Radio-frequency (RF) matching network for fast impedance tuning
Some embodiments are directed to a tuning circuit. The tuning circuit generally includes: a first impedance coupled between a first terminal and a second terminal of the tuning circuit, wherein the first terminal is coupled to a generator and the second terminal is coupled to a load; a second impedance coupled between the first impedance of the tuning circuit and a reference potential node; and a signal path coupled to the first impedance or the second impedance, the signal path comprising an inductive element and a first switch coupled to the inductive element, wherein a control input of the first switch is coupled to a control input of the tuning circuit configured to receive a control signal associated with a pulsed voltage (PV) waveform.
1 . A tuning circuit, comprising:
a first impedance circuit coupled between a first terminal and a second terminal of the tuning circuit, wherein the first terminal is coupled to a generator and the second terminal is coupled to a load, the first impedance circuit being on a series path between the first terminal and the second terminal;
a second impedance circuit coupled between the first impedance circuit and a reference potential node; and
a signal path coupled to the first impedance circuit or the second impedance circuit, the signal path comprising an inductive element and a first switch coupled in parallel with the inductive element to form a parallel circuit, the parallel circuit being between the series path and the reference potential node, wherein a control input of the first switch is coupled to a control input of the tuning circuit configured to receive a control signal associated with a pulsed voltage (PV) waveform.
2 . The tuning circuit of claim 1 , wherein the parallel circuit further comprises a capacitive element coupled in series with the first switch.
3 . The tuning circuit of claim 1 , wherein the signal path including the parallel circuit is coupled in parallel with the first impedance circuit or the second impedance circuit.
4 . The tuning circuit of claim 1 , wherein the signal path further comprises a capacitive element coupled to the parallel circuit.
5 . The tuning circuit of claim 4 , wherein the signal path further comprises a second switch coupled between the capacitive element and the parallel circuit.
6 . The tuning circuit of claim 1 , wherein the signal path further comprises a second switch coupled in parallel with the second impedance circuit, the second switch being between the parallel circuit and the first terminal.
7 . The tuning circuit of claim 1 , wherein the signal path is in parallel with the first impedance circuit or the second impedance circuit, the first switch being in series with the inductive element.
8 . The tuning circuit of claim 7 , wherein the signal path comprises at least one capacitive element in series with the inductive element.
9 . A plasma processing system having the tuning circuit of claim 1 , the plasma processing system further including a controller having an output coupled to the control input of the tuning circuit, wherein the controller is configured to:
generate the control signal based on the PV waveform; and
provide the control signal to the control input of the tuning circuit.
10 . The plasma processing system of claim 9 , further comprising a PV waveform generator configured to deliver the PV waveform to an electrode disposed within a plasma chamber of the plasma processing system.
11 . The tuning circuit of claim 1 , wherein the control signal is configured to control the first switch based on stage transitions associated with the PV waveform.
12 . The tuning circuit of claim 1 , wherein the control signal is configured to control the first switch based on a processing chamber being in a sheath collapse stage or an ion current stage.
13 . A match circuit, comprising:
a tuning circuit including:
a first impedance circuit coupled between a first terminal and a second terminal of the tuning circuit, wherein the first terminal is coupled to a generator and the second terminal is coupled to a load;
a second impedance circuit coupled between the first impedance circuit and a reference potential node; and
a signal path coupled to the first impedance circuit or the second impedance, the signal path comprising an inductive element and a first switch coupled to the inductive element, wherein a control input of the first switch is coupled to a control input of the tuning circuit configured to receive a control signal associated with a pulsed voltage (PV) waveform; and
a bias circuit; and
a filter coupled between the control input of the tuning circuit and an output of the bias circuit.
14 . A method of processing a substrate in a plasma processing system, comprising:
generating a control signal based on a pulsed voltage (PV) waveform provided to an electrode of a processing chamber; and
providing the control signal to a control input for a tuning circuit, the tuning circuit further comprises:
a first impedance circuit coupled between a first terminal and a second terminal of the tuning circuit, wherein the first terminal is coupled to a generator and the second terminal is coupled to the processing chamber, the first impedance circuit being on a series path between the first terminal and the second terminal;
a second impedance circuit coupled between the first impedance circuit and a reference potential node; and
a signal path coupled to the first impedance circuit or the second impedance circuit, the signal path comprising an inductive element and a first switch coupled in parallel with the inductive element to form a parallel circuit, the parallel circuit being between the series path and the reference potential node, wherein a control input of the first switch is coupled to the control input of the tuning circuit.
15 . The method of claim 14 , further comprising controlling, via the control signal, the first switch based on stage transitions associated with the PV waveform.
16 . The method of claim 14 , further comprising controlling, via the control signal, the first switch based on the processing chamber being in a sheath collapse stage or an ion current stage.
17 . An apparatus for processing a substrate in a plasma processing system, comprising:
a pulsed voltage (PV) waveform generator configured to generate a PV waveform provided to an electrode of a processing chamber;
a tuning circuit including:
a first impedance circuit coupled between a first terminal and a second terminal of the tuning circuit, the first impedance circuit being on a series path between the first terminal and the second terminal;
a second impedance circuit coupled between the first terminal of the tuning circuit and a reference potential node; and
a signal path coupled to the first impedance circuit or the second impedance circuit, the signal path comprising an inductive element and a first switch coupled in parallel with the inductive element to form a parallel circuit, the parallel circuit being between the series path and the reference potential node, wherein a control input of the first switch is coupled to a control input of the tuning circuit; and
a controller configured to provide a control signal to the control input of the tuning circuit based on the PV waveform.