Patent ID: 9218943
Filing Date: 2015-12-22
Classification: H01J

Abstract:
1. A plasma processing apparatus comprising: a processing chamber including a dielectric window; a substrate holder capable of holding a target substrate within the processing chamber; a processing gas supply unit that supplies a processing gas into the processing chamber to perform a plasma process on the substrate; multiple antennas provided outside the dielectric window to generate plasma of the processing gas by an induced coupling within the processing chamber; a high frequency power supply unit that includes a high frequency power supply and a matching unit and supplies to the multiple antennas a high frequency power having a frequency for generating a high frequency electric discharge of the processing gas; a primary coil connected to a terminal of the high frequency power supply unit; multiple secondary coils, each being coupled with the primary coil by electromagnetic induction and electrically connected to a corresponding antenna of the multiple antennas, thereby forming closed-loop secondary circuits, mutual inductances between the primary coil and each of the multiple secondary coils being constant; multiple variable capacitors, each being provided in each of the secondary circuits; and a capacitance varying unit configured to vary electrostatic capacitances of the variable capacitors and control directions of currents flowing through the secondary circuits, wherein, the electrostatic capacitances of the variable capacitors are smaller or greater than an electrostatic capacitance that allows a serial resonance to occur within the secondary circuits, wherein the primary coil, the multiple secondary coils, and the multiple antennas have a common axis, and the multiple secondary coils are overlapped with each other when viewed from the multiple antennas, wherein the primary coil and the multiple secondary coils are located above the multiple antennas, and the multiple antennas each having a different diameter are arranged concentrically on a same plane such that the multiple secondary coils are located between the primary coil and the multiple antennas at respective different vertical heights above the multiple antennas.