Impedance matching device

Abstract

This disclosure provides an impedance matcher that does not require the output of a timing signal for acquiring load information from a high-frequency power supply to the impedance matcher. [Solution] The impedance matching device (first matching device 20) according to this disclosure includes a matching circuit 23, a matching device setting value information output unit 28 that outputs a matching device setting value corresponding to the elapsed time or a command signal corresponding to the matching device setting value based on first matching device setting value information ST2 which shows the relationship between the elapsed time from the start of the period within the time of one period of amplitude modulation when the first high-frequency power supplies 10, 10A perform amplitude modulation control, and a control unit 25 that outputs a control signal to the matching circuit 23. In this case, the matching device setting value information output unit 28 uses the time when a period start signal PS common to the first high-frequency power supplies 10, 10A is input or the time when the period start signal PS is input plus a delay time as the starting point.

Description

Technical Field

[0001] The present disclosure relates to an impedance matcher.

Background Art

[0002] For example, a high-frequency power supply system used in a plasma processing apparatus has two high-frequency power supply devices (a first high-frequency power supply and a second high-frequency power supply), and outputs high-frequency voltages (traveling-wave voltages) with different fundamental frequencies (frequencies of fundamental waves) from each power supply toward a load. For example, the first high-frequency power supply supplies high-frequency power (first traveling-wave power) to the load by outputting a high-frequency voltage (traveling-wave voltage VF1) having a fundamental frequency F1 suitable for plasma generation. The second high-frequency power supply supplies high-frequency power (second traveling-wave power) to the load by outputting a high-frequency voltage (traveling-wave voltage VF2) having a fundamental frequency F2 suitable for ion acceleration (fundamental frequency F1 > fundamental frequency F2) (see Patent Document 1).

[0003] Also, a first impedance matcher (hereinafter, the first matcher) is provided between the first high-frequency power supply and the load, and the value of an internal variable element (for example, the capacitance value of a variable capacitor) is adjusted so that the power value of the reflected wave power at the output end of the first high-frequency power supply (the input end of the first impedance matcher) becomes small, thereby performing impedance matching. Also, a second impedance matcher (hereinafter, the second matcher) is provided between the second high-frequency power supply and the load, and impedance matching is performed by adjusting the value of an internal variable element (for example, the capacitance value of a variable capacitor) so that the power value of the reflected wave power at the output end of the second high-frequency power supply (the input end of the second impedance matcher) becomes small. Note that the matcher may be expressed as a matching device.

[0004] High-frequency power supply devices, such as first and second high-frequency power supplies, may perform two-stage amplitude modulation, which involves repeatedly switching between an ON operation that outputs a high-frequency voltage (high-frequency power) and an OFF operation that does not output a high-frequency voltage (high-frequency power). Alternatively, instead of ON and OFF operations, two-stage amplitude modulation may be performed, which involves repeatedly switching between a first level and a second level. Furthermore, various output controls are performed, such as gradually decreasing or increasing the output level or gradually decreasing or increasing the duty cycle (see Patent Document 2). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2024-95370 [Patent Document 2] Japanese Patent Publication No. 2021-57929 [Overview of the project] [Problems that the invention aims to solve]

[0006] In an impedance matching device, in order to perform impedance matching accurately, load information is acquired for a period of time exceeding a predetermined power value, and the matching operation is performed based on the acquired load information.

[0007] In the high-frequency power supply system described above, when the high-frequency power supply unit performs amplitude modulation, a period start signal (corresponding to the synchronization pulse signal in Patent Document 1) can be transmitted externally to each device (high-frequency power supply unit, impedance matcher). This allows the impedance matcher to recognize the starting point of the period within the time of one period of amplitude modulation.

[0008] As described in Patent Document 1, if a high-frequency power supply device is designed to repeatedly switch between ON and OFF operations, the ON period and the OFF period can be determined by an externally input period start signal. Therefore, the impedance matching device only needs to acquire load information during a predetermined period within the ON period. For example, load information can be acquired from the time a predetermined period has elapsed since the start of the ON period until the end of the ON period.

[0009] However, as described in Patent Document 2, when a high-frequency power supply device performs complex amplitude modulation control, such as gradually decreasing or increasing the output level or gradually decreasing or increasing the duty cycle, the period for which the above load information should be acquired cannot be determined by the period start signal alone.

[0010] Therefore, it is conceivable to output an acquisition timing signal from the high-frequency power supply to the impedance matching unit to specify the period during which load information should be acquired.

[0011] Such acquisition timing signals need to be output from the high-frequency power supply to the impedance matcher in accordance with the target power value of the high-frequency power supply. However, depending on the communication status between the high-frequency power supply and the external control device, it may not be possible to output the acquisition timing signal from the high-frequency power supply to the impedance matcher at the appropriate timing.

[0012] This disclosure provides an impedance matcher that eliminates the need to output a timing signal for acquiring load information from a high-frequency power supply to the impedance matcher. [Means for solving the problem]

[0013] The impedance matcher according to this disclosure comprises an input terminal connectable to a high-frequency power supply that supplies high-frequency power, an output terminal connectable to a load, a matching circuit that includes a variable element internally and can change the impedance as seen from the input terminal, an impedance matcher setting information output unit that outputs the impedance matcher setting value corresponding to the elapsed time or a command signal corresponding to the impedance matcher setting value based on impedance matcher setting value information that shows the relationship between the elapsed time from the start of the period within the time period of one period of amplitude modulation when the high-frequency power supply performs amplitude modulation control, and a control unit that outputs a control signal to the matching circuit based on the impedance matcher setting value or the command signal output from the impedance matcher setting value information output unit, wherein the impedance matcher setting value information output unit is a signal generated for each time period of one period of amplitude modulation, and the start time is the time when a period start signal common to the high-frequency power supply is input or the time when the period start signal is input plus a delay time. [Effects of the Invention]

[0014] According to the impedance matching device described herein, it is possible to eliminate the need to output a timing signal for acquiring load information from the high-frequency power supply to the impedance matching device. [Brief explanation of the drawing]

[0015] [Figure 1] A diagram showing the configuration of a high-frequency power supply system according to an embodiment. [Figure 2] A diagram illustrating an example of amplitude-modulated waveform, load information acquisition period, and period start signal in an embodiment. [Figure 3] A diagram illustrating an example of setting value information in an embodiment. [Figure 4] A diagram illustrating other examples of setting value information in the embodiment. [Figure 5] A diagram illustrating other examples of setting value information in the embodiment. [Figure 6] A diagram illustrating other examples of setting value information in the embodiment. [Figure 7] A diagram for explaining another example of an amplitude modulation waveform, an acquisition period of load information, and a period start signal in an embodiment. [Figure 8] A diagram for explaining another setting example of set value information in an embodiment. [Figure 9] A diagram showing another example of an amplitude modulation waveform of a first high-frequency power supply in an embodiment. [Figure 10] A diagram showing an example of set value information for a first high-frequency power supply corresponding to FIG. 9 in an embodiment. [Figure 11] A diagram showing a configuration of a high-frequency power supply system according to a modification of an embodiment.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of a high-frequency power supply system according to the present disclosure will be described with reference to the drawings.

[0017] FIG. 1 is a diagram showing a configuration of a high-frequency power supply system 1.

[0018] The high-frequency power supply system 1 is a device that supplies high-frequency power to a load 103 (for example, a plasma processing device PA) by outputting a high-frequency voltage having a fundamental frequency (the frequency of the fundamental wave) in the RF band (RF: Radio Frequency) from a high-frequency power supply device. Such a high-frequency power supply system 1 includes, for example, a first high-frequency power supply device (hereinafter referred to as the first high-frequency power supply) 10, a second high-frequency power supply device (hereinafter referred to as the second high-frequency power supply) 30, a first impedance matcher (hereinafter referred to as the first matcher) 20, a second impedance matcher (hereinafter referred to as the second matcher) 40, and a superimposed output unit 50.

[0019] The first high-frequency power supply 10 outputs a high-frequency voltage toward the load 103 via the first matcher 20. The second high-frequency power supply 30 outputs a high-frequency voltage having the same or different fundamental frequency as the first high-frequency power supply 10 toward the load 103 via the second matcher 40.

[0020] Furthermore, in this specification, the fundamental frequency of the first high-frequency power supply 10 is denoted as fundamental frequency F1 (an example of the first fundamental frequency), and the fundamental frequency of the second high-frequency power supply 30 is denoted as fundamental frequency F2 (an example of the second fundamental frequency).

[0021] It should be noted that the high-frequency power supply system 1 may not have the second high-frequency power supply 30, second matching circuit 40, and superimposed output unit 50 described above. In other words, the high-frequency power supply system 1 may have a single first high-frequency power supply 10 as the high-frequency power supply and a single first matching circuit 20 as the matching circuit, and only the high-frequency voltage (high-frequency power) output from the first high-frequency power supply 10 may be supplied to the load 103 via the first matching circuit 20. Of course, it is also possible to use three or more high-frequency power supply devices and corresponding matching circuits.

[0022] In addition to the high-frequency power supply units 10 and 30, a DC power supply unit that supplies DC voltage to the load 103 may also be provided, but this is omitted in this embodiment.

[0023] Furthermore, the high-frequency voltage output from the first high-frequency power supply 10 toward the load 103 is denoted as the forward wave voltage VF1, the high-frequency voltage reflected from the load 103 side and returning to the first high-frequency power supply 10 is denoted as the reflected wave voltage VR1, the high-frequency power output from the first high-frequency power supply 10 toward the load 103 is denoted as the forward wave power PF1, and the high-frequency power reflected from the load 103 side and returning to the first high-frequency power supply 10 is denoted as the reflected wave power PR1.

[0024] Furthermore, the high-frequency voltage output from the second high-frequency power supply 30 toward the load 103 is denoted as the forward wave voltage VF2, the high-frequency voltage reflected from the load 103 side and returning to the second high-frequency power supply 30 is denoted as the reflected wave voltage VR2, the high-frequency power output from the second high-frequency power supply 30 toward the load 103 is denoted as the forward wave power PF2, and the high-frequency power reflected from the load 103 side and returning to the second high-frequency power supply 30 is denoted as the reflected wave power PR2.

[0025] Furthermore, the power value of the forward wave power PF1 is defined as the forward wave power value pf1, the power value of the reflected wave power PR1 is defined as the reflected wave power value pr1, the power value obtained by subtracting the reflected wave power value pr1 from the forward wave power value pf1 is defined as the load-side power value pL1, the power value of the forward wave power PF2 is defined as the forward wave power value pf2, the power value of the reflected wave power PR2 is defined as the reflected wave power value pr2, and the power value obtained by subtracting the reflected wave power value pr2 from the forward wave power value pf2 is defined as the load-side power value pL2.

[0026] Furthermore, in this specification, the reflection coefficient expressed as the ratio of the reflected wave voltage to the forward wave voltage (reflected wave voltage / forward wave voltage) is denoted as ρ, and the absolute value (magnitude) of the reflection coefficient ρ is denoted as Γ. Therefore, the reflection coefficient on the first high-frequency power supply 10 side is denoted as reflection coefficient ρ1, the reflection coefficient on the second high-frequency power supply 30 side is denoted as reflection coefficient ρ2, the absolute value of the reflection coefficient on the first high-frequency power supply 10 side is denoted as reflection coefficient absolute value Γ1, and the absolute value of the reflection coefficient on the second high-frequency power supply 30 side is denoted as reflection coefficient absolute value Γ2.

[0027] Furthermore, subscripts are used as needed to indicate corresponding parts. For example, "1" is used for the system of the first high-frequency power supply 10 and the first matching circuit 20, "2" is used for the system of the second high-frequency power supply 30 and the second matching circuit 40, "g" is used for the first high-frequency power supply 10 and the second high-frequency power supply 30, and "m" is used for the first matching circuit 20 and the second matching circuit 40.

[0028] Furthermore, high-frequency power supply devices such as the first high-frequency power supply 10 and the second high-frequency power supply 30 can reduce the power value of the reflected wave by changing the frequency of the output forward wave voltage. Hereafter, this function will be referred to as "frequency matching". When frequency matching is performed, the fundamental frequency of the forward wave voltage is not constant but fluctuates, but the term fundamental frequency (fundamental frequency F1 and fundamental frequency F2 in the above example) will be used to include cases where the fundamental frequency fluctuates.

[0029] Furthermore, high-frequency power supply devices such as the first high-frequency power supply 10 and the second high-frequency power supply 30 may perform frequency modulation control to reduce the power value of reflected wave power caused by, for example, intermodulation distortion (IMD). Even when frequency modulation control is performed, the fundamental frequency of the forward wave voltage is not constant but fluctuates, but the expression fundamental frequency (fundamental frequency F1 and fundamental frequency F2 in the above example) is used.

[0030] The first high-frequency power supply 10 supplies forward wave power PF1 to the load 103 by outputting a forward wave voltage VF1 having a fundamental frequency F1. At this time, feedback control is performed so as to reduce the error between the forward wave power value pf1 and the target power value pt1. This type of power control is called constant forward wave power control (constant PF control).

[0031] Furthermore, it is possible to implement feedback control to reduce the error between the load-side power value pL1 and the target power value pt1. This type of power control is called constant load-side power control (constant PL control). However, in the following explanation, we will mainly use the case of constant traveling wave power control as an example.

[0032] The traveling wave voltage VF1 has a relatively high fundamental frequency F1 suitable for plasma generation. The fundamental frequency F1 is, for example, 40.68 MHz. Of course, the fundamental frequency F1 is not limited to 40.68 MHz; it may also be an industrial RF band frequency such as 13.56 MHz or 27.12 MHz.

[0033] The first high-frequency power supply 10 not only provides a continuous wave output with a constant forward wave power value pf1 or load-side power value pL1, but can also output a target power value that can be changed within a predetermined period. Since changing the target power value changes the amplitude of the output forward wave voltage VF1, this type of output control is referred to as amplitude modulation control in this specification. For simplicity, it is also referred to as amplitude modulation. Amplitude modulation control can also be performed with the second high-frequency power supply 30.

[0034] For example, a two-stage amplitude modulation may be performed, which involves repeatedly switching between an ON operation that outputs a forward wave power value pf1 and an OFF operation that does not output a forward wave power value pf1 at a predetermined period. Alternatively, instead of ON and OFF operations, a two-stage amplitude modulation may be performed that alternates between a first level and a second level, or a multi-stage amplitude modulation with three or more levels may be performed.

[0035] Furthermore, it is configured to allow various output controls, such as output control that gradually decreases or increases the output level, output control that gradually decreases or increases the duty cycle, frequency modulation control that changes the fundamental frequency F1, and frequency matching.

[0036] The second high-frequency power supply 30 supplies forward wave power PF2 to the load 103 by outputting a forward wave voltage VF2 having a fundamental frequency F2. The fundamental frequency F2 is the same as or different from the fundamental frequency F1.

[0037] In this case, the second high-frequency power supply 30 is subjected to feedback control (constant forward wave power control) to reduce the error between the forward wave power value pf2 and the target power value pt2. Similar to the first high-frequency power supply 10, feedback control (constant load-side power control) may also be performed to reduce the error between the load-side power value pL2 and the target power value pt2, but below we will mainly explain using the case where constant forward wave power control is performed as an example.

[0038] The traveling wave voltage VF2 has a relatively low fundamental frequency F2, suitable for ion acceleration, for example. The fundamental frequency F2 is, for example, 400 kHz. Of course, the fundamental frequency F2 is not limited to 400 kHz and may be other frequencies. For example, it may be an industrial RF band frequency such as 13.56 MHz or 27.12 MHz. Also, the fundamental frequency F2 is not necessarily limited to a frequency lower than the fundamental frequency F1, and may be the same frequency as the fundamental frequency F1 or a frequency higher than the fundamental frequency F1.

[0039] This second high-frequency power supply 30 is configured to allow various output controls, similar to the first high-frequency power supply 10.

[0040] The superimposed output unit 50 is electrically connected, for example, between the first high-frequency power supply 10 and the second high-frequency power supply 30 and the load 103.

[0041] The load 103 may be, for example, a plasma processing apparatus PA. The plasma processing apparatus PA is, for example, of a parallel plate type, with a lower electrode EL1 and an upper electrode EL2 facing each other in a chamber CH. A substrate SB to be processed may be placed on the lower electrode EL1. The first high-frequency power supply and the second high-frequency power supply are electrically connected to the lower electrode EL1 via a superimposed output unit 50. The upper electrode EL2 is electrically connected to ground potential. The chamber CH is connected to a gas supply device (not shown) via an air supply pipe and to a vacuum device (not shown) via an exhaust pipe.

[0042] If the load 103 is a plasma processing apparatus PA, the superimposed output unit 50 may be electrically connected between the first high-frequency power supply 10 and the second high-frequency power supply 30 and the lower electrode EL1 of the plasma processing apparatus PA.

[0043] The external control device 101 is a device that provides various commands (such as a command to start outputting the forward wave voltage) IS and various setting values ​​(such as a target power value) St to the high-frequency power supply system 1. It can also be used to acquire and analyze information (monitoring information) IFM such as the forward wave power value pf1 calculated by the first high-frequency power supply 10. Furthermore, it can provide various setting values ​​St, such as the time of one period of amplitude modulation, to the period start signal generator 102, which will be described later. This makes it possible to change the time of one period of amplitude modulation.

[0044] In the example shown in Figure 1, various commands IS and setting values ​​St output from the external control device 101 are transmitted to the first matching unit 20 via the first high-frequency power supply communication unit 11, which will be described later. Similarly, various commands IS and setting values ​​St output from the external control device 101 are transmitted to the second matching unit 40 via the second high-frequency power supply communication unit 21, which will also be described later. However, the various commands IS and setting values ​​St may also be transmitted directly from the external control device 101 to the first matching unit 20 and the second matching unit 40, respectively.

[0045] It should be noted that the high-frequency power supply system 1 and the load 103 (for example, the plasma processing device PA) are not limited to the configuration shown in Figure 1. For example, there are various configurations, such as one in which there is no superimposed output unit 50 that superimposes the traveling wave voltage VF1 and the traveling wave voltage VF2, and the traveling wave voltage VF1 output from the first high-frequency power supply 10 is supplied to the upper electrode EL2 (in this case, unlike in Figure 1, it is not electrically connected to ground potential) via the first matching unit 20, and the traveling wave voltage VF2 output from the second high-frequency power supply 30 is supplied to the lower electrode EL1 via the second matching unit 40. The high-frequency power supply system of this embodiment can also be used in such other configurations.

[0046] The period start signal generator 102 outputs a period start signal PS at intervals corresponding to one period of amplitude modulation.

[0047] Figure 2 illustrates an example of amplitude-modulated waveform, load information IFL acquisition period, and period start signal PS. In the example in Figure 2, the duration of one period of amplitude modulation is 2,000 μs, illustrating a case where the same waveform is repeatedly amplitude-modulated.

[0048] Here, the time on the horizontal axis represents the elapsed time from the start of the period within the duration of one period of amplitude modulation. Therefore, when amplitude modulation is repeated, it represents the time from the start of the period within the duration of the newly starting amplitude modulation period. In other words, the time at the start of the period is 0 (zero).

[0049] Furthermore, the load information acquisition period refers to a specific period during which the impedance matching devices (first matching device 20 and second matching device 40) acquire information on the reflection coefficient ρ or the load-side impedance Z necessary for impedance matching.

[0050] Figure 2(a) shows an example of the amplitude-modulated waveform of the first high-frequency power supply 10, demonstrating that the forward wave power value pf1 changes over time within one period of amplitude modulation. In this way, the first high-frequency power supply 10 can change its output level in multiple stages.

[0051] In this embodiment, the fundamental frequency F1 of the traveling wave voltage VF1 is, for example, 40.68 MHz, so it is not possible to show the exact waveform in the figure. Therefore, in Figure 2(a), the waveform of the traveling wave voltage VF1 is omitted, and the magnitude of the traveling wave power value pf1 is shown. This is the same not only in Figure 2(a) but also in other figures such as Figure 2(c).

[0052] Note that the vertical axis in Figure 2(a) may sometimes represent the magnitude of the load-side power value pL1, but for the sake of simplicity, it is shown as the magnitude of the traveling wave power value pf1. The same applies to Figure 7(a), which will be discussed later.

[0053] Figure 2(b) shows an example of the acquisition period for load information IFL (reflection coefficient ρ or load-side impedance Z) in the first matching circuit 20. In Figure 2(b), the period when the target power value of the first high-frequency power supply 10 is highest is defined as a specific period, and the figure shows the case where the first matching circuit 20 acquires load information IFL during this specific period.

[0054] The first matching unit 20 may acquire load information (reflection coefficient ρ or load-side impedance Z) IF for the entire duration of one amplitude modulation cycle and perform matching operations using the acquired load information IFL, or it may acquire load information IFL for a specific period and perform matching operations based on the acquired load information IFL. In this case, for other periods, matching operations can be performed assuming the same load information IFL as for the specific period. Of course, the specific period is not limited to the period in which the target power value of the first high-frequency power supply 10 is highest.

[0055] Figure 2(c) shows an example of the amplitude-modulated waveform of the second high-frequency power supply 30, demonstrating that the forward wave power value pf2 changes over time within one period of amplitude modulation. In this way, the second high-frequency power supply 30 can change its output level in multiple stages.

[0056] Note that while the vertical axis in Figure 2(c) may sometimes represent the magnitude of the load-side power value pL2, for the sake of simplicity, it is shown as the magnitude of the traveling wave power value pf2. The same applies to Figure 7(c), which will be discussed later.

[0057] Figure 2(d) shows an example of the acquisition period for load information IFL (reflection coefficient ρ or load-side impedance Z) in the second matching unit 40. In Figure 2(d), the period during which the target power value of the second high-frequency power supply 30 is highest is defined as a specific period, and the figure shows the case in which the second matching unit 40 acquires load information IFL during this specific period.

[0058] The second matching unit 40 may acquire load information (reflection coefficient ρ or load-side impedance Z) IFL for the entire duration of one amplitude modulation cycle and perform matching operations using the acquired load information IFL, or it may acquire load information IFL for a specific period and perform matching operations based on the acquired load information IFL. In this case, for other periods, matching operations can be performed assuming the same load information IFL as for the specific period. Of course, the specific period is not limited to the period in which the target power value of the first high-frequency power supply 10 is highest.

[0059] Furthermore, the second matching unit 40 does not need to acquire load information IFL for the entire duration of a specific period. For example, immediately after changing the target power value of the first high-frequency power supply 10, the state of the load 103 becomes unstable, so the load information IFL may be acquired after a predetermined time has elapsed since changing the target power value of the first high-frequency power supply 10.

[0060] Furthermore, it is not necessary to change the variable value of the variable element inside the matching circuit 23 for the first matching circuit throughout the entire period. For example, the variable value of the variable element may be maintained immediately after changing the target power value of the first high-frequency power supply 10.

[0061] Figure 2(e) shows an example of a period start signal PS, where the period time is set to match the duration of one period of amplitude modulation. As can be seen from Figure 2, the starting point (start time) of the amplitude modulation period can be determined by the period start signal PS.

[0062] In the example shown in Figure 2(e), the period start signal PS is a pulse signal that changes from a low level to a high level at the starting point of the amplitude modulation period. However, the relative magnitudes before and after the change are not limited to the example shown in Figure 2(e). For example, it may be a pulse signal that changes from a high level to a low level. Alternatively, it may be a signal transmitted via serial communication (for example, a bit pattern of a predetermined length) instead of a pulse signal.

[0063] By using this period start signal PS, control timings such as the output start timing of high-frequency voltages can be synchronized between receiving devices. In other words, the period start signal PS functions as a signal to control synchronization in the device to which the period start signal PS is supplied.

[0064] For example, if the devices to be synchronized are the first high-frequency power supply 10, the first matching circuit 20, the second high-frequency power supply 30, and the second matching circuit 40, then the period start signal PS should be supplied to these devices. Of course, if the devices to be synchronized are the first high-frequency power supply 10 and the first matching circuit 20, then the period start signal PS should be supplied to the first high-frequency power supply 10 and the first matching circuit 20.

[0065] The duration of one period of amplitude modulation is not fixed but can be changed. Therefore, the period start signal generator 102 is configured to allow setting the duration of one period required to generate the period start signal PS. For example, the external control device 101 can output information about the duration of one period, and this information can be stored in the memory unit (not shown) of the period start signal generator 102. It is also possible to adjust the timing of the generation of the period start signal PS. For example, the period start signal PS can be output when a command IS is received from the external control device 101.

[0066] Furthermore, in the example shown in Figure 1, the period start signal generator 102 is located outside the first high-frequency power supply 10, but it may be located in another location, such as inside the first high-frequency power supply 10.

[0067] <Outline Operation Description of High-Frequency Power Supply System 1> The traveling wave voltage VF1 (traveling wave power value pf1) output from the first high-frequency power supply 10 can be supplied to the lower electrode EL1 of the load 103 (for example, the plasma processing apparatus PA) via the first matching unit 20 and the superimposed output unit 50. The traveling wave voltage VF2 (traveling wave power value pf2) output from the second high-frequency power supply 30 can be supplied to the lower electrode EL1 of the plasma processing apparatus PA via the second matching unit 40 and the superimposed output unit 50.

[0068] In other words, in this embodiment, the superimposed output unit 50 superimposes the traveling wave voltage VF1 and the traveling wave voltage VF2 and supplies them to the lower electrode EL1. As a result, the plasma processing device PA generates plasma between the lower electrode EL1 and the upper electrode EL2. Furthermore, the first matching unit 20 performs a first matching operation to match the impedance of the first high-frequency power supply 10 side with the impedance of the load 103 side, and the second matching unit 40 performs a second matching operation to match the impedance of the second high-frequency power supply 30 side with the impedance of the load 103 side.

[0069] The first high-frequency power supply 10 and the second high-frequency power supply 30 each control their output power to achieve predetermined target power values. When the first high-frequency power supply 10 performs amplitude modulation, the target power value is changed at predetermined intervals. Similarly, when the second high-frequency power supply 30 performs amplitude modulation, the target power value is also changed at predetermined intervals.

[0070] Here, the predetermined time corresponds to the elapsed time within the duration of one period of amplitude modulation, with the time at the start of the period set to 0.

[0071] In the high-frequency power supply system 1, as the amplitude modulation output pattern becomes more complex, setting target power values ​​and other parameters also becomes more complex, requiring considerable effort. Therefore, in this embodiment, target power values ​​and other parameters are set based on the setting value information ST described later, thereby reducing the effort required for setting.

[0072] In this embodiment, the setting value information ST used in the first high-frequency power supply 10 is designated as the setting value information ST1 for the first high-frequency power supply, the setting value information ST used in the first matching circuit 20 is designated as the setting value information ST2 for the first matching circuit, the setting value information ST used in the second high-frequency power supply is designated as the setting value information ST3 for the second high-frequency power supply, and the setting value information ST used in the second matching circuit 40 is designated as the setting value information ST4 for the second matching circuit.

[0073] The following provides a detailed explanation of the first high-frequency power supply 10 and the first matching circuit 20, followed by an explanation of the setting value information ST and related matters. Note that the second high-frequency power supply 30 and the second matching circuit 40 have the same basic functions as the first high-frequency power supply 10 and the first matching circuit 20, respectively, and therefore their explanations are omitted.

[0074] <Details of the first high-frequency power supply 10> The configuration of the first high-frequency power supply 10 will be described below with reference to Figure 1.

[0075] The first high-frequency power supply 10 includes a communication unit 11 for the first high-frequency power supply, a first high-frequency voltage output unit 12, a sensor 13 for the first high-frequency power supply, a first power information calculation unit 14, a first control target switching unit 15, a first power control unit 16, and a reference clock generation unit 17 for the first high-frequency power supply. The first power control unit 16 includes a first comparison unit 161 and a first compensation unit 162.

[0076] Furthermore, the first high-frequency power supply 10 includes a first high-frequency power supply information storage unit 18 and a first high-frequency power supply setting value information output unit 19. The first high-frequency power supply information storage unit 18 stores the first high-frequency power supply setting value information ST1.

[0077] The first high-frequency power supply setting value information ST1 is information that shows the relationship between the elapsed time from the start of the period within the time of one period of amplitude modulation and the first high-frequency power supply setting value.

[0078] The first high-frequency power supply setting value information output unit 19 outputs a first high-frequency power supply setting value corresponding to the elapsed time or a command signal corresponding to the first high-frequency power supply setting value, based on the first high-frequency power supply setting value information ST1.

[0079] In the first high-frequency power supply 10, the calculation and signal processing parts can be configured, for example, with circuits such as a CPU (Central Processing Unit) and FPGA (Field Programmable Gate Array), and storage media such as memory. Furthermore, it can control the operation of each part according to a control program pre-stored in ROM (Read Only Memory), and can perform processing such as input / output, calculation, and time measurement. The first high-frequency power supply 10 is equipped with a first high-frequency power supply reference clock generation unit 17, and processing is executed at each control cycle based on the clock signal output from the first high-frequency power supply reference clock generation unit 17. In this embodiment, the frequency of the reference clock of the first high-frequency power supply reference clock generation unit 17 is 100 MHz, but is not limited to this frequency.

[0080] Furthermore, in the first matching circuit 20, the second high-frequency power supply 30, and the second matching circuit 40, which will be described later, the calculation processing and signal processing parts can be configured by, for example, a CPU, FPGA or other circuits, memory or other storage media. A reference clock generation unit is also provided. As these are the same as described above, the explanation of the first matching circuit 20, the second high-frequency power supply 30, and the second matching circuit 40 will be omitted when describing them.

[0081] The first high-frequency power supply communication unit 11 can communicate with other devices.

[0082] The first high-frequency power supply communication unit 11 can, for example, output signals generated inside the first high-frequency power supply 10 to other devices. Furthermore, the first high-frequency power supply communication unit 11 can, for example, input commands IS and various setting values ​​St output from an external control device 101 and output them to various parts within the first high-frequency power supply 10. Additionally, the first high-frequency power supply communication unit 11 can input a period start signal PS output by a period start signal generator 102 and output it to various parts within the first high-frequency power supply 10.

[0083] In addition, the first high-frequency power supply communication unit 11 can communicate with the external control device 101, the period start signal generator 102, the first matching unit 20, the second matching unit 40, etc., but a detailed explanation is omitted. In this embodiment, various types of communication methods, such as serial communication, can be used. Furthermore, communication includes the output and input of voltage signals (high level (e.g., a 5V voltage signal) and low level (e.g., a 0V voltage signal)).

[0084] The first high-frequency voltage output unit 12 outputs a traveling wave voltage VF1. At that time, the output level of the first high-frequency voltage output unit 12 is controlled based on the amplitude control signal Vcnt from the first compensation unit 162, so that it can output high-frequency power of a desired power value.

[0085] Furthermore, as described above, high-frequency power supply devices such as the first high-frequency power supply 10 and the second high-frequency power supply 30 are capable of performing frequency matching and frequency modulation control. Therefore, the first high-frequency power supply 10 sets the necessary information when performing frequency matching and frequency modulation control. The necessary information includes, for example, frequency-related information such as the fundamental frequency, offset frequency, and frequency variation range.

[0086] Furthermore, necessary information is set as first high-frequency power supply setting value information ST1, and this first high-frequency power supply setting value information ST1 is stored in the first high-frequency power supply information storage unit 18. The first high-frequency power supply setting value information output unit 19 can read the first high-frequency power supply setting value information ST1 from the first high-frequency power supply information storage unit 18 and output it to the first high-frequency voltage output unit 12. The first high-frequency voltage output unit 12 can use this first high-frequency power supply setting value information ST1 as input for control.

[0087] It is not necessary to set all the settings required for controlling the first high-frequency power supply 10 as the setting value information ST1 for the first high-frequency power supply. For example, setting values ​​used for control other than amplitude modulation control may be input from the external control device 101. Also, even if a setting value is used for amplitude modulation control, if it is a fixed value, it does not need to be set as the setting value information ST1 for the first high-frequency power supply, but can be stored separately.

[0088] This also applies to the first matching unit 20, the second high-frequency power supply 30, and the second matching unit 40, which will be described later; it is not necessary to set all the setting values ​​required for controlling the device as setting value information ST.

[0089] The first high-frequency power supply sensor 13 is located at the output terminal of the first high-frequency power supply 10 and passes the traveling wave voltage VF1 output from the first high-frequency voltage output unit 12 to the first matching unit 20. It also detects the traveling wave voltage VF1 output from the first high-frequency voltage output unit 12 and outputs the detected signal, the traveling wave voltage detection signal vf1g, to the first power information calculation unit 14. Furthermore, it detects the reflected wave voltage VR1 reflected from the load 103 side and returning to the first high-frequency power supply 10, and outputs the detected signal, the reflected wave voltage detection signal vr1g, to the first power information calculation unit 14. For example, a directional coupler can be used for the first high-frequency power supply sensor 13.

[0090] An A / D converter (not shown) may be provided between the first high-frequency power supply sensor 13 and the first power information calculation unit 14.

[0091] The first power information calculation unit 14 receives the forward wave voltage detection signal vf1g and the reflected wave voltage detection signal vr1g output from the first high-frequency power supply sensor 13, and calculates and outputs the forward wave power value pf1, the reflected wave power value pr1, the load-side power value pL1, and the absolute value of the reflection coefficient Γ1 based on the input signals. Since the calculation methods for these values ​​are well known, a detailed explanation will be omitted, but for example, they can be calculated as shown below. The calculated information can be output to an external control device 101 or the like as monitor information IFM.

[0092] Furthermore, it is also possible to calculate the forward wave power value pf1 for each output level during amplitude modulation. For example, a period start signal PS may be input to recognize the period start time of amplitude modulation. This allows the first power information calculation unit 14 to recognize the output level during amplitude modulation. The same applies to the reflected wave power value pr1, the load-side power value pL1, and the absolute value of the reflection coefficient Γ1.

[0093] (1) Power value of the traveling wave pf1 The first power information calculation unit 14 calculates the forward wave power value pf1 based on the input forward wave voltage detection signal vf1g. For example, the input forward wave voltage detection signal vf1g is squared, then unnecessary frequency component information is cut out using a low-pass filter (e.g., an IIR filter) that extracts the desired components, and then the forward wave power value pf1 is calculated by multiplying it by a constant for conversion to the forward wave power value pf1. The forward wave power value pf1 can be calculated, for example, by the forward wave voltage detection signal vf1g^2 / R (R: gain corresponding to the resistance value).

[0094] (2) Reflected wave power value pr1 The first power information calculation unit 14 calculates the reflected wave power value pr1 based on the input reflected wave voltage detection signal vr1g. For example, the input reflected wave voltage detection signal vr1g is squared, then unnecessary frequency component information is cut out using a low-pass filter (e.g., an IIR filter) that extracts the desired components, and then the reflected wave power value pr1 is calculated by multiplying by a constant for conversion to the reflected wave power value pr1. The reflected wave power value pr1 can be calculated, for example, by the reflected wave voltage detection signal vr1g^2 / R (R: gain corresponding to the resistance value).

[0095] (3) Load-side power value pL1 The first power information calculation unit 14 calculates the load-side power value pL1 based on the forward wave power value pf1 and the reflected wave power value pr1 calculated above. For example, it can be calculated by subtracting the reflected wave power value pr1 from the forward wave power value pf1.

[0096] (4) Absolute value of the reflection coefficient Γ1 The first power information calculation unit 14 calculates the absolute value of the reflection coefficient Γ1 based on the forward wave power value pf1 and the reflected wave power value pr1. The absolute value of the reflection coefficient Γ1 can be calculated, for example, by √(reflected wave power value pr1 / forward wave power value pf1).

[0097] The first control target switching unit 15 receives the forward wave power value pf1 and the load-side power value pL1 as inputs and outputs one of them to the first comparison unit 161 as the control target. The control target is determined, for example, based on a command signal IS output from the external control device 101 or the first high-frequency power supply setting value information output unit 19. If the forward wave power value pf1 is selected as the control target, forward wave power constant control is performed, and if the load-side power value pL1 is selected as the control target, load-side power constant control is performed.

[0098] The first comparison unit 161 subtracts the controlled power value (traveling wave power value pf1 or load-side power value pL1) from the target power value pt1, and outputs the subtraction result as error information Δpf1 to the first compensation unit 162. The target power value pt1 is output from the first high-frequency power supply setting value information output unit 19.

[0099] The first compensation unit 162 generates an amplitude control signal Vcnt to control the amplitude of the traveling wave voltage VF1 in accordance with the error information Δpf1 and outputs it to the first high-frequency voltage output unit 12. This allows the amplitude of the traveling wave voltage VF1 to be adjusted, and consequently, the traveling wave power value pf1 to be adjusted.

[0100] For example, if the target power value pt1 is 1,000[W] and the traveling wave power value pf1 is 950[W], then there is a 50[W] deficit compared to the target power value pt1. Therefore, the first compensation unit 162 determines and outputs the magnitude of the amplitude control signal Vcnt so that the traveling wave power value pf1 supplied to the load 103 is increased by 50[W]. Known methods such as PI control and PID control can be used to control the amplitude of the traveling wave voltage VF1 in this way.

[0101] In this case, the first high-frequency power supply setting value information output unit 19 outputs a corresponding target power value pt1 in accordance with the change in the output level during amplitude modulation, so that the forward wave power value pf1 can be changed in multiple stages.

[0102] <Details of the first matching unit 20> The first matching unit 20 includes an input terminal 20a, an output terminal 20b, a communication terminal 20c, a communication terminal 20d, a communication unit 21 for the first matching unit, a sensor 22 for the first matching unit, a matching circuit 23 for the first matching unit, a calculation unit 24 for the first matching unit, a control unit 25 for the first matching unit, and a reference clock generation unit 26 for the first matching unit.

[0103] Furthermore, the first matching unit 20 includes a first matching unit information storage unit 27 and a first matching unit setting value information output unit 28. The first matching unit information storage unit 27 stores the first matching unit setting value information ST2.

[0104] The input terminal 20a can be connected to the first high-frequency power supply 10. When the first high-frequency power supply 10 is connected, the input terminal 20a can receive power from the first high-frequency power supply 10.

[0105] A load 103 can be connected to the output terminal 20b via the superimposed output unit 50. When the load 103 is connected via the superimposed output unit 50, the output terminal 20b can supply power to the load 103 via the superimposed output unit 50.

[0106] A first high-frequency power supply 10 can be connected to the communication terminal 20c. When the first high-frequency power supply 10 is connected to the communication terminal 20c, the communication unit 21 for the first matching unit can communicate with the first high-frequency power supply 10 via the communication terminal 20c.

[0107] Other devices can be connected to the communication terminal 20d. When other devices are connected to the communication terminal 20d, the first matching unit communication unit 21 can communicate with the other devices via the communication terminal 20d. For example, it can receive the period start signal PS output by the period start signal generator 102 and output it to the first matching unit setting value information output unit 28, the first matching unit calculation unit 24, and the first matching unit control unit 25.

[0108] In this embodiment, various types of communication methods, such as serial communication, can be used for communication. Furthermore, communication also includes the output and input of voltage signals (high-level (e.g., a 5V voltage signal) and low-level (e.g., a 0V voltage signal)).

[0109] In addition, the first matching unit communication unit 21 can communicate with the external control device 101, the period start signal generator 102, the first high-frequency power supply 10, the second high-frequency power supply 30, and the second matching unit 40, but a detailed explanation will be omitted.

[0110] The first matching unit sensor 22 is located near the input terminal 20a of the first matching unit 20 and detects information for calculating the load-side impedance Z1 viewed from the input terminal 20a of the first matching unit 20 (equivalent to the output terminal of the first high-frequency power supply 10) towards the load 103, or information for calculating the reflection coefficient ρ1 at the input terminal 20a of the first matching unit 20. Since the load-side impedance Z1 and the reflection coefficient ρ1 are mutually convertible, either one may be detected.

[0111] When calculating the load-side impedance Z1, for example, a voltage detector and a current detector are used as the first matching circuit sensor 22. In this case, the voltage at the input terminal of the first matching circuit 20 is detected by the voltage detector, and a voltage detection signal v1 is output as the detection signal. In addition, the current at the input terminal 20a of the first matching circuit 20 is detected by the current detector, and a current detection signal i1 is output as the detection signal. The voltage detection signal v1 and the current detection signal i1 are output to the first matching circuit calculation unit 24.

[0112] When calculating the reflection coefficient ρ1 at the input terminal 20a of the first matching unit 20, for example, a directional coupler is used as the sensor 22 for the first matching unit. In this case, the forward wave voltage VF1 output from the first high-frequency power supply 10 is detected, and a forward wave voltage detection signal vf1m is output as the detection signal. At the same time, the reflected wave voltage VR1 reflected back from the load 103 side is detected, and a reflected wave voltage detection signal vr1m is output as the detection signal. The forward wave voltage detection signal vf1m and the reflected wave voltage detection signal vr1m are output to the calculation unit 24 for the first matching unit.

[0113] An A / D converter (not shown) may be provided between the first matching unit sensor 22 and the first matching unit calculation unit 24.

[0114] The first matching circuit 23 is provided between the first matching sensor 22 and the superimposed output unit 50. This first matching circuit 23 is equipped with a variable element, such as a variable capacitor (also called a variable condenser) whose capacitance can be changed, and the variable value of the variable element (capacitance in the case of a variable capacitor, or inductance in the case of a variable inductor) is changed by a command from the first matching control unit 25, which will be described later, so that the load-side impedance Z1 viewed from the input terminal of the first matching unit 20 to the load 103 can be adjusted. In some cases, a variable inductor is provided as the variable element. Furthermore, a drive circuit (not shown) is provided to change the capacitance of the variable element by a command from the first matching control unit 25.

[0115] In addition to variable elements, inductors with fixed inductance are often included. Furthermore, capacitors with fixed capacitance may also be present.

[0116] Such a matching circuit 23 for the first matching circuit often uses a matching circuit such as an inverted L-type (also called an L-type) or π-type.

[0117] There are various types of variable capacitors. For example, there are variable capacitors that change capacitance by changing the distance between electrodes. There are also variable capacitors that change the overall capacitance by connecting multiple capacitors in parallel with a switch and changing the state of the switch (ON / OFF). Thus, the types of variable capacitors are not limited.

[0118] The first matching unit calculation unit 24 calculates the reflection coefficient ρ1 or the load-side impedance Z1 based on the information output from the first matching unit sensor 22, and outputs it to the first matching unit control unit 25 as load information IFL for the first matching unit 20. This reflection coefficient ρ1 and load-side impedance Z1 are load information IFL representing the state of the load. The first matching unit calculation unit 24 may also be equipped with a filter on the input side to remove unwanted signal components (e.g., harmonic components). The filter type can be selected as appropriate.

[0119] Furthermore, the calculated load information IFL may be output externally via the first matching unit communication unit 21. In Figure 1, an example is shown in which the load information IFL is transmitted to the external control device 101 via the first matching unit communication unit 21 and the first high-frequency power supply communication unit 11, but it may also be transmitted to the external control device 101 directly from the first matching unit communication unit 21 without going through the first high-frequency power supply communication unit 11.

[0120] The reflection coefficient ρ1 can be calculated, for example, from the reflected wave voltage detection signal vr1m / forward wave voltage detection signal vf1m. The load side impedance Z1 can be calculated, for example, from the voltage detection signal v1 / current detection signal i1. Furthermore, the load side impedance Z1 can be calculated, for example, based on the magnitude of the voltage detection signal v1, the magnitude of the current detection signal i1, and the phase difference θ between the voltage detection signal v1 and the current detection signal i1. Since the methods for calculating the reflection coefficient ρ1 and load side impedance Z1 are well known, a detailed explanation is omitted.

[0121] Furthermore, since the reflection coefficient ρ1 and the load-side impedance Z1 are mutually convertible, in order to simplify the explanation, the calculation unit 24 for the first matching circuit may be described in terms of either the reflection coefficient ρ1 or the load-side impedance Z1 only in the following explanation.

[0122] The first matching circuit control unit 25 uses the load information IFL from the first matching circuit 20 output from the first matching circuit calculation unit 24 to output a command signal to control the variable value of the variable element inside the first matching circuit 23 so that the absolute value Γ1 of the reflection coefficient ρ1 approaches the target absolute value Γ0 (usually 0). In other words, it outputs a command signal to control the variable value of the variable element inside the first matching circuit 23 so that the load-side impedance Z1 becomes the complex conjugate of the output impedance Z0 of the first high-frequency power supply 10. For example, if the variable element in the first matching circuit 23 is a variable capacitor, it outputs a command signal to control its capacitance. More specifically, for example, it calculates the capacitance of the variable capacitor that is predicted to bring the absolute value Γ1 of the reflection coefficient ρ1 closest to the target absolute value Γ0, and outputs a command signal to the drive circuit that drives the variable capacitor so that its capacitance is that value.

[0123] When performing the control described above, the first matching unit control unit 25 can use the setting value information ST2 for the first matching unit 20 output from the first matching unit setting value information output unit 28 or the command signal corresponding to said setting value information ST2. In addition, it can synchronize with other devices using the period start signal PS.

[0124] <About the setting value information ST> The ST setting information allows for a variety of configurations. Below, we will explain the ST setting information and related matters using several configuration examples.

[0125] (1) Example of setting value information ST (Part 1) Figure 3 is a diagram illustrating an example of setting value information.

[0126] Figure 3(a) shows an example of the setting value information ST1 for the first high-frequency power supply, corresponding to Figure 2(a). The setting value information ST1 for the first high-frequency power supply includes the following setting items: "No." indicating the order, duration [μs], and target power value [W] for the first high-frequency power supply.

[0127] Figure 3(b) shows an example of the first matching device setting value information ST2 corresponding to Figure 2(b). The first matching device setting value information ST2 shows the relationship between the order "No.", the duration [μs], and the acquisition period of load information IFL.

[0128] Figure 3(c) shows an example of the setting value information ST3 for the second high-frequency power supply, corresponding to Figure 2(c). The setting value information ST3 for the second high-frequency power supply includes the following setting items: "No." indicating the order, duration [μs], and target power value [W] for the second high-frequency power supply.

[0129] Figure 3(d) shows an example of the setting value information ST4 for the second matching unit, corresponding to Figure 2(d). The setting value information ST4 for the second matching unit shows the relationship between the order "No.", the duration [μs], and the acquisition period of the load information IFL.

[0130] Here, when the load information IFL acquisition period is "1", it indicates the period during which load information IFL is acquired, and when it is "0", it indicates the period during which load information IFL is not acquired.

[0131] Note that the order of the columns in Figures 3(a) to 3(d) is not significant. Also, the information constituting the setting value information ST is read sequentially by the corresponding setting value information output units 19 and 28, so the "No." information is not essential. This concept is also true hereafter.

[0132] Thus, the setting value information ST can be represented in a table format. The setting value information ST is composed of multiple sets of information, as shown by the dashed line in Figure 3(a), for example, and one set of information shown by the dashed line in Figure 3(a) includes information on elapsed time and information on at least one setting item (for example, target power value).

[0133] The setting values ​​stored as setting value information ST are read sequentially by the corresponding setting value information output units (for example, the setting value information output unit 19 for the first high-frequency power supply, the setting value information output unit 28 for the first matching unit), and the corresponding processing is performed.

[0134] In the example shown in Figure 3(a), the target power value is stored as the setting value information ST1 for the first high-frequency power supply. Therefore, the setting value information output unit 19 for the first high-frequency power supply outputs the setting value of the target power value corresponding to the elapsed time to the first comparison unit 161. For example, the information of 100W, which is the setting value of the target power value of the first high-frequency power supply 10 for period No. 2, is output to the first comparison unit 161 as the target power value pt1. This allows the first high-frequency power supply 10 to control the power value it outputs.

[0135] Therefore, by using the information from the setting value information ST1, the first high-frequency power supply 10 can perform amplitude modulation as shown in Figure 2(a). Furthermore, by using the information from the setting value information ST2, the first matching unit 20 can acquire load information IFL at the appropriate timing.

[0136] Thus, even when performing complex amplitude modulation as shown in Figure 2, setting the set value (target power value, etc.) is easy, as shown in Figure 3, because it only requires setting a set value (target power value, etc.) corresponding to the elapsed time from the start of the period within the duration of one period of amplitude modulation.

[0137] As shown in Figure 2, amplitude modulation often involves the repetition of the same waveform. In this case, the setting value information ST shown in Figures 3(a) to 3(d) can be used repeatedly. That is, it is sufficient to set the setting value information ST for one period of amplitude modulation.

[0138] (2) Example of setting value information ST (Part 2) Figure 4 is a diagram illustrating other examples of setting value information.

[0139] Figure 4(a) shows another example of the setting value information ST1 for the first high-frequency power supply, corresponding to Figure 2(a).

[0140] Figure 4(b) also shows another example of the setting value information ST2 for the first matching unit, corresponding to Figure 2(b).

[0141] Furthermore, Figure 4(c) shows another example of the setting value information ST3 for the second high-frequency power supply, corresponding to Figure 2(c).

[0142] Furthermore, Figure 4(d) shows another example of the setting value information ST4 for the second matching unit, corresponding to Figure 2(d).

[0143] These Figures 4(a) to 4(d) show the setting value information in Figures 3(a) to 3(d) converted from duration [μs] to elapsed time [μs].

[0144] In other words, while Figure 3 uses duration as the time element, it can also be expressed as elapsed time, as in Figure 4. For example, in Figure 3(a), the duration of No. 1 is 100 μs and the duration of No. 2 is 100 μs, so the elapsed time at the start of execution of No. 3 is 200 μs. Therefore, the elapsed time at the start of execution of No. 3 in Figure 4(a) is 200 μs. Also, as mentioned above, in the example in Figure 2, the time of one period of amplitude modulation is 2,000 μs, so the elapsed time at the start of execution of No. 20 in Figure 4(a) is 1,900 μs, and the duration of No. 20 is 100 μs.

[0145] As can be seen from the above, time can be expressed as duration or elapsed time, but in either case, the set value information ST shown in Figures 3 and 4 shows the relationship between the elapsed time from the start of the period and the set value within the time of one period of amplitude modulation.

[0146] The operation of each device will be explained below assuming that the moment the period start signal PS is input is considered the starting point of the period within the time period of one amplitude modulation period (elapsed time is 0).

[0147] In the examples shown in Figures 3 and 4, the first matching unit 20 acquires load information IFL during periods No. 9 and No. 13. Therefore, the first matching unit setting value information output unit 28 outputs a command signal to the first matching unit control unit 24 during periods No. 9 and No. 13 to adopt the load information IFL output from the first matching unit calculation unit 24. The first matching unit control unit 24 uses the adopted load information IFL to perform matching operations so that the absolute value Γ1 of the reflection coefficient ρ1 approaches the target reflection coefficient absolute value Γ0 (usually 0).

[0148] In this case, even outside of periods No. 9 and No. 13, matching operations are performed using the load information IFL acquired during periods No. 9 and No. 13. Furthermore, the examples shown in Figures 3 and 4 indicate that the second matching unit 40 acquires load information IFL during period No. 1. Therefore, the second matching unit 40 acquires load information IFL during period No. 1 and performs matching operations using the acquired load information IFL. This control is the same as that of the first matching unit 20, so the explanation is omitted.

[0149] By doing so, control corresponding to Figure 2 can be performed.

[0150] Here, the setting value information ST shown in Figures 3 and 4 can be simplified. For example, in Figures 3(b) and 4(b), the setting value for the load information acquisition period for periods No. 1 to No. 8 is the same 0, so it can be combined into one. Specifically, in Figure 3(b), Set the duration of period No. 1 to 800 μs and the period for acquiring shipment information to 0. Set the duration of period No. 2 to 100 μs and the period for acquiring shipment information to 1. Set the duration of period No. 3 to 300 μs and the period for acquiring shipment information to 0. Set the duration of period No. 4 to 100 μs and the period for acquiring shipment information to 1. The duration of period No. 5 can be set to 700 μs, and the period for acquiring shipment information can be set to 0.

[0151] In Figure 4(b), the same concept can be used to group together parts with the same settings.

[0152] However, the setting value information ST shown in Figures 3 and 4 has not been simplified in order to clarify its correspondence with Figure 2.

[0153] In other words, the setting value information ST2 for the first matching unit shown in Figures 3(b) and 4(b) is set at the same time interval as the setting value information ST1 for the first high-frequency power supply shown in Figures 3(a) and 4(a). Similarly, the setting value information ST4 for the second matching unit shown in Figures 3(d) and 4(d) is set at the same time interval as the setting value information ST3 for the second high-frequency power supply shown in Figures 3(c) and 4(c).

[0154] This is because, in the examples shown in Figures 3 and 4, the acquisition period of load information IFL in the impedance matching devices (first matching device 20, second matching device 40) is related to the target power values ​​of the corresponding high-frequency power supply devices (first high-frequency power supply 10, second high-frequency power supply 30).

[0155] In such cases, as shown in Figures 3 and 4, the time interval for the impedance matching device setting information (setting value information for the first matching device, setting value information for the second matching device) may be set to the same time interval as the setting value information (setting value information for the first high-frequency power supply, setting value information for the second high-frequency power supply) for the corresponding high-frequency power supply devices (first high-frequency power supply 10, second high-frequency power supply 30). In this way, the acquisition period for load information IFL in the impedance matching devices (first matching device 20, second matching device 40) can be easily set.

[0156] (3) Example of setting value information (Part 3) Figure 5 is a diagram illustrating other examples of setting value information.

[0157] Figure 5(a) shows an example of the setting value information ST1 for the first high-frequency power supply, corresponding to Figure 2(a). Figure 5(b) is the same as Figure 3(a).

[0158] Figure 5(b) shows another example of the setting value information ST2 for the first matching unit, corresponding to Figure 2(b). This Figure 5(b) is the same as Figure 5(a).

[0159] Figure 5(c) shows an example of the setting value information ST3 for the second high-frequency power supply, corresponding to Figure 2(c). This Figure 5(c) is the same as Figure 5(c).

[0160] Figure 5(d) shows another example of the setting value information ST4 for the second matching unit, corresponding to Figure 2(d). This Figure 5(d) is the same as Figure 5(c).

[0161] As described above, if the acquisition period of load information IFL is related to the target power value, the setting value information ST1 for the first high-frequency power supply can be used as the setting value information ST2 for the first matching circuit. Similarly, the setting value information ST3 for the second high-frequency power supply can be used as the setting value information ST4 for the second matching circuit.

[0162] In such cases, the first and second matching systems can separately store the relationship between the target power value and the acquisition period of load information IFL. For example, the first matching unit 20 can recognize a target power value of 800W for the first high-frequency power supply 10 as the period for acquiring load information. Alternatively, the system can automatically determine which period among the set value information has the highest target power value to use as the load information acquisition period.

[0163] Of course, instead of using the period with the highest target power value as the load information acquisition period, a predetermined range (for example, the period when the target power value is 600W or higher) may be used as the load information acquisition period.

[0164] The control in each device is the same as in Figures 3 and 4, so the explanation is omitted. Note that in Figure 5, time is represented as duration, but it may also be represented as elapsed time.

[0165] As shown in Figure 5, it is only necessary to copy the setting value information ST (setting value information ST1 for the first high-frequency power supply, setting value information ST3 for the second high-frequency power supply) of the corresponding high-frequency power supply devices (first high-frequency power supply 10, second high-frequency power supply 30). Furthermore, it becomes possible to perform control based on the target power value information of the high-frequency power supply devices (first high-frequency power supply 10, second high-frequency power supply 30).

[0166] (4) Example of setting value information (Part 4) Figure 6 is a diagram illustrating other examples of setting value information.

[0167] Figure 6(a) shows the first high-frequency power supply setting information ST1 shown in Figure 3(a), with the addition of fundamental frequency and control method as setting items.

[0168] Figure 6(b) is the same as the setting value information ST2 for the first matching unit shown in Figure 3(b). Therefore, the explanation is omitted.

[0169] Figure 6(c) shows the setting value information ST3 for the second high-frequency power supply shown in Figure 3(c), with the addition of fundamental frequency and control method as setting items.

[0170] Figure 6(d) is the same as the setting value information ST4 for the second matching unit shown in Figure 3(d). Therefore, the explanation is omitted.

[0171] As shown in Figures 6(a) and 6(c), in addition to the "No." and duration [μs] setting items in the setting value information ST, multiple types of settings can be set. In the case of Figure 6, in both Figure 6(a) and Figure 6(c), the target power value, fundamental frequency, and control method are the three setting items other than "No." and duration [μs]. Note that in the control method, "PL" indicates constant load-side power control, and "PF" indicates constant traveling wave power control.

[0172] In the example shown in Figure 6(a), the target power value for period No. 1 is 0W, so the first high-frequency power supply 10 does not output high-frequency power.

[0173] Subsequently, during period No. 2, high-frequency power is output from the first high-frequency power supply 10 under the conditions of a target power value of 100W, a fundamental frequency of 40.68MHz, and a control method of constant load-side power control. This constant load-side power control continues until period No. 3. During period No. 4, the control method becomes constant forward-wave power control, and this constant forward-wave power control continues until period No. 20.

[0174] Subsequently, during period No. 8, the fundamental frequency changes from 40.68MHz to 40.78MHz. The fundamental frequency remains 40.78MHz until period No. 14, but returns to 40.68MHz during period No. 15. After that, the fundamental frequency remains 40.68MHz until period No. 20.

[0175] After the period for No. 20 ends, it returns to No. 1, and the setting value information for the first high-frequency power supply is used repeatedly. Of course, this does not apply if the amplitude modulation control is terminated, or if the setting value information is changed.

[0176] Furthermore, the target power value information in the first high-frequency power supply setting value information ST1 shown in Figure 6(a) is read out from the first high-frequency power supply information storage unit 18 as the target power value pt1 in Figure 1.

[0177] The fundamental frequency information in the first high-frequency power supply setting value information ST1 shown in Figure 6(a) is read out from the first high-frequency power supply information storage unit 18 as information such as the frequency information FR in Figure 1. This frequency information FR is output, for example, to the first high-frequency voltage output unit 12.

[0178] The control method information in the first high-frequency power supply setting value information ST1 shown in Figure 6(a) is read from the first high-frequency power supply information storage unit 18 as the control method information in Figure 1. This control method information is output, for example, to the first control target switching unit 15.

[0179] In the example shown in Figure 6(c), during period No. 1, high-frequency power is output from the second high-frequency power supply 30 under the conditions that the target power value is 800W, the fundamental frequency is 400kHz, and the control method is constant load-side power control.

[0180] Subsequently, during the No. 2 period, the target power value was changed to 500W, the fundamental frequency to 410kHz, and the control method to constant forward wave power control.

[0181] Subsequently, during period No. 3, the target power value is changed to 0W, the fundamental frequency to 400kHz, and the control method to constant forward wave power control. However, since the target power value is 0W, the second high-frequency power supply 30 does not output high-frequency power.

[0182] After the period for No. 3 ends, the process returns to No. 1, and the setting value information ST3 for the second high-frequency power supply is used repeatedly. Of course, this does not apply if the amplitude modulation control is terminated, or if the setting value information ST is changed.

[0183] The information in the setting value information ST3 for the second high-frequency power supply shown in Figure 6(c) is read from the information storage unit 29 for the second high-frequency power supply. This is the same as in the case of the first high-frequency power supply 10 shown in Figure 6(a), so the explanation is omitted.

[0184] In this way, by setting the appropriate settings and values ​​for each device, it becomes possible to perform a wide range of control operations.

[0185] Of course, other settings can be configured besides those listed above. For example, various settings can be configured, such as command values ​​for frequency matching and command values ​​for frequency modulation control to suppress IMD.

[0186] (5) Example of setting value information (Part 5) Figure 7 illustrates another example of the amplitude-modulated waveform, the acquisition period of load information IFL, and the period start signal PS. Similar to the example in Figure 2, the duration of one period of amplitude modulation is 2,000 μs, illustrating a case where the amplitude modulation of the same waveform is repeated.

[0187] As shown in Figures 7(a) and 7(b), Figure 7 shows an example in which the start time of one cycle of amplitude modulation of the first high-frequency power supply 10 and the start time of one cycle of amplitude modulation of the first matching unit 20 are set later than the time when the cycle start signal PS is input, compared to Figure 2.

[0188] Furthermore, Figure 7 shows an example of setting the power ramp time when changing the target power value of the high-frequency power in the second high-frequency power supply 30, as shown in Figure 7(c). The power ramp time for the target power value is the time it takes to slowly change the target power value in a ramp-like manner.

[0189] Furthermore, as shown in Figure 7(d), the acquisition period of load information IFL in the second matching unit 40 is matched to the power ramp time setting of the second high-frequency power supply 30.

[0190] Figure 8 is a diagram illustrating other examples of setting value information. This Figure 8 is an example of setting value information ST for each device corresponding to Figure 7.

[0191] Figure 8(a) shows an example of the setting value information ST1 for the first high-frequency power supply.

[0192] Figure 8(a) shows the result of setting a delay time (200 μS) to the duration of period No. 1 of the first high-frequency power supply setting information ST1 shown in Figure 6(a).

[0193] A positive delay time indicates that the start time of amplitude modulation in the first high-frequency power supply 10 is later than the time the period start signal PS was input. A negative delay time indicates the opposite.

[0194] Therefore, the start time of one cycle of amplitude modulation of the first high-frequency power supply 10 is 200 μS later than the time when the cycle start signal PS is input. Then, the amplitude modulation of the first high-frequency power supply 10 is performed based on the information from period No. 2 to No. 21. After No. 21, it returns to No. 2, so from the second cycle of amplitude modulation onwards, the amplitude modulation is performed based on the information from period No. 2 to No. 21 without any delay time.

[0195] Figure 8(b) shows an example of the setting value information ST2 for the first matching unit. In Figure 8(b), the delay time is set in accordance with the setting value information ST1 for the first high-frequency power supply in Figure 8(a).

[0196] Therefore, processing in the first matching unit 20 starts 200 μS later than the time the period start signal PS is input and is performed based on the information from period No. 2 to No. 21. After No. 21, it returns to No. 2, so from the second period of amplitude modulation, amplitude modulation is performed without delay based on the information from period No. 2 to No. 21.

[0197] Figure 8(c) shows an example of the setting value information ST3 for the second high-frequency power supply. This Figure 8(c) is the same as the setting value information ST3 for the second high-frequency power supply shown in Figure 6(c), but with the addition of power lamp time as a setting item.

[0198] As shown in Figure 8(c), since power ramp times are set for periods No. 1 and No. 2 of the second high-frequency power supply 30, the amplitude modulation waveform of the second high-frequency power supply 30 will be as shown in Figure 7(c).

[0199] Figure 8(d) shows an example of the setting value information ST4 for the second matching unit. In Figure 8(d), the acquisition period for load information IFL is set to correspond to the power ramp time set in the setting value information ST3 for the second high-frequency power supply in Figure 8(c).

[0200] In other words, the duration of period No. 1 of the second high-frequency power supply 30 is 250 μs, but since the power lamp time is set to 100 μs, the target power value of 800 W is reached 150 μs after 100 μs has elapsed since the start of period No. 1. Therefore, in the setting value information ST4 for the second matching unit, the duration of period No. 1 is set to 100 μs, and load information IFL is not acquired during this period. Also, the duration of period No. 2 is set to 150 μs, and load information IFL is acquired during this period.

[0201] Since load information IFL is not acquired during the subsequent period, the duration of period No. 3 is set to 1750 μs, and load information IFL is not acquired during this period.

[0202] As can be seen from Figures 7 and 8, in the first high-frequency power supply 10 and the first matching unit 20, which have a delay time set, the starting point of the period within the time of one period of amplitude modulation is delayed by the amount of the delay time. Therefore, the first high-frequency power supply 10 and the first matching unit 20 do not use the time when the period start signal PS is input as the starting point of the period within the time of one period of amplitude modulation, but rather use a time that is shifted by the amount of the delay time as the starting point.

[0203] In other words, the starting point of a period within the duration of one amplitude modulation period is defined as the time at which the period start signal PS, which is generated at each cycle of amplitude modulation, is input, or the time at which the period start signal PS is input plus a delay time.

[0204] The above example shows how to set a delay time for the first high-frequency power supply 10 and the first matching circuit 20, but a delay time may also be set for the second high-frequency power supply 30 and the second matching circuit 40.

[0205] Furthermore, although the above example shows setting the power ramp time for the second high-frequency power supply 30, the power ramp time may also be set for the first high-frequency power supply 10. Of course, the first matching unit 20 should set the setting value information ST2 for the first matching unit, taking into account the power ramp time set for the first high-frequency power supply 10.

[0206] (6) Example of setting value information (Part 6) Figure 9 shows another example of the amplitude modulation waveform of the first high-frequency power supply 10.

[0207] Figure 10 shows an example of the setting value information ST1 for the first high-frequency power supply, corresponding to Figure 9.

[0208] Figure 10 shows that the number of repetitions can be set for a consecutive set of information in the setting value information ST1.

[0209] In Figure 9, during the initial period of one amplitude modulation cycle, the target power value changes from 1000W → 900W → 1000W → 900W. That is, the part where it changes from 1000W to 900W is repeated twice. Therefore, as shown in Figure 10, the number of repetitions for this period should be set to 2. This makes it easier to set the target power value.

[0210] In contrast, the period during which the target power value changes from 800W to 700W does not involve repetition, so the number of repetitions is 1. Note that if the number of repetitions is 1, the number of repetitions can be omitted.

[0211] Furthermore, in Figure 9, the waveform for the period from 0 to 1,400 μs elapsed from the start of the period within one period of amplitude modulation is repeated even in the period from 1,400 to 2,800 μs. Therefore, the number of repetitions for the information for the period from 0 to 1,400 μs elapsed should be set to 2.

[0212] Similarly, for information obtained during the period of 2,800 to 3,600 μs, the number of repetitions should be set to 2.

[0213] Thus, the number of sets of information to be repeated is arbitrary. For example, you could set the number of repetitions for two sets of information, or for three sets of information.

[0214] Furthermore, the number of repetitions may be set for information that includes other information along with the information for which the number of repetitions has been set.

[0215] Furthermore, although not shown in Figures 9 and 10, you may also set the number of repetitions for the entire set of information.

[0216] As can be seen from the example above, being able to set the number of repetitions for information with a set number of repetitions and for other information makes it easy to create long-term setting information. This is extremely useful in plasma processing processes, where such repetition patterns are numerous.

[0217] Of course, the above concept also applies to other setting value information (setting value information ST2 for the first matching unit, setting value information ST3 for the second high-frequency power supply, and setting value information ST4 for the second matching unit).

[0218] As explained above, in this embodiment, when performing amplitude modulation, setting value information ST for each device is used, making it easy to set the amplitude modulation.

[0219] <Effects of not using the setting value information ST for high-frequency power supply devices> As described above, in recent years, advancements in plasma processing processes have led to more complex amplitude modulation waveforms, such as those involving amplitude modulation with three or more level changes. Consequently, the amount of information transmitted from the external control device 101 to the high-frequency power supply unit is increasing. As a result, the time required to transmit high-frequency power supply setting value information from the external control device 101 to the high-frequency power supply unit is increasing (for example, to about 1 ms). This makes it impossible to meet the requirement to change setting values ​​such as target power values ​​in a short time (for example, within a few hundred μs).

[0220] For example, when amplitude modulation is performed using a high-frequency power supply (e.g., a first high-frequency power supply 10, a second high-frequency power supply 30), it is necessary to set the following (i) to (iii) values ​​at predetermined intervals. These setting values ​​are transmitted from the external control device 101 to the high-frequency power supply in accordance with the progress of the plasma processing process.

[0221] However, this transmission cannot be made in advance with sufficient time to spare; it must be sent immediately before the time when the target power value or other settings are changed.

[0222] (i) Information on the frequency (reciprocal of the period time) or period time for a given period (ii) Information on target power values ​​for each level (iii) Information on duty cycle

[0223] For example, when performing amplitude modulation as described in Figures 9 and 10, the periods No. 1 and No. 2 are predetermined periods, and information on the five setting values ​​(A) to (C) below must be transmitted from the external control device 101 to the high-frequency power supply devices 10 and 30 immediately before the start of period No. 1.

[0224] Although periods No. 1 and No. 2 are repeated twice, the process automatically repeats until the setting information for the next predetermined period is transmitted from the external control device 101 to the high-frequency power supply devices 10 and 30. Therefore, no further transmission is required during the second repetition. As a result, the total time, including the repetition of the predetermined periods (periods No. 1 and No. 2), is 400 μs.

[0225] (A) Frequency (reciprocal of period time) or period time over a specified period The frequency is 5,000 Hz, and the period time is 200 μs. (B) Information on target power values Target power value for period No. 1: 1,000W Target power value for period No. 2: 900W (C) Duty cycle information Duration of period No. 1 / (Duration of period No. 1 + Duration of period No. 2): 50% Duration of period No. 2 / (Duration of period No. 1 + Duration of period No. 2): 50%

[0226] Next, setting No. 3 and No. 4 as predetermined periods (number of repetitions: 1), it is necessary to transmit information on a total of 5 setting values ​​from the external control device 101 to the high-frequency power supply devices 10 and 30 just before the start of the period for No. 3.

[0227] As mentioned above, the total time for the previous predetermined period (periods No. 1 and No. 2) is 400 μs. Therefore, within this 400 μs time, it is necessary to transmit information on a total of 5 setting values ​​from the external control device 101 to the high-frequency power supply devices 10 and 30. However, with the current level of technology, it is difficult to complete the transmission in such a short time.

[0228] Next, with periods No. 5 and No. 6 set as predetermined periods (number of repetitions: 3), it is necessary to transmit the set value information (information on a total of 5 set values) from the external control device 101 to the high-frequency power supply devices 10 and 30 just before the start of period No. 5. However, since the total time of the previous predetermined period (periods No. 3 and No. 4) is 400 μs, it is difficult to complete the transmission of the set value information within this time.

[0229] Subsequently, the process proceeds in the following order: Period No. 1 and No. 2 (number of repetitions: 2) → Period No. 3 and No. 4 (number of repetitions: 1) → Period No. 5 and No. 6 (number of repetitions: 3) → Period No. 7 and No. 8 (number of repetitions: 2) → Period No. 9 and No. 10 (number of repetitions: 2) → Period No. 7 and No. 8 (number of repetitions: 2) → Period No. 9 and No. 10 (number of repetitions: 2).

[0230] However, since the total time for each period is short, it is difficult to complete the transmission of the setting value information.

[0231] Therefore, if the setting value information ST for the high-frequency power supply is not used, it is difficult to perform amplitude modulation as described in Figures 9 and 10.

[0232] In contrast, when using setting value information ST for high-frequency power supply devices, the setting value information ST1 and ST3 necessary for amplitude modulation can be pre-set in the high-frequency power supply devices 10 and 30 when amplitude modulation is performed in the high-frequency power supply devices 10 and 30. Therefore, even amplitude modulation that requires changing setting values ​​in a shorter time than the time required to transmit various setting value St from the external control device 101 to the high-frequency power supply devices 10 and 30 can be realized. For example, even complex amplitude modulation as described in Figures 9 and 10 can be realized.

[0233] In recent years, complex amplitude-modulated waveforms have been required. Furthermore, there is a demand for rapidly changing setting values ​​such as target power values. Even in such cases, as described above, by using the setting value information ST for high-frequency power supplies, it becomes possible to rapidly change setting values ​​such as target power values ​​in the high-frequency power supply. Therefore, the effects obtained in this embodiment are extremely useful.

[0234] <Regarding the setting value information ST for impedance matching devices> An impedance matching device performs impedance matching according to the output state of the high-frequency power supply. Therefore, it is conceivable that the high-frequency power supply output an acquisition timing signal to the impedance matching device to specify the period during which load information should be acquired.

[0235] However, as described above, depending on the communication status between the high-frequency power supply unit and the external control unit, there may be cases where the high-frequency power supply unit cannot perform processing properly.

[0236] For example, the following (1) to (3) are possible. (1) If the target power value is changed by an external control device, the acquisition timing signal may be shifted. (2) The signal line used to transmit the acquisition timing signal may be affected by noise and may malfunction. (3) Depending on the surrounding environment, such as the installation location of the high-frequency power supply and impedance matching unit, it may not be possible to connect the signal lines.

[0237] In this situation, it is undesirable for the high-frequency power supply to output an acquisition timing signal to the impedance matcher to specify the period during which load information should be acquired, as this increases the computational load on the high-frequency power supply. However, if the impedance matcher uses set value information ST, there is no need for the high-frequency power supply to output an acquisition timing signal to the impedance matcher to specify the period during which load information should be acquired.

[0238] The above example shows the use of setting value information ST in both the high-frequency power supply and the impedance matcher. However, the high-frequency power supply may not use setting value information ST, while the impedance matcher may use setting value information ST.

[0239] As a modified example of the embodiment, the high-frequency power supply system 1A may be configured as shown in Figure 11. Figure 11 is a diagram showing the configuration of the high-frequency power supply system 1A according to a modified example of the embodiment.

[0240] Figure 11 shows an example where the high-frequency power supply does not use the set value information ST, but the impedance matching circuit does. In Figure 11, the high-frequency power supply consists of a first high-frequency power supply 10A and a second high-frequency power supply 30A, and the impedance matching circuit consists of a first matching circuit 20 and a second matching circuit 40.

[0241] Unlike the first high-frequency power supply 10 shown in Figure 2, the first high-frequency power supply 10A shown in Figure 11 does not have a first high-frequency power supply information storage unit 18, a first high-frequency power supply setting value information ST1, and a first high-frequency power supply setting value information output unit 19. Therefore, the first high-frequency power supply 10A shown in Figure 11 receives a target power value pt1 (a type of various setting value St) output from the external control device 101 via the first high-frequency power supply communication unit 11, and outputs the input target power value pt1 to the first comparison unit 161.

[0242] Furthermore, the first high-frequency power supply 10A shown in Figure 11 receives the command signal IS output from the external control device 101 via the first high-frequency power supply communication unit 11 and outputs the input command signal IS to the first control target switching unit 15. The command signal IS here is a type of command signal IS, which is a signal for switching the control target. The first control target switching unit 15 determines the control target based on the command signal IS. This enables constant forward wave power control or constant load-side power control.

[0243] The first high-frequency power supply 10A shown in Figure 11 also receives frequency information FR (a type of various setting value St) from the external control device 101 as needed. If the input information is frequency information FR, it is output to, for example, the first high-frequency voltage output unit 12.

[0244] The other configurations of the first high-frequency power supply 10A shown in Figure 11 are the same as those of the first high-frequency power supply 10 described in Figure 2.

[0245] Furthermore, the second high-frequency power supply 30A shown in Figure 11 has the same basic function as the first high-frequency power supply 10A shown in Figure 11, so its explanation will be omitted.

[0246] Thus, even when an impedance matching device uses set value information ST, the high-frequency power supply does not necessarily have to use set value information ST.

[0247] [Note 1] An impedance matching device provided between a high-frequency power supply that supplies high-frequency power to a load and the load, It has a variable element inside, and is a matching circuit that can change the impedance as seen from the input terminal of the impedance matching device, A matching unit setting value information output unit outputs a matching unit setting value corresponding to the elapsed time or a command signal corresponding to the matching unit setting value, based on matching unit setting value information that shows the relationship between the elapsed time from the start of the period within the time period of one period of amplitude modulation when the high-frequency power supply performs amplitude modulation control, A control unit that outputs a control signal to the matching circuit based on the matching circuit setting value or command signal output from the matching circuit setting value information output unit, It is equipped with, The matching unit output unit outputs a signal generated at each time period of the amplitude modulation, with the starting point being the time when a period start signal common to the high-frequency power supply is input, or the time obtained by adding a delay time to the time when the period start signal is input. Impedance matching device. <Effects> In the present invention, the time at which a period start signal, generated for each period of amplitude modulation, is input, or the time obtained by adding a delay time to the time at which the period start signal is input, is set as the starting point of the period within the time of one period of amplitude modulation. Based on matching circuit setting value information that shows the relationship between the elapsed time from this starting point and the matching circuit setting value, the matching circuit setting value corresponding to the elapsed time or a command signal corresponding to the matching circuit setting value can be output. Since the period start signal is shared with the high-frequency power supply, control can be performed in accordance with the pulse modulation of the high-frequency power supply based on the matching circuit setting information. Therefore, it becomes unnecessary to output an acquisition timing signal from the high-frequency power supply to the impedance matching circuit. [Note 2] The aforementioned matching device setting value includes the setting value for the load information acquisition period. The impedance matching device described in Appendix 1. <Effects> When a high-frequency power supply performs amplitude modulation, the period for acquiring load information in the impedance matching circuit can be easily set. [Note 3] The aforementioned matching device setting information can be used repeatedly. An impedance matching device as described in Appendix 1 or Appendix 2. <Effects> If it is possible to repeatedly use the matching circuit configuration information, the configuration becomes simpler because it is only necessary to set the matching circuit configuration information for a relatively short period of time.

[0248] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of symbols]

[0249] 1.1A High-Frequency Power Supply System 10,10A 1st high frequency power supply 20 1st matching box 30,30A 2nd high frequency power supply 40 Second matching box 50 Superimposed Output Section 21 Communication Unit for the First Matching Unit 22 Sensor for the first matching unit 23 Matching circuit for the first matching box 24 First matching box calculation unit 25 Control Unit for First Matching Unit 26. Reference clock generation unit for the first matching unit 27 Information storage unit for the first matching unit 28 Output unit for setting value information for the first matching unit ST2 First Matching Device Setting Information PS cycle start signal

Claims

1. An input terminal that can be connected to a high-frequency power supply that provides high-frequency power, An output terminal that can be connected to a load, It has a variable element inside, and a matching circuit that can change the impedance as seen from the input terminal, A matching unit setting value information output unit outputs the matching unit setting value corresponding to the elapsed time or a command signal corresponding to the matching unit setting value, based on matching unit setting value information that shows the relationship between the elapsed time from the start of the period within the time period of one period of amplitude modulation when the high-frequency power supply performs amplitude modulation control, A control unit that outputs a control signal to the matching circuit based on the matching circuit setting value or command signal output from the matching circuit setting value information output unit, It is equipped with, The matching unit output unit outputs a signal generated at each time period of the amplitude modulation, with the starting point being the time when a period start signal common to the high-frequency power supply is input, or the time obtained by adding a delay time to the time when the period start signal is input. Impedance matching device.

2. The matching device setting value includes the setting value for the period for acquiring load information related to the load. The impedance matching device according to claim 1.

3. The aforementioned matching device setting information can be used repeatedly. An impedance matching device according to claim 1 or 2.

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