Plasma processing apparatus and plasma processing method

A plasma processing apparatus comprising:

• a processing chamber including a dielectric window;
• an RF power supply unit;
• an RF antenna including an inner coil and an outer coil that are spaced apart from each other in a radial direction and respectively arranged at an inner portion and an outer portion outside the dielectric window, the inner coil and the outer coil being electrically connected in parallel to the RF power supply unit;
• a substrate supporting unit, provided in the processing chamber, configured to mount thereon a target substrate to be processed;
• a processing gas supply unit configured to supply a desired processing gas to the processing chamber to perform a desired plasma process on the target substrate, wherein the RF power supply unit is configured to supply an RF power for RF discharge of the processing gas to the RF antenna to generate a plasma of the processing gas by an inductive coupling in the processing chamber;
• a floating coil that is electrically floating and arranged at a position outside the dielectric window, wherein the floating coil is to be coupled with at least one of the inner coil and the outer coil of the RF antenna by electromagnetic induction;
• a variable capacitor provided in a loop of the floating coil and having an electrostatic capacitance;
• and
• a capacitance control unit configured to change a direction of a current flowing through the floating coil and to improve uniformity of a plasma density distribution below the floating coil in a radial direction with respect to the floating coil by dynamically varying the electrostatic capacitance of the variable capacitor,
• wherein the floating coil and the RF antenna are arranged in a same plane.