Patent ID: 7527016

Claim:
An apparatus which performs a plasma process on a target substrate by using plasma, comprising: an airtight process chamber which accommodates the target substrate; a gas supply system which supplies a process gas into the process chamber; an exhaust system which exhausts an interior of the process chamber and sets the interior of the process chamber to a vacuum state; first and second electrodes arranged in the process chamber to oppose each other, an RF field, which turns the process gas into plasma by excitation, being formed between the first and second electrodes; an RF power supply connected to one of the first or second electrodes through a first interconnection and configured to supply RF power; a matching circuit arranged between said one of the first and second electrodes and the RF power supply on the first interconnection and configured to serve to automatically perform input impedance matching relative to the RF power; an impedance setting section provided in addition to the matching circuit and arranged between said one of the first and second electrodes and the matching circuit on the first interconnection, the impedance setting section being configured to select a higher harmonic of a fundamental frequency of the RF power, which is input from the plasma into the first interconnection, and to set an impedance relative to the selected higher harmonic thereby causing the higher harmonic to increase by a resonance action, the impendence setting section being capable of changing the selected higher harmonic to be treated as a resonance target; and a controller which supplies a control signal for controlling the impedance setting section to control a characteristic of a plasma process performed in the process chamber, wherein the impedance setting section comprises: an impedance change unit connected to the first interconnection through a shunt and configured to select the higher harmonic as a resonance target, and a filter disposed on the shunt between the first interconnection and the impedance change unit and configured to cut off the fundamental frequency of the RF power.