High-frequency power supply device

Abstract

To generate a modulation signal of a period similar to that of a high frequency voltage output from a second power supply in a first power supply.SOLUTION: A high-frequency power supply device includes: a first power supply that supplies a first high-frequency power having a first base frequency to a load; a second power supply that supplies a second high-frequency power having a second base frequency lower than the first base frequency to the load; a first matching part; and a second matching part connected between the second power supply and the load. The second matching part generates a timing control signal of which the frequency is lower than the second base frequency on the basis of detection information of the second high frequency voltage, and supplies the timing control signal to the first power supply. The first power supply sets a start phase of a modulation signal in accordance with the timing control signal when a frequency modulation control that the frequency is modulated by the modulation signal having the first high frequency voltage at the frequency similar to the second base frequency, and outputs the frequency as a modulation wave is performed, and the modulation signal is generated in accordance with the start phase of the modulation signal, and the frequency modulation control of the first high frequency voltage is performed by using the modulation signal.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a high-frequency power supply device.

Background Art

[0002] The high-frequency power supply device used in a plasma processing apparatus has two high-frequency power supplies (a first power supply and a second power supply), and outputs high-frequency voltages with different fundamental frequencies (the frequencies of the fundamental waves) from each power supply toward a load. For example, the first power supply supplies a first high-frequency power to the load by outputting a first high-frequency voltage having a first fundamental frequency F1 suitable for plasma generation. The second power supply supplies a second high-frequency power to the load by outputting a second high-frequency voltage having a second fundamental frequency F2 (the first fundamental frequency F1 > the second fundamental frequency F2) suitable for ion acceleration. (See Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such a case, intermodulation distortion (IMD) occurs, and on the first power supply side, a phenomenon occurs in which the reflected wave power fluctuates according to the period of the second fundamental frequency F2. In order to reduce the reflected wave power caused by this intermodulation distortion, a technique for performing frequency modulation control on the first high-frequency voltage is known. At this time, based on the information of the second fundamental frequency F2 of the second power supply that is known in advance (for example, the information that it is 400 kHz is known), a modulation signal having the same frequency as the second fundamental frequency F2 is generated, and the generated modulation signal is used to perform frequency modulation control on the first power supply.

[0005] However, the period of the pseudo-generated modulation signal is different from the period of the high-frequency voltage output from the second power supply. When the periods of both are different in this way, the effect of reducing the reflected wave power caused by intermodulation distortion by frequency modulation control is reduced.

[0006] The present disclosure provides a high-frequency power supply device that can generate a modulation signal having the same period as the period of the high-frequency voltage output from a second power supply in a first power supply.

Means for Solving the Problem

[0007] The high-frequency power supply device according to the present disclosure includes a first power supply capable of supplying first high-frequency power to a load by outputting a first high-frequency voltage having a first fundamental frequency, a second power supply for supplying second high-frequency power to the load by outputting a second high-frequency voltage having a second fundamental frequency lower than the first fundamental frequency, a first matching unit connected between the first power supply and the load, and a second matching unit connected between the second power supply and the load. The second matching unit generates a timing control signal having a frequency lower than the second fundamental frequency based on the detection information of the second high-frequency voltage and supplies it to the first power supply. When the first power supply performs frequency modulation control to frequency-modulate the first high-frequency voltage with a modulation signal having the same frequency as the second fundamental frequency and output it as a modulated wave, the start phase of the modulation signal is set according to the timing control signal, the modulation signal is generated according to the start phase of the modulation signal, and the first high-frequency voltage is frequency-modulated using the modulation signal.

Advantages of the Invention

[0008] According to the high-frequency power supply device of the present disclosure, in the first power supply, a modulation signal having the same period as the period of the high-frequency voltage output from the second power supply can be generated.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of a high-frequency power supply device according to the present disclosure will be described with reference to the drawings.

[0011] (Embodiment) The high-frequency power supply device according to the embodiment is a device that supplies high-frequency power to a load (for example, a plasma processing device) by outputting a high-frequency voltage having a frequency in the RF band (RF: Radio Frequency). Such a high-frequency power supply device has two high-frequency power supplies (a first power supply and a second power supply), and outputs high-frequency voltages having different fundamental frequencies (frequencies of fundamental waves) (also referred to as output frequencies) from each power supply toward the load. For example, the first power supply supplies the first high-frequency power to the load by outputting a first high-frequency voltage having a first fundamental frequency F1 suitable for plasma generation. The second power supply supplies the second high-frequency power to the load by outputting a second high-frequency voltage having a second fundamental frequency F2 (the first fundamental frequency F1 > the second fundamental frequency F2) suitable for ion acceleration.

[0012] When supplying a plurality of high-frequency powers with a high-low difference from a plurality of power supplies to the load in this way, due to the influence of intermodulation distortion, a phenomenon occurs in which the reflected wave power fluctuates according to the fundamental period (period of the fundamental wave) on the second power supply side on the first power supply side. Therefore, it is not possible to efficiently supply high-frequency power from the first power supply to the load. Thus, in this embodiment, frequency modulation control is performed as follows to reduce the reflected wave power caused by intermodulation distortion.

[0013] Note that the high-frequency voltage output from the first power supply and traveling toward the load is referred to as the first traveling wave voltage, and the high-frequency voltage reflected from the load side and returning to the first power supply is referred to as the first reflected wave voltage. The high-frequency voltage output from the second power supply and traveling toward the load is referred to as the second traveling wave voltage, and the high-frequency voltage reflected from the load side and returning to the second power supply is referred to as the second reflected wave voltage.

[0014] FIG. 1 is a diagram showing the configuration of the high-frequency power supply device 1. The high-frequency power supply device 1 is applied to the plasma processing device PA. The plasma processing device PA is, for example, a parallel plate type, and the lower electrode EL1 and the upper electrode EL2 face each other in the chamber CH. A substrate SB to be processed can be placed on the lower electrode EL1. The high-frequency power supply device 1 is electrically connected to the lower electrode EL1. The upper electrode EL2 is electrically connected to the 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.

[0015] The high-frequency power supply device 1 includes an HF power supply (first power supply) 10, an LF power supply (second power supply) 20, and a superimposing integrator 30. The HF power supply 10 supplies the first high-frequency power (first traveling wave power) to the load by outputting a first high-frequency voltage (first traveling wave voltage) having a first fundamental frequency F1. The first high-frequency voltage mainly has a relatively high first fundamental frequency F1 suitable for plasma generation. The first fundamental frequency F1 is, for example, 40.68 MHz. The HF power supply 10 is also called a source power supply. Note that the fundamental frequency F1 is not limited to 40.68 MHz, and may be a frequency in the industrial RF band (Radio Frequency) such as 13.56 MHz or 27.12 MHz.

[0016] The LF power supply 20 supplies the second high-frequency power (second traveling wave power) to the load by outputting a second high-frequency voltage (second traveling wave voltage) having a second fundamental frequency F2 lower than the first fundamental frequency F1. The second high-frequency voltage has a relatively low second fundamental frequency F2 suitable for ion acceleration. The second fundamental frequency F2 is, for example, 400 kHz. The LF power supply 20 is also called a bias power supply. Note that the second fundamental frequency F2 is not limited to 400 kHz, and may be other frequencies.

[0017] The superimposition matcher 30 is electrically connected to the HF power supply 10 and the LF power supply 20 respectively. The superimposition matcher 30 is electrically connected between the HF power supply 10 and the LF power supply 20 and the lower electrode EL1. The superimposition matcher 30 performs a first matching operation for matching the impedance on the HF power supply 10 side and the impedance on the lower electrode EL1 side, and a second matching operation for matching the impedance on the LF power supply 20 side and the impedance on the lower electrode EL1 side. In a state where the first matching operation and the second matching operation are performed, the superimposition matcher 30 receives the first high-frequency power from the HF power supply 10, receives the second high-frequency power from the LF power supply 20, superimposes the first high-frequency power and the second high-frequency power, and supplies the superimposed power to the lower electrode EL1.

[0018] Note that the high-frequency power supply device 1 and the plasma processing device PA are not limited to the configuration of FIG. 1. For example, there are various configurations such as a configuration in which the first high-frequency power output from the HF power supply 10 is supplied to the upper electrode EL2 via the superimposition matcher 30, and the second high-frequency power output from the LF power supply 20 is supplied to the lower electrode EL1 via the superimposition matcher 30. It is possible to use the high-frequency power supply device 1 for such other configurations.

[0019] The superimposition matcher 30 includes an HF matching unit (first matching unit) 31 and an LF matching unit (second matching unit) 32. The HF matching unit 31 is electrically connected between the HF power supply 10 and the lower electrode EL1. The LF matching unit 32 is electrically connected between the LF power supply 20 and the lower electrode EL1. The HF matching unit 31 performs the first matching operation, and the LF matching unit 32 performs the second matching operation.

[0020] The HF matching unit 31 includes a sensor 311, a control circuit 312, and a matching circuit 313. The sensor 311 detects the waveform signal SG1f of the first traveling wave voltage output from the HF power supply 10 and also detects the waveform signal SG1r of the first reflected wave voltage reflected from the matching circuit 313 side. The matching circuit 313 has a variable impedance circuit, and according to the waveform signal SG1f and the waveform signal SG1r detected by the sensor 311 (for example, so that the reflection coefficient calculated from the waveform signal SG1f and the waveform signal SG1r becomes small), the control circuit 312 changes the impedance value of the variable impedance circuit. Of course, the impedance value of the variable impedance circuit may be changed so that the reflected wave power, rather than the reflection coefficient, becomes small. The variable impedance circuit includes, for example, a variable capacitor and an inductor (not shown), and the impedance value can be changed by changing the capacitance of the variable capacitor (the same applies to the LF matching unit 32). Also, in the above example, the reflection coefficient was calculated using the waveform signal SG1f of the first traveling wave voltage and the waveform signal SG1r of the first reflected wave voltage, but it is also possible to detect the voltage waveform signal and the current waveform signal and calculate the reflection coefficient based on them (the same applies to the LF matching unit 32).

[0021] The LF matching unit 32 includes a sensor 321 (detection unit 321), a control circuit 322, and a matching circuit 323. The control circuit 322 includes a pulse conversion circuit 3221 (conversion unit 3221) and a frequency division processing unit 3222 (frequency division unit 3222). The sensor 321 detects the waveform signal SG2f of the second traveling wave voltage output from the LF power supply 20 and also detects the waveform signal SG2r of the second reflected wave voltage reflected from the matching circuit 323 side. The matching circuit 323 has a variable impedance circuit, and according to the waveform signal SG2f and the waveform signal SG2r detected by the sensor 321 (for example, so that the reflection coefficient calculated from the waveform signal SG2f and the waveform signal SG2r becomes small), the control circuit 322 changes the impedance value of the variable impedance circuit in the matching circuit 323. Of course, the impedance value of the variable impedance circuit may be changed so that the reflected wave power, rather than the reflection coefficient, becomes small.

[0022] The pulse conversion circuit 3221 converts the waveform signal SG2f of the second traveling wave voltage detected by the sensor 321 into a pulse signal. The pulse signal is converted into a rectangular signal having the second fundamental frequency F2. The pulse conversion circuit 3221 has a comparator and uses the comparator to convert a sine wave signal into a rectangular signal. The frequency division processing unit 3222 frequency-divides the pulse signal having the second fundamental frequency F2 by N and generates a timing control signal TC having a frequency F3. N is an integer of 2 or more. The frequency F3 is a frequency that is at least 1 / N times or less of the fundamental frequency F1. Thereby, the edge timing of the timing control signal TC can be made to coincide with a predetermined phase timing in the second high-frequency voltage.

[0023] When F2 = 400 kHz and N = 10, F3 = F2 × 1 / N = 400 kHz × 1 / 10 = 40 kHz. Since the timing control signal TC is a signal generated according to the second traveling wave voltage, it can be a signal synchronized with the second traveling wave voltage. The frequency division processing unit 3222 supplies the timing control signal TC having the frequency F3 to the HF power supply 10.

[0024] The HF power supply 10 receives the timing control signal TC generated by the LF matching unit 32. The HF power supply 10 generates a modulation fundamental wave signal corresponding to the second traveling wave voltage according to the timing control signal TC. The HF power supply 10 generates a modulation signal having the same period as the period of the second traveling wave voltage (second high-frequency voltage) output from the LF power supply 20 using the modulation fundamental wave signal. The frequency of the first traveling wave voltage (first high-frequency voltage) output from the HF power supply 10 is frequency-modulated using this modulation signal.

[0025] The HF power supply 10 includes a phase setting unit 11, a direct digital synthesizer (DDS) 12 (DDS: Direct Digital Synthesizer), a multiplier 13, an HF fundamental wave frequency setting unit 14, an adder 15, a direct digital synthesizer (DDS) 16, a processing unit 17, a basic clock generation unit 18, an LF fundamental wave frequency setting unit 19, and a frequency offset amount setting unit 131.

[0026] The LF fundamental wave frequency setting unit 19 generates frequency information of a modulation fundamental wave whose frequency is the second fundamental frequency F2. The frequency information is information that sequentially includes amplitudes for each clock timing according to the frequency of the modulation fundamental wave signal to be generated (for example, a sine wave signal). The LF fundamental wave frequency setting unit 19 directly supplies the frequency information of the modulation fundamental wave signal to the digital synthesis unit 12.

[0027] The phase setting unit 11 receives the timing control signal TC from the superposition matcher 30 and sets the modulation start phase at which modulation in the modulation fundamental wave signal should start. Thereby, the phase setting unit 11 can set the modulation start phase at which modulation should start at the same timing as the second high-frequency voltage of the LF power supply. The phase setting unit 11 directly supplies the information on the modulation start phase to the digital synthesis unit 12.

[0028] The basic clock generation unit 18 generates a basic clock signal. The basic clock signal is pre-adjusted to be a signal synchronized with the second traveling wave voltage and has a frequency that is an integer multiple of the second fundamental frequency F2. When F2 = 400 kHz, the frequency of the basic clock signal may be = F2 × 250 = 400 kHz × 250 = 100 MHz. The basic clock generation unit 18 supplies the basic clock signal to the digital synthesis unit 12 and the digital synthesis unit 16 respectively. Note that the basic clock generation unit 18 can be configured by, for example, a crystal oscillator or the like.

[0029] The direct digital synthesizer 12 receives the information on the modulation start phase from the phase setting unit 11, the clock signal from the basic clock generation unit 18, and the frequency information of the modulation fundamental wave signal from the LF fundamental wave frequency setting unit 19. While using the clock signal, the direct digital synthesizer 12 generates a modulation fundamental wave signal having the same frequency as the second fundamental frequency F2 by using the modulation start phase, the frequency information, and the amplitude information. The modulation fundamental wave signal is generated, for example, as a sine wave signal according to the frequency information and the amplitude information with reference to the modulation start phase. The direct digital synthesizer 12 supplies the modulation fundamental wave signal to the multiplier 13. Note that the modulation fundamental wave signal is a signal corresponding to the second traveling wave voltage generated by the LF power supply 20, and the period of the modulation fundamental wave signal is the same as the period of the second traveling wave voltage.

[0030] The frequency offset setting unit 131 sets the frequency offset ΔF to be applied to each of a plurality of phases within one period in the modulation fundamental wave signal, and supplies the information on the frequency offset ΔF to the multiplier 13. The frequency offset ΔF can vary, for example, in the range of -ΔFmax to +ΔFmax according to the phase at the time of modulation. For example, ΔFmax = 1.2 MHz.

[0031] The multiplier 13 receives the modulation fundamental wave signal from the direct digital synthesizer 12 and the information on the frequency offset ΔF from the frequency offset setting unit 131. The multiplier 13 multiplies the modulation fundamental wave signal by the frequency offset ΔF, and supplies the multiplication result to the adder 15 as a modulation signal.

[0032] The HF fundamental wave frequency setting unit 14 generates the frequency information of the fundamental wave signal having the frequency of the first fundamental frequency F1. The frequency information is information sequentially including the amplitude for each clock timing according to the frequency of the fundamental wave signal to be generated (for example, a sine wave signal). The HF fundamental wave frequency setting unit 14 supplies the frequency information of the fundamental wave signal to the adder 15.

[0033] The adder 15 receives a fundamental wave signal having a first fundamental frequency F1 from the HF fundamental frequency setting unit 14 and receives a modulation signal from the multiplier 13. The adder 15 adds the modulation signal to the fundamental wave signal to generate frequency information indicating the first fundamental frequency F1 + ΔF. The adder 15 directly supplies the frequency information to the direct digital synthesizer 16.

[0034] The direct digital synthesizer 16 receives the frequency information from the adder 15 and receives amplitude information from the HF power supply 10. The direct digital synthesizer 16 uses the frequency information and the amplitude information to generate a modulated wave in which a fundamental wave having a first fundamental frequency F1 is frequency-modulated by a frequency offset amount ΔF. The direct digital synthesizer 16 supplies the modulated wave to the processing unit 17.

[0035] The processing unit 17 performs predetermined processing on the modulated wave output from the direct digital synthesizer 16. The processing unit 17 includes an amplifier, a filter, a synthesizer, etc. The predetermined processing includes an amplification process for amplifying the modulated wave, a filter process for detecting forward waves and reflected waves in the modulated wave by a superheterodyne method or the like, and a synthesis process for synthesizing the deviation from the target power of the forward wave power and feeding it back to the direct digital synthesizer 16. The processing unit 17 outputs the processed modulated wave (the first forward wave voltage) to the superimposition matcher 30.

[0036] Next, the operation of the high-frequency power supply device 1 will be described with reference to FIGS. 2 to 5. FIG. 2 is a sequence chart showing the operation of the high-frequency power supply device 1. FIGS. 3 to 5 are waveform charts showing the operation of the high-frequency power supply device 1.

[0037] The LF power supply 20 generates a second forward wave voltage in response to a start command of the high-frequency power supply device 1 and outputs it to the LF matching unit 32 of the superimposition matcher 30 (S1).

[0038] The LF matching unit 32 detects the waveform signal SG2f of the second traveling wave voltage output from the LF power supply 20, and also detects the waveform signal SG2r of the second reflected wave voltage reflected from the matching circuit 323 side. (S2). The LF matching unit 32 detects a sine-wave-shaped waveform signal SG2f having the second fundamental frequency F2, as shown in, for example, FIG. 3(a). The waveform signal SG2f has, for example, a period corresponding to one period of the fundamental period of the LF power supply 20 during the periods of timings t1 to t2, t2 to t3, ···, t40 to t41, respectively.

[0039] The LF matching unit 32 converts the waveform signal SG2f into a pulse signal (S3). The LF matching unit 32 may generate a pulse signal as shown in FIG. 3(b) by setting the H level when the amplitude of the sine-wave signal exceeds the amplitude center indicated by the dashed line in FIG. 3(a) and the L level when it is below the amplitude center. The pulse signal has, for example, a period corresponding to one period of the fundamental period of the LF power supply 20 during the periods of timings t1 to t2, t2 to t3, ···, t40 to t41, respectively.

[0040] The LF matching unit 32 divides the pulse signal having the second fundamental frequency F2 by N to generate a timing control signal TC having the frequency F3. There is a relationship of F3 = F2 × 1 / N. The LF matching unit 32 divides, for example, the pulse signal shown in FIG. 3(b) by 20 to generate the timing control signal TC shown in FIG. 3(c). FIG. 3(c) illustrates the case where N = 20. The LF matching unit 32 outputs the timing control signal TC to the HF power supply 10. The timing control signal TC has, for example, a period corresponding to N times (e.g., 20 times) the fundamental period of the LF power supply 20 during the periods of timings t1 to t21 and t21 to t41, respectively.

[0041] The HF power supply 10 sets the phase at which modulation should start according to the timing control signal TC (S5), and generates a modulation fundamental wave signal (S6). The HF power supply 10 receives, for example, the timing control signal TC shown in Fig. 4(a). The HF power supply 10 starts generating the modulation fundamental wave signal from the timing t1 synchronized with the timing control signal TC shown in Fig. 4(a). That is, from timing t1, the HF power supply 10 synchronizes with the basic clock signal shown in Fig. 4(b) and generates a stepped signal as shown in Fig. 4(d) while referring to the frequency information as shown in Fig. 4(c). When the HF power supply 10 finishes referring to the amplitude for one cycle in the frequency information at timings t1 to t2, it returns to and refers to the amplitude at the beginning of one cycle in the frequency information at the next timing t2. This is repeated for each cycle of the sine wave. The HF power supply 10 smoothes the stepped signal shown in Fig. 4(d) to generate a sine-wave-like modulation fundamental wave signal as shown in Fig. 4(e). The HF power supply 10 multiplies the modulation fundamental wave signal by the frequency offset ΔF to obtain a modulation signal (S7). The modulation signal includes the frequency offset ΔF. The HF power supply 10 adds the modulation signal to the fundamental wave signal to generate frequency information indicating the frequency F1 + ΔF. Thereby, the HF power supply 10 frequency-modulates the fundamental wave having the first fundamental frequency F1 by the frequency modulation amount ΔF to generate a modulated wave (S8).

[0042] Note that, as shown in Fig. 5(a), the HF power supply 10 may reset the setting of the phase at which modulation should start at each edge timing t1, t21, t41 of the timing control signal TC, and repeat the processes of S5 to S8. The HF power supply 10 can be regarded as having completed the frequency modulation control, for example, in response to the reflection coefficient R (or the reflected wave power) falling below the threshold value. Thereby, the accuracy of the frequency modulation control can be improved.

[0043] When the frequency modulation control is completed, the HF power supply 10 generates a first high-frequency voltage (first traveling wave voltage) using the modulated wave and outputs it to the HF matching unit 31 of the superimposed matching unit 30 (S9).

[0044] The HF matching unit 31 detects the waveform signal SG1f of the first traveling wave voltage output from the HF power supply 10 and also detects the waveform signal SG1r of the reflected wave voltage reflected from the matching circuit 312 side (S10). The LF matching unit 32 of the superimposed matching unit 30 performs a second matching operation on the LF power supply 20 side and the lower electrode EL1 side according to the waveform signal SG2f and the waveform signal SG2r detected in S2 (S11). In parallel therewith, the HF matching unit 31 performs a first matching operation on the HF power supply 10 side and the lower electrode EL1 side according to the waveform signal SG1f and the waveform signal SG1r detected in S10 (S12). The superimposed matching unit 30 receives the first traveling wave voltage from the HF power supply 10 at the HF matching unit 31 and the second traveling wave voltage from the LF power supply 20 at the LF matching unit 32 in a state where the first matching operation and the second matching operation have been performed. The superimposed matching unit 30 superimposes the first traveling wave voltage (first high-frequency power) of the HF matching unit 31 and the second traveling wave voltage (second high-frequency power) of the LF matching unit 32, and supplies the superimposed traveling wave voltage (superimposed high-frequency power) to the lower electrode EL1 (S13).

[0045] As described above, in this embodiment, in the high-frequency power supply device 1, the LF matching unit 32 generates the timing control signal TC according to the second traveling wave voltage and supplies it to the HF power supply 10. The HF power supply 10 sets the start phase of the modulation signal according to the timing control signal TC, and generates a modulation signal according to the start phase of the modulation signal. The HF power supply 10 frequency-modulation controls the first traveling wave voltage (first high-frequency voltage) using the modulation signal. Thereby, the influence of intermodulation distortion can be suppressed with high precision.

[0046] Note that the timing control signal CT supplied from the frequency division processing unit 3222 shown in FIG. 1 to the phase setting unit 11 has a relatively low frequency as shown in FIG. 3(c). For example, if the frequency of the timing control signal TC is 100 kHz or less, a cable cheaper than a coaxial cable can be used for the communication line connecting the frequency division processing unit 3222 of the LF matching unit 32 and the phase setting unit 11 of the HF power supply 10. The inexpensive cable is, for example, a cable that does not have an outer conductor outside the inner conductor in a cross-sectional view, that is, does not have a shield wire outside the signal wire. Thereby, the cost of the high-frequency power supply device 1 can be reduced.

[0047] Although some embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, as well as in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0048] 1 High-frequency power supply device 10 HF power supply 20 LF power supply 30 Superposition integrator 31 HF integration section 32 LF integration section

Claims

1. A first power supply capable of supplying first high-frequency power to a load by outputting a first high-frequency voltage having a first fundamental frequency; A second power supply that supplies second high-frequency power to the load by outputting a second high-frequency voltage having a second fundamental frequency lower than the first fundamental frequency; A first matching unit connected between the first power supply and the load; A second matching unit connected between the second power supply and the load; comprising: The second matching unit generates a timing control signal having a frequency lower than the second fundamental frequency based on detection information of the second high-frequency voltage and supplies the timing control signal to the first power supply; When the first power supply performs frequency modulation control to frequency-modulate the first high-frequency voltage with a modulation signal having the same frequency as the second fundamental frequency and output it as a modulated wave, the first power supply sets the start phase of the modulation signal according to the timing control signal, generates the modulation signal according to the start phase of the modulation signal, and performs frequency modulation control on the first high-frequency voltage using the modulation signal. High-frequency power supply device.

2. The second matching unit extracts a pulse signal having the same period as the second fundamental frequency from the detection information of the second high-frequency voltage, and generates the timing control signal by dividing the pulse signal. The high-frequency power supply device according to claim 1.

3. The second matching unit: A detection unit that detects the second high-frequency voltage and outputs a detection waveform signal; A conversion unit that converts the detection waveform signal into the pulse signal; A frequency division unit that divides the pulse signal to generate the timing control signal; having: The high-frequency power supply device according to claim 2.

4. When N is an integer of 2 or more, the frequency of the timing control signal is a frequency that is at least 1 / N times or less of the second fundamental frequency. The high-frequency power supply device according to any one of claims 1 to 3.

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