Plasma control apparatus
A plasma control apparatus includes a power source unit, a resonance producing unit, and a voltmeter. The resonance producing unit includes an LC circuit formed by a coil L 1 and a capacitor C 1 connected to each other, and a sensor S 2 configured to detect a phase difference between current flowing in and voltage applied to the LC circuit, and the capacitor C 1 of the LC circuit has a capacitance larger than an expected capacitance of the plasma P. The power source unit 1 configured to control the magnitude of radio-frequency power to be supplied in such a manner as to bring the voltage measured with the voltmeter 5 close to a set voltage as a target, and controls the frequency of the radio-frequency power to be supplied in such a manner as to minimize the phase difference detected with the sensor S 2.
1. A plasma control apparatus for supplying radio-frequency power to a plasma processing apparatus,
the plasma processing apparatus comprising a coil for generating inductively coupled plasma or an electrode for generating capacitively coupled plasma, and a stage on which a substrate is placed, the placed substrate being subjected to processing using any one of the inductively coupled plasma and the capacitively coupled plasma, wherein
the plasma control apparatus comprises:
a power source unit configured to supply radio-frequency power to the stage;
a resonance producing unit interposed between the power source unit and the stage, and configured to apply the radio-frequency power supplied from the power source unit to the stage; and
a voltmeter configured to measure a voltage of the stage,
the resonance producing unit comprises:
an LC circuit formed by a coil and a first capacitor and a second capacitor where a first end of the first capacitor is connected to the coil and a second end of the first capacitor is connected in parallel to the substrate stage and a first end of the second capacitor; wherein a second end of the second capacitor is connected to ground;
and a sensor configured to detect a phase difference between current flowing in and voltage applied to the LC circuit,
a capacitance of the second capacitor of the LC circuit is larger than an expected capacitance of the plasma,
the expected capacitance of the plasma is 100 pF to 110 pF when the radio-frequency power supplied from the power source unit has a frequency of 2 MHz, and 400 pF to 1200 pF when the radio-frequency power supplied from the power source unit has a frequency of 380 kHz,
the power source unit is configured to control a magnitude of the radio-frequency power to be supplied in such a manner as to bring the voltage measured with the voltmeter close to a set voltage as a target, and is configured to control a frequency of the radio-frequency power to be supplied in such a manner as to minimize the phase difference detected with the sensor, and the plasma control apparatus does not comprise an impedance matching device that performs impedance matching between the power source unit and the plasma in a mechanically driven way.
2. A plasma control apparatus for supplying radio-frequency power to a plasma processing apparatus,
the plasma processing apparatus comprising a plasma generating electrode for generating capacitively coupled plasma, and a stage on which a substrate is placed, the placed substrate being subjected to processing using the capacitively coupled plasma, wherein
the plasma control apparatus comprises:
a power source unit configured to supply radio-frequency power to the plasma generating electrode;
a resonance producing unit interposed between the power source unit and the plasma generating electrode, and configured to apply the radio-frequency power supplied from the power source unit to the plasma generating electrode; and
a voltmeter configured to measure a voltage of the plasma generating electrode,
the resonance producing unit comprises:
an LC circuit formed by a coil and a first capacitor and a second capacitor where a first end of the first capacitor is connected to the coil and a second end of the first capacitor is connected in parallel to the plasma generating electrode and a first end of the second capacitor; wherein a second end of the second capacitor is connected to ground;
and a sensor configured to detect a phase difference between current flowing in and voltage applied to the LC circuit,
a capacitance of the second capacitor of the LC circuit is larger than an expected capacitance of the plasma,
the expected capacitance of the plasma is 100 pF to 110 pF when the radio-frequency power supplied from the power source unit has a frequency of 2 MHz, and 400 pF to 1200 pF when the radio-frequency power supplied from the power source unit has a frequency of 380 kHz,
the power source unit is configured to control a magnitude of the radio-frequency power to be supplied in such a manner as to bring the voltage measured with the voltmeter close to a set voltage as a target, and is configured to control a frequency of the radio-frequency power to be supplied in such a manner as to minimize the phase difference detected with the sensor, and
the plasma processing apparatus does not comprise an impedance matching device that performs impedance matching between the power source unit and the plasma in a mechanically driven way.