Monitoring method and plasma processing apparatus

A plasma processing apparatus, comprising:

• a chamber;
• a plasma generator configured to generate plasma in the chamber;
• a substrate support in the chamber, the substrate support including heaters each located in a corresponding zone of a plurality of zones in the substrate support;
• a heater controller configured to provide power to the heaters in the plurality of zones;
• and
• a controller configured to:
• determine first power provided from the heater controller to the corresponding heater in each of the plurality of zones when the plasma is generated in the chamber and each of the plurality of zones is controlled to be at a constant temperature with the corresponding heater in the zone, and
• determine a heat flux from the plasma to each of the plurality of zones by dividing a difference between second power and the first power provided to the corresponding heater in the zone by an area of the zone,
• wherein for each zone, the second power to the corresponding heater is provided when no plasma is generated in the chamber and the zone is controlled to be at the constant temperature with the corresponding heater in the zone.