Plasma processing apparatus
A plasma processing apparatus includes a radio-frequency (RF) power supply; a pair of plasma electrodes, and a matcher disposed between the pair of plasma electrodes and the RF power supply. The matcher includes an RF feed line supplied with RF power from the RF power supply; a ground line; a first load line connected to one of the plasma electrodes; a second load line connected to the other of the plasma electrodes; an impedance matching circuit connected to the RF feed line, the first load line, the second load line, and the ground line, and including variable reactance elements; an RF sensor that is provided in the RF feed line and detects the RF power; a voltage sensor that detects a first peak value; and a matcher controller that controls the variable reactance elements by inputting detected values from the RF sensor and the voltage sensor.
1 . A plasma processing apparatus comprising:
a radio-frequency (RF) power supply;
a pair of plasma electrodes; and
a matching box disposed between the pair of plasma electrodes and the RF power supply,
wherein the matching box includes:
an RF feed line through which RF power is supplied from the RF power supply,
a ground line that is grounded,
a first load line connected to one of the pair of plasma electrodes,
a second load line connected to a remaining one of the pair of plasma electrodes;
an impedance matching circuit connected to the RF feed line, the first load line, the second load line, and the ground line, and including a plurality of variable reactance elements;
an RF sensor provided in the RF feed line and configured to detect the RF power;
a voltage sensor including a peak detection circuit and configured to detect a peak value of a potential difference waveform that is a peak value of a potential difference, the peak detection circuit including a plurality of sensors respectively connected to the first load line, the second load line and the ground line, and
a matching box controller configured to control the plurality of variable reactance elements by inputting detected values from the RF sensor and the voltage sensor.
2 . The plasma processing apparatus according to claim 1 , wherein the impedance matching circuit includes:
a first variable reactance element disposed between the RF feed line and the ground line;
a second variable reactance element disposed between the RF feed line and the first load line;
a third variable reactance element disposed between the first load line and the second load line; and
a fourth variable reactance element disposed between the second load line and the ground line.
3 . The plasma processing apparatus according to claim 2 , wherein the first variable reactance element and the second variable reactance element are variable capacitors, and
the third variable reactance element and the fourth variable reactance element are variable inductors.
4 . The plasma processing apparatus according to claim 1 , wherein the peak detection circuit includes:
a first voltage sensor configured to detect a first peak value that is a peak value of a potential difference waveform between the first load line and the ground line, and
a second voltage sensor configured to detect a second peak value that is a peak value of a potential difference waveform between the second load line and the ground line.
5 . The plasma processing apparatus according to claim 4 , wherein the peak detection circuit further includes:
a third voltage sensor configured to detect a third peak value that is a peak value of a potential difference waveform between the first load line and the second load line.
6 . The plasma processing apparatus according to claim 1 , wherein the impedance matching circuit includes:
a first variable reactance element disposed between the RF feed line and the ground line;
a second variable reactance element disposed between the RF feed line and the first load line; and
a third variable reactance element disposed between the first load line and the second load line, and
wherein the second load line and the ground line are connected.
7 . The plasma processing apparatus according to claim 1 , wherein each of the plurality of the variable reactance elements is one of a variable capacitor having an adjustable capacitance and a variable inductor having an adjustable inductance.
8 . The plasma processing apparatus according to claim 1 , wherein the pair of plasma electrodes are disposed to face each other, and
wherein a plasma partition wall is provided between the pair of plasma electrodes to partition a plasma generation space.
9 . The plasma processing apparatus according to claim 1 , wherein the matching box controller is configured to control the plurality of variable reactance elements such that the detected peak value becomes a predetermined set value.