Plasma processing apparatus

A plasma processing apparatus comprising:

• a plasma processing chamber;
• a substrate support disposed in the plasma processing chamber, the substrate support including an electrostatic chuck;
• a first ring disposed on the electrostatic chuck so as to surround a substrate to be disposed on the electrostatic chuck, the first ring including an inner annular portion, an intermediate annular portion, and an outer annular portion, a top surface of the inner annular portion being higher than a top surface of the intermediate annular portion, a top surface of the outer annular portion being higher than the top surface of the inner annular portion;
• a second ring disposed on the top surface of the intermediate annular portion of the first ring and having a thickness equal to or less than the intermediate annular portion, wherein a top surface of the second ring is positioned at a first height and the first height is greater than a height of the top surface of the inner annular portion of the first ring and is less than a height of the top surface of the outer annular portion of the first ring;
• and
• an actuator configured to vertically move the second ring so as to maintain the top surface of the second ring at the first height.