Plasma Processing Equipment

Abstract

To provide a technique for reducing energy of ions incident toward a substrate mounted on a lower electrode.SOLUTION: Provided is a plasma processing apparatus according to one exemplary embodiment. The plasma processing apparatus includes: a lower electrode provided in a chamber and included in a substrate support part mounting a substrate thereon; an upper electrode provided in the chamber and disposed to face the lower electrode; a gas supply part supplying a processing gas between the upper electrode and the lower electrode; a high-frequency power supply electrically connected to the upper electrode and generating a plasma of the processing gas by applying a high-frequency voltage to the upper electrode; and a circuit part electrically connected between the high-frequency power supply and the lower electrode and providing a potential to the lower electrode. The circuit part provides the potential to the lower electrode by causing a current to flow from the high-frequency power supply toward the lower electrode when a potential of the high-frequency power supply is higher than a potential of the lower electrode.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An exemplary embodiment of the present disclosure relates to a plasma processing apparatus. [Background technology]

[0002] Plasma processing is widely used for processing substrates such as semiconductor wafers. Patent Documents 1 and 2 disclose techniques for controlling the impedance of a current path connected to a lower electrode of a high-frequency current used for plasma generation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-108413 A [Patent Document 2] JP 2015-124398 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for reducing the energy of ions incident on a substrate placed on a lower electrode. [Means for solving the problem]

[0005] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a lower electrode, an upper electrode, a gas supply, a high frequency power supply, and a circuit unit. The lower electrode is included in a substrate support provided in the chamber and configured to place a substrate thereon. The upper electrode is provided in the chamber and disposed to face the lower electrode. The gas supply unit is configured to supply a process gas between the upper electrode and the lower electrode. The high frequency power supply is electrically connected to the upper electrode and configured to generate plasma of the process gas by applying a high frequency voltage to the upper electrode. The circuit unit is electrically connected between the high frequency power supply and the lower electrode and configured to provide a potential to the lower electrode. The circuit unit is configured to provide a potential to the lower electrode by passing a current from the high frequency power supply toward the lower electrode when the potential of the high frequency power supply is higher than the potential of the lower electrode. Effect of the Invention

[0006] According to one exemplary embodiment, the energy of ions incident on a substrate placed on a lower electrode is reduced. [Brief description of the drawings]

[0007] [Figure 1] 1 is a diagram showing a configuration of a plasma processing apparatus according to an exemplary embodiment; [Diagram 2] FIG. 2 is a diagram showing an example of a circuit portion. [Diagram 3] FIG. 1 is a diagram showing the configuration of a plasma processing apparatus including an example of a power regulator. [Figure 4] FIG. 2 is a diagram showing an example of a circuit portion. [Diagram 5] FIG. 2 is a diagram showing an example of a circuit portion. [Figure 6] FIG. 2 is a diagram showing an example of a circuit portion. [Figure 7] FIG. 13 is a diagram showing a simulation result of a plasma processing apparatus according to an exemplary embodiment. [Figure 8] FIG. 13 is a diagram showing a simulation result of a conventional plasma processing apparatus. [Figure 9] FIG. 13 is a diagram showing a simulation result of a plasma processing apparatus according to an exemplary embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Various exemplary embodiments are described below.

[0009] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a lower electrode, an upper electrode, a gas supply, a high frequency power supply, and a circuit unit. The lower electrode is included in a substrate support provided in the chamber and configured to place a substrate thereon. The upper electrode is provided in the chamber and disposed to face the lower electrode. The gas supply unit is configured to supply a process gas between the upper electrode and the lower electrode. The high frequency power supply is electrically connected to the upper electrode and configured to generate plasma of the process gas by applying a high frequency voltage to the upper electrode. The circuit unit is electrically connected between the high frequency power supply and the lower electrode and configured to provide a potential to the lower electrode. The circuit unit is configured to provide a potential to the lower electrode by passing a current from the high frequency power supply toward the lower electrode when the potential of the high frequency power supply is higher than the potential of the lower electrode.

[0010] In the plasma processing apparatus equipped with the circuit unit, the potential of the lower electrode becomes equal to or higher than the potential of the high frequency power supply that provides the potential to the upper electrode. Therefore, the sheath voltage of the sheath region formed at the boundary between the plasma and the substrate placed on the lower electrode during plasma generation becomes lower. As a result, the energy of ions in the plasma that may collide with the substrate is reduced.

[0011] Furthermore, when plasma is formed in the space between the sidewall of the electrically grounded chamber and the lower electrode, power may flow from the lower electrode to ground through the sidewall. In a plasma processing apparatus having a circuit unit according to an exemplary embodiment, the potential of the lower electrode is equal to or higher than the potential of the high frequency power supply that provides a potential to the upper electrode. Therefore, the sheath voltage that may occur when power flows from the lower electrode to ground through the sidewall is approximately the same as the sheath voltage that may occur when power does not flow from the lower electrode to ground through the sidewall. In this way, even when power flows from the lower electrode to ground through the sidewall, an increase in the sheath voltage can be avoided.

[0012] In one exemplary embodiment, the circuit portion may include a diode, an anode of the diode may be electrically connected to the high frequency power source, and a cathode of the diode may be connected to the lower electrode.

[0013] In one exemplary embodiment, the circuit portion may include a diode and a Zener diode. The diode and the Zener diode may be connected in series. The anode of the diode may be electrically connected to a high frequency power source. The cathode of the diode may be electrically connected to the cathode of the Zener diode. The anode of the Zener diode may be electrically connected to the bottom electrode.

[0014] In one exemplary embodiment, the circuit portion may include a diode and a resistor. The diode and the resistor may be connected in series. The anode of the diode may be electrically connected to a high frequency power source. The cathode of the diode may be electrically connected to the bottom electrode via the resistor.

[0015] In one exemplary embodiment, the circuit portion may include a diode and an inductor. The diode and the inductor may be connected in series. The anode of the diode may be electrically connected to a high frequency power source. The cathode of the diode may be electrically connected to the lower electrode via the inductor.

[0016] In one exemplary embodiment, the circuit section may have a first potential meter, a second potential meter, a switch element, and a drive circuit. The switch element may be electrically connected between the high frequency power supply and the lower electrode, and configured to turn on and off the conduction between the high frequency power supply and the lower electrode. The first potential meter may be electrically connected between the high frequency power supply and the drive circuit, and may measure the potential of the high frequency power supply to generate a first measurement result and output the first measurement result to the drive circuit. The second potential meter may be electrically connected between the lower electrode and the drive circuit, and may measure the potential of the lower electrode to generate a second measurement result and output the second measurement result to the drive circuit. The drive circuit may drive the switch element to turn on the conduction between the high frequency power supply and the lower electrode when the potential of the high frequency power supply is higher than the potential of the lower electrode based on the first measurement result and the second measurement result. The drive circuit may be configured to drive the switch element to turn off the conduction between the high frequency power supply and the lower electrode when the potential of the high frequency power supply is equal to or lower than the potential of the lower electrode based on the first measurement result and the second measurement result.

[0017] In one exemplary embodiment, the apparatus may further include a power regulator electrically connected between the RF power source and the upper electrode and configured to adjust the power supplied from the RF power source to the upper electrode. The circuit unit may be electrically connected between a line electrically connecting the RF power source and the power regulator and the lower electrode. The power regulator may be configured to measure the power supplied from the RF power source to the upper electrode and control the RF power source to increase or decrease the power output by the RF power source according to the measurement result.

[0018] Various exemplary embodiments will be described in detail below with reference to the drawings. In addition, the same or corresponding parts in each drawing will be given the same reference numerals. FIG. 1 is a diagram that shows a schematic diagram of a plasma processing apparatus according to one exemplary embodiment. The plasma processing apparatus 1 shown in FIG. 1 includes a chamber 10. The chamber 10 provides an internal space therein. The chamber 10 may include a chamber body 12. The chamber body 12 has a substantially cylindrical shape. The internal space of the chamber 10 is provided in the chamber body 12. The chamber body 12 is formed of a metal such as aluminum. The chamber body 12 is electrically grounded. Note that the sidewall of the chamber body 12 may provide a passage through which the substrate W passes when it is transported. In addition, a gate valve may be provided along the sidewall of the chamber body 12 to open and close this passage.

[0019] The plasma processing apparatus 1 further includes a substrate support 14. The substrate support 14 is installed inside the chamber 10. The substrate support 14 is configured to support a substrate W placed thereon. The substrate support 14 has a main body. The main body of the substrate support 14 is formed of, for example, aluminum nitride, and may have a disk shape. The substrate support 14 may be supported by a support member 16. The support member 16 extends upward from the bottom of the chamber 10. The substrate support 14 includes a lower electrode 18. The lower electrode 18 is included in the substrate support 14 and is embedded in the main body of the substrate support 14.

[0020] The plasma processing apparatus 1 further includes an upper electrode 20. The upper electrode 20 is provided in the chamber 10 and above the substrate support 14. The upper electrode 20 is disposed to face the lower electrode 18. The upper electrode 20 constitutes the ceiling of the chamber 10. The upper electrode 20 is electrically isolated from the chamber body 12. In one embodiment, the upper electrode 20 is fixed to the upper part of the chamber body 12 via an insulating member 21.

[0021] In one embodiment, the upper electrode 20 is configured as a shower head. The upper electrode 20 provides a gas diffusion space 20d therein. The upper electrode 20 further provides a plurality of gas holes 20h. The plurality of gas holes 20h extend downward from the gas diffusion space 20d and open toward the internal space of the chamber 10. That is, the plurality of gas holes 20h connect the gas diffusion space 20d and the internal space of the chamber 10.

[0022] The plasma processing apparatus 1 further includes a gas supply unit 22. The gas supply unit 22 is configured to supply a gas into the chamber 10. The gas supply unit 22 is configured to supply a processing gas between the upper electrode 20 and the lower electrode 18. The gas supply unit 22 is connected to the gas diffusion space 20d via a pipe 23. The gas supply unit 22 may include one or more gas sources, one or more flow rate controllers, and one or more opening and closing valves. Each of the one or more gas sources is connected to the pipe 23 via a corresponding flow rate controller and a corresponding opening and closing valve.

[0023] In one embodiment, the gas supply unit 22 may supply a film formation gas. That is, the plasma processing apparatus 1 may be a film formation apparatus. The film formed on the substrate W using the film formation gas may be an insulating film. In another embodiment, the gas supply unit 22 may supply an etching gas. That is, the plasma processing apparatus 1 may be a plasma etching apparatus.

[0024] The plasma processing apparatus 1 further includes an exhaust device 24. The exhaust device 24 includes a pressure controller such as an automatic pressure control valve and a vacuum pump such as a turbo molecular pump or a dry pump. The exhaust device 24 is connected to the internal space of the chamber 10 via an exhaust pipe from an exhaust port 12e provided in a side wall of the chamber body 12.

[0025] The plasma processing apparatus 1 further includes a high-frequency power supply 26. The high-frequency power supply 26 is electrically connected to the upper electrode 20 via a matching device 28. The high-frequency power supply 26 may include the matching device 28. The high-frequency power supply 26 is configured to generate plasma of a processing gas supplied from the gas supply unit 22 to between the upper electrode 20 and the lower electrode 18 by applying a high-frequency voltage to the upper electrode 20. In one embodiment, the high-frequency power supply 26 generates high-frequency power. The frequency of the high-frequency power may be any frequency. The frequency of the high-frequency power may be 13.56 MHz or less. The frequency of the high-frequency power may be 2 MHz or less. The frequency of the high-frequency power may be 20 kHz or more.

[0026] The high frequency power supply 26 is connected to the upper electrode 20 via a matching device 28. High frequency power from the high frequency power supply 26 is supplied to the upper electrode 20 via the matching device 28. The matching device 28 has a matching circuit that matches the impedance of the load of the high frequency power supply 26 to the output impedance of the high frequency power supply 26.

[0027] In another embodiment, the high frequency power supply 26 may be configured to periodically apply a DC voltage pulse to the upper electrode 20. The frequency that defines the period during which the DC voltage pulse from the high frequency power supply 26 is applied to the upper electrode 20 is, for example, 10 kHz or more and 10 MHz or less. When the high frequency power supply 26 is configured to periodically apply a DC voltage pulse to the upper electrode 20, the plasma processing apparatus 1 does not need to include the matching unit 28.

[0028] The plasma processing apparatus 1 further includes a ring electrode 30. The ring electrode 30 has an annular shape. The ring electrode 30 may be divided into a plurality of electrodes arranged along the circumferential direction. The ring electrode 30 is provided around the substrate support 14 so as to surround the outer periphery of the substrate support 14. A gap is provided between the ring electrode 30 and the outer periphery of the substrate support 14, but this gap does not have to be provided. The ring electrode 30 is electrically grounded.

[0029] In one embodiment, the plasma processing apparatus 1 further includes a gas supply unit 32. The gas supply unit 32 supplies a purge gas so that the purge gas flows upward through the gap between the ring electrode 30 and the substrate support 14. The gas supply unit 32 supplies the purge gas into the chamber 10 through a gas introduction port 12p. In the illustrated example, the gas introduction port 12p is provided in the wall of the chamber body 12 below the substrate support 14. The purge gas supplied by the gas supply unit 32 may be an inert gas, for example, a rare gas.

[0030] When plasma processing is performed on the substrate W in the plasma processing apparatus 1, a processing gas is supplied from the gas supply unit 22 into the chamber 10. Then, a pulse of high frequency power or DC voltage is applied from the high frequency power supply 26 to the upper electrode 20. As a result, plasma is generated from the processing gas in the chamber 10. The substrate W on the substrate support 14 is processed by chemical species from the generated plasma. For example, the chemical species from the plasma form a film on the substrate W. Alternatively, the chemical species from the plasma etch the substrate W.

[0031] In one embodiment, the plasma processing apparatus 1 further includes a circuit unit 4. The circuit unit 4 is electrically connected between the high frequency power supply 26 and the lower electrode 18. The circuit unit 4 is configured to provide a potential to the lower electrode 18. More specifically, the circuit unit 4 is configured to provide a potential to the lower electrode 18 by causing a current to flow from the high frequency power supply 26 to the lower electrode 18 when the potential of the high frequency power supply 26 is higher than the potential of the lower electrode 18.

[0032] 2, the circuit unit 4 may include a diode 4a. The anode of the diode 4a is electrically connected to the high frequency power supply 26 via a matching unit 28. The cathode of the diode 4a is connected to the lower electrode 18.

[0033] According to the plasma processing apparatus 1 equipped with the circuit unit 4, the circuit unit 4 makes the potential of the lower electrode 18 equal to or higher than the potential of the high frequency power supply 26 that provides a potential to the upper electrode 20. Therefore, the sheath voltage of the sheath region formed at the boundary between the plasma and the substrate W placed on the lower electrode 18 during plasma generation is lowered. As a result, the energy of ions in the plasma that may collide with the substrate W is reduced.

[0034] Furthermore, when plasma is formed in the space between the sidewall 12S of the chamber body 12, which is electrically grounded, and the lower electrode 18, power may flow from the lower electrode 18 to the ground through the sidewall 12S along the power flow path EP. Now, refer to FIG. 8. In the plasma processing apparatus 1 without the circuit unit 4, the sheath voltage (waveform G3) that may occur when power flows from the lower electrode 18 to the ground through the sidewall 12S is higher than the sheath voltage (waveform G4) that may occur when power does not flow from the lower electrode 18 to the ground through the sidewall 12S. In contrast, in the plasma processing apparatus 1 with the circuit unit 4, the potential of the lower electrode 18 is equal to or higher than the potential of the high frequency power supply 26 that provides the potential to the upper electrode 20. For this reason, as shown in FIG. 7, the sheath voltage (waveform G1) that may occur when power flows from the lower electrode 18 to the ground through the sidewall 12S is approximately the same as the sheath voltage (waveform G2) that may occur when power does not flow from the lower electrode 18 to the ground through the sidewall 12S. In this way, even when power flows from the lower electrode 18 to the ground via the side wall 12S, an increase in the sheath voltage can be avoided.

[0035] The above-mentioned effects of the plasma processing apparatus 1 having the circuit unit 4 are achieved not only in the plasma processing apparatus 1 having the circuit unit 4 shown in FIG. 2, but also in the plasma processing apparatus 1 having the circuit units 4 shown in each of FIGS. 3 to 6 described below.

[0036] In one embodiment, as shown in FIG. 3, the plasma processing apparatus 1 may include a power regulator 5. The power regulator 5 is electrically connected between the high frequency power supply 26 and the upper electrode 20. The power regulator 5 is electrically connected to the high frequency power supply 26 via a matching device 28. The circuit unit 4 is electrically connected between a line electrically connecting the high frequency power supply 26 and the power regulator 5 and the lower electrode 18. The line is electrically connected to the high frequency power supply 26 via the matching device 28. The power regulator 5 is configured to adjust the power supplied from the high frequency power supply 26 to the upper electrode 20. More specifically, the power regulator 5 is configured to measure the power supplied from the high frequency power supply 26 to the upper electrode 20, and to control the high frequency power supply 26 so as to increase or decrease the power output by the high frequency power supply 26 according to the measurement result.

[0037] The power regulator 5 can suitably control the power supplied from the radio frequency power supply 26 to the upper electrode 20. For example, in the space below the lower electrode 18, power may flow to the ground along the power flow path EP through the side wall 12S, reducing the power from the radio frequency power supply 26 to the upper electrode 20. Even in this case, the power regulator 5 can compensate for this reduction in power by increasing the output power to the radio frequency power supply 26.

[0038] In one embodiment, as shown in FIG. 4, the circuit unit 4 may include a diode 4a and a Zener diode 4b. The diode 4a and the Zener diode 4b may be connected in series. The anode of the diode 4a is electrically connected to the high frequency power supply 26 via a matching device 28. The cathode of the diode 4a is electrically connected to the cathode of the Zener diode 4b. The anode of the Zener diode 4b is electrically connected to the lower electrode 18. In addition, the plasma processing apparatus 1 including the circuit unit 4 shown in FIG. 4 may further include a power regulator 5 shown in FIG. 3.

[0039] The Zener diode 4b of the circuit unit 4 provides a potential difference between the high frequency power supply 26 and the lower electrode 18. As shown in the graph of Fig. 9, by increasing or decreasing this potential difference (horizontal axis of the graph of Fig. 9), the sheath potential (vertical axis of the graph of Fig. 9) of the sheath region formed at the boundary between the substrate W on the lower electrode 18 and the plasma is increased or decreased. Therefore, the circuit unit 4 having the Zener diode 4b can adjust the sheath potential to a suitable value. Such an effect by the circuit unit 4 having the Zener diode 4b can be similarly achieved by the circuit unit 4 having a resistor 4c and an inductor shown in Fig. 5, which will be described later.

[0040] In one embodiment, as shown in FIG. 5, the circuit section 4 may have a diode 4a and a resistor 4c. The diode 4a and the resistor 4c may be connected in series. The anode of the diode 4a may be electrically connected to the high frequency power supply 26 via a matching device 28. The cathode of the diode 4a may be electrically connected to the lower electrode 18 via the resistor 4c. The plasma processing apparatus 1 including the circuit section 4 shown in FIG. 5 may further include the power regulator 5 shown in FIG. 3. The resistor 4c may be a variable resistor, and the resistance value of the resistor 4c, which is a variable resistor, may be suitably adjusted by, for example, a control device (not shown) that controls the operation of the plasma processing apparatus 1.

[0041] In one embodiment, the circuit unit 4 shown in FIG. 5 may include an inductor instead of the resistor 4c. This inductor may be connected in series with the diode 4a. The anode of the diode 4a may be electrically connected to the high-frequency power supply 26 via a matching device 28. The cathode of the diode 4a may be electrically connected to the lower electrode 18 via an inductor. In addition, the plasma processing apparatus 1 in which the circuit unit 4 shown in FIG. 5 includes an inductor instead of the resistor 4c may further include the power regulator 5 shown in FIG. 3. This inductor may be a variable inductor, and the inductance of the variable inductor may be suitably adjusted by, for example, a control device (not shown) that controls the operation of the plasma processing apparatus 1.

[0042] 6, the circuit section 4 may include a potential meter 4f, a potential meter 4g, a switch element 4d, and a drive circuit 4e. The switch element 4d may be electrically connected between the high frequency power supply 26 and the lower electrode 18. The switch element 4d may be electrically connected to the high frequency power supply 26 via a matching device 28. The switch element 4d may be configured to turn on and off the conduction between the high frequency power supply 26 and the lower electrode 18.

[0043] The potential meter 4f may be electrically connected between the high frequency power supply 26 and the drive circuit 4e. The potential meter 4f may be electrically connected to the high frequency power supply 26 via the matching device 28. The potential meter 4f may measure the potential of the high frequency power supply 26 to generate a first measurement result and output the first measurement result to the drive circuit 4e. The potential meter 4g may be electrically connected between the lower electrode 18 and the drive circuit 4e. The potential meter 4g may measure the potential of the lower electrode 18 to generate a second measurement result and output the second measurement result to the drive circuit 4e.

[0044] The drive circuit 4e can be configured, based on the above first and second measurement results, to drive the switch element 4d to turn on conduction between the radio frequency power supply 26 and the lower electrode 18 when the potential of the radio frequency power supply 26 is higher than the potential of the lower electrode 18. The drive circuit 4e can be configured, based on the above first and second measurement results, to drive the switch element 4d to turn off conduction between the radio frequency power supply 26 and the lower electrode 18 when the potential of the radio frequency power supply 26 is equal to or lower than the potential of the lower electrode 18.

[0045] The plasma processing apparatus 1 including the circuit unit 4 shown in FIG. 6 may further include the power regulator 5 shown in FIG.

[0046] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. In addition, elements in different embodiments can be combined to form other embodiments.

[0047] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims. [Explanation of symbols]

[0048] 1...plasma processing apparatus, 10...chamber, 12S...side wall, 14...substrate support, 18...lower electrode, 20...upper electrode, 22...gas supply section, 26...high frequency power supply, 32...gas supply section, 4...circuit section, 4a...diode, 4b...Zener diode, 4c...resistor, 4d...switching element, 4e...driving circuit, 4f...potential meter, 4g...potential meter, 5...power regulator, W...substrate.

Claims

1. A chamber; a lower electrode included in a substrate support provided in the chamber and configured to support a substrate thereon; an upper electrode provided in the chamber and arranged to face the lower electrode; a gas supply configured to supply a process gas between the upper electrode and the lower electrode; a high frequency power source electrically connected to the upper electrode and configured to generate plasma of the processing gas by applying a high frequency voltage to the upper electrode; a circuit portion electrically connected between the high frequency power source and the lower electrode and configured to provide a potential to the lower electrode; Equipped with the circuit unit is configured to provide a potential to the lower electrode by causing a current to flow from the high frequency power source to the lower electrode when the potential of the high frequency power source is higher than the potential of the lower electrode. Plasma processing equipment.

2. the circuit portion includes a diode; The anode of the diode is electrically connected to the high frequency power source, The cathode of the diode is connected to the lower electrode. The plasma processing apparatus according to claim 1 .

3. the circuit portion includes a diode and a Zener diode, the diode and the Zener diode are connected in series; The anode of the diode is electrically connected to the high frequency power source, the cathode of the diode is electrically connected to the cathode of the Zener diode; The anode of the Zener diode is electrically connected to the lower electrode. The plasma processing apparatus according to claim 1 .

4. the circuit portion includes a diode and a resistor; the diode and the resistor are connected in series; The anode of the diode is electrically connected to the high frequency power source, The cathode of the diode is electrically connected to the lower electrode via the resistor. The plasma processing apparatus according to claim 1 .

5. the circuit portion includes a diode and an inductor; the diode and the inductor are connected in series; The anode of the diode is electrically connected to the high frequency power source, the cathode of the diode is electrically connected to the lower electrode via the inductor; The plasma processing apparatus according to claim 1 .

6. the circuit section includes a first potential measuring device, a second potential measuring device, a switch element, and a drive circuit; the switch element is electrically connected between the high frequency power supply and the lower electrode and is configured to turn on and off conduction between the high frequency power supply and the lower electrode; the first potential measuring device is electrically connected between the high frequency power supply and the drive circuit, measures a potential of the high frequency power supply to generate a first measurement result, and outputs the first measurement result to the drive circuit; the second potential measuring device is electrically connected between the lower electrode and the drive circuit, measures the potential of the lower electrode to generate a second measurement result, and outputs the second measurement result to the drive circuit; the drive circuit is configured to drive the switch element to turn on conduction between the radio frequency power supply and the lower electrode when a potential of the radio frequency power supply is higher than a potential of the lower electrode, and to drive the switch element to turn off conduction between the radio frequency power supply and the lower electrode when a potential of the radio frequency power supply is equal to or lower than a potential of the lower electrode, based on the first measurement result and the second measurement result. The plasma processing apparatus according to claim 1 .

7. a power regulator electrically connected between the high frequency power supply and the upper electrode and configured to regulate the power supplied from the high frequency power supply to the upper electrode; the circuit unit is electrically connected between the lower electrode and a line electrically connecting the high frequency power source and the power regulator; the power regulator is configured to measure the power supplied from the high frequency power supply to the upper electrode, and to control the high frequency power supply so as to increase or decrease the power output by the high frequency power supply in accordance with a measurement result. The plasma processing apparatus according to any one of claims 1 to 6.

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