a power supply supplying bias power for attracting charged particles in the plasma;
• a switch individually supplying the bias power supplied from the power supply to the plurality of electrodes;
• and
• controller circuitry configured to control the switch to independently adjust a potential for each zone.