Plasma processing apparatus with heater and power frequency control

A plasma processing apparatus comprising:

• a chamber;
• a substrate support disposed in the chamber and including a lower electrode, an electrostatic chuck disposed on the lower electrode, and at least one heater that is a resistance heating element disposed in the electrostatic chuck;
• a radio frequency power supply electrically connected to the lower electrode;
• a DC power supply configured to apply a negative voltage to an edge ring disposed on the substrate support;
• a first controller configured to control the radio frequency power supply and the DC power supply;
• and
• a second controller configured to control a power supplied from a heater power supply to the heater such that a difference between a current temperature and a set temperature of the heater is reduced,
• wherein the first controller controls the radio frequency power supply to supply a pulsed radio frequency power to the lower electrode periodically with a cycle defined by a first frequency, and controls the DC power supply to apply a pulsed negative voltage to the edge ring periodically with the cycle,
• the second controller includes a heater controller configured to control the power by obtaining a resistance value of the heater from a sample value of a current supplied to the heater and a sample value of a voltage applied to the heater and determining the current temperature from the resistance value, and
• the first frequency is different from a second frequency that is a sampling frequency of the sample value of the current and the sample value of the voltage in the second controller.