Patent ID: 8293068
Filing Date: 2012-10-23
Classification: H01J

Abstract:
1. A plasma processing apparatus, comprising: a vacuum-evacuable processing chamber; a lower central electrode for mounting thereon a substrate to be processed in the processing chamber; a lower peripheral electrode electrically insulated from the lower central electrode and surrounding an outer periphery of the lower central electrode in an annular shape; an upper electrode provided above the lower central electrode and the lower peripheral electrode to face the electrodes; a processing gas supply unit for supplying a processing gas to a processing space formed between the upper electrode and the lower central electrode and the lower peripheral electrode; a radio frequency (RF) power supply for outputting an RF power for generating a plasma of the processing gas by an RF discharge; a power feed conductor connected to a rear surface of the lower peripheral electrode to supply the RF power from the RF power supply mainly to the lower peripheral electrode; and a variable capacitance coupling unit for electrically connecting the lower central electrode with the lower peripheral electrode by capacitance coupling with a variable impedance, the variable capacitance coupling unit being disposed between the lower central electrode and the lower peripheral electrode in order to supply a part of the RF power from the RF power supply to the lower central electrode, wherein the variable capacitance coupling unit includes an annular hollow dielectric provided between the lower central electrode and the lower peripheral electrode and the hollow dielectric accommodates therein a conductor plate movable in a predetermined direction.