Plasma treatment device and plasma treatment method

Abstract

A plasma processing apparatus includes a chamber (10), a substrate support (11), at least one antenna (14), and a radio-frequency generator (31a). The chamber (10) includes a dielectric window (101). The dielectric window (101) is between the substrate support (11) and the antenna (14). The radio-frequency generator (31a) generates first radio-frequency power and second radio-frequency power. The first radio-frequency power has a first frequency. The second radio-frequency power has a second frequency. The dielectric window (101) has a larger dielectric loss at the second frequency than at the first frequency.

Description

Plasma processing apparatus and plasma processing method

[0001] SUMMARY OF THE INVENTION Exemplary embodiments of the present disclosure relate to a plasma processing apparatus and a plasma processing method.

[0002] A plasma processing apparatus is used in plasma processing of a substrate. The plasma processing apparatus includes a chamber, a substrate support, an antenna, a gas supply, and a high-frequency power supply. The chamber includes a dielectric window. The substrate support is provided within the chamber. The antenna is provided outside the chamber. The dielectric window is disposed between the substrate support and the antenna. The gas supply is configured to supply gas into the chamber. The high-frequency power supply is electrically connected to the antenna. The high-frequency power supply supplies high-frequency power to the antenna. Patent Document 1 listed below discloses such a plasma processing apparatus.

[0003] JP 2011-119658 A

[0004] The present disclosure provides techniques to reduce the consumption of dielectric windows.

[0005] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, at least one antenna, a gas supply, and an RF generator. The chamber includes a dielectric window. The substrate support is disposed within the chamber. The at least one antenna is disposed outside the chamber. The dielectric window is disposed between the substrate support and the at least one antenna. The gas supply is configured to supply gas into the chamber. The RF generator is electrically connected to the at least one antenna. The RF generator is configured to generate a first high frequency power and a second high frequency power. The first high frequency power has a first frequency. The second high frequency power has a second frequency. The dielectric loss in the dielectric window for the second frequency is greater than the dielectric loss in the dielectric window for the first frequency.

[0006] According to one exemplary embodiment, consumption of the dielectric window can be reduced.

[0007] 5A and 5B are diagrams for explaining an example of the configuration of an inductively coupled plasma processing apparatus; FIG. 5B is a diagram illustrating the configuration of a power supply system and a control system in a plasma processing apparatus according to an exemplary embodiment; FIG. 5C is a timing chart of first and second high frequency powers in a plasma processing apparatus according to an exemplary embodiment; and FIG. 5D is a diagram illustrating the configuration of a power supply system and a control system in a plasma processing apparatus according to another exemplary embodiment. FIG. 5A is a plan view of an antenna according to an exemplary embodiment; FIG. 5B is a plan view of an antenna according to another exemplary embodiment; and FIG. 5C is a plan view of an antenna according to yet another exemplary embodiment. FIG. 6A is a diagram illustrating an example of a power spectrum of high frequency power having multiple frequency components; FIG. 6B is a diagram illustrating an example of multiple measured values ​​representing the coupling efficiency of the multiple frequency components of FIG. 6A to plasma; FIG. 6C is a diagram illustrating an example of a power spectrum of high frequency power having multiple frequency components; and FIG. 6D is a diagram illustrating an example of multiple measured values ​​representing the coupling efficiency of the multiple frequency components of FIG. 6C to plasma. FIG. 7A is a diagram illustrating an example of a power spectrum of second high frequency power having multiple frequency components. 7A and 7B are diagrams illustrating an example of a plurality of measurement values ​​representing the coupling efficiency of the plurality of frequency components to the plasma of FIG. 7A. FIG. 7C is a diagram illustrating an example of a power spectrum of the second high frequency power having a plurality of frequency components.

[0032] FIG. 7B is a diagram illustrating an example of a plurality of measurement values ​​representing the coupling efficiency of the plurality of frequency components to the plasma of FIG. 7A. FIG. 7C is a diagram illustrating an example of a power spectrum of the second high frequency power having a plurality of frequency components.

[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] An example of the configuration of a plasma processing system will be described below: Fig. 1 is a diagram illustrating an example of the configuration of an inductively coupled plasma processing apparatus.

[0010] The plasma processing system includes an inductively coupled plasma processing apparatus 1 and a control unit 2. The inductively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing chamber 10 includes a dielectric window 101. The plasma processing apparatus 1 also includes a substrate support 11, a gas inlet, and an antenna 14. The substrate support 11 is disposed within the plasma processing chamber 10. The antenna 14 is provided outside the chamber 10. The antenna 14 may be formed of a coil wound around an axis extending in the vertical direction. The antenna 14 is disposed, for example, on or above the plasma processing chamber 10 (i.e., on or above the dielectric window 101). The dielectric window 101 is disposed between the substrate support 11 and the antenna 14. The plasma processing chamber 10 has a plasma processing space 10s defined by the dielectric window 101, a sidewall 102 of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas into the plasma processing space 10s and at least one gas exhaust port for exhausting gas from the plasma processing space 10s. The plasma processing chamber 10 is grounded.

[0011] 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.

[0012] 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 bias electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic 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 (Radio Frequency) power supply 31 and / or a DC (Direct Current) power supply 32 (described later) may be disposed within the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple bias electrodes. Alternatively, the electrostatic electrode 1111b may function as a bias electrode. Therefore, the substrate support 11 includes at least one bias electrode.

[0013] 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.

[0014] 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.

[0015] The gas inlet is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. In one embodiment, the gas inlet includes a center gas injector (CGI) 13. The center gas injector 13 is disposed above the substrate support 11 and attached to a central opening formed in the dielectric window 101. The center gas injector 13 has at least one gas supply port 13a, at least one gas flow path 13b, and at least one gas inlet port 13c. The process gas supplied to the gas supply port 13a passes through the gas flow path 13b and is introduced into the plasma processing space 10s from the gas inlet port 13c. Note that the gas inlet may include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 102 in addition to or instead of the center gas injector 13.

[0016] 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 gas inlet through 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 one or more flow modulation devices to modulate or pulse the flow rate of the at least one process gas.

[0017] 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 bias electrode and the antenna 14. This causes a plasma to be formed from at least one process gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of a plasma generating unit configured to generate a plasma from one or more process gases in the plasma processing chamber 10. Furthermore, by supplying a bias RF signal to the at least one bias electrode, a bias potential is generated on the substrate W, thereby attracting ions in the formed plasma to the substrate W.

[0018] 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 (RF generating unit) is coupled to the antenna 14 and configured to generate a source RF signal (source RF power) for plasma generation via at least one impedance matching circuit. 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 the antenna 14.

[0019] The second RF generator 31b is coupled to at least one bias 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 bias electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0020] 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 bias DC generator 32a. In one embodiment, the bias DC generator 32a is connected to at least one bias electrode and configured to generate a bias DC signal. The generated bias DC signal is applied to the at least one bias electrode.

[0021] In various embodiments, the bias DC signal may be pulsed. In this case, a sequence of voltage pulses is applied to at least one bias electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the bias DC generator 32a and at least one bias electrode. Thus, the bias DC generator 32a and the waveform generator constitute a voltage pulse generator. The voltage pulses may have 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 cycle. Note that the bias DC generator 32a may be provided in addition to the RF power supply 31 or may be provided instead of the second RF generator 31b.

[0022] 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.

[0023] 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).

[0024] Reference will now be made to FIG. 2 . FIG. 2 is a diagram illustrating the configuration of a power supply system and a control system in a plasma processing apparatus according to an exemplary embodiment. As shown in FIG. 2 , the plasma processing apparatus 1 may include a control unit 2. In the plasma processing apparatus 1, the first RF generating unit 31 a may be controlled by the control unit 2. In one embodiment, the first RF generating unit 31 a may be composed of a single high-frequency power supply 300. The high-frequency power supply 300 may include a signal generator and an amplifier. The signal generator outputs a signal having a frequency specified by the control unit 2 to the amplifier. The amplifier amplifies the signal input from the signal generator to generate high-frequency power and output the high-frequency power. The gain of the amplifier may be specified by the control unit 2.

[0025] The first RF generating unit 31a is configured to generate a first radio frequency power RF1 and a second radio frequency power RF2. The first radio frequency power RF1 has a first frequency. The second radio frequency power RF2 has a second frequency. The first frequency and the second frequency are different from each other. For example, the second frequency may be 1% or more higher than the first frequency.

[0026] The first RF generating unit 31a may be electrically connected to the antenna 14 via a directional coupler 310, a sensor 33, and a matching unit 34. The directional coupler 310 measures the power level of the traveling wave of the high-frequency power (each of the first high-frequency power RF1 and the second high-frequency power RF2) output from the first RF generating unit 31a and the power level of the reflected wave of the high-frequency power. The directional coupler 310 may, for example, determine a reflection coefficient of the high-frequency power (each of the first high-frequency power RF1 and the second high-frequency power RF2) output from the high-frequency power supply 300. The reflection coefficient is determined from the power level of the traveling wave and the power level of the reflected wave. The reflection coefficient is notified to the control unit 2 from the directional coupler 310. The directional coupler 310 may be integrated with the high-frequency power supply 300.

[0027] The sensor 33 is, for example, a voltage / current sensor. The sensor 33 measures the voltage and current of the radio frequency power (each of the first radio frequency power RF1 and the second radio frequency power RF2) supplied to the antenna 14. The sensor 33 may determine a reflection coefficient of the radio frequency power (each of the first radio frequency power RF1 and the second radio frequency power RF2) from the measured voltage and current. The sensor 33 may notify the control unit 2 of the reflection coefficient.

[0028] The matching circuit 34 includes an impedance matching circuit having a variable impedance. The matching circuit 34 is connected between the first RF generating unit 31a and the antenna 14. The matching circuit 34 is configured to match the load impedance of the first RF generating unit 31a to the output impedance of the first RF generating unit 31a. The variable impedance of the matching circuit 34 can be controlled by the control unit 2.

[0029] In one embodiment, the plasma processing apparatus 1 may further include a first filter 35, an impedance converter 36, and a second filter 37. The first filter 35 is configured to selectively pass the first radio frequency power RF1. The second filter 37 is configured to selectively pass the second radio frequency power RF2. The first filter 35 and the second filter 37 are each connected in parallel between the matching device 34 and the antenna 14. The matching device 34, the first filter 35, and the antenna 14 form a first electrical path. The first radio frequency power RF1 is supplied to the antenna 14 via the first electrical path. The matching device 34, the second filter 37, and the antenna 14 form a second electrical path. The second radio frequency power RF2 is supplied to the antenna 14 via the second electrical path.

[0030] The impedance converter 36 is connected between one of the first filter 35 and the second filter 37 and the antenna 14. In the example shown in FIG. 2 , the impedance converter 36 is connected between the first filter 35 and the antenna 14.

[0031] The matching circuit 34 may be configured to match the load impedance for the frequency of the high-frequency power selectively passed by the other of the first filter 35 and the second filter 37 to the output impedance of the first RF generating unit 31 a. In the example shown in Fig. 2, the matching circuit 34 is configured to match the load impedance for the second frequency to the output impedance of the first RF generating unit 31 a.

[0032] The impedance converter 36 is configured to match the load impedance for the frequency of the high frequency power selectively passed by one of the first filter 35 and the second filter 37 to the output impedance of the first RF generating unit 31 a. In the example shown in Fig. 2, the impedance converter 36 is configured to match the load impedance for the frequency of the first high frequency power RF1 selectively passed by the first filter 35 to the output impedance of the first RF generating unit 31 a. The impedance converter 36 may be configured by a transformer.

[0033] The dielectric window 101 is made of a material that causes a larger dielectric loss in the dielectric window 101 at a second frequency than at a first frequency. That is, the second frequency is a frequency at which the dielectric loss in the dielectric window 101 is larger than at the first frequency. Each of the first frequency and the second frequency may be set according to the material of the dielectric window 101. For example, the dielectric window 101 may be made of a material that causes a maximum dielectric loss at a second frequency. The frequency at which the dielectric loss of the material is maximum can be adjusted by adjusting the type and concentration of a dopant contained in the material.

[0034] The first RF generator 31a is configured to generate a first radio frequency power RF1. In one embodiment, the first RF generator 31a may be configured to generate the first radio frequency power RF1 to ignite a plasma in the chamber 10. The first radio frequency power RF1 may be supplied to the antenna 14 via a first electrical path. The first RF generator 31a is configured to generate a second radio frequency power RF2. In one embodiment, the first RF generator 31a may be configured to generate a second radio frequency power RF2 to maintain the ignited plasma in the chamber 10. The second radio frequency power RF2 may be supplied to the antenna 14 via a second electrical path.

[0035] When the dielectric loss in the dielectric window 101 is small, the loss of electrical energy coupled to the plasma is suppressed, and therefore, by supplying the first high frequency power RF1 to the antenna 14 to ignite the plasma, it is possible to efficiently ignite the plasma in the chamber 10.

[0036] If the dielectric loss in the dielectric window 101 is large, the potential difference between the potential of the bottom surface of the dielectric window 101 and the potential of the plasma becomes small. Therefore, if the dielectric loss in the dielectric window 101 is large, the energy of ions colliding from the plasma with the dielectric window 101 is kept low. Therefore, after the plasma is ignited, by using the second high frequency power RF2 to maintain the plasma, it is possible to suppress wear of the dielectric window 101.

[0037] Furthermore, in the plasma processing apparatus 1, matching of the load impedance for one of the first frequency and the second frequency is performed by the matching device 34, and matching of the load impedance for the other frequency is performed by the impedance converter 36. Therefore, the plasma processing apparatus 1 can have a simple configuration for its power supply system.

[0038] Referring now to FIG. 3 , which is a timing chart of the first and second radio frequency powers in a plasma processing apparatus according to an exemplary embodiment. The first RF generating unit 31 a may be configured to simultaneously generate the first and second radio frequency powers RF1 and RF2 after generating only the first radio frequency power RF1 and before generating only the second radio frequency power RF2. In one embodiment, the first RF generating unit 31 a is configured to simultaneously supply the first and second radio frequency powers RF1 and RF2 to the antenna 14 after supplying only the first radio frequency power RF1 to the antenna 14 and before supplying only the second radio frequency power RF2 to the antenna 14. After a period T1 during which only the first radio frequency power RF1 is supplied to the antenna 14 and before a period T2 during which only the second radio frequency power RF2 is supplied to the antenna 14, there may be a period T3 during which the first and second radio frequency powers RF1 and RF2 are simultaneously supplied to the antenna 14.

[0039] In another embodiment, the first RF generating unit 31a may supply both the first radio frequency power RF1 and the second radio frequency power RF2 to the antenna 14 during the period T1. However, the power level of the second radio frequency power RF2 during the period T1 is lower than the power level of the second radio frequency power RF2 during the period T2. Alternatively, the first RF generating unit 31a may supply both the first radio frequency power RF1 and the second radio frequency power RF2 to the antenna 14 during the period T2. However, the power level of the first radio frequency power RF1 during the period T2 is lower than the power level of the first radio frequency power RF1 during the period T1. Alternatively, the first RF generating unit 31a may supply the antenna 14 with the first radio frequency power RF1 having a power level higher than the power level of the first radio frequency power RF1 during the period T2 during the period T3 between the periods T1 and T2. The power level of the first high frequency power RF1 in the period T3 may be the same as the power level of the first high frequency power RF1 in the period T1. Furthermore, the first RF generation unit 31a may supply the second high frequency power RF2 in the period T3 to the antenna 14, the second high frequency power RF2 having a power level higher than the power level of the second high frequency power RF2 in the period T1. The power level of the second high frequency power RF2 in the period T3 may be the same as the power level of the second high frequency power RF2 in the period T2.

[0040] Referring now to Figure 4, which shows the configuration of a power supply system and a control system in a plasma processing apparatus according to another exemplary embodiment, the plasma processing apparatus 1A shown in Figure 4 will be described below from the perspective of differences between the configurations of the power supply system and the control system of the plasma processing apparatus 1A and the configurations of the power supply system and the control system of the plasma processing apparatus 1.

[0041] The first RF generating unit 31a of the plasma processing apparatus 1A includes a plurality of radio frequency power sources 301 and 302. The radio frequency power source 301 (first radio frequency power source) is configured to generate a first radio frequency power RF1. The radio frequency power source 302 (second radio frequency power source) is configured to generate a second radio frequency power RF2. The plasma processing apparatus 1A does not necessarily have to include the first filter 35, the impedance converter 36, and the second filter 37. The plasma processing apparatus 1A further includes a directional coupler 311, a sensor 331, a matching device 341, a directional coupler 312, a sensor 332, and a matching device 342.

[0042] The high frequency power supply 301 is electrically connected to the antenna 14 via the directional coupler 311, the sensor 331, and the matching device 341. The matching device 341 is configured to match the load impedance for the first frequency to the output impedance of the high frequency power supply 301.

[0043] The directional coupler 311 measures the power level of the forward wave of the first high frequency power RF1 and the power level of the reflected wave of the first high frequency power RF1. The directional coupler 311 may determine a reflection coefficient of the first high frequency power RF1. The reflection coefficient is determined from the power level of the forward wave and the power level of the reflected wave. The reflection coefficient is notified from the directional coupler 311 to the control unit 2. The directional coupler 311 may be integrated with the high frequency power supply 301.

[0044] The sensor 331 is, for example, a voltage / current sensor. The sensor 331 measures the voltage and current of the first high frequency power RF1 supplied to the antenna 14. The sensor 331 may determine the reflection coefficient of the first high frequency power RF1 from the measured voltage and current. The sensor 331 may notify the control unit 2 of the reflection coefficient.

[0045] The high frequency power supply 302 is electrically connected to the antenna 14 via the directional coupler 312, the sensor 332, and the matching box 342. The matching box 342 is configured to match the load impedance for the second frequency to the output impedance of the high frequency power supply 302.

[0046] The directional coupler 312 measures the power level of the forward wave of the second high frequency power RF2 and the power level of the reflected wave of the second high frequency power RF2. The directional coupler 312 may determine a reflection coefficient of the second high frequency power RF2. The reflection coefficient is determined from the power level of the forward wave and the power level of the reflected wave. The reflection coefficient is notified from the directional coupler 312 to the control unit 2. The directional coupler 312 may be integrated with the high frequency power supply 302.

[0047] The sensor 332 is, for example, a voltage / current sensor. The sensor 332 measures the voltage and current of the second high frequency power RF2 supplied to the antenna 14. The sensor 332 may determine the reflection coefficient of the second high frequency power RF2 from the measured voltage and current. The sensor 332 may notify the control unit 2 of the reflection coefficient.

[0048] 5A to 5C, in the plasma processing apparatus according to various exemplary embodiments, the antenna may be configured with a plurality of antennas.

[0049] Fig. 5(a) is a plan view of an antenna in one exemplary embodiment. Fig. 5(b) is a plan view of an antenna in another exemplary embodiment. Fig. 5(c) is a plan view of an antenna in yet another exemplary embodiment. Plasma processing apparatuses according to various exemplary embodiments may include antenna 14A shown in Fig. 5(a), antenna 14B shown in Fig. 5(b), or antenna 14C shown in Fig. 5(c) instead of antenna 14.

[0050] Each of the antennas 14A, 14B, and 14C includes a first antenna 141 and a second antenna 142. Each of the first antenna 141 and the second antenna 142 may be formed from a coil wound around an axis extending in the vertical direction. Each of the first antenna 141 and the second antenna 142 has a circular shape in a plan view. The central axis of the second antenna 142 may be located on the central axis of the chamber 10. The first antenna 141 is smaller than the second antenna 142.

[0051] In the antenna 14A, the first antenna 141 and the second antenna 142 are arranged so as not to overlap each other in a plan view. In the antenna 14A, the outer periphery of the first antenna 141 and the outer periphery of the second antenna 142 may be arranged so as to circumscribe each other in a plan view.

[0052] In the antenna 14B, the first antenna 141 and the second antenna 142 are arranged to overlap each other in a plan view. As shown in Fig. 5B, the first antenna 141 and the second antenna 142 may share a central axis.

[0053] In the antenna 14C, the first antenna 141 and the second antenna 142 are arranged to overlap each other in a plan view. As shown in Fig. 5C, the central axis of the first antenna 141 may be provided at a position offset from the central axis of the second antenna 142. The outer periphery of the first antenna 141 and the inner periphery of the second antenna 142 may be arranged to be inscribed in a plan view.

[0054] In each of the antennas 14A, 14B, and 14C, only the first radio frequency power RF1 of the first radio frequency power RF1 and the second radio frequency power RF2 may be supplied to the first antenna 141. Only the second radio frequency power RF2 of the first radio frequency power RF1 and the second radio frequency power RF2 may be supplied to the second antenna 142. Note that both the first radio frequency power RF1 and the second radio frequency power RF2 may be supplied to at least one of the first antenna 141 and the second antenna 142.

[0055] In one embodiment, the control unit 2 may be configured to identify the first frequency and use the first high frequency power RF1 having the identified first frequency for igniting the plasma. Hereinafter, the process of the control unit 2 identifying the first frequency will be described with reference to (a) to (d) of FIG. 6 .

[0056] FIG. 6A is a diagram illustrating an example of a power spectrum of high-frequency power having multiple frequency components. As shown in FIG. 6A, the first RF generating unit 31a may be configured to generate high-frequency power having multiple frequency components. The high-frequency power shown in FIG. 6A has multiple frequency components Sa1 to San, where n is an integer greater than or equal to 2. The power level of each of the multiple frequency components Sa1 to San is a predetermined power level P. The control unit 2 controls the first RF generating unit 31a to supply high-frequency power having multiple frequency components to the antenna 14. In the plasma processing apparatus 1A, the high-frequency power having multiple frequency components may be generated by the high-frequency power supply 301.

[0057] 6B is a diagram showing an example of multiple measured values ​​representing the coupling efficiency of the multiple frequency components of FIG. 6A to the plasma. The control unit 2 uses multiple measured values ​​to identify the first frequency. The multiple measured values ​​represent the coupling efficiency of each of the multiple frequency components Sa1 to San to the plasma. The multiple measured values ​​may be, for example, reflection coefficients of each of the multiple frequency components Sa1 to San acquired by the directional coupler 310 or the sensor 33, or the directional coupler 311 or the sensor 331. Alternatively, the multiple measured values ​​may be load power levels of each of the multiple frequency components Sa1 to San acquired by the sensor 33 or the sensor 331. The load power level is the difference between the power level of the forward wave and the power level of the reflected wave of each of the multiple frequency components Sa1 to San.

[0058] The control unit 2 uses multiple measurement values ​​to identify the frequency of the component having the greatest coupling efficiency among the multiple frequency components Sa1 to San as the first frequency. In the example shown in Figure 6(b), the frequency component having the greatest coupling efficiency among the multiple frequency components Sa1 to San is frequency component Sa2.

[0059] In one embodiment, the control unit 2 may update the first frequency by causing the first RF generating unit 31a to generate high-frequency power including multiple frequency components Sb1 to Sbm having a frequency pitch narrower than the frequency pitch of the multiple frequency components Sa1 to San. The control unit 2 may be configured to use the first high-frequency power RF1 having the updated first frequency to ignite plasma. Note that in the plasma processing apparatus 1A, the high-frequency power including multiple frequency components may be generated by the high-frequency power supply 301.

[0060] FIG. 6C illustrates an example of a power spectrum of high-frequency power having multiple frequency components. The high-frequency power illustrated in FIG. 6C has multiple frequency components Sb1 to Sbm, where m is an integer greater than or equal to 2. The power level of each of the multiple frequency components Sb1 to Sbn is a predetermined power level P. The band including the multiple frequency components Sb1 to Sbm is narrower than the band including the multiple frequency components Sa1 to San. The band including the multiple frequency components Sb1 to Sbm includes a frequency component (e.g., frequency component Sa2) that has the highest coupling efficiency among the multiple frequency components Sa1 to San. The frequency component Sa2 may be the center frequency of the band including the multiple frequency components Sb1 to Sbm.

[0061] 6D is a diagram showing an example of multiple measured values ​​representing the coupling efficiency of the multiple frequency components of FIG. 6C to the plasma. The control unit 2 uses the multiple measured values ​​to update the first frequency. The multiple measured values ​​represent the coupling efficiency of each of the multiple frequency components Sb1 to Sbn to the plasma. The multiple measured values ​​may be, for example, reflection coefficients of each of the multiple frequency components Sb1 to Sbn acquired by the directional coupler 310 or the sensor 33, or the directional coupler 311 or the sensor 331. Alternatively, the multiple measured values ​​may be load power levels of each of the multiple frequency components Sb1 to Sbn acquired by the sensor 33 or the sensor 331. The load power level is the difference between the power level of the forward wave and the power level of the reflected wave of each of the multiple frequency components Sb1 to Sbn.

[0062] The control unit 2 may use a plurality of measurement values ​​to identify the frequency of the component having the greatest coupling efficiency among the plurality of frequency components Sb1 to Sbn, and update the first frequency using the identified frequency. In the example of (d) in FIG. 6, the frequency component having the greatest coupling efficiency among the plurality of frequency components Sb1 to Sbm is frequency component Sb4.

[0063] In one embodiment, after ignition of the plasma, the control unit 2 may maintain the plasma using the second high frequency power RF2 including multiple frequency components, and may also perform load power control of the multiple frequency components of the second high frequency power RF2. Below, with reference to Figures 7(a) to 7(c), a process in which the control unit 2 performs load power control of the multiple frequency components of the second high frequency power RF2 will be described.

[0064] FIG. 7A illustrates an example of a power spectrum of a second high-frequency power having multiple frequency components. The first RF generator 31a may be configured to generate a second high-frequency power having multiple frequency components as shown in FIG. 7A after plasma ignition. The second high-frequency power illustrated in FIG. 7A has multiple frequency components S1 to Sn, where n is an integer greater than or equal to 2. The power level of each of the multiple frequency components S1 to Sn is a predetermined power level P. The controller 2 controls the first RF generator 31a to supply the second high-frequency power having multiple frequency components to the antenna 14. In the plasma processing apparatus 1A, the second high-frequency power having multiple frequency components may be generated by the high-frequency power supply 302.

[0065] 7B is a diagram showing an example of multiple measured values ​​representing coupling efficiencies to plasma corresponding to the multiple frequency components in FIG. 7A. The control unit 2 uses multiple measured values ​​to control the load power of the multiple frequency components of the second high frequency power RF2. The multiple measured values ​​represent the coupling efficiencies to plasma of each of the multiple frequency components S1 to Sn. The multiple measured values ​​may be, for example, reflection coefficients of each of the multiple frequency components S1 to Sn acquired by the directional coupler 310 or the sensor 33, or the directional coupler 312 or the sensor 332. Alternatively, the multiple measured values ​​may be load power levels of each of the multiple frequency components S1 to Sn acquired by the sensor 33 or the sensor 332. The load power level is the difference between the power level of the forward wave and the power level of the reflected wave of each of the multiple frequency components S1 to Sn.

[0066] 7C is a diagram showing an example of a power spectrum of the second radio frequency power RF2 having a plurality of frequency components. The control unit 2 adjusts the power levels of the plurality of frequency components of the second radio frequency power RF2 using a plurality of measurement values, as shown in FIG. 7C, so that the load power levels of the plurality of frequency components of the second radio frequency power RF2 approach their respective designated levels. In one example, the control unit 2 may adjust the power levels of the plurality of frequency components of the second radio frequency power RF2 so that the load power levels of the plurality of frequency components of the second radio frequency power RF2 are approximately the same.

[0067] An example of a plasma processing method will be described below with reference to Fig. 8. Fig. 8 is a flow chart of a plasma processing method according to one exemplary embodiment. The plasma processing method shown in Fig. 8 (hereinafter referred to as "method MT") can be performed using plasma processing apparatus 1 or 1A. Below, as one embodiment, method MT performed using plasma processing apparatus 1 will be described.

[0068] The method MT includes steps STa and STb. In step STa, a first high frequency power RF1 is supplied from the first RF generator 31a to the antenna 14. In one embodiment, in step STa, the first high frequency power RF1 may be supplied from the first RF generator 31a to the antenna 14 to ignite plasma in the chamber 10 of the plasma processing apparatus 1. In step STb, a second high frequency power RF2 may be supplied from the first RF generator 31a to the antenna 14. In one embodiment, in step STb, the second high frequency power RF2 may be supplied from the first RF generator 31a to the antenna 14 to maintain the plasma ignited in the chamber 10.

[0069] In one embodiment, when the method MT is performed using the plasma processing apparatus 1, in the step STa, a first radio frequency power RF1 may be supplied from the radio frequency power supply 300. In the step STb, a second radio frequency power RF2 may be supplied from the radio frequency power supply 300.

[0070] In one embodiment, when the method MT is performed using the plasma processing apparatus 1, high-frequency power that has selectively passed through the first filter 35 may be supplied in the process STa. High-frequency power that has selectively passed through the second filter 37 may be supplied in the process STb.

[0071] In one embodiment, when the method MT is performed using the plasma processing apparatus 1A, in the process STa, a first radio frequency power RF1 may be supplied from the radio frequency power supply 301. In the process STb, a second radio frequency power RF2 may be supplied from the radio frequency power supply 302.

[0072] In one embodiment, when the method MT is performed using a plasma processing apparatus including any one of the antennas 14A, 14B, and 14C, in step STa, the first radio frequency power RF1 may be supplied to the first antenna 141. In step STb, the second radio frequency power RF2 may be supplied to the second antenna 142.

[0073] In one embodiment, the method MT may include a step STc. In the example of FIG. 8 , the step STc is performed after the step STa and before the step STb. In this case, in the step STa, only the first radio frequency power RF1 is supplied from the first RF generating unit 31a to the antenna 14. In the step STc, the first radio frequency power RF1 and the second radio frequency power RF2 are simultaneously supplied from the first RF generating unit 31a to the antenna 14. In the step STb, only the second radio frequency power RF2 is supplied from the first RF generating unit 31a to the antenna 14.

[0074] In one embodiment, the method MT may include steps STd and STe. In the example of Fig. 8, steps STd and STe are performed before step STa. In step STd, high-frequency power having multiple frequency components Sa1 to San is supplied to the antenna 14 (see Fig. 6(a)).

[0075] In the process STe, the frequency of the component having the greatest coupling efficiency among the plurality of frequency components Sa1 to San supplied to the antenna 14 is identified as the first frequency. The first frequency is identified based on a plurality of measurement values ​​(see FIG. 6B ) representing the plasma coupling efficiency of each of the plurality of frequency components Sa1 to San. The plurality of measurement values ​​may be, for example, reflection coefficients of each of the plurality of frequency components Sa1 to San acquired by the directional coupler 310 or the sensor 33, or the directional coupler 311 or the sensor 331. Alternatively, the plurality of measurement values ​​may be load power levels of each of the plurality of frequency components Sa1 to San acquired by the sensor 33 or the sensor 331. The load power level is the difference between the power level of the forward wave and the power level of the reflected wave of each of the plurality of frequency components Sa1 to San. In the process STa, a first high-frequency power RF1 having the first frequency identified in the process STe may be supplied.

[0076] In one embodiment, the process STd and the process STe may be performed again. In this case, in the process STd that is performed again, high-frequency power including multiple frequency components Sb1 to Sbm having a frequency pitch narrower than the frequency pitch of the multiple frequency components Sa1 to San may be supplied to the antenna 14 (see (c) of FIG. 6). In the process STe that is performed again, the frequency of the component having the highest coupling efficiency among the multiple frequency components Sb1 to Sbm supplied to the antenna 14 may be updated as the first frequency. The first frequency is updated based on multiple measurement values ​​that represent the plasma coupling efficiencies of the multiple frequency components Sb1 to Sbm, respectively (see (d) of FIG. 6). In the process STa, the first high-frequency power RF1 having the first frequency that was updated in the process STe that is performed again may be supplied.

[0077] 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.

[0078] Various exemplary embodiments included in the present disclosure are now described in [E1] to [E16] below.

[0079] [E1] A plasma processing apparatus comprising: a chamber including a dielectric window; a substrate support provided within the chamber; at least one antenna provided outside the chamber, the dielectric window being disposed between the substrate support and the at least one antenna; a gas supply configured to supply gas into the chamber; and an RF generator electrically connected to the at least one antenna, wherein the RF generator is configured to generate a first RF power having a first frequency and a second RF power having a second frequency, and a dielectric loss in the dielectric window for the second frequency is greater than a dielectric loss in the dielectric window for the first frequency. [E2] The plasma processing apparatus of E1, wherein the RF generator is configured to generate the first RF power to ignite plasma in the chamber, and generate the second RF power to maintain the plasma ignited in the chamber. [E3] The plasma processing apparatus of E1 or E2, wherein the RF generator is configured from a single RF power source.[E4] The plasma processing apparatus according to any one of E1 to E3, further comprising: a matching box connected between the RF generating unit and the at least one antenna; a first filter configured to selectively pass the first high frequency power and connected between the matching box and the at least one antenna; a second filter configured to selectively pass the second high frequency power and connected between the matching box and the at least one antenna; and an impedance converter connected between one of the first filter and the second filter and the at least one antenna, wherein the matching box is configured to match a load impedance for a frequency of the high frequency power selectively passed by the other of the first filter and the second filter to an output impedance of the RF generating unit, and the impedance converter is configured to match a load impedance for a frequency of the high frequency power selectively passed by the one filter to an output impedance of the RF generating unit. [E5] The plasma processing apparatus of E1 or E2, wherein the RF generation unit includes: a first high frequency power supply configured to generate the first high frequency power; and a second high frequency power supply configured to generate the second high frequency power. [E6] The plasma processing apparatus of any one of E1 to E5, wherein the at least one antenna includes: a first antenna that receives the first high frequency power; and a second antenna that receives the second high frequency power. [E7] The plasma processing apparatus of any one of E1 to E6, wherein the RF generation unit is configured to simultaneously supply the first high frequency power and the second high frequency power to the at least one antenna after supplying only the first high frequency power to the at least one antenna and before supplying only the second high frequency power to the at least one antenna.[E8] The plasma processing apparatus according to any one of E1 to E7, further comprising a control unit configured to: control the RF generating unit to supply high-frequency power having a plurality of frequency components to the at least one antenna; and identify, as the first frequency, a frequency of the component having the greatest coupling efficiency among the plurality of frequency components based on a plurality of measurement values ​​obtained by a sensor, the plurality of measurement values ​​representing coupling efficiencies of each of the plurality of frequency components to plasma. [E9] A plasma processing method comprising: (a) a step of supplying first high frequency power having a first frequency from an RF generating unit to at least one antenna in a plasma processing apparatus, the plasma processing apparatus comprising: the chamber including a dielectric window; a substrate support provided within the chamber; the at least one antenna located outside the chamber, the dielectric window being disposed between the substrate support and the at least one antenna; and the RF generating unit electrically connected to the at least one antenna; and (b) a step of supplying second high frequency power having a second frequency from the RF generating unit to the at least one antenna, wherein a dielectric loss in the dielectric window for the second frequency is greater than a dielectric loss in the dielectric window for the first frequency. [E10] The plasma processing method according to E9, wherein in (a), the first high frequency power is supplied from the RF generating unit to the at least one antenna to ignite plasma in the chamber, and in (b), the second high frequency power is supplied from the RF generating unit to the at least one antenna to maintain the plasma ignited in the chamber. [E11] The plasma processing method according to E9 or E10, wherein the RF generating unit is composed of a single high frequency power supply, and in (a), the first high frequency power is supplied from the single high frequency power supply, and in (b), the second high frequency power is supplied from the single high frequency power supply.[E12] The plasma processing apparatus further includes: a matching box connected between the RF generating unit and the at least one antenna; a first filter configured to selectively pass the first high frequency power and connected between the matching box and the at least one antenna; a second filter configured to selectively pass the second high frequency power and connected between the matching box and the at least one antenna; and an impedance converter connected between one of the first filter and the second filter and the at least one antenna, wherein the matching box is configured to match a load impedance for a frequency of the high frequency power selectively passed by the other of the first filter and the second filter to an output impedance of the RF generating unit, and the impedance converter is configured to match a load impedance for a frequency of the high frequency power selectively passed by the one filter to an output impedance of the RF generating unit, and wherein in (a), the high frequency power selectively passed through the first filter is supplied, and in (b), the high frequency power selectively passed through the second filter is supplied. The plasma processing method according to any one of E9 to E11. [E13] The plasma processing method according to E9 or E10, wherein the RF generating unit includes: a first high frequency power supply configured to generate the first high frequency power; and a second high frequency power supply configured to generate the second high frequency power, wherein in (a), the first high frequency power is supplied from the first high frequency power supply, and in (b), the second high frequency power is supplied from the second high frequency power supply. [E14] The plasma processing method according to any one of E9 to E13, wherein the at least one antenna includes: a first antenna that receives the first high frequency power; and a second antenna that receives the second high frequency power, wherein in (a), the first high frequency power is supplied to the first antenna, and in (b), the second high frequency power is supplied to the second antenna.[E15] The plasma processing method according to any one of E9 to E14, further comprising: (c) simultaneously supplying the first high frequency power and the second high frequency power to the at least one antenna after supplying only the first high frequency power from the RF generating unit to the at least one antenna in (a) and before supplying only the second high frequency power from the RF generating unit to the at least one antenna in (b). [E16] The plasma processing method according to any one of E9 to E15, further comprising: (d) supplying high frequency power having a plurality of frequency components to the at least one antenna; and (e) identifying, as the first frequency, a frequency of a component having a maximum coupling efficiency among the plurality of frequency components based on a plurality of measurement values ​​obtained by a sensor, the plurality of measurement values ​​representing coupling efficiencies of the plurality of frequency components to plasma, wherein the first high frequency power having the first frequency identified in (e) is supplied to the at least one antenna in (a).

[0080] 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.

[0081] 1, 1A...plasma processing apparatus, 2...control unit, 10...chamber, 11...substrate support unit, 14, 14A, 14B, 14C...antenna, 20...gas supply unit, 31a...first RF generation unit, 33, 331, 332...sensor, 34, 341, 342...matching unit, 35...first filter, 36...impedance converter, 37...second filter, 101...dielectric window, 300, 301, 302...high frequency power supply, 310, 311, 312...directional coupler, RF1...first high frequency power, RF2...second high frequency power.

Claims

1. A plasma processing apparatus comprising: a chamber including a dielectric window; a substrate support provided within the chamber; at least one antenna provided outside the chamber, the dielectric window being positioned between the substrate support and the at least one antenna; a gas supply configured to supply gas into the chamber; and an RF generator electrically connected to the at least one antenna, wherein the RF generator is configured to generate a first high frequency power having a first frequency and a second high frequency power having a second frequency, and a dielectric loss in the dielectric window for the second frequency is greater than a dielectric loss in the dielectric window for the first frequency.

2. The plasma processing apparatus according to claim 1, wherein the RF generating unit is configured to generate the first high frequency power to ignite plasma in the chamber, and to generate the second high frequency power to maintain the plasma ignited in the chamber.

3. The plasma processing apparatus according to claim 1 or 2, wherein the RF generating unit is composed of a single high-frequency power source.

4. The plasma processing apparatus according to claim 1 or 2, further comprising: a matching box connected between the RF generating unit and the at least one antenna; a first filter configured to selectively pass the first high frequency power and connected between the matching box and the at least one antenna; a second filter configured to selectively pass the second high frequency power and connected between the matching box and the at least one antenna; and an impedance converter connected between one of the first filter and the second filter and the at least one antenna, wherein the matching box is configured to match a load impedance for a frequency of high frequency power selectively passed by the other of the first filter and the second filter to an output impedance of the RF generating unit, and the impedance converter is configured to match a load impedance for a frequency of high frequency power selectively passed by the one filter to an output impedance of the RF generating unit.

5. The plasma processing apparatus according to claim 1, wherein the RF generating unit includes: a first high frequency power supply configured to generate the first high frequency power; and a second high frequency power supply configured to generate the second high frequency power.

6. The plasma processing apparatus according to claim 1 or 2, wherein the at least one antenna includes: a first antenna that receives the first high frequency power; and a second antenna that receives the second high frequency power.

7. The plasma processing apparatus according to claim 1 or 2, wherein the RF generating unit is configured to simultaneously supply the first high frequency power and the second high frequency power to the at least one antenna after supplying only the first high frequency power to the at least one antenna and before supplying only the second high frequency power to the at least one antenna.

8. A plasma processing apparatus as described in claim 1 or 2, further comprising a control unit configured to: control the RF generating unit to supply high-frequency power having a plurality of frequency components to the at least one antenna; and identify, as the first frequency, the frequency of the component having the greatest coupling efficiency among the plurality of frequency components based on a plurality of measurement values ​​obtained by a sensor and representing the coupling efficiency of each of the plurality of frequency components to plasma.

9. A plasma processing method comprising: (a) a step of supplying first high frequency power having a first frequency from an RF generating unit to at least one antenna in a plasma processing apparatus, the plasma processing apparatus comprising: the chamber including a dielectric window; a substrate support unit provided within the chamber; the at least one antenna provided outside the chamber, the dielectric window being positioned between the substrate support unit and the at least one antenna; and the RF generating unit electrically connected to the at least one antenna; and (b) a step of supplying second high frequency power having a second frequency from the RF generating unit to the at least one antenna, wherein a dielectric loss in the dielectric window for the second frequency is greater than a dielectric loss in the dielectric window for the first frequency.

10. The plasma processing method according to claim 9, wherein in (a), the first high frequency power is supplied from the RF generating unit to the at least one antenna to ignite plasma in the chamber, and in (b), the second high frequency power is supplied from the RF generating unit to the at least one antenna to maintain the plasma ignited in the chamber.

11. The plasma processing method according to claim 9 or 10, wherein the RF generating unit is composed of a single high-frequency power supply, and in (a), the first high-frequency power is supplied from the single high-frequency power supply, and in (b), the second high-frequency power is supplied from the single high-frequency power supply.

12. The plasma processing apparatus further comprises: a matching box connected between the RF generating unit and the at least one antenna; a first filter configured to selectively pass the first high frequency power and connected between the matching box and the at least one antenna; a second filter configured to selectively pass the second high frequency power and connected between the matching box and the at least one antenna; and an impedance converter connected between one of the first filter and the second filter and the at least one antenna, wherein the matching box is configured to match a load impedance for a frequency of the high frequency power selectively passed by the other of the first filter and the second filter to an output impedance of the RF generating unit, and the impedance converter is configured to match a load impedance for a frequency of the high frequency power selectively passed by the one filter to an output impedance of the RF generating unit, wherein in (a), the high frequency power selectively passed through the first filter is supplied, and in (b), the high frequency power selectively passed through the second filter is supplied. The plasma processing method according to claim 9 or 10.

13. The plasma processing method according to claim 9 or 10, wherein the RF generating unit includes: a first high frequency power supply configured to generate the first high frequency power; and a second high frequency power supply configured to generate the second high frequency power; and wherein in (a), the first high frequency power is supplied from the first high frequency power supply; and in (b), the second high frequency power is supplied from the second high frequency power supply.

14. The plasma processing method according to claim 9 or 10, wherein the at least one antenna includes a first antenna that receives the first high frequency power and a second antenna that receives the second high frequency power, and wherein in (a), the first high frequency power is supplied to the first antenna, and in (b), the second high frequency power is supplied to the second antenna.

15. The plasma processing method according to claim 9 or 10, further comprising: (c) a step of simultaneously supplying the first high frequency power and the second high frequency power to the at least one antenna after supplying only the first high frequency power from the RF generating unit to the at least one antenna in (a) and before supplying only the second high frequency power from the RF generating unit to the at least one antenna in (b).

16. The plasma processing method according to claim 9 or 10, further comprising the steps of: (d) supplying high-frequency power having a plurality of frequency components to the at least one antenna; and (e) identifying, as the first frequency, the frequency of the component having the greatest coupling efficiency among the plurality of frequency components based on a plurality of measurement values ​​obtained by a sensor and representing the coupling efficiency of each of the plurality of frequency components to the plasma, wherein the first high-frequency power having the first frequency identified in (e) is supplied to the at least one antenna in (a).