Plasma processing device

Abstract

The disclosed plasma processing device includes a chamber, a substrate support unit, a power dissipation member, a power transmission coil, a power reception coil, a rectifying / smoothing unit, an electricity storage unit, a high-frequency power feeding line, a high-frequency power supply, and a ground pipe. The substrate support unit is disposed in the chamber. The power dissipation member is disposed in the chamber or the substrate support unit. The power transmission coil and the power reception coil are electromagnetically inductively coupled with each other. The rectifying / smoothing unit converts power from the power reception coil to DC power. The electricity storage unit is connected between the rectifying / smoothing unit and the power dissipation member. The high-frequency power supply generates high-frequency power to be supplied via the high-frequency power feeding line. The ground pipe extends through the inside of the power reception coil and the inside of the power transmission coil. The high-frequency power feeding line extends through the ground pipe outside the chamber.

Description

Plasma processing equipment

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

[0002] A plasma processing apparatus is used in plasma processing. The plasma processing apparatus includes a chamber and a substrate support (mounting table) disposed within the chamber. The substrate support has a base (lower electrode) and an electrostatic chuck for holding the substrate. A temperature adjustment element (e.g., a heater) for adjusting the temperature of the substrate is provided within the electrostatic chuck. A filter is also provided between the temperature adjustment element and a power supply for the temperature adjustment element to attenuate or block high-frequency noise entering lines such as power supply lines and / or signal lines from high-frequency electrodes and / or other electrical components within the chamber. One such plasma processing apparatus is described in Japanese Patent Application Laid-Open No. 2003-222994.

[0003] Japanese Patent Application Laid-Open No. 2015-173027

[0004] SUMMARY OF THE INVENTION An exemplary embodiment of the present disclosure provides a technique for reducing the space required for high frequency power supply lines outside a chamber in a plasma processing apparatus that supplies power to power consuming members within the chamber by electromagnetic inductive coupling.

[0005] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a plasma processing chamber, a substrate support, a power consuming member, a power transmitting coil, a power receiving coil, a rectifying and smoothing unit, a power storage unit, a high-frequency power supply line, a high-frequency power supply, and a ground pipe. The substrate support is disposed within the plasma processing chamber. The power consuming member is disposed within the plasma processing chamber or within the substrate support. The power receiving coil is capable of receiving power from the power transmitting coil via electromagnetic inductive coupling. The rectifying and smoothing unit is configured to convert power from the power receiving coil into direct current power. The power storage unit is electrically connected between the rectifying and smoothing unit and the power consuming member. The high-frequency power supply is configured to generate high-frequency power that is supplied into the plasma processing chamber via the high-frequency power supply line. The ground pipe extends through the inside of the power receiving coil and the inside of the power transmitting coil and is electrically grounded. The high-frequency power supply line extends through the ground pipe outside the plasma processing chamber.

[0006] According to one exemplary embodiment, in a plasma processing apparatus that supplies power to a power consuming member in a chamber by electromagnetic inductive coupling, it is possible to reduce the space required for high-frequency power supply lines outside the chamber.

[0007] 1 is a diagram for explaining an example of the configuration of a plasma processing system; FIG. 1 is a diagram for explaining an example of the configuration of a capacitively coupled plasma processing apparatus; FIG. 2 is a diagram schematically showing a plasma processing apparatus according to an exemplary embodiment; FIG. 3 is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment; FIG. 4 is a diagram schematically showing a plasma processing apparatus according to yet another exemplary embodiment; FIG. 5 is a diagram schematically showing a plasma processing apparatus according to yet another exemplary embodiment; FIG. 6 is a diagram schematically showing a power transmitting unit according to an exemplary embodiment; FIG. 7 is a diagram showing a power transmitting coil unit and a power receiving coil unit according to an exemplary embodiment; FIG. 8 is a diagram showing a power transmitting coil unit and a power receiving coil unit according to an exemplary embodiment; FIG. 9 is a graph showing impedance characteristics of a power receiving coil unit according to an exemplary embodiment; FIG. 10 is a diagram showing an RF filter according to an exemplary embodiment; FIG. 11 is a diagram showing a rectifying and smoothing unit according to an exemplary embodiment; FIG. 12 is a diagram showing an RF filter according to an exemplary embodiment; FIG. 13 is a diagram showing a communication unit of a power transmitting unit and a communication unit of the rectifying and smoothing unit according to an exemplary embodiment; FIG. 14 is a diagram schematically showing a plasma processing apparatus according to yet another exemplary embodiment; 23 is a diagram showing a communication unit of a power transmitting unit and a communication unit of a rectifying and smoothing unit according to another exemplary embodiment. FIG. 23 is a diagram schematically showing a plasma processing apparatus according to yet another exemplary embodiment. FIG. 23 is a diagram schematically showing a plasma processing apparatus according to yet another exemplary embodiment. FIG. 23 is a diagram schematically showing a plasma processing apparatus according to yet another exemplary embodiment. Each of (a) and (b) of FIG. 23 is a diagram showing a power storage unit according to an exemplary embodiment. FIG. 23 is a diagram showing a voltage-controlled converter according to an exemplary embodiment. FIG. 23 is a diagram showing a constant voltage control unit according to an exemplary embodiment. FIG. 23 is a diagram showing a constant voltage control unit according to another exemplary embodiment. FIG. 23 is a diagram schematically showing a plasma processing apparatus according to yet another exemplary embodiment. FIG. 23 is a diagram showing a power transmitting coil unit and a power receiving coil unit in a plasma processing apparatus according to yet another exemplary embodiment. FIG. 23 is a diagram showing a power transmitting coil unit and a power receiving coil unit in a plasma processing apparatus according to yet another exemplary embodiment.1A and 1B are diagrams illustrating a power transmitting coil unit and a power receiving coil unit in a plasma processing apparatus according to still another exemplary embodiment, a plasma processing apparatus according to still another exemplary embodiment, and a power transmitting coil unit and a power receiving coil unit in a plasma processing apparatus according to still another exemplary embodiment.

[0008] Various exemplary embodiments will be described in detail below with reference to the drawings, in which the same or equivalent parts are designated by the same reference numerals.

[0009] FIG. 1 is a diagram illustrating an exemplary configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0010] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), or surface wave plasma (SWP). Various types of plasma generators may be used, including alternating current (AC) plasma generators and direct current (DC) plasma generators. In one embodiment, the AC signal (AC power) used in the AC plasma generator has a frequency in the range of 100 kHz to 10 GHz. Thus, AC signals include radio frequency (RF) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0011] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. This program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0012] The following describes a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0013] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0014] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0015] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode (also referred to as an attraction electrode, chucking electrode, or clamping electrode) 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that the annular region 111b may also be provided by another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Furthermore, at least one RF / DC electrode coupled to an RF power supply 31 and / or a DC power supply 32, which will be described later, may be disposed within the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal, which will be described later, is supplied to the at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple lower electrodes. Furthermore, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0016] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0017] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow passage 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow passage 1110a. In one embodiment, the flow passage 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0018] The showerhead 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The process gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0019] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0020] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. This generates a plasma from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generation unit 12. Furthermore, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0021] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0022] The second RF generator 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0023] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to the at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to the at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0024] In various embodiments, the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof pulse waveform. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0025] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s is regulated by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0026] In the capacitively coupled plasma processing apparatus 1, the upper electrode is disposed such that a plasma processing space is located between the upper electrode and the substrate support 11. A high-frequency power supply such as the first RF generating unit 31a is electrically connected to the upper electrode or a lower electrode in the substrate support 11. When the plasma processing apparatus 1 is an inductively coupled plasma processing apparatus, an antenna is disposed such that a plasma processing space is located between the antenna and the substrate support 11. A high-frequency power supply such as the first RF generating unit 31a is electrically connected to the antenna. When the plasma processing apparatus 1 is a plasma processing apparatus that generates plasma using surface waves such as microwaves, an antenna is disposed such that a plasma processing space is located between the antenna and the substrate support 11. A high-frequency power supply such as the first RF generating unit 31a is electrically connected to the antenna via a waveguide.

[0027] Plasma processing apparatuses according to various exemplary embodiments will be described below. Each of the plasma processing apparatuses described below is configured to supply power to at least one power consuming member in a chamber 10 by wireless power supply (electromagnetic inductive coupling), and may have the same configuration as the plasma processing apparatus 1.

[0028] Fig. 3 is a schematic diagram of a plasma processing apparatus according to an exemplary embodiment. The plasma processing apparatus 100A shown in Fig. 3 includes at least one high-frequency power supply 300, a power receiving coil unit 140, a power storage unit 160, and at least one power consuming member 240 (see Figs. 25 and 26). The plasma processing apparatus 100A may further include a power transmitting unit 120, a power transmitting coil unit 130, a rectifying / smoothing unit 150, a constant voltage control unit 180 (an example of a voltage control unit), a ground frame 110, and a matching unit 301.

[0029] At least one high frequency power supply 300 includes a first RF generating unit 31 a and / or a second RF generating unit 31 b. At least one high frequency power supply 300 is electrically connected to the substrate support 11 via a matching unit 301. The matching unit 301 includes at least one impedance matching circuit.

[0030] The ground frame 110 includes the chamber 10 and is electrically grounded. The ground frame 110 electrically separates an internal space 110h (RF-Hot space) from an external space 110a (atmospheric space). The ground frame 110 surrounds the substrate support 11 disposed within the space 110h. In the plasma processing apparatus 100A, the rectifier / smoothing unit 150, the power storage unit 160, and the constant voltage control unit 180 are disposed within the space 110h. In addition, in the plasma processing apparatus 100A, the power transmission unit 120, the power transmission coil unit 130, and the power receiving coil unit 140 are disposed within the space 110a. The space 110h includes a reduced pressure space (vacuum space) and a non-reduced pressure space (non-vacuum space). The reduced pressure space is the space within the chamber 10, and the non-reduced pressure space is the space outside the chamber 10. The substrate support 11 and the substrate W are disposed within the reduced pressure space. The rectifying and smoothing unit 150, the power storage unit 160, and the constant voltage control unit 180 are arranged in the non-reduced pressure space.

[0031] The devices arranged in the space 110a, i.e., the power transmitting unit 120, the power transmitting coil unit 130, and the power receiving coil unit 140, are covered by a metal housing made of a metal such as aluminum, and the metal housing is grounded. This suppresses leakage of high-frequency noise caused by high-frequency power such as the first RF signal (source RF signal) and / or the second RF signal (bias RF signal). An insulation distance is provided between the metal housing and each power supply line. In the following description, high-frequency power such as the first RF signal and / or the second RF signal propagating toward the power transmitting unit 120 may be referred to as high-frequency noise, common-mode noise, or conductive noise.

[0032] The power transmitting unit 120 is electrically connected between an AC power source 400 (e.g., a commercial AC power source) and the power transmitting coil unit 130. The power transmitting unit 120 receives the frequency of AC power from the AC power source 400 and converts the frequency of the AC power into a transmission frequency, thereby generating AC power having the transmission frequency, i.e., transmission AC power.

[0033] The power transmitting coil section 130 includes a power transmitting coil 131 (see FIG. 9 ), which will be described later. The power transmitting coil 131 is electrically connected to the power transmitting section 120. The power transmitting coil 131 receives transmitted AC power from the power transmitting section 120 and wirelessly transmits the transmitted AC power to the power receiving coil 141.

[0034] The power receiving coil unit 140 includes a power receiving coil 141 (see FIG. 9 ), which will be described later. The power receiving coil 141 is electromagnetically inductively coupled to the power transmitting coil 131. Electromagnetic inductive coupling includes magnetic field coupling and electric field coupling. Magnetic field coupling also includes magnetic field resonance (also referred to as magnetic resonance). The distance between the power receiving coil 141 and the power transmitting coil 131 is set so as to suppress common mode noise (conductive noise). The distance between the power receiving coil 141 and the power transmitting coil 131 is set to a distance that allows power to be fed. The distance between the power receiving coil 141 and the power transmitting coil 131 is set so that the attenuation of high-frequency power (i.e., high-frequency noise) between the power receiving coil 141 and the power transmitting coil 131 is equal to or less than a threshold, and so that the power receiving coil 141 can receive power from the power transmitting coil 131. The attenuation threshold is set to a value that sufficiently prevents damage or malfunction of the power transmitting unit 120. The attenuation threshold is, for example, −20 dB. The transmitted AC power received by the power receiving coil section 140 is output to the rectifying and smoothing section 150 .

[0035] The rectifying and smoothing unit 150 is electrically connected between the power receiving coil unit 140 and the power storage unit 160. The rectifying and smoothing unit 150 generates DC power by full-wave rectifying and smoothing the AC power transmitted from the power receiving coil unit 140. The DC power generated by the rectifying and smoothing unit 150 is stored in the power storage unit 160. The power storage unit 160 is electrically connected between the rectifying and smoothing unit 150 and the constant voltage control unit 180. Note that the rectifying and smoothing unit 150 may generate DC power by half-wave rectifying and smoothing the AC power transmitted from the power receiving coil unit 140.

[0036] The rectifying and smoothing unit 150 and the power transmitting unit 120 are electrically connected to each other via a signal line 1250. The rectifying and smoothing unit 150 transmits an instruction signal to the power transmitting unit 120 via the signal line 1250. The instruction signal is a signal for instructing the power transmitting unit 120 to supply or stop supplying transmission AC power. The instruction signal may include a status signal, an abnormality detection signal, and a cooling control signal for the power transmitting coil unit 130 and the power receiving coil unit 140. The status signal is a value of the voltage, current, power magnitude, and / or phase detected by the voltage detector 155v (see FIG. 14 ) and the current detector 155i (see FIG. 14 ) of the rectifying and smoothing unit 150. The abnormality detection signal is a signal for notifying the power transmitting unit 120 of the occurrence of a failure and / or temperature abnormality in the rectifying and smoothing unit 150. The cooling control signal controls the cooling mechanisms provided in the power transmitting coil unit 130 and the power receiving coil unit 140. The cooling control signal controls, for example, the number of revolutions of a fan in the case of air cooling, or the flow rate and / or temperature of the coolant in the case of liquid cooling.

[0037] The constant voltage control unit 180 applies a voltage to at least the power consuming member 240 using the power stored in the power storage unit 160. The constant voltage control unit 180 can control the application of a voltage to at least the power consuming member 240 and the stopping of the application.

[0038] In the plasma processing apparatus 100A, the power receiving coil 141 functions as a filter for high-frequency noise caused by high-frequency power such as the first RF signal and / or the second RF signal, thereby suppressing propagation of the high-frequency noise to a power supply outside the plasma processing apparatus.

[0039] Please refer to Fig. 4. Fig. 4 is a diagram schematically illustrating a plasma processing apparatus according to another exemplary embodiment. The plasma processing apparatus 100B shown in Fig. 4 will be described below from the viewpoint of its differences from the plasma processing apparatus 100A.

[0040] The plasma processing apparatus 100B further includes a voltage-controlled converter 170. The voltage-controlled converter 170 is a DC-DC converter and is connected between the power storage unit 160 and the constant voltage control unit 180. The voltage-controlled converter 170 can be configured to input a constant output voltage to the constant voltage control unit 180 even when a voltage fluctuation occurs in the power storage unit 160. Note that the voltage fluctuation in the power storage unit 160 can occur as a voltage drop corresponding to the stored power when the power storage unit 160 is configured as an electric double layer, for example.

[0041] Please refer to Fig. 5. Fig. 5 is a diagram schematically illustrating a plasma processing apparatus according to yet another exemplary embodiment. The plasma processing apparatus 100C shown in Fig. 5 will be described below from the viewpoint of its differences from the plasma processing apparatus 100B.

[0042] The plasma processing apparatus 100C further includes an RF filter 190. The RF filter 190 is connected between the rectifying / smoothing unit 150 and the power transmitting unit 120. The RF filter 190 constitutes a part of the signal line 1250. The RF filter 190 has a characteristic of suppressing the propagation of high-frequency power (high-frequency noise) through the signal line 1250. That is, the RF filter 190 includes a low-pass filter that has a high impedance with respect to high-frequency noise (conductive noise) but has a characteristic of passing a relatively low-frequency instruction signal.

[0043] In the plasma processing apparatus 100C, the power storage unit 160, the voltage-controlled converter 170, and the constant-voltage control unit 180 are integrated with one another. That is, the power storage unit 160, the voltage-controlled converter 170, and the constant-voltage control unit 180 are all disposed in a single metal housing or formed on a single circuit board. This shortens the length of each of the pair of power supply lines (positive and negative lines) connecting the power storage unit 160 and the voltage-controlled converter 170. Furthermore, the lengths of the pair of power supply lines connecting the power storage unit 160 and the voltage-controlled converter 170 can be made equal. Furthermore, the lengths of the pair of power supply lines (positive and negative lines) connecting the voltage-controlled converter 170 and the constant-voltage control unit 180 can be made equal. This reduces device malfunction and damage caused by normal mode noise (the potential difference between the positive and negative lines). If another metal body that shields the electromagnetic field is provided around the housing inside the chamber 10, the single housing does not have to be made of metal.

[0044] Please refer to Fig. 6. Fig. 6 is a diagram schematically illustrating a plasma processing apparatus according to yet another exemplary embodiment. The plasma processing apparatus 100D shown in Fig. 6 will be described below from the viewpoint of differences from the plasma processing apparatus 100C.

[0045] The plasma processing apparatus 100D does not include an RF filter 190. In the plasma processing apparatus 100D, the rectifying / smoothing unit 150 includes a communication unit 151, which is a wireless unit. The communication unit 151 is arranged in a non-reduced pressure space. The power transmitting unit 120 also includes a communication unit 121, which is a wireless unit. The communication unit 121 is arranged in the space 110a. The above-mentioned instruction signal is transmitted between the rectifying / smoothing unit 150 and the power transmitting unit 120 using the communication unit 151 and the communication unit 121. Details of the communication unit 121 and the communication unit 151 will be described later.

[0046] Please refer to Fig. 7. Fig. 7 is a diagram schematically illustrating a plasma processing apparatus according to yet another exemplary embodiment. Hereinafter, a plasma processing apparatus 100E shown in Fig. 7 will be described in terms of its differences from the plasma processing apparatus 100D.

[0047] The plasma processing apparatus 100E further includes an RF filter 200. The RF filter 200 is connected between the power receiving coil section 140 and the rectifying and smoothing section 150. The RF filter 200 has a characteristic of reducing or blocking high frequency noise propagating from the power receiving coil section 140 to the power transmitting coil 131 and the power transmitting section 120. Details of the RF filter 200 will be described later.

[0048] Hereinafter, the configuration of each unit for wireless power supply in the plasma processing apparatus according to various exemplary embodiments will be described in detail.

[0049] [Configuration of power transmission unit]

[0050] 8 is a diagram illustrating a power transmission unit according to an exemplary embodiment. As described above, the power transmission unit 120 receives the frequency of AC power from the AC power source 400 and converts the frequency of the AC power to a transmission frequency, thereby generating transmission AC power having the transmission frequency.

[0051] In one embodiment, the power transmission unit 120 includes a control unit 122, a rectification and smoothing unit 123, and an inverter 124. The control unit 122 is configured from a processor such as a CPU or a programmable logic device such as an FPGA (Field-Programmable Gate Array).

[0052] The rectifying and smoothing unit 123 includes a rectifying circuit and a smoothing circuit. The rectifying circuit includes, for example, a diode bridge. The smoothing circuit includes, for example, a line capacitor. The rectifying and smoothing unit 123 generates DC power by full-wave rectifying and smoothing the AC power from the AC power supply 400. Note that the rectifying and smoothing unit 123 may also generate DC power by half-wave rectifying and smoothing the AC power from the AC power supply 400.

[0053] The inverter 124 generates transmission AC power having a transmission frequency from the DC power output by the rectifying and smoothing unit 123. The inverter 124 is, for example, a full-bridge inverter and includes a plurality of triacs or a plurality of switching elements (e.g., FETs). The inverter 124 generates transmission AC power by ON / OFF control of the plurality of triacs or the plurality of switching elements by the control unit 122. The transmission AC power output from the inverter 124 is output to the power transmitting coil unit 130.

[0054] The power transmitting unit 120 may further include a voltage detector 125v, a current detector 125i, a voltage detector 126v, and a current detector 126i. The voltage detector 125v detects a voltage value between a pair of power supply lines connecting the rectifying and smoothing unit 123 and the inverter 124. The current detector 125i detects a current value between the rectifying and smoothing unit 123 and the inverter 124. The voltage detector 126v detects a voltage value between a pair of power supply lines connecting the inverter 124 and the power transmitting coil unit 130. The current detector 126i detects a current value between the inverter 124 and the power transmitting coil unit 130. The voltage value detected by the voltage detector 125v, the current value detected by the current detector 125i, the voltage value detected by the voltage detector 126v, and the current value detected by the current detector 126i are notified to the control unit 122.

[0055] The power transmitting unit 120 includes the above-described communication unit 121. The communication unit 121 includes a driver 121d, a transmitter 121tx, and a receiver 121rx. The transmitter 121tx is a transmitter of a wireless signal or a transmitter of an optical signal. The receiver 121rx is a receiver of a wireless signal or a receiver of an optical signal. The communication unit 121 drives the transmitter 121tx using the driver 121d to output a signal from the control unit 122 as a wireless signal or an optical signal from the transmitter 121tx. The signal output from the transmitter 121tx is received by the communication unit 151 (see FIG. 14 ), which will be described later. Furthermore, the communication unit 121 receives a signal such as the above-described instruction signal from the communication unit 151 using the receiver 121rx and inputs the received signal to the control unit 122 via the driver 121d. The control unit 122 switches between outputting and stopping the transmitted AC power by controlling the inverter 124 in accordance with the instruction signal received from the communication unit 151 via the communication unit 121, the voltage value detected by the voltage detector 125v, the current value detected by the current detector 125i, the voltage value detected by the voltage detector 126v, and the current value detected by the current detector 126i.

[0056] [Power transmitting coil section and power receiving coil section]

[0057] Please refer to FIGS. 9 to 11. Each of FIGS. 9 to 11 is a diagram illustrating a power transmitting coil unit and a power receiving coil unit according to an exemplary embodiment. As shown in FIG. 9, the power transmitting coil unit 130 may include a resonant capacitor 132a and a resonant capacitor 132b in addition to the power transmitting coil 131. The resonant capacitor 132a is connected between one end of the power transmitting coil 131 and one of a pair of power feed lines connecting the power transmitting unit 120 and the power transmitting coil unit 130. The resonant capacitor 132b is connected between the other end of the power transmitting coil 131 and the other of the pair of power feed lines. The power transmitting coil 131, the resonant capacitor 132a, and the resonant capacitor 132b form a resonant circuit with respect to the transmission frequency. That is, the power transmitting coil 131, the resonant capacitor 132a, and the resonant capacitor 132b have a resonant frequency that substantially matches the transmission frequency. Note that the power transmitting coil unit 130 does not necessarily include either the resonant capacitor 132a or the resonant capacitor 132b.

[0058] As shown in FIGS. 10 and 11 , the power transmitting coil unit 130 may further include a metal housing 130g. The metal housing 130g has an open end and is grounded. The power transmitting coil 131 is disposed within the metal housing 130g with an insulating distance maintained. The power transmitting coil unit 130 may further include a heat sink 134, a back ferrite material 135, and a thermally conductive sheet 136. The heat sink 134 is disposed within the metal housing 130g and supported by the metal housing 130g. The back ferrite material 135 is disposed on the heat sink 134. The thermally conductive sheet 136 is disposed on the back ferrite material 135. The power transmitting coil 131 is disposed on the thermally conductive sheet 136 and faces the power receiving coil 141 via the open end of the metal housing 130g. As shown in FIG. 11 , a resonant capacitor 132a and a resonant capacitor 132b may also be housed within the metal housing 130g.

[0059] As shown in FIG. 9 , the power receiving coil section 140 includes a power receiving coil 141. The power receiving coil 141 is electromagnetically inductively coupled to the power transmitting coil 131. The power receiving coil section 140 may include a resonant capacitor 142a and a resonant capacitor 142b in addition to the power receiving coil 141. The resonant capacitor 142a is connected between one of a pair of power feed lines extending from the power receiving coil section 140 and one end of the power receiving coil 141. The resonant capacitor 142b is connected between the other of the pair of power feed lines and the other end of the power receiving coil 141. The power receiving coil 141, the resonant capacitor 142a, and the resonant capacitor 142b form a resonant circuit with respect to the transmission frequency. That is, the power receiving coil 141, the resonant capacitor 142a, and the resonant capacitor 142b have a resonant frequency that approximately matches the transmission frequency. Note that the power receiving coil section 140 does not necessarily include either the resonant capacitor 142a or the resonant capacitor 142b.

[0060] As shown in FIGS. 10 and 11 , the power receiving coil unit 140 may further include a metal housing 140g. The metal housing 140g has an open end and is grounded. The power receiving coil 141 is disposed within the metal housing 140g with an insulating distance maintained. The power receiving coil unit 140 may further include a spacer 143, a heat sink 144, a back ferrite material 145, and a thermally conductive sheet 146. The spacer 143 is disposed within the metal housing 140g and supported by the metal housing 140g. The spacer 143 will be described later. The heat sink 144 is disposed on the spacer 143. The back ferrite material 145 is disposed on the heat sink 144. The thermally conductive sheet 146 is disposed on the back ferrite material 145. The power receiving coil 141 is disposed on the thermally conductive sheet 146 and faces the power transmitting coil 131 via the open end of the metal housing 140g. As shown in FIG. 11, a resonant capacitor 142a and a resonant capacitor 142b may be further housed within the metal housing 140g.

[0061] The spacer 143 is made of a dielectric material and is provided between the power receiving coil 141 and the metal housing 140g (ground). The spacer 143 provides a stray capacitance between the power receiving coil 141 and the ground.

[0062] [Impedance characteristics of receiving coil]

[0063] Please refer to Fig. 12. Fig. 12 is a graph showing the impedance characteristics of the receiving coil section according to one exemplary embodiment. Fig. 12 shows the impedance characteristics of the receiving coil section 140 depending on the thickness of the spacer 143. The thickness of the spacer 143 corresponds to the distance between the heat sink 144 and the metal housing 140g. As shown in Fig. 12, the receiving coil section 140 has a frequency f Ｈ and frequency f ＬThe power receiving coil section 140 can adjust the impedance of each of the first and second RF signals. Therefore, the power receiving coil section 140 can provide high impedance at each of the two frequencies of high frequency power used in the plasma processing apparatus, such as the first RF signal and the second RF signal. Furthermore, since high impedance can be obtained in the power receiving coil section 140, high frequency power loss can be suppressed and a high processing rate (e.g., etching rate) can be achieved.

[0064] [RF filter 200]

[0065] Please refer to FIG. 13. FIG. 13 is a diagram illustrating an RF filter according to an exemplary embodiment. As shown in FIG. 13, an RF filter 200 is connected between the receiving coil section 140 and the rectifying and smoothing section 150. The RF filter 200 includes an inductor 201a, an inductor 201b, a terminating capacitor 202a, and a terminating capacitor 202b. One end of the inductor 201a is connected to the resonant capacitor 142a, and the other end of the inductor 201a is connected to the rectifying and smoothing section 150. One end of the inductor 201b is connected to the resonant capacitor 142b, and the other end of the inductor 201b is connected to the rectifying and smoothing section 150. The terminating capacitor 202a is connected between one end of the inductor 201a and ground. The terminating capacitor 202b is connected between one end of the inductor 201b and ground. The inductor 201a and the terminating capacitor 202a form a low-pass filter. The inductor 201b and the terminating capacitor 202b also form a low-pass filter. The RF filter 200 provides high impedance at each of the two frequencies of the RF power used in the plasma processing apparatus, i.e., the first RF signal and the second RF signal, thereby suppressing the loss of the RF power and achieving a high processing rate (e.g., etching rate).

[0066] [Rectification and smoothing section]

[0067] Please refer to FIG. 14. FIG. 14 is a diagram showing a rectifying and smoothing unit according to one exemplary embodiment. In one embodiment, the rectifying and smoothing unit 150 includes a control unit 152, a rectifying circuit 153, and a smoothing circuit 154. The rectifying circuit 153 is connected between the power receiving coil unit 140 and the smoothing circuit 154. The smoothing circuit 154 is connected between the rectifying circuit 153 and the power storage unit 160. The control unit 152 is configured by a processor such as a CPU or a programmable logic device such as an FPGA (Field-Programmable Gate Array). Note that the control unit 152 may be the same as or different from the control unit 122.

[0068] The rectifier circuit 153 outputs power generated by full-wave rectification of the AC power from the power receiving coil section 140. The rectifier circuit 153 is, for example, a diode bridge. Note that the rectifier circuit 153 may also output power generated by half-wave rectification of the AC power from the power receiving coil section 140.

[0069] The smoothing circuit 154 generates DC power by smoothing the power from the rectifying circuit 153. The smoothing circuit 154 may include an inductor 1541a, a capacitor 1542a, and a capacitor 1542b. One end of the inductor 1541a is connected to one of a pair of inputs of the smoothing circuit 154. The other end of the inductor 1541a is connected to the positive output (V ＯＵＴ＋ The positive output of the rectifying and smoothing unit 150 is connected to one end of each of one or more capacitors of the power storage unit 160 via a positive line 160p (see (a) and (b) of FIG. 23 ) of a pair of power supply lines described later.

[0070] One end of the capacitor 1542a is connected to one of the pair of inputs of the smoothing circuit 154 and one end of the inductor 1541a. The other end of the capacitor 1542a is connected to the other of the pair of outputs of the smoothing circuit 154 and the negative output (V ＯＵＴ－). The negative output of the rectifying and smoothing unit 150 is connected to the other end of each of one or more capacitors of the power storage unit 160 via a negative line 160m (see (a) and (b) of Figure 23) of a pair of power supply lines described later. One end of the capacitor 1542b is connected to the other end of the inductor 1541a. The other end of the capacitor 1542b is connected to the other of the pair of outputs of the smoothing circuit 154 and the negative output (V ＯＵＴ－ ) is connected.

[0071] The rectifying and smoothing unit 150 may further include a voltage detector 155v and a current detector 155i. The voltage detector 155v detects a voltage value between the positive output and the negative output of the rectifying and smoothing unit 150. The current detector 155i detects a current value between the rectifying and smoothing unit 150 and the power storage unit 160. The voltage value detected by the voltage detector 155v and the current value detected by the current detector 155i are notified to the control unit 152. The control unit 152 generates the above-mentioned instruction signal according to the power stored in the power storage unit 160. For example, when the power stored in the power storage unit 160 is equal to or less than a first threshold, the control unit 152 generates an instruction signal to instruct the power transmitting unit 120 to supply power, i.e., to output transmitted AC power. The first threshold is, for example, the power consumption of a load such as the power consuming member 240. Alternatively, the second threshold may be a value obtained by multiplying the power consumption of a load such as power consuming member 240 by a certain value (for example, a value in the range of 1 to 3) in consideration of a margin of error. On the other hand, when the power stored in power storage unit 160 is greater than the second threshold, control unit 152 generates an instruction signal to instruct power transmission unit 120 to stop power supply, i.e., to stop output of transmitted AC power. The second threshold is a value that does not exceed the limit storage power of power storage unit 160. The second threshold is, for example, a value obtained by multiplying the limit storage power of power storage unit 160 by a certain value (for example, a value equal to or less than 1).

[0072] The rectifying and smoothing unit 150 includes the above-described communication unit 151. The communication unit 151 includes a driver 151d, a transmitter 151tx, and a receiver 151rx. The transmitter 151tx is a transmitter of a wireless signal or a transmitter of an optical signal. The receiver 151rx is a receiver of a wireless signal or a receiver of an optical signal. The communication unit 151 drives the transmitter 151tx using the driver 151d to output a signal from the control unit 122, such as an instruction signal, as a wireless signal or an optical signal from the transmitter 151tx. The signal output from the transmitter 151tx is received by the communication unit 121 of the power transmitting unit 120. Furthermore, the communication unit 151 receives the signal from the communication unit 121 using the receiver 151rx and inputs the received signal to the control unit 152 via the driver 151d.

[0073] [RF filter 190]

[0074] Please refer to FIG. 15 . FIG. 15 is a diagram showing an RF filter 190 according to an exemplary embodiment. As shown in FIG. 15 , the signal line 1250 may include a first signal line electrically connecting the signal output (Tx) of the power transmitting unit 120 and the signal input (Rx) of the rectifying and smoothing unit 150, and a second signal line electrically connecting the signal input (Rx) of the power transmitting unit 120 and the signal output (Tx) of the rectifying and smoothing unit 150. The signal line 1250 may include a signal line connecting the first reference voltage terminal (VCC) of the power transmitting unit 120 and the first reference voltage terminal (VCC) of the rectifying and smoothing unit 150, and a signal line connecting the second reference voltage terminal (GND) of the power transmitting unit 120 and the second reference voltage terminal (GND) of the rectifying and smoothing unit 150. The signal line 1250 may be a shielded cable covered with a shield at ground potential. In this case, the multiple signal lines constituting the signal line 1250 may be individually covered with a shield or may be collectively covered with a shield. The RF filter 190 provides a low-pass filter for each of the multiple signal lines constituting the signal line 1250. The low-pass filter may be an LC filter including an inductor and a capacitor. The inductor of the low-pass filter forms part of the corresponding signal line. The capacitor is connected between one end of the inductor connected to the power transmitting unit 120 and ground. The RF filter 190 makes it possible to suppress the propagation of high-frequency power (high-frequency noise) via the signal line 1250 between the rectifying / smoothing unit 150 and the power transmitting unit 120.

[0075] [Communication unit of the power transmission unit and communication unit of the rectification and smoothing unit]

[0076] Please refer to FIGS. 16 to 18. FIG. 16 is a diagram illustrating a communication unit of the power transmitting unit and a communication unit of the rectifying / smoothing unit according to one exemplary embodiment. FIGS. 17 and 18 are each a diagram schematically illustrating a plasma processing apparatus according to yet another exemplary embodiment. As shown in FIGS. 6, 7, 16, 17, and 18, the communication units 121 and 151 may be configured to transmit signals, such as the instruction signals, between them via wireless communication. The communication via wireless communication may be optical communication. When the communication units 121 and 151 transmit signals between them via wireless communication, the communication units 121 and 151 may be located in any position as long as there is no shielding between them. According to the example shown in these figures, the RF filter 190 is not required. Note that in various exemplary embodiments, including the example shown in FIGS. 16 to 18, the signal line 1250 may be a shielded cable covered with a shield at ground potential. In this case, the multiple signal lines that make up signal line 1250 may be individually covered with a shield, or may be collectively covered with a shield.

[0077] Please refer to FIGS. 19 to 22. FIG. 19 is a diagram illustrating a communication unit of the power transmitting unit and a communication unit of the rectifying / smoothing unit according to another exemplary embodiment. FIGS. 20 to 22 are each a schematic diagram of a plasma processing apparatus according to yet another exemplary embodiment. As shown in FIGS. 19 to 22, the communication units 121 and 151 may be configured to transmit signals (optical signals) such as the instruction signals described above between them via an optical fiber 1260, i.e., via optical fiber communication. When the communication units 121 and 151 transmit signals between them via the optical fiber 1260, the communication units 121 and 151 may be located at any position as long as the bending radius of the optical fiber 1260 is within the allowable range. In the examples shown in these figures, the RF filter 190 is not required.

[0078] [Power storage unit]

[0079] Please refer to Fig. 23(a) and Fig. 23(b). Each of Fig. 23(a) and Fig. 23(b) is a diagram showing a power storage unit according to one exemplary embodiment. As shown in Fig. 23(a), the power storage unit 160 includes a capacitor 161. The capacitor 161 is connected between a pair of power supply lines, that is, a positive line 160p and a negative line 160m. The positive line 160p is connected to the positive output (V ＯＵＴ＋ ) toward the load. The negative line 160m extends from the negative output (V ＯＵＴ－ ) to the load. The capacitor 161 may be a polarized capacitor. The capacitor 161 may be an electric double layer or a lithium ion battery.

[0080] As shown in FIG. 23(b), the power storage unit 160 may include multiple capacitors 161. The multiple capacitors 161 are connected in series between a positive line 160p and a negative line 160m. The multiple capacitors 161 may have the same capacitance or different capacitances. Each of the multiple capacitors 161 may be a polarized capacitor. Each of the multiple capacitors 161 may be an electric double layer or a lithium-ion battery. The power storage unit 160 must be used under conditions where the sum of its input voltage and the line potential difference due to normal mode noise is lower than the allowable input voltage. When the power storage unit 160 includes multiple capacitors 161 connected in series, the allowable input voltage of the power storage unit 160 increases. Therefore, according to the example shown in FIG. 23(b), the noise resistance of the power storage unit 160 is improved.

[0081] [Voltage Control Converter]

[0082] Please refer to FIG. 24. FIG. 24 is a diagram showing a voltage-controlled converter according to one exemplary embodiment. The voltage-controlled converter 170 is a DC-DC converter. The voltage-controlled converter 170 is connected between the power storage unit 160 and the constant voltage control unit 180. The positive input (V ＩＮ＋ ) is connected to the positive line 160p.ＩＮ－ ) is connected to the negative line 160m. ＯＵＴ＋ ) is the positive input (V ＩＮ＋ ) connected to the negative output (V ＯＵＴ－ ) is the negative input (V ＩＮ－ ) is connected.

[0083] The voltage-controlled converter 170 may include a control unit 172, a low-pass filter 173, a transformer 174, and a capacitor 175. The low-pass filter 173 may include an inductor 1731a, a capacitor 1732a, and a capacitor 1732b. One end of the inductor 1731a is connected to the positive input (V ＩＮ＋ The other end of the inductor 1731a is connected to one end of the primary coil of the transformer 174. One end of the capacitor 1732a is connected to one end of the inductor 1731a and the positive input (V ＩＮ＋ The other end of the capacitor 1732a is connected to the negative input (V ＩＮ－ ) of the voltage-controlled converter 170. One end of the capacitor 1732b is connected to the other end of the inductor 1731a. The other end of the capacitor 1732b is connected to the negative input (V ＩＮ－ ) is connected.

[0084] The transformer 174 includes a primary coil 1741, a secondary coil 1742, and a switch 1743. The other end of the primary coil 1741 is connected to the negative input (V ＩＮ－ One end of the secondary coil 1742 is connected to one end of the capacitor 175 and the positive output (V ＯＵＴ＋ The other end of the secondary coil 1742 is connected to the other end of the capacitor 175 and the negative output (V ＯＵＴ－ ) is connected.

[0085] A driver 1744 is connected to the switch 1743. The driver 1744 opens and closes the switch 1743. When the switch 1743 is closed, that is, when the other end of the primary coil 1741 and the negative input (V ＩＮ－ ) is in a conducting state, the other end of the primary coil 1741 is connected to the negative input (V ＩＮ－ ), and DC power from the voltage control converter 170 is supplied to the constant voltage control unit 180. On the other hand, when the switch 1743 is open, that is, when the other end of the primary coil 1741 and the negative input (V ＩＮ－ ) is in a non-conducting state, the other end of the primary coil 1741 and the negative input (V ＩＮ－ ) is disconnected, and the supply of DC power from the voltage control converter 170 to the constant voltage control unit 180 is cut off.

[0086] The voltage-controlled converter 170 may further include a voltage detector 176v and a current detector 176i. The voltage detector 176v detects the voltage value across both ends of the secondary coil 1742 or the voltage value between the positive output and negative output of the voltage-controlled converter 170. The current detector 176i measures the current value between the other end of the secondary coil 1742 and the negative output of the voltage-controlled converter 170. The voltage value detected by the voltage detector 176v and the current value detected by the current detector 176i are notified to the control unit 172. Note that the control unit 172 may be the same as or different from at least one of the control unit 122 and the control unit 152.

[0087] When the voltage value detected by voltage detector 176v is equal to or greater than a threshold value, control unit 172 controls driver 1744 to cut off the supply of DC power from voltage-controlled converter 170 to constant voltage control unit 180. The voltage value between the positive output and negative output of voltage-controlled converter 170 is the sum of the output voltage value of voltage-controlled converter 170 and the line potential difference due to normal mode noise. In this embodiment, it is possible to prevent damage to the load of voltage-controlled converter 170 due to overvoltage caused by the line potential difference due to normal mode noise.

[0088] [Constant voltage control section]

[0089] 25 and 26 are diagrams illustrating a constant voltage control unit 180 according to some exemplary embodiments. The constant voltage control unit 180 is connected between the power storage unit 160 and at least one power consuming member 240, and is configured to control application of a voltage (application of a DC voltage) to the at least one power consuming member 240 and its stopping.

[0090] The constant voltage control unit 180 includes a control unit 182 and at least one switch 183. The positive input (V ＩＮ＋ ) is connected to the power consuming member 240 via the switch 183. The negative input (V ＩＮ－ ) is connected to the power consuming member 240. The switch 183 is controlled by the control unit 182. When the switch 183 is closed, a DC voltage from the constant voltage control unit 180 is applied to the power consuming member 240. When the switch 183 is open, the application of the DC voltage from the constant voltage control unit 180 to the power consuming member 240 is stopped. Note that the control unit 182 may be the same as or different from at least one of the control units 122, 152, and 172.

[0091] 25 and 26, the plasma processing apparatus includes a plurality of power consuming members 240. The constant voltage control unit 180 includes a control unit 182 and a plurality of switches 183. The positive input (V ＩＮ＋ ) is connected to a plurality of power consuming components 240 via a plurality of switches 183. The negative input (V ＩＮ－ ) is connected to a plurality of power consuming components 240 .

[0092] In the embodiments shown in FIGS. 25 and 26 , the power consumption members 240 may include a plurality of heaters (resistance heating elements). The heaters may be provided within the substrate support 11. In the embodiment shown in FIG. 25 , a plurality of resistors 260 are disposed near the heaters, respectively. Each of the resistors 260 has a resistance value that changes with temperature. Each of the resistors 260 is, for example, a thermistor. Each of the resistors 260 is connected in series with a reference resistor (not shown). The constant voltage control unit 180 includes a plurality of measuring units 184. Each of the measuring units 184 applies a reference voltage to a series connection between a corresponding resistor of the resistors 260 and the reference resistor, and detects a voltage value across the resistor. Each of the measuring units 184 notifies the control unit 182 of the detected voltage value. The control unit 182 identifies the temperature of the area where the corresponding heater is located from the notified voltage value, and controls the application of DC voltage to the corresponding heater so that the temperature of the area approaches the target temperature. Note that optical fiber thermometers may be provided instead of the multiple resistors 260. In this case, wiring between the multiple resistors 260 and the multiple measuring units 184 is not required, and the influence of high-frequency conductive noise on the power consuming member 240 can be eliminated.

[0093] In the embodiment shown in FIG. 26 , the constant voltage control unit 180 includes a voltage detector 185v and multiple current detectors 185i. The voltage detector 185v detects the voltage value applied to each of the multiple heaters. The multiple current detectors 185i measure the value of the current supplied to a corresponding one of the multiple heaters, i.e., the current value. The multiple measurement units 184 determine the resistance value of a corresponding one of the multiple heaters from the current value detected by the corresponding one of the multiple current detectors 185i and the voltage value detected by the voltage detector 185v. The control unit 182 determines the temperature of each of the multiple regions in which the multiple heaters are located, based on the detected resistance value of each of the multiple heaters. The control unit 182 controls the application of DC voltage to each of the multiple heaters so as to bring the temperature of each of the multiple regions closer to a target temperature.

[0094] A plasma processing apparatus according to yet another exemplary embodiment will be described below with reference to Figures 27 and 28. Figure 27 is a diagram showing a plasma processing apparatus according to yet another exemplary embodiment. Figure 28 is a diagram showing a power transmitting coil section and a power receiving coil section in a plasma processing apparatus according to yet another exemplary embodiment. The plasma processing apparatus 100G shown in Figure 27 will be described below from the perspective of differences between it and the plasma processing apparatus 100E.

[0095] As described above, the space 110h includes the space inside the chamber 10 (plasma processing space 10s) and the space 110u, which is a non-reduced pressure space. The rectifying / smoothing unit 150, the power storage unit 160, the voltage control converter 170, and the constant voltage control unit 180 are arranged in the space 110u.

[0096] The plasma processing apparatus 100G further includes a metal housing 340g. The metal housing 340g is disposed in the space 110a. The metal housing 340g is grounded. As shown in FIG. 28 , the metal housing 340g defines a shielded space 340s, and the power transmitting coil 131 and the power receiving coil 141 are housed within the shielded space 340s. The metal housing 340g may further house an RF filter 200 within the shielded space 340s. The shielded space 340s may include a space 340s1 and a space 340s2. The power transmitting coil 131 and the power receiving coil 141 are housed within the space 340s1. The space 340s2 is located above the space 340s1. The RF filter 200 is housed within the space 340s2.

[0097] The metal housing 340g includes a first rear wall 340g1, a second rear wall 340g2, and a side wall 340g3. The first rear wall 340g1 has a generally flat plate shape and extends behind the power transmitting coil 131 relative to the power receiving coil 141. The second rear wall 340g2 has a generally flat plate shape and extends behind the power receiving coil 141 relative to the power transmitting coil 131. The side wall 340g3 has a cylindrical shape. Together with the first rear wall 340g1 and the second rear wall 340g2, the side wall 340g3 defines a space 340s1. The side wall 340g3 surrounds the outer periphery of the power transmitting coil 131 and the outer periphery of the power receiving coil 141.

[0098] A spacer 133, a base plate 138, a back surface ferrite material 135, and a heat conduction sheet 136 are arranged in this order within the shielded space 340s and between the first rear wall 340g1 and the power transmitting coil 131. The spacer 133 is interposed between the first rear wall 340g1 and the base plate 138 and supports the base plate 138. The base plate 138 is, for example, a glass epoxy substrate. The back surface ferrite material 135 extends between the base plate 138 and the power transmitting coil 131. That is, the back surface ferrite material 135 is arranged on the back side of the power transmitting coil 131. The heat conduction sheet 136 extends between the power transmitting coil 131 and the back surface ferrite material 135.

[0099] Additionally, a spacer 143, a base plate 148, a back surface ferrite material 145, and a heat conduction sheet 146 are arranged in this order within the shielded space 340s and between the second rear wall 340g2 and the power receiving coil 141. The spacer 143 is interposed between the second rear wall 340g2 and the base plate 148 and supports the base plate 148. The base plate 148 is, for example, a glass epoxy substrate. The back surface ferrite material 145 extends between the base plate 148 and the power receiving coil 141. That is, the back surface ferrite material 145 is arranged on the back side of the power receiving coil 141. The heat conduction sheet 146 is interposed between the power receiving coil 141 and the back surface ferrite material 145.

[0100] The plasma processing apparatus 100G may further include an inner ferrite material 345a and an outer ferrite material 345b. The inner ferrite material 345a has a generally cylindrical shape. The inner ferrite material 345a extends through the inside of the power transmitting coil 131 and the inside of the power receiving coil 141. The inner ferrite material 345a may extend from the back surface ferrite material 135 to the back surface ferrite material 145. The outer ferrite material 345b has a generally cylindrical shape. The outer ferrite material 345b extends through the outside of the power transmitting coil 131 and the outside of the power receiving coil 141 so as to surround the power transmitting coil 131 and the power receiving coil 141. The outer ferrite material 345b may extend from the back surface ferrite material 135 to the back surface ferrite material 145.

[0101] Similar to the various exemplary embodiments described above, the radio frequency power supply 300 may be electrically coupled to the substrate support 11 via a radio frequency power supply line 302. The radio frequency power supply line 302 extends from the substrate support 11 through the space 110u to the space 110a, connects to the matching unit 301, and is electrically coupled to the radio frequency power supply 300 via the matching unit 301. In the space 110a, the radio frequency power supply line 302 passes through a ground pipe 304 and is surrounded by the ground pipe 304. The ground pipe 304 is a cylindrical conductor and is electrically grounded. The ground pipe 304 may be electrically connected to the ground frame 110. The ground pipe 304 may extend from the ground frame 110 to the matching unit 301.

[0102] In the plasma processing apparatus 100G, the ground pipe 304 extends through the inside of the power transmitting coil 131 and the inside of the power receiving coil 141. The ground pipe 304 may be spaced apart from the inner ferrite material 345a and pass through the inner ferrite material 345a. The ground pipe 304 and the inner ferrite material 345a may be spaced apart from each other by an insulation distance or more.

[0103] In the plasma processing apparatus 100G, the high-frequency power supply line 302 and the ground pipe 304 extend through the inside of the power transmitting coil 131 and the inside of the power receiving coil 141 in the space 110a. This makes it possible to reduce the space required for the high-frequency power supply line 302 outside the chamber 10. Therefore, the plasma processing apparatus 100G provides a high degree of freedom in the layout of other components in the space 110a. Furthermore, since a large amount of space is available in the space 110a, the power transmitting coil 131 and the power receiving coil 141 can each be made large. As a result, high power can be transmitted.

[0104] Furthermore, the back ferrite material 135, the back ferrite material 145, the inner ferrite material 345a, and the outer ferrite material 345b suppress leakage of magnetic flux, thereby achieving high power transmission efficiency between the power transmitting coil 131 and the power receiving coil 141.

[0105] The backside ferrite material 135, the backside ferrite material 145, the inner ferrite material 345a, and the outer ferrite material 345b may be made of manganese-zinc ferrite, nickel-zinc ferrite, or a nanocrystalline soft magnetic material. In this case, when the transmission frequency is 1 MHz or less, a high magnetic permeability can be achieved to achieve a high magnetic flux confinement effect at the transmission frequency, and conductive noise can be efficiently converted into heat.

[0106] Reference will now be made to FIGS. 29 and 30 . Each of FIGS. 29 and 30 is a diagram illustrating a power transmitting coil unit and a power receiving coil unit in a plasma processing apparatus according to yet another exemplary embodiment. The configurations illustrated in FIGS. 29 and 30 can be employed in the plasma processing apparatus 100G in place of the configuration illustrated in FIG. 28 . As illustrated in FIG. 29 , a rectifying / smoothing unit 150 may be disposed in the space 340s2 instead of the RF filter 200. As illustrated in FIG. 30 , the RF filter 200 and the rectifying / smoothing unit 150 may be disposed in the space 340s2. Note that in the configuration illustrated in FIG. 30 , the rectifying / smoothing unit 150 is connected to the power storage unit 160 via the RF filter 200.

[0107] A plasma processing apparatus according to yet another exemplary embodiment will be described below with reference to Figures 31 and 32. Figure 31 is a diagram showing a plasma processing apparatus according to yet another exemplary embodiment. Figure 32 is a diagram showing a power transmitting coil section and a power receiving coil section in a plasma processing apparatus according to yet another exemplary embodiment. The plasma processing apparatus 100Gb shown in Figures 31 and 32 will be described below from the perspective of differences between it and the plasma processing apparatus 100G.

[0108] The plasma processing apparatus 100Gb further includes a driving system 340d and a sensor 340m. The driving system 340d is configured to move the power transmitting coil 131 to change the distance between the power transmitting coil 131 and the power receiving coil 141, i.e., the length of the gap between the power transmitting coil 131 and the power receiving coil 141.

[0109] In the plasma processing apparatus 100Gb, the driving system 340d may be configured to move the power transmitting coil assembly 131. The power transmitting coil assembly 131 includes a power transmitting coil 131, a base plate 138, a backside ferrite material 135, and a heat conductive sheet 136.

[0110] The drive system 340d includes at least one actuator. The at least one actuator is configured with a hydraulic or pneumatic cylinder, a motor, a piezoelectric element, or the like. The drive system 340d may include multiple actuators. The drive system 340d may detect the parallelism of the power transmitting coil 131 and the power receiving coil 141 using a sensor 340m, and may control the at least one actuator based on the detection result of the sensor 340m to keep the power transmitting coil 131 and the power receiving coil 141 parallel to each other.

[0111] 32, RF filter 200 is disposed in space 340s2, but in plasma processing apparatus 100Gb, rectification / smoothing unit 150 may be disposed in space 340s2 instead of RF filter 200, as in the configuration shown in Fig. 29. Alternatively, in plasma processing apparatus 100Gb, both rectification / smoothing unit 150 and RF filter 200 may be disposed in space 340s2, as in the configuration shown in Fig. 30.

[0112] According to the plasma processing apparatus 100Gb described above, the distance between the transmitting coil 131 and the receiving coil 141 can be changed, thereby improving the efficiency of power transmission between the transmitting coil 131 and the receiving coil 141 and suppressing high-frequency noise (or conductive noise) from the receiving coil 141 to the transmitting coil 131.

[0113] The plasma processing apparatus 100G and the plasma processing apparatus 100Gb may not include the inner ferrite material 345a or the outer ferrite material 345b. The plasma processing apparatus 100G and the plasma processing apparatus 100Gb may not include both the inner ferrite material 345a and the outer ferrite material 345b. The plasma processing apparatus 100G and the plasma processing apparatus 100Gb may not include either or both of the back surface ferrite material 135 and the back surface ferrite material 145.

[0114] 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. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0115] Various exemplary embodiments included in the present disclosure are now described in [E1] to [E10] below.

[0116] a power receiving coil capable of receiving power from the power receiving coil by electromagnetic induction coupling; a rectifying and smoothing unit configured to convert power from the power receiving coil into DC power; a power storage unit electrically connected between the rectifying and smoothing unit and the power consuming member; a radio frequency power supply line; a radio frequency power source configured to generate radio frequency power to be supplied into the plasma processing chamber via the radio frequency power supply line; and an electrically grounded ground pipe extending through the inside of the power receiving coil and the inside of the power transmitting coil, wherein the radio frequency power supply line extends through the inside of the ground pipe outside the plasma processing chamber.

[0117] [E2] The plasma processing apparatus according to E1, further comprising an inner ferrite material having a cylindrical shape and extending through the inside of the receiving coil and the inside of the transmitting coil, wherein the ground pipe is spaced from the inner ferrite material and passes through the inner ferrite material.

[0118] [E3] The plasma processing apparatus according to E1 or E2, further comprising an outer ferrite material having a cylindrical shape and extending outside the receiving coil and outside the transmitting coil so as to surround the receiving coil and the transmitting coil.

[0119] [E4] The plasma processing apparatus according to any one of E1 to E3, further comprising a ground frame that is grounded and surrounds the substrate support together with the plasma processing chamber, and the ground pipe is electrically connected to the ground frame.

[0120] [E5] The plasma processing apparatus according to E4, further comprising a matching section connected between the high frequency power supply and the power supply line, wherein the ground pipe extends between the ground frame and the matching section.

[0121] [E6] The plasma processing apparatus according to any one of claims 1 to 5, further comprising a metal housing surrounding the power transmitting coil and the power receiving coil.

[0122] [E7] The plasma processing apparatus according to E6, further comprising an RF filter having a characteristic of suppressing propagation of the high-frequency power and connected between the receiving coil and the rectifying and smoothing unit, wherein the RF filter is disposed within the metal casing.

[0123] [E8] The plasma processing apparatus according to E6, wherein the rectifying and smoothing unit is disposed inside the metal housing.

[0124] [E9] The plasma processing apparatus according to claim 6, further comprising an RF filter having a characteristic of suppressing propagation of the high frequency power and connected between the rectifying / smoothing unit and the power storage unit, wherein the rectifying / smoothing unit and the RF filter are arranged within the metal housing.

[0125] [E10] The plasma processing apparatus according to any one of E1 to E9, further comprising a drive system configured to move the power transmitting coil to change the distance between the power receiving coil and the power transmitting coil.

[0126] 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.

[0127] 1...plasma processing apparatus, 10...chamber, 11...substrate support portion, 110...ground frame, 120...power transmission portion, 130...power transmission coil portion, 131...power transmission coil, 140...power receiving coil portion, 141...power receiving coil, 150...rectification / smoothing portion, 180...constant voltage control portion, 240...power consuming member, 300...high frequency power source, 302...high frequency power supply line, 304...ground pipe

Claims

1. A plasma processing apparatus comprising: a plasma processing chamber; a substrate support disposed within the plasma processing chamber; a power-consuming member disposed within the plasma processing chamber or within the substrate support; a power transmission coil; a power reception coil capable of receiving power by electromagnetic induction from the power transmission coil; a rectifying and smoothing unit configured to convert the power from the power reception coil into DC power; a power storage unit electrically connected between the rectifying and smoothing unit and the power-consuming member; a high-frequency power supply line; a high-frequency power source configured to generate high-frequency power supplied into the plasma processing chamber via the high-frequency power supply line; and a ground pipe extending through the inside of the power reception coil and the inside of the power transmission coil and being electrically grounded, wherein the high-frequency power supply line extends through the ground pipe outside the plasma processing chamber.

2. The plasma processing apparatus according to claim 1, further comprising an inner ferrite material having a cylindrical shape and extending through the inside of the power reception coil and the inside of the power transmission coil, wherein the ground pipe is spaced apart from the inner ferrite material and passes through the inner ferrite material.

3. The plasma processing apparatus according to claim 1, further comprising an outer ferrite material having a cylindrical shape and extending through the outside of the power reception coil and the outside of the power transmission coil so as to surround the power reception coil and the power transmission coil.

4. The plasma processing apparatus according to claim 1, further comprising a ground frame that is grounded and surrounds the substrate support together with the plasma processing chamber, wherein the ground pipe is electrically connected to the ground frame.

5. The plasma processing apparatus according to claim 4, further comprising a matching unit connected between the high-frequency power source and the power supply line, wherein the ground pipe extends between the ground frame and the matching unit.

6. The plasma processing apparatus according to claim 1, further comprising a metal casing surrounding the power transmission coil and the power reception coil.

7. The plasma processing apparatus according to claim 6, further comprising an RF filter having a characteristic of suppressing propagation of the high-frequency power and connected between the power receiving coil and the rectifying and smoothing unit, wherein the RF filter is disposed within the metal housing.

8. The plasma processing apparatus according to claim 6, wherein the rectifying and smoothing unit is disposed within the metal housing.

9. The plasma processing apparatus according to claim 6, further comprising an RF filter having a characteristic of suppressing propagation of the high-frequency power and connected between the rectifying and smoothing unit and the power storage unit, wherein the rectifying and smoothing unit and the RF filter are disposed within the metal housing.

10. The plasma processing apparatus according to any one of claims 1 to 9, further comprising a drive system configured to move the power transmission coil in order to change a distance between the power receiving coil and the power transmission coil.

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