Substrate support assembly, plasma processing apparatus, and plasma processing method

A plasma processing apparatus comprising:

• a plasma processing chamber;
• a substrate support assembly disposed in the plasma processing chamber, and
• a DC power source,
• wherein the substrate support assembly includes:
• an electrostatic chuck having a central region and an annular region, the annular region surrounding the central region;
• at least one piezoelectric device disposed on the annular region of the electrostatic chuck, the at least one piezoelectric device having a variable thickness in response to a voltage applied by the DC power source;
• an annular electrostatic chuck disposed on the at least one piezoelectric device;
• and,
• a focus ring disposed on the annular electrostatic chuck so as to surround a substrate on the central region of the electrostatic chuck, the focus ring being vertically shifted by a variation in thicknesses of the at least one piezoelectric device.

A method of plasma processing comprising:

• providing a processing apparatus comprising:
• a plasma processing chamber;
• a substrate support assembly disposed in the plasma processing chamber, and
• a DC power source,
• wherein the substrate support assembly includes:
• an electrostatic chuck having a central region and an annular region, the annular region surrounding the central region;
• at least one piezoelectric device disposed on the annular region of the electrostatic chuck, the at least one piezoelectric device having a variable thickness in response to a voltage applied by the DC power source;
• an annular electrostatic chuck disposed on the at least one piezoelectric device;
• and
• a focus ring disposed on the annular electrostatic chuck so as to surround a substrate on the central region of the electrostatic chuck, the focus ring being vertically shifted by a variation in thicknesses of the at least one piezoelectric device, the method further comprising:
• adjusting the thicknesses of the at least one piezoelectric device to at least one of:
• (i) shift a vertical position of the focus ring, or (ii) suppress gap formation between the focus ring and the annular region;
• and
• generating a plasma in the plasma processing chamber while mounting the substrate on the central region.