US Patent 9293299 Plasma processing apparatus

In an inductively coupled plasma processing apparatus, it is possible to control a plasma density distribution while suppressing a wavelength effect within a RF antenna. Provided at a ceiling of a chamber 10 or above a dielectric window 52 is a circular ring-shaped RF antenna 54 for generating inductively coupled plasma within the chamber 10. This RF antenna 54 includes two coil segments 84(1) and 84(2) each having a semicircular arc shape. The coil segments 84(1) and 84(2) are electrically connected to each other in parallel with respect to a high frequency power supply unit 62. On the dielectric window 52, a circular ring-shaped floating coil 60 having a variable capacitor 58 coupled to the RF antenna 54 by an electromagnetic induction is provided. The variable capacitor 58 is varied in a certain range by a capacitance varying unit 82 under the control of a main controller 80.