WO2013132591A1 - High frequency power source device and matching method therefor - Google Patents

High frequency power source device and matching method therefor Download PDF

Info

Publication number
WO2013132591A1
WO2013132591A1 PCT/JP2012/055653 JP2012055653W WO2013132591A1 WO 2013132591 A1 WO2013132591 A1 WO 2013132591A1 JP 2012055653 W JP2012055653 W JP 2012055653W WO 2013132591 A1 WO2013132591 A1 WO 2013132591A1
Authority
WO
WIPO (PCT)
Prior art keywords
control
matching
frequency
power supply
frequency power
Prior art date
Application number
PCT/JP2012/055653
Other languages
French (fr)
Japanese (ja)
Inventor
藤本　直也
規一 加藤
関向　賢一
高橋　直人
Original Assignee
株式会社日立国際電気
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社日立国際電気 filed Critical 株式会社日立国際電気
Priority to JP2014503319A priority Critical patent/JP6045118B2/en
Priority to PCT/JP2012/055653 priority patent/WO2013132591A1/en
Publication of WO2013132591A1 publication Critical patent/WO2013132591A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/38—Impedance-matching networks
    • H03H7/40—Automatic matching of load impedance to source impedance
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32009—Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources
    • H01J37/32082—Radio frequency generated discharge
    • H01J37/32137—Radio frequency generated discharge controlling of the discharge by modulation of energy
    • H01J37/32155—Frequency modulation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32009—Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources
    • H01J37/32082—Radio frequency generated discharge
    • H01J37/32174—Circuits specially adapted for controlling the RF discharge
    • H01J37/32183—Matching circuits
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32917—Plasma diagnostics
    • H01J37/3299—Feedback systems
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H2242/00—Auxiliary systems
    • H05H2242/20—Power circuits
    • H05H2242/26—Matching networks

Definitions

  • the present invention relates to a high frequency power supply device and a matching method thereof.
  • Plasma processing equipment is used in semiconductor manufacturing processes such as etching and thin film formation.
  • a high frequency power supply device is used as a power supply source of the plasma processing apparatus.
  • it is necessary to match the impedance between the high frequency power supply and the plasma processing apparatus (load).
  • the following two methods are known as methods for matching impedance.
  • the first method is a method in which a matching unit is inserted between the high frequency power supply device and the load.
  • This matching device is generally composed of a variable capacitor and an inductance. Since the high frequency power supply device is required to have a high withstand voltage performance, a vacuum capacitor is often used as a variable capacitor of the matching unit.
  • the second method is a method of adjusting the oscillation frequency of the high frequency power supply device.
  • the former method has a wide matching range, it takes time to control the constants of the matching device.
  • the latter method can be controlled in a shorter time than the former method, but has a narrow matching range.
  • Patent Document 1 There is a technique described in Patent Document 1 as a technique using these methods in combination.
  • the oscillation frequency is changed to match the resonance frequency of the impedance of the load before discharge until plasma is generated, and after the plasma is generated, the oscillation frequency is set in advance.
  • the matching unit is controlled by switching to a fixed frequency. Accordingly, Patent Document 1 generates plasma promptly and maintains the generated plasma stably.
  • the plasma processing apparatus used in the semiconductor manufacturing process may change conditions such as gas type, gas flow rate, pressure, and power depending on the process. When these conditions are changed, the impedance characteristics of the plasma processing apparatus change. Therefore, it is required to expand the matching range of the high-frequency power supply so that matching can be performed under all conditions.
  • the technique described in Patent Document 1 described above performs control of the oscillation frequency and control of the matching unit, but the matching range is the same as when each control is performed independently.
  • the present invention has been made in view of the above circumstances, and an object thereof is to provide a high-frequency power supply device having a wider matching range and a matching method thereof.
  • a frequency oscillator having a variable oscillation frequency in a high frequency power supply device that supplies high frequency power to a load via a matching unit having a variable constant.
  • An amplifier that amplifies the output of the frequency oscillator and outputs the amplified output to the matching unit, a detection unit that detects a matching state value indicating a matching state between the high-frequency power supply device and the load, and the matching state value
  • a control unit that simultaneously executes a first control for controlling the oscillation frequency of the frequency oscillator based on the second control and a second control for controlling a constant of the matching unit based on the matching state value. did.
  • a high frequency power supply device in a high frequency power supply device that supplies high frequency power to a load via a matching unit having a variable constant, a frequency oscillator having a variable oscillation frequency, and the frequency oscillator
  • An amplifier that amplifies an output and outputs the amplified output to the matching unit; a detection unit that detects a matching state value indicating a matching state between the high-frequency power supply device and the load; and the frequency oscillator based on the matching state value
  • a control unit that switches between and executes a first control that controls an oscillation frequency and a second control that controls a constant of the matching unit based on the matching state value, and the control unit When switching from the first control to the second control, performing the second control while maintaining the control result of the first control, and when switching from the second control to the first control, Configured to perform the first control while maintaining the control result of the second control.
  • the high frequency power supply device in the matching method of the high frequency power supply device in which the constant of the matching unit and the oscillation frequency of the frequency oscillator are variable, the high frequency power supply device and the power supply destination thereof A matching state value indicating a matching state between the load and a first control for controlling an oscillation frequency of the frequency oscillator based on the matching state value; and a constant of the matching unit based on the matching state value
  • the second control for controlling is performed at the same time.
  • the high frequency power supply device in the matching method of the high frequency power supply device in which the constant of the matching unit and the oscillation frequency of the frequency oscillator are variable, the high frequency power supply device and the power supply destination thereof A matching state value indicating a matching state between the load and a first control for controlling an oscillation frequency of the frequency oscillator based on the matching state value; and a constant of the matching unit based on the matching state value
  • the second control is performed while maintaining the control result of the first control.
  • the first control is performed while maintaining the control result of the second control.
  • the matching range can be expanded by performing the control of the oscillation frequency and the control of the matching device in cooperation.
  • FIG. 1 It is a block diagram which shows the structure of the high frequency power supply device which concerns on this invention. It is a figure which shows an example of the impedance characteristic of the load connected to the high frequency power supply device which concerns on this invention. It is a figure which shows an example of the impedance characteristic of the load connected to the high frequency power supply device which concerns on this invention. It is a circuit diagram which shows an example of the circuit structure of the matching device shown in FIG. It is a figure which shows an example of the impedance characteristic of the matching device shown in FIG. It is a figure which shows the change of the characteristic when the characteristic shown in FIG. 3 and the characteristic shown in FIG. 5 are combined.
  • FIG. 9 is a time chart showing an alignment state when the processes shown in FIGS. 7 and 8 are executed.
  • FIG. It is a flowchart which shows the first half part of the process of the frequency control which concerns on the 2nd Embodiment of this invention, and a matching device control.
  • FIG. 12 is a time chart showing a matching state when the processing shown in FIGS.
  • FIG. 10 and 11 is executed. It is a flowchart which shows the first half part of the process of the frequency control which concerns on the 3rd Embodiment of this invention, and a matching device control. It is a flowchart which shows the latter half part of the process of the frequency control which concerns on the 3rd Embodiment of this invention, and a matching device control.
  • FIG. 15 is a time chart showing a matching state when the processes shown in FIGS. 13 and 14 are executed.
  • FIG. It is a flowchart which shows the first half part of the process of the frequency control which concerns on the 4th Embodiment of this invention, and a matching device control.
  • FIG. 18 is a time chart showing an alignment state when the processing shown in FIGS. 16 and 17 is executed.
  • FIG. 1 is a block diagram of the high-frequency power supply device according to the first embodiment.
  • the high frequency power supply device 1 includes a frequency oscillator 10, an RF amplifier 11, a directional coupler 12, a detection circuit 13, and a control unit 14.
  • a load 3 is connected to the output side of the high frequency power supply device 1 through a matching unit 2.
  • the high frequency power supply device 1 outputs high frequency power of several MHz to several tens of MHz, for example.
  • the frequency oscillator 10 has a variable oscillation frequency and outputs a high frequency according to an instruction from the control unit 14.
  • the output of the frequency oscillator 10 is input to the RF amplifier 11.
  • the RF amplifier 11 amplifies the input to a predetermined level (for example, several kW to several tens kW) and outputs the amplified signal.
  • the output of the RF amplifier 11 is supplied to the load 3 via the matching unit 2.
  • the load 3 is, for example, a plasma processing apparatus used in a semiconductor manufacturing process such as etching or thin film formation, more specifically, a dielectric load (such as a coil) wound around a chamber of the plasma processing apparatus.
  • a plasma processing apparatus used in a semiconductor manufacturing process such as etching or thin film formation
  • a dielectric load such as a coil
  • the plasma processing apparatus When the plasma processing apparatus is supplied with electric power of an appropriate frequency and level, it causes parallel resonance by the principle of a helical resonator, for example, and generates plasma.
  • impedance characteristics change depending on conditions such as gas supplied to the chamber, pressure in the chamber, and applied power.
  • a directional coupler 12 is provided between the RF amplifier 11 and the matching unit 2.
  • the directional coupler 12 extracts a traveling wave from the high frequency power supply device 1 toward the load 3 and a reflected wave reflected from the load 3 to the high frequency power supply device 1.
  • the traveling wave and the reflected wave extracted by the directional coupler 12 are input to the detection circuit 13.
  • the detection circuit 13 outputs signals representing the traveling wave power Pf and the reflected wave power Pr to the control unit 14.
  • the directional coupler 12 may be provided separately from the high frequency power supply device 1.
  • the directional coupler 12 may be provided between the matching unit 2 and the load 3.
  • the matching unit 2 may be provided inside the high frequency power supply device 1.
  • the control unit 14 controls the oscillation frequency of the frequency oscillator 10 and the constant of the matching unit 2 based on the traveling wave power Pf and the reflected wave power Pr.
  • the control of the oscillation frequency of the frequency oscillator 10 is referred to as “frequency control”
  • the constant control of the matching device 2 is referred to as “matching device control”.
  • FIG. 2 shows an example of frequency characteristics.
  • FIG. 2 is a diagram in which impedance is plotted on a Smith chart using frequency as a parameter. This Smith chart is a diagram normalized by 50 ⁇ , where point a1 indicates the frequency fa1, point b1 indicates the frequency fb1, and point c1 indicates the impedance at the frequency fc1.
  • the oscillation frequency may be controlled so that the impedance is b1 where the impedance is 50 ⁇ , that is, the frequency is fb1.
  • the example of FIG. 2 shows frequency characteristics that can be matched only by frequency control.
  • FIG. 3 shows another example of frequency characteristics.
  • the impedance locus does not pass through a point of 50 ⁇ , matching cannot be achieved only by frequency control.
  • the inventor has found that even if the frequency characteristic is the characteristic shown in FIG. 3, matching can be achieved by combining matching unit control.
  • the topology of the matching device is important.
  • FIG. 4 shows a circuit configuration example of a matching device suitable for the frequency characteristics shown in FIG. In the circuit configuration example shown in FIG. 4, a variable capacitor is provided in parallel with the load.
  • FIG. 5 shows an impedance locus of the circuit shown in FIG.
  • FIG. 5 shows a locus when a capacitor is connected in parallel to a 50 ⁇ load for the sake of simplicity.
  • a locus in which the impedance goes to zero is drawn.
  • the points a2, b2, and c2 move to points a3, b3, and c3, respectively, as shown in FIG. In this state, matching can be achieved by performing frequency control so that the impedance is at point b3.
  • the matching unit suitable for the frequency characteristics shown in FIG. 3 is configured as the circuit shown in FIG. 4
  • the loci of the respective impedances are not parallel. If the impedance trajectory with respect to frequency matches the impedance trajectory when the constant of the matching unit is changed (parallel), the matching range cannot be expanded even if frequency control and matching unit control are combined. .
  • the impedance locus with respect to the frequency and the impedance locus when the constants of the matching unit are changed not parallel for example, orthogonal
  • the impedance locus with respect to the frequency can be made a locus that passes 50 ⁇ .
  • the locus when the constant of the matching device is changed is not parallel to the locus of the impedance with respect to the frequency. If this condition is satisfied, it becomes possible to match various frequency characteristics by combining frequency control and matching device control, and the matching range can be expanded.
  • the frequency characteristic of the load 3 is the characteristic shown in FIG. 3, and the matching unit 2 has the circuit configuration shown in FIG.
  • the variable capacitor constituting the matching unit 2 is a vacuum capacitor, and the capacity is changed by driving an electric motor or the like.
  • the frequency characteristics and the circuit configuration are not limited to those shown in the drawing as long as the above conditions are satisfied.
  • the circuit configuration may be, for example, a configuration in which a variable capacitor is connected in series with the load 3 or a configuration in which an inductor and a capacitor are combined.
  • FIG. 7 is a flowchart showing the frequency control operation executed by the control unit 14, and FIG. 8 is a flowchart showing the matching unit control operation executed by the control unit 14.
  • the control unit 14 executes frequency control and matching unit control while switching between them. Either frequency control or matching unit control may be executed first after the high-frequency power supply device 1 is activated, but in this embodiment, frequency control is executed first. This is because the frequency control generally has a smaller time constant than the matching unit control, and the time required for convergence is shorter. When it is desired to try matching in a wide range at first, the matching device control may be executed first.
  • the frequency control flag is ON (S10).
  • the frequency control flag is a flag that permits execution of frequency control, and the initial value is ON (permission permission).
  • the frequency control flag is OFF, the subsequent processing is skipped.
  • VSWR Voltage standing wave ratio.
  • VS (t) which is the current value of the voltage standing wave ratio
  • VS (t) is calculated according to the following equation 1 (S11).
  • Pf and Pr are traveling wave power and reflected wave power, respectively.
  • VS (t) (Pf + Pr) / (Pf ⁇ Pr) Equation 1
  • the follow-up control is control for changing the oscillation frequency in accordance with VS (t). If the follow-up control is not being executed, it is determined whether or not the sweep control (SWEEP control) is being executed (S13). When the sweep control is not being executed, an initial value (initial frequency) is set to the oscillation frequency F (t) and the frequency oscillator 10 is operated (S14). Then, the operating time of the frequency oscillator 10 at the initial frequency is measured (S15). Until the predetermined time elapses (until the time is up), the processing from S10 to S14 is repeated. On the other hand, when the predetermined time has elapsed, the process shifts to the sweep control (S16) and returns to S10.
  • SWEEP control sweep control
  • the frequency changing direction is determined to be a specific direction (down in this embodiment).
  • the change direction is determined based on VS (t ⁇ 1) which is the previous value of VSWR (VSWR before the previous follow-up control) and current value VS (t). To do. Specifically, when VS (t ⁇ 1) is equal to or higher than VS (t), that is, when VSWR is improved by the previous tracking control, the direction is the same as the previous time. Conversely, if VS (t ⁇ 1) is lower than VS (t), that is, if VSWR has deteriorated due to the previous tracking control, the direction is the reverse of the previous time.
  • a frequency change width ⁇ F is determined (S21).
  • the change width ⁇ F is determined according to VS (t). Specifically, the change width ⁇ F is increased as VS (t) is larger (away from the target value). As a result, VS (t) can be brought closer to the target value more quickly, and the target value can be accurately followed in the vicinity of the target value.
  • F (t) is updated by adding or subtracting ⁇ F to F (t), which is the current oscillation frequency (S22).
  • F (t) is stored as the previous value VS (t-1) (S23), and the oscillation frequency is controlled to the new F (t) updated in S22 (S24).
  • VS (t) after the oscillation frequency is changed is calculated, and it is determined whether or not the VS (t) has reached the target value (S25).
  • the target VSWR is 1.
  • the follow-up control frequency Fcnt (n) is counted up (S26), and it is determined whether or not this Fcnt (n) exceeds a predetermined number (for example, 100 times). (S27).
  • Fcnt (n) does not exceed the predetermined number of times, that is, when improvement of VS (t) by frequency control is still expected, the process returns to S10 and frequency control is continued.
  • Fcnt (n) exceeds the predetermined number of times, improvement of VS (t) cannot be expected even if the frequency control is further performed.
  • the frequency control flag is turned OFF and the matching unit control flag (initial (Value OFF) is set to ON (S28), and the process returns to S10.
  • the frequency control flag is set to OFF, the result of S10 is negative in the next loop, so that frequency control is not executed.
  • the value of the follow-up control count Fcnt (n) is reset to 0 (S29), and the process returns to S10.
  • the frequency control may be stopped for a certain time.
  • the process shown in FIG. 8 is executed simultaneously (in parallel) with the process shown in FIG.
  • the matching unit control first, it is determined whether or not the matching unit control flag is ON (S50).
  • the matching unit control flag permits execution of matching unit control when it is ON.
  • the matching unit control flag has the initial value OFF, and is set to ON simultaneously with the frequency control flag being turned OFF in the process shown in FIG. Therefore, the matching device control is not executed when the high frequency power supply device 1 is started, and the frequency control is switched to the matching device control.
  • the oscillation frequency of the oscillator 10 is maintained at the latest F (t) set by the frequency control.
  • the matcher control flag When the matcher control flag is ON, VS (t) is calculated (S51), and the constant change direction (down or UP) is determined (S52).
  • the matcher control is the first time, the constant changing direction is determined to be a specific direction (up direction in this embodiment).
  • the matcher control is performed for the second time or later, the change direction is determined based on VS (t ⁇ x), which is VSWR before the previous matcher control, and the current value VS (t). Specifically, when VS (t ⁇ x) is equal to or higher than VS (t), that is, when the VSWR is improved by the previous matcher control, the direction is the same as the previous time. On the other hand, when VS (t ⁇ x) is lower than VS (t), that is, when VSWR has deteriorated due to the previous matcher control, the reverse direction is set.
  • a constant change width ⁇ C is determined (S53).
  • the change width ⁇ C is determined according to VS (t), similarly to ⁇ F. Specifically, the change width ⁇ C is increased as VS (t) increases (away from the target value). As a result, VS (t) can be brought closer to the target value more quickly, and the target value can be accurately followed in the vicinity of the target value.
  • the constant controlled by the matching unit control is specifically the capacitance of the variable capacitor, and the unit of ⁇ C is, for example, pF (pico farad).
  • the matching unit control count Ccnt (n) is counted up (S58), and it is determined whether or not this Ccnt (n) exceeds a predetermined number (for example, 5 times). (S59).
  • Ccnt (n) does not exceed the predetermined number of times, that is, when improvement of VS (t) by the matching device control is still expected, the process returns to S50 and the matching device control is continued.
  • Ccnt (n) exceeds the predetermined number of times, improvement of VS (t) cannot be expected even if the matching unit control is continued further. Therefore, the frequency control flag is turned ON and the matching unit control flag is set.
  • matcher control flag is set to OFF in S60, the matcher control is not executed because the result in S50 is negative in the next loop.
  • frequency control is executed by the processing shown in FIG. In other words, the matching device control is switched to the frequency control. At this time, the constant of the matching unit 2 is maintained at the latest C (t) set by the matching unit control.
  • the matching device control is switched to the frequency control, it is affirmed in S12 of FIG. 7 and the follow-up control is executed.
  • FIG. 9 is a time chart showing a matching state when the frequency control shown in FIG. 7 and the matching unit control shown in FIG. 8 are executed.
  • FIG. 9 when the frequency control cannot be matched, matching can be achieved by switching to the matching device control while maintaining the frequency set by the frequency control.
  • the matching cannot be achieved even by the matching unit control, it is possible to gradually approach the target value by switching to the frequency control again and attempting the matching while maintaining the constant set by the matching unit control.
  • the constant is shown to be changed after a while after the start of the matching unit control. However, in actuality, the constant gradually approaches the set constant.
  • the frequency control and the matching device control are switched and executed, and when the frequency control is switched to the matching device control, the frequency control is performed.
  • the matcher control is performed while maintaining the control result (latest F (n)) and switching from the matcher control to the frequency control, the frequency is maintained while maintaining the matcher control result (latest C (t)).
  • Control was executed. Further, if VS (t) does not reach the target value even if frequency control (follow-up control) is executed a predetermined number of times, switching from frequency control to matching device control is performed, and VS (t) is executed even if matching device control is executed a predetermined number of times. When the value does not reach the target value, switching from matcher control to frequency control (follow-up control) is performed.
  • the matching range can be expanded by performing the frequency control and the matching unit control in cooperation.
  • FIG. 10 is a flowchart showing the first half of the frequency control and matching unit control processing according to the second embodiment of the present invention
  • FIG. 11 is a flowchart showing the second half of the processing shown in FIG.
  • VS (t) and the VSWR change rate Fvs by frequency control are calculated (S100).
  • S100 VS (t)
  • the above Equation 1 is used.
  • the unit of Fvs is percent, and the following formula 2 is used for the calculation.
  • Fvs ((VS (t ⁇ 1) / VS (t)) ⁇ 100) ⁇ 100 Equation 2
  • FIG. 12 is a time chart showing a matching state when the frequency control and matching unit control shown in FIGS. 10 and 11 are executed.
  • the frequency control fails to match, switching to the matching device control is performed while maintaining the frequency set by the frequency control.
  • the constant is changed a predetermined number of times (one time in the present embodiment) by the matching unit control, and when the change of the constant is completed, the frequency control is returned again to try the matching.
  • the matching unit control may be continuously performed a plurality of times and then returned to the frequency control.
  • the matching range can be expanded by performing the frequency control and the matching unit control in cooperation.
  • matching device control that requires time for operation is executed a predetermined number of times to shift to frequency control, the matching device control is continued until it is determined that matching cannot be achieved by the matching device control. Compared to this form, shortening of the matching time can be expected. Further, if the number of times of matching device control is reduced, the life of the matching device having mechanically operating parts can be extended.
  • FIG. 13 is a flowchart showing the first half of the frequency control and matching unit control processing according to the third embodiment of the present invention
  • FIG. 14 is a flowchart showing the second half of the processing shown in FIG.
  • VS (t), Fvs, and the VSWR change rate Cvs by the matching unit control are calculated (S200).
  • the above equation 1 is used for calculating VS (t), and the above equation 2 is used for calculating Fvs.
  • the unit of Cvs is percent, and the following formula 3 is used for the calculation.
  • Cvs ((VS (t ⁇ x) / VS (t)) ⁇ 100) ⁇ 100 Equation 3
  • the process proceeds to the process of FIG. 14 to determine whether or not the constant is being changed, specifically, whether or not the variable capacitor is being driven (S222).
  • This process is determined by counting the elapsed time from the start of driving of the variable capacitor or detecting the capacitance of the variable capacitor, as in S124 of FIG.
  • the interrupting flag is set to ON (S223). If the suspension flag is not set to ON, whether or not the absolute value of Cvs is below a first predetermined value Cvsref1 (for example, 5%), that is, whether the change in VS (t) due to matching device control is small It is determined whether or not (S224). In S224, it may be determined whether or not the absolute value of Cvs is below the first predetermined value Cvsref1 for a predetermined number of times.
  • matching unit control similar to S119 to S123 of FIG. 11 is performed in S225 to S229. I do.
  • the matching device control initial flag is set to OFF (S230), and the process returns to S200 to execute frequency control (follow-up control).
  • the interrupting flag is set to ON. (S231).
  • the suspension flag is a flag indicating whether or not to match the matching unit control.
  • the interrupting flag When the interrupting flag is set to ON, it is affirmed in S223 in the next loop, and it is determined whether Cvs is below a second predetermined value Cvsref2 (S232).
  • the second predetermined value Cvsref2 is set to ⁇ 20%, for example.
  • a negative value of Cvs means that VS (t) has increased. That is, the determination in S232 corresponds to determining whether or not VS (t) has deteriorated to a predetermined rate or more during interruption of the matching unit control.
  • FIG. 15 is a time chart showing a matching state when the frequency control and matching unit control shown in FIGS. 13 and 14 are executed.
  • the frequency control is simultaneously performed while changing the constant in the matching unit control, so that the matching time can be shortened.
  • a difference may be provided in the matching operation speed of each control. That is, if one control has a matching speed sufficiently higher than the other control, hunting does not occur. For example, if the matching operation speed (frequency change period) of frequency matching is 1 ms, the matching operation speed (constant change period) of the matcher control may be 10 ms or more.
  • the matching range can be expanded by performing the frequency control and the matching unit control in cooperation. Furthermore, since the frequency control and the matching device control are executed simultaneously (the frequency control is executed even when the constant of the matching device 2 is changed), the matching time can be shortened. Further, the frequency control has a higher operation speed and resolution than the matching unit control that operates the variable capacitor. Therefore, by executing the frequency control simultaneously with the matching unit control, it is possible to follow a small change in impedance more accurately.
  • FIG. 16 is a flowchart showing the first half of the frequency control and matching unit control processing according to the fourth embodiment of the present invention
  • FIG. 17 is a flowchart showing the second half of the processing shown in FIG.
  • VS (t) is calculated according to the above-described equation (1) (S300).
  • S301 to S305 matching unit control similar to S119 to S123 in FIG. 11 is performed.
  • the matching unit control number Ccnt (n) is counted up (S307), and it is determined whether or not this Ccnt (n) exceeds a predetermined number (for example, five times). (S308).
  • Ccnt (n) does not exceed the predetermined number of times, that is, when improvement of VS (t) due to matching device control is still expected, the processing returns to S300 and matching device control is continued.
  • FIG. 18 is a time chart showing a matching state when the frequency control and matching device control shown in FIGS. 16 and 17 are executed. As shown in FIG. 18, after matching is performed by the matching unit control, frequency control is executed. This is because the operation speed and resolution follow a small change in impedance after matching with frequency control higher than matching device control.
  • the matching range can be expanded by performing the frequency control and the matching unit control in cooperation. Furthermore, after matching is performed by matching device control, frequency control is executed, so that it is possible to accurately follow small changes in impedance after matching.
  • VSWR is calculated as a value indicating the matching state, but impedance may be calculated.
  • other indicators may be used as long as they indicate the matching state, such as a coefficient indicating the degree of reflection.
  • the present invention can be used in a high-frequency power supply device that supplies power to a plasma processing apparatus or the like.

Abstract

Provided is a high frequency power source device, and matching method therefor, in which the constant of a matching unit and the oscillating frequency of a frequency oscillator are variable, wherein the following are carried out simultaneously: frequency control in which a matching state value indicating the matching state between the high frequency power source and a load which is the destination of the supplied power is detected, and the oscillating frequency of the frequency oscillator is controlled on the basis of the matching state value; and matching unit control in which the constant of the matching unit is controlled on the basis of the matching state value. The oscillation frequency is continually updated by frequency control, even while the constant is being updated by matching unit control.

Description

高周波電源装置およびその整合方法High frequency power supply device and matching method thereof
　本発明は、高周波電源装置およびその整合方法に関する。 The present invention relates to a high frequency power supply device and a matching method thereof.
　エッチングや薄膜形成といった半導体製造工程では、プラズマ処理装置が用いられる。このプラズマ処理装置の電源供給源として、高周波電源装置が用いられる。高周波電源装置からプラズマ処理装置に効率良く電力を供給するには、高周波電源とプラズマ処理装置（負荷）との間でインピーダンスを整合させる必要がある。 Plasma processing equipment is used in semiconductor manufacturing processes such as etching and thin film formation. A high frequency power supply device is used as a power supply source of the plasma processing apparatus. In order to efficiently supply power from the high frequency power supply device to the plasma processing apparatus, it is necessary to match the impedance between the high frequency power supply and the plasma processing apparatus (load).
インピーダンスを整合させる方式として、以下の２つの方式が知られている。１つ目の方式は、高周波電源装置と負荷との間に整合器を挿入する方式である。この整合器は、一般に、可変コンデンサやインダクタンスから構成される。高周波電源装置は高い耐圧性能が要求されることから、整合器の可変コンデンサとして真空コンデンサが使用されることが多い。２つ目の方式は、高周波電源装置の発振周波数を調整する方式である。 The following two methods are known as methods for matching impedance. The first method is a method in which a matching unit is inserted between the high frequency power supply device and the load. This matching device is generally composed of a variable capacitor and an inductance. Since the high frequency power supply device is required to have a high withstand voltage performance, a vacuum capacitor is often used as a variable capacitor of the matching unit. The second method is a method of adjusting the oscillation frequency of the high frequency power supply device.
前者の方式は、整合範囲が広いが整合器の定数の制御に時間を要する。一方、後者の方式は、前者に比べて短時間で制御が可能であるが、整合範囲が狭い。 Although the former method has a wide matching range, it takes time to control the constants of the matching device. On the other hand, the latter method can be controlled in a shorter time than the former method, but has a narrow matching range.
　これらの方式を併用した技術として、特許文献１に記載される技術がある。特許文献１に記載される技術は、プラズマが発生するまでは、発振周波数を放電前の負荷のインピーダンスの共振周波数に整合するように変化させ、プラズマが発生した後は、発振周波数を予め設定された固定の周波数に切り替えて整合器の制御を行う。これにより、特許文献１は、プラズマを速やかに発生させると共に、発生したプラズマを安定に維持するようにしている。 There is a technique described in Patent Document 1 as a technique using these methods in combination. In the technique described in Patent Document 1, the oscillation frequency is changed to match the resonance frequency of the impedance of the load before discharge until plasma is generated, and after the plasma is generated, the oscillation frequency is set in advance. The matching unit is controlled by switching to a fixed frequency. Accordingly, Patent Document 1 generates plasma promptly and maintains the generated plasma stably.
特許第２８８４０５６号Japanese Patent No. 2884056
　半導体製造工程で用いるプラズマ処理装置は、プロセスによってガスの種類やガス流量、圧力、電力等の条件を変更することがある。これらの条件を変更した場合、プラズマ処理装置のインピーダンス特性が変化する。そのため、全ての条件で整合できるよう、高周波電源装置の整合範囲を広げることが要求される。上記した特許文献１に記載される技術は、発振周波数の制御と整合器の制御を行っているが、整合範囲はそれぞれの制御を単独で行ったときと変わらない。 The plasma processing apparatus used in the semiconductor manufacturing process may change conditions such as gas type, gas flow rate, pressure, and power depending on the process. When these conditions are changed, the impedance characteristics of the plasma processing apparatus change. Therefore, it is required to expand the matching range of the high-frequency power supply so that matching can be performed under all conditions. The technique described in Patent Document 1 described above performs control of the oscillation frequency and control of the matching unit, but the matching range is the same as when each control is performed independently.
　本発明は上記実情に鑑みて為されたもので、より広い整合範囲を有する高周波電源装置およびその整合方法を提供することにある。 The present invention has been made in view of the above circumstances, and an object thereof is to provide a high-frequency power supply device having a wider matching range and a matching method thereof.
　上記課題を解決するために、本発明に係る高周波電源装置にあっては、定数が可変である整合器を介して高周波電力を負荷に供給する高周波電源装置において、発振周波数が可変である周波数発振器と、前記周波数発振器の出力を増幅して前記整合器に出力する増幅器と、前記高周波電源装置と前記負荷との間の整合状態を示す整合状態値を検出する検出部と、前記整合状態値に基づいて前記周波数発振器の発振周波数を制御する第１の制御と、前記整合状態値に基づいて前記整合器の定数を制御する第２の制御とを同時に実行する制御部と、を備えるように構成した。 In order to solve the above-mentioned problem, in the high frequency power supply device according to the present invention, a frequency oscillator having a variable oscillation frequency in a high frequency power supply device that supplies high frequency power to a load via a matching unit having a variable constant. An amplifier that amplifies the output of the frequency oscillator and outputs the amplified output to the matching unit, a detection unit that detects a matching state value indicating a matching state between the high-frequency power supply device and the load, and the matching state value A control unit that simultaneously executes a first control for controlling the oscillation frequency of the frequency oscillator based on the second control and a second control for controlling a constant of the matching unit based on the matching state value. did.
　また、本発明に係る高周波電源装置にあっては、定数が可変である整合器を介して高周波電力を負荷に供給する高周波電源装置において、発振周波数が可変である周波数発振器と、前記周波数発振器の出力を増幅して前記整合器に出力する増幅器と、前記高周波電源装置と前記負荷との間の整合状態を示す整合状態値を検出する検出部と、前記整合状態値に基づいて前記周波数発振器の発振周波数を制御する第１の制御と、前記整合状態値に基づいて前記整合器の定数を制御する第２の制御とを切り替えて実行する制御部と、を備えると共に、前記制御部は、前記第１の制御から前記第２の制御に切り替えるとき、前記第１の制御の制御結果を維持したまま前記第２の制御を行い、前記第２の制御から前記第１の制御に切り替えるとき、前記第２の制御の制御結果を維持したまま前記第１の制御を行うように構成した。 Further, in the high frequency power supply device according to the present invention, in a high frequency power supply device that supplies high frequency power to a load via a matching unit having a variable constant, a frequency oscillator having a variable oscillation frequency, and the frequency oscillator An amplifier that amplifies an output and outputs the amplified output to the matching unit; a detection unit that detects a matching state value indicating a matching state between the high-frequency power supply device and the load; and the frequency oscillator based on the matching state value A control unit that switches between and executes a first control that controls an oscillation frequency and a second control that controls a constant of the matching unit based on the matching state value, and the control unit When switching from the first control to the second control, performing the second control while maintaining the control result of the first control, and when switching from the second control to the first control, Configured to perform the first control while maintaining the control result of the second control.
　また、本発明に係る高周波電源装置の整合方法にあっては、整合器の定数と周波数発振器の発振周波数が可変である高周波電源装置の整合方法において、前記高周波電源装置とその電力供給先である負荷との間の整合状態を示す整合状態値を検出し、前記整合状態値に基づいて前記周波数発振器の発振周波数を制御する第１の制御と、前記整合状態値に基づいて前記整合器の定数を制御する第２の制御とを同時に実行するように構成した。 Further, in the matching method of the high frequency power supply device according to the present invention, in the matching method of the high frequency power supply device in which the constant of the matching unit and the oscillation frequency of the frequency oscillator are variable, the high frequency power supply device and the power supply destination thereof A matching state value indicating a matching state between the load and a first control for controlling an oscillation frequency of the frequency oscillator based on the matching state value; and a constant of the matching unit based on the matching state value The second control for controlling is performed at the same time.
また、本発明に係る高周波電源装置の整合方法にあっては、整合器の定数と周波数発振器の発振周波数が可変である高周波電源装置の整合方法において、前記高周波電源装置とその電力供給先である負荷との間の整合状態を示す整合状態値を検出し、前記整合状態値に基づいて前記周波数発振器の発振周波数を制御する第１の制御と、前記整合状態値に基づいて前記整合器の定数を制御する第２の制御とを切り替えて実行すると共に、前記第１の制御から前記第２の制御に切り替えるとき、前記第１の制御の制御結果を維持したまま前記第２の制御を行い、前記第２の制御から前記第１の制御に切り替えるとき、前記第２の制御の制御結果を維持したまま前記第１の制御を行うように構成した。 Further, in the matching method of the high frequency power supply device according to the present invention, in the matching method of the high frequency power supply device in which the constant of the matching unit and the oscillation frequency of the frequency oscillator are variable, the high frequency power supply device and the power supply destination thereof A matching state value indicating a matching state between the load and a first control for controlling an oscillation frequency of the frequency oscillator based on the matching state value; and a constant of the matching unit based on the matching state value When switching from the first control to the second control, the second control is performed while maintaining the control result of the first control. When switching from the second control to the first control, the first control is performed while maintaining the control result of the second control.
　本発明に係る高周波電源装置およびその整合方法によれば、発振周波数の制御と整合器の制御とを連携して行うことで、整合範囲を広げることができる。 According to the high frequency power supply device and the matching method thereof according to the present invention, the matching range can be expanded by performing the control of the oscillation frequency and the control of the matching device in cooperation.
本発明に係る高周波電源装置の構成を示すブロック図である。It is a block diagram which shows the structure of the high frequency power supply device which concerns on this invention. 本発明に係る高周波電源装置に接続される負荷のインピーダンス特性の一例を示す図である。It is a figure which shows an example of the impedance characteristic of the load connected to the high frequency power supply device which concerns on this invention. 本発明に係る高周波電源装置に接続される負荷のインピーダンス特性の一例を示す図である。It is a figure which shows an example of the impedance characteristic of the load connected to the high frequency power supply device which concerns on this invention. 図１に示す整合器の回路構成の一例を示す回路図である。It is a circuit diagram which shows an example of the circuit structure of the matching device shown in FIG. 図１に示す整合器のインピーダンス特性の一例を示す図である。It is a figure which shows an example of the impedance characteristic of the matching device shown in FIG. 図３に示す特性と図５に示す特性とを組み合せたときの特性の変化を示す図である。It is a figure which shows the change of the characteristic when the characteristic shown in FIG. 3 and the characteristic shown in FIG. 5 are combined. 本発明の第１の実施の形態に係る周波数制御の処理を示すフローチャートである。It is a flowchart which shows the process of the frequency control which concerns on the 1st Embodiment of this invention. 本発明の第１の実施の形態に係る整合器制御の処理を示すフローチャートである。It is a flowchart which shows the process of the matching device control which concerns on the 1st Embodiment of this invention. 図７および図８に示す処理を実行したときの整合状態を示すタイムチャートである。FIG. 9 is a time chart showing an alignment state when the processes shown in FIGS. 7 and 8 are executed. FIG. 本発明の第２の実施の形態に係る周波数制御と整合器制御の処理の前半部分を示すフローチャートである。It is a flowchart which shows the first half part of the process of the frequency control which concerns on the 2nd Embodiment of this invention, and a matching device control. 本発明の第２の実施の形態に係る周波数制御と整合器制御の処理の後半部分を示すフローチャートである。It is a flowchart which shows the second half part of the process of the frequency control which concerns on the 2nd Embodiment of this invention, and a matching device control. 図１０および図１１に示す処理を実行したときの整合状態を示すタイムチャートである。12 is a time chart showing a matching state when the processing shown in FIGS. 10 and 11 is executed. 本発明の第３の実施の形態に係る周波数制御と整合器制御の処理の前半部分を示すフローチャートである。It is a flowchart which shows the first half part of the process of the frequency control which concerns on the 3rd Embodiment of this invention, and a matching device control. 本発明の第３の実施の形態に係る周波数制御と整合器制御の処理の後半部分を示すフローチャートである。It is a flowchart which shows the latter half part of the process of the frequency control which concerns on the 3rd Embodiment of this invention, and a matching device control. 図１３および図１４に示す処理を実行したときの整合状態を示すタイムチャートである。FIG. 15 is a time chart showing a matching state when the processes shown in FIGS. 13 and 14 are executed. FIG. 本発明の第４の実施の形態に係る周波数制御と整合器制御の処理の前半部分を示すフローチャートである。It is a flowchart which shows the first half part of the process of the frequency control which concerns on the 4th Embodiment of this invention, and a matching device control. 本発明の第４の実施の形態に係る周波数制御と整合器制御の処理の後半部分を示すフローチャートである。It is a flowchart which shows the second half part of the process of the frequency control which concerns on the 4th Embodiment of this invention, and a matching device control. 図１６および図１７に示す処理を実行したときの整合状態を示すタイムチャートである。FIG. 18 is a time chart showing an alignment state when the processing shown in FIGS. 16 and 17 is executed.
　　以下、本発明に係る高周波電源装置およびその整合方法について、図面を参照しながら説明する。 Hereinafter, a high frequency power supply device and a matching method thereof according to the present invention will be described with reference to the drawings.
図１は、第１の実施の形態に係る高周波電源装置のブロック図である。
高周波電源装置１は、周波数発振器１０と、ＲＦ増幅器１１と、方向性結合器１２と、検出回路１３と、制御部１４とを備える。高周波電源装置１の出力側には、整合器２を介して負荷３が接続される。高周波電源装置１は、例えば数ＭＨｚから数十ＭＨｚの高周波電力を出力する。 FIG. 1 is a block diagram of the high-frequency power supply device according to the first embodiment.
The high frequency power supply device 1 includes a frequency oscillator 10, an RF amplifier 11, a directional coupler 12, a detection circuit 13, and a control unit 14. A load 3 is connected to the output side of the high frequency power supply device 1 through a matching unit 2. The high frequency power supply device 1 outputs high frequency power of several MHz to several tens of MHz, for example.
周波数発振器１０は、発振周波数が可変であり、制御部１４からの指示に応じた周波数の高周波を出力する。周波数発振器１０の出力は、ＲＦ増幅器１１に入力される。ＲＦ増幅器１１は、入力を所定のレベル（例えば数ｋＷから数十ｋＷ）まで増幅させて出力する。ＲＦ増幅器１１の出力は、整合器２を介して負荷３に供給される。 The frequency oscillator 10 has a variable oscillation frequency and outputs a high frequency according to an instruction from the control unit 14. The output of the frequency oscillator 10 is input to the RF amplifier 11. The RF amplifier 11 amplifies the input to a predetermined level (for example, several kW to several tens kW) and outputs the amplified signal. The output of the RF amplifier 11 is supplied to the load 3 via the matching unit 2.
負荷３は、例えば、エッチングや薄膜形成といった半導体製造工程で使用されるプラズマ処理装置、より具体的には、プラズマ処理装置のチャンバに巻きつけられた誘電性の負荷（コイル等）である。プラズマ処理装置は、適切な周波数とレベルの電力供給を受けると、例えばヘリカルレゾネータの原理で並列共振を起こし、プラズマを発生させる。また、プラズマ処理装置は、チャンバに供給されるガスやチャンバ内の圧力、印加電力等の条件により、インピーダンス特性が変化する。 The load 3 is, for example, a plasma processing apparatus used in a semiconductor manufacturing process such as etching or thin film formation, more specifically, a dielectric load (such as a coil) wound around a chamber of the plasma processing apparatus. When the plasma processing apparatus is supplied with electric power of an appropriate frequency and level, it causes parallel resonance by the principle of a helical resonator, for example, and generates plasma. In the plasma processing apparatus, impedance characteristics change depending on conditions such as gas supplied to the chamber, pressure in the chamber, and applied power.
ＲＦ増幅器１１と整合器２の間には、方向性結合器１２が設けられる。方向性結合器１２は、高周波電源装置１から負荷３に向かう進行波と、負荷３から高周波電源装置１に反射された反射波を取り出す。
方向性結合器１２で取り出された進行波と反射波は検出回路１３に入力される。検出回路１３は、進行波電力Ｐｆと反射波電力Ｐｒを表す信号を制御部１４に出力する。
尚、方向性結合器１２は、高周波電源装置１と別個に設けてもよい。また、方向性結合器１２は、整合器２と負荷３の間に設けるようにしてもよい。また、整合器２は、高周波電源装置１の内部に設けてもよい。 A directional coupler 12 is provided between the RF amplifier 11 and the matching unit 2. The directional coupler 12 extracts a traveling wave from the high frequency power supply device 1 toward the load 3 and a reflected wave reflected from the load 3 to the high frequency power supply device 1.
The traveling wave and the reflected wave extracted by the directional coupler 12 are input to the detection circuit 13. The detection circuit 13 outputs signals representing the traveling wave power Pf and the reflected wave power Pr to the control unit 14.
The directional coupler 12 may be provided separately from the high frequency power supply device 1. The directional coupler 12 may be provided between the matching unit 2 and the load 3. The matching unit 2 may be provided inside the high frequency power supply device 1.
負荷３のインピーダンスの変化に応じて高周波電源装置１と負荷３のインピーダンスに不整合が生じると、反射波が発生する。反射波が多くなれば、負荷３に供給される電力が反射波の電力分だけ少なくなり、プラズマを安定に発生できなくなる。このインピーダンスの不整合を解消するために、制御部１４は、進行波電力Ｐｆと反射波電力Ｐｒに基づき、周波数発振器１０の発振周波数と、整合器２の定数を制御する。以下、周波数発振器１０の発振周波数の制御を「周波数制御」と呼び、整合器２の定数の制御を「整合器制御」と呼ぶ。 When a mismatch occurs between the impedance of the high frequency power supply device 1 and the load 3 in accordance with the change in the impedance of the load 3, a reflected wave is generated. If the number of reflected waves increases, the power supplied to the load 3 decreases by the amount of reflected wave power, and plasma cannot be generated stably. In order to eliminate this impedance mismatch, the control unit 14 controls the oscillation frequency of the frequency oscillator 10 and the constant of the matching unit 2 based on the traveling wave power Pf and the reflected wave power Pr. Hereinafter, the control of the oscillation frequency of the frequency oscillator 10 is referred to as “frequency control”, and the constant control of the matching device 2 is referred to as “matching device control”.
　ここで、負荷のインピーダンスの周波数特性（以下、単に「周波数特性」と呼ぶ）と、整合器のトポロジーについて説明する。
周波数制御でインピーダンスを整合させる場合、周波数特性に応じて整合範囲が制限される。
図２に、周波数特性の一例を示す。図２は、周波数をパラメータとして、スミスチャート上にインピーダンスをプロットした図である。このスミスチャートは５０Ωで正規化した図で、ａ１点は周波数ｆａ１、ｂ１点は周波数ｆｂ１、ｃ１点は周波数ｆｃ１のときのインピーダンスを示している。 Here, the frequency characteristic of the impedance of the load (hereinafter simply referred to as “frequency characteristic”) and the topology of the matching device will be described.
When impedance is matched by frequency control, the matching range is limited according to frequency characteristics.
FIG. 2 shows an example of frequency characteristics. FIG. 2 is a diagram in which impedance is plotted on a Smith chart using frequency as a parameter. This Smith chart is a diagram normalized by 50Ω, where point a1 indicates the frequency fa1, point b1 indicates the frequency fb1, and point c1 indicates the impedance at the frequency fc1.
周波数制御でインピーダンスを整合させる場合には、インピーダンスが５０Ωであるｂ１点になるように、つまり周波数がｆｂ１になるように発振周波数を制御すればよい。図２の例では、周波数制御のみで整合がとれる周波数特性を示している。 When matching the impedance by frequency control, the oscillation frequency may be controlled so that the impedance is b1 where the impedance is 50Ω, that is, the frequency is fb1. The example of FIG. 2 shows frequency characteristics that can be matched only by frequency control.
図３に、周波数特性の他の例を示す。図３に示す周波数特性では、インピーダンスの軌跡が５０Ωの点を通らないため、周波数制御だけでは整合を取ることができない。
しかしながら、周波数特性が図３に示す特性であっても、整合器制御を組み合せることで、整合を取ることが可能となることを発明者は知見した。周波数制御に整合器制御を組み合せるにあたり、整合器のトポロジーが重要となる。図４に、図３に示す周波数特性に適した整合器の回路構成例を示す。図４に示す回路構成例では、負荷に対して並列に可変コンデンサを設けた。 FIG. 3 shows another example of frequency characteristics. In the frequency characteristics shown in FIG. 3, since the impedance locus does not pass through a point of 50Ω, matching cannot be achieved only by frequency control.
However, the inventor has found that even if the frequency characteristic is the characteristic shown in FIG. 3, matching can be achieved by combining matching unit control. In combining the matching device control with the frequency control, the topology of the matching device is important. FIG. 4 shows a circuit configuration example of a matching device suitable for the frequency characteristics shown in FIG. In the circuit configuration example shown in FIG. 4, a variable capacitor is provided in parallel with the load.
図５に、図４に示す回路のインピーダンスの軌跡を示す。図５では、説明を簡単にするため、５０Ωの負荷にコンデンサを並列に接続したときの軌跡を示している。図５に示すように、コンデンサの容量が大きくなるに従い、インピーダンスがゼロに向かう軌跡を描く。この特性を図３に示す周波数特性に組み合せると、図６のようにａ２点、ｂ２点、ｃ２点は、それぞれａ３点、ｂ３点、ｃ３点に移動する。この状態で、インピーダンスがｂ３点になるように周波数制御を行うことで整合を取ることができる。 FIG. 5 shows an impedance locus of the circuit shown in FIG. FIG. 5 shows a locus when a capacitor is connected in parallel to a 50Ω load for the sake of simplicity. As shown in FIG. 5, as the capacitance of the capacitor increases, a locus in which the impedance goes to zero is drawn. When this characteristic is combined with the frequency characteristic shown in FIG. 3, the points a2, b2, and c2 move to points a3, b3, and c3, respectively, as shown in FIG. In this state, matching can be achieved by performing frequency control so that the impedance is at point b3.
ここで、図３に示す周波数特性に好適な整合器を図４に示す回路構成とした理由について説明する。図３と図５を比較してわかるように、それぞれのインピーダンスの軌跡は並行しない。仮に、周波数に対するインピーダンスの軌跡と、整合器の定数を変更したときのインピーダンスの軌跡が一致（並行）するならば、周波数制御と整合器制御を組み合わせたとしても、整合範囲を広げることは出来ない。一方、周波数に対するインピーダンスの軌跡と、整合器の定数を変更したときのインピーダンスの軌跡を並行させない（例えば直交させる）ことで、周波数に対するインピーダンスの軌跡を、５０Ωを通過する軌跡にすることができる。 Here, the reason why the matching unit suitable for the frequency characteristics shown in FIG. 3 is configured as the circuit shown in FIG. 4 will be described. As can be seen by comparing FIG. 3 and FIG. 5, the loci of the respective impedances are not parallel. If the impedance trajectory with respect to frequency matches the impedance trajectory when the constant of the matching unit is changed (parallel), the matching range cannot be expanded even if frequency control and matching unit control are combined. . On the other hand, by making the impedance locus with respect to the frequency and the impedance locus when the constants of the matching unit are changed not parallel (for example, orthogonal), the impedance locus with respect to the frequency can be made a locus that passes 50Ω.
そこで、負荷の周波数特性に応じて、整合器のトポロジーを見直す必要がある。具体的には、上記のように、周波数に対するインピーダンスの軌跡に対して、整合器の定数を変更したときの軌跡が並行しないようにする。この条件を満たせば、周波数制御と整合器制御を組み合せることで多様な周波数特性に対して整合を取ることが可能となり、整合範囲を広げることができる。 Therefore, it is necessary to review the topology of the matching device according to the frequency characteristics of the load. Specifically, as described above, the locus when the constant of the matching device is changed is not parallel to the locus of the impedance with respect to the frequency. If this condition is satisfied, it becomes possible to match various frequency characteristics by combining frequency control and matching device control, and the matching range can be expanded.
本実施例では、負荷３の周波数特性は図３に示す特性であり、整合器２は図４に示す回路構成であるものとする。
また、本実施例では、整合器２を構成する可変コンデンサは真空コンデンサであり、電動モータ等を駆動して容量を変更するものとする。
尚、周波数特性や回路構成は上記の条件を満たしていればよく、図示のものに限定されるものではない。回路構成としては、例えば、負荷３に対して直列に可変コンデンサを接続した構成や、インダクタとコンデンサを組み合わせた構成であってもよい。 In this embodiment, it is assumed that the frequency characteristic of the load 3 is the characteristic shown in FIG. 3, and the matching unit 2 has the circuit configuration shown in FIG.
In the present embodiment, the variable capacitor constituting the matching unit 2 is a vacuum capacitor, and the capacity is changed by driving an electric motor or the like.
The frequency characteristics and the circuit configuration are not limited to those shown in the drawing as long as the above conditions are satisfied. The circuit configuration may be, for example, a configuration in which a variable capacitor is connected in series with the load 3 or a configuration in which an inductor and a capacitor are combined.
　次いで、制御部１４で実行される周波数制御と整合器制御について説明する。 Next, frequency control and matching unit control executed by the control unit 14 will be described.
　図７は、制御部１４で実行される周波数制御の動作を示すフローチャートであり、図８は、制御部１４で実行される整合器制御の動作を示すフローチャートである。
　本実施例では、制御部１４において、周波数制御と整合器制御を相互に切り替えながら実行する。周波数制御と整合器制御は、高周波電源装置１の起動後、どちらを先に実行してもよいが、本実施例では周波数制御を先に実行する。これは、一般に周波数制御の方が整合器制御よりも時定数が小さく、収束に要する時間が短いためである。最初に広い範囲で整合を試みたい場合などは、整合器制御を先に実行してもよい。 FIG. 7 is a flowchart showing the frequency control operation executed by the control unit 14, and FIG. 8 is a flowchart showing the matching unit control operation executed by the control unit 14.
In the present embodiment, the control unit 14 executes frequency control and matching unit control while switching between them. Either frequency control or matching unit control may be executed first after the high-frequency power supply device 1 is activated, but in this embodiment, frequency control is executed first. This is because the frequency control generally has a smaller time constant than the matching unit control, and the time required for convergence is shorter. When it is desired to try matching in a wide range at first, the matching device control may be executed first.
　図７に示す周波数制御の動作について説明すると、先ず、周波数制御フラグがＯＮか否か判断する（Ｓ１０）。周波数制御フラグは、周波数制御の実行を許可するフラグであり、初期値はＯＮ（実行許可）である。
　周波数制御フラグがＯＦＦの場合は以降の処理をスキップする。一方、周波数制御フラグがＯＮのときはＶＳＷＲ（ｖｏｌｔａｇｅ
ｓｔａｎｄｉｎｇ ｗａｖｅ ｒａｔｉｏ。電圧定在波比）の今回値であるＶＳ（ｔ）を算出する。ＶＳ（ｔ）は次の式１に従って算出する（Ｓ１１）。ＰｆとＰｒは、それぞれ進行波電力と反射波電力である。
ＶＳ（ｔ）＝（Ｐｆ＋Ｐｒ）／（Ｐｆ－Ｐｒ）　　式１ The operation of the frequency control shown in FIG. 7 will be described. First, it is determined whether or not the frequency control flag is ON (S10). The frequency control flag is a flag that permits execution of frequency control, and the initial value is ON (permission permission).
When the frequency control flag is OFF, the subsequent processing is skipped. On the other hand, when the frequency control flag is ON, VSWR (Voltage
standing wave ratio. VS (t) which is the current value of the voltage standing wave ratio) is calculated. VS (t) is calculated according to the following equation 1 (S11). Pf and Pr are traveling wave power and reflected wave power, respectively.
VS (t) = (Pf + Pr) / (Pf−Pr) Equation 1
　次いで、追従制御を実行中か否か判断する（Ｓ１２）。追従制御とは、ＶＳ（ｔ）に応じて発振周波数を変更する制御である。追従制御を実行中でない場合は、掃引制御（ＳＷＥＥＰ制御）を実行中か否か判断する（Ｓ１３）。掃引制御を実行中でない場合は、発振周波数Ｆ（ｔ）に初期値（初期周波数）を設定して周波数発振器１０を動作させる（Ｓ１４）。そして、初期周波数による周波数発振器１０の動作時間を計時する（Ｓ１５）。所定時間経過するまで（タイムＵＰするまで）はＳ１０からＳ１４の処理を繰り返す。一方、所定時間経過した場合は掃引制御に移行し（Ｓ１６）、Ｓ１０に戻る。 Next, it is determined whether follow-up control is being executed (S12). The follow-up control is control for changing the oscillation frequency in accordance with VS (t). If the follow-up control is not being executed, it is determined whether or not the sweep control (SWEEP control) is being executed (S13). When the sweep control is not being executed, an initial value (initial frequency) is set to the oscillation frequency F (t) and the frequency oscillator 10 is operated (S14). Then, the operating time of the frequency oscillator 10 at the initial frequency is measured (S15). Until the predetermined time elapses (until the time is up), the processing from S10 to S14 is repeated. On the other hand, when the predetermined time has elapsed, the process shifts to the sweep control (S16) and returns to S10.
　掃引制御に移行すると、次回のループにおいてＳ１３で肯定され、掃引制御が実行される（Ｓ１７）。掃引制御では、周波数を大きく動かしながらＶＳ（ｔ）が低下するポイントをサーチする。
掃引制御を行いながらＶＳ（ｔ）を所定値ＶＳｒｅｆと比較し（Ｓ１８）、ＶＳ（ｔ）が所定値ＶＳｒｅｆを下回った場合は追従制御に移行する（Ｓ１９）。ＶＳ（ｔ）が所定値ＶＳｒｅｆを下回わらない場合はＳ１０に戻って掃引制御を継続する。 When the control is shifted to the sweep control, an affirmative determination is made in S13 in the next loop, and the sweep control is executed (S17). In the sweep control, a search is made for a point at which VS (t) decreases while the frequency is moved greatly.
While performing the sweep control, VS (t) is compared with the predetermined value VSref (S18), and when VS (t) falls below the predetermined value VSref, the control shifts to the follow-up control (S19). If VS (t) does not fall below the predetermined value VSref, the process returns to S10 and the sweep control is continued.
追従制御に移行すると、次回のループにおいてＳ１２で肯定され、周波数変更方向（ｄｏｗｎまたはＵＰ）の決定処理が行われる（Ｓ２０）。
追従制御が初回であるときは、周波数の変更方向は特定の方向（本実施例ではｄｏｗｎとする）に決定される。一方、追従制御が２回目以降であるときは、ＶＳＷＲの前回値（前回の追従制御を行う前のＶＳＷＲ）であるＶＳ（ｔ－１）と今回値ＶＳ（ｔ）に基づいて変更方向を決定する。具体的には、ＶＳ（ｔ－１）がＶＳ（ｔ）以上、即ち、前回の追従制御によってＶＳＷＲが改善している場合には、前回と同一方向とする。逆に、ＶＳ（ｔ－１）がＶＳ（ｔ）を下回っている、即ち、前回の追従制御によってＶＳＷＲが悪化している場合には、前回と逆方向とする。 When the control is shifted to the follow-up control, an affirmative determination is made in S12 in the next loop, and a process for determining the frequency change direction (down or UP) is performed (S20).
When the follow-up control is the first time, the frequency changing direction is determined to be a specific direction (down in this embodiment). On the other hand, when the follow-up control is the second time or later, the change direction is determined based on VS (t−1) which is the previous value of VSWR (VSWR before the previous follow-up control) and current value VS (t). To do. Specifically, when VS (t−1) is equal to or higher than VS (t), that is, when VSWR is improved by the previous tracking control, the direction is the same as the previous time. Conversely, if VS (t−1) is lower than VS (t), that is, if VSWR has deteriorated due to the previous tracking control, the direction is the reverse of the previous time.
次いで、周波数の変更幅ΔＦを決定する（Ｓ２１）。変更幅ΔＦは、ＶＳ（ｔ）に応じて決定される。具体的には、ＶＳ（ｔ）が大きいほど（目標値から離れているほど）、変更幅ΔＦを大きくする。これにより、ＶＳ（ｔ）をより速やかに目標値に近づけることができると共に、目標値近傍では精度良く目標値に追従させることができる。 Next, a frequency change width ΔF is determined (S21). The change width ΔF is determined according to VS (t). Specifically, the change width ΔF is increased as VS (t) is larger (away from the target value). As a result, VS (t) can be brought closer to the target value more quickly, and the target value can be accurately followed in the vicinity of the target value.
　周波数の変更方向と変更幅ΔＦを決定すると、現在の発振周波数であるＦ（ｔ）にΔＦを加算あるいは減算して、Ｆ（ｔ）を更新する（Ｓ２２）。次いで、ＶＳ（ｔ）を前回値ＶＳ（ｔ－１）として記憶し（Ｓ２３）、発振周波数をＳ２２で更新した新たなＦ（ｔ）に制御する（Ｓ２４）。 When the frequency change direction and change width ΔF are determined, F (t) is updated by adding or subtracting ΔF to F (t), which is the current oscillation frequency (S22). Next, VS (t) is stored as the previous value VS (t-1) (S23), and the oscillation frequency is controlled to the new F (t) updated in S22 (S24).
　次いで、発振周波数が変更された後のＶＳ（ｔ）を算出し、当該ＶＳ（ｔ）が目標値に達しているか否か判断する（Ｓ２５）。本実施例では、目標とするＶＳＷＲを１とする。 Next, VS (t) after the oscillation frequency is changed is calculated, and it is determined whether or not the VS (t) has reached the target value (S25). In this embodiment, the target VSWR is 1.
　ＶＳ（ｔ）が目標値に達していない場合は、追従制御回数Ｆｃｎｔ（ｎ）をカウントアップし（Ｓ２６）、このＦｃｎｔ（ｎ）が所定回数（例えば１００回）を超えているか否か判断する（Ｓ２７）。Ｆｃｎｔ（ｎ）が所定回数を超えていない場合、即ち、周波数制御によるＶＳ（ｔ）の改善がまだ見込まれる場合は、Ｓ１０に戻って周波数制御を継続する。
一方、Ｆｃｎｔ（ｎ）が所定回数を超えているときは、周波数制御をこれ以上行ってもＶＳ（ｔ）の改善は期待できないため、周波数制御フラグをＯＦＦにすると共に、整合器制御フラグ（初期値ＯＦＦ）をＯＮに設定し（Ｓ２８）、Ｓ１０に戻る。周波数制御フラグがＯＦＦに設定されると、次回のループにおいてＳ１０で否定されるため、周波数制御が実行されないことになる。 When VS (t) has not reached the target value, the follow-up control frequency Fcnt (n) is counted up (S26), and it is determined whether or not this Fcnt (n) exceeds a predetermined number (for example, 100 times). (S27). When Fcnt (n) does not exceed the predetermined number of times, that is, when improvement of VS (t) by frequency control is still expected, the process returns to S10 and frequency control is continued.
On the other hand, when Fcnt (n) exceeds the predetermined number of times, improvement of VS (t) cannot be expected even if the frequency control is further performed. Therefore, the frequency control flag is turned OFF and the matching unit control flag (initial (Value OFF) is set to ON (S28), and the process returns to S10. When the frequency control flag is set to OFF, the result of S10 is negative in the next loop, so that frequency control is not executed.
　また、ＶＳ（ｔ）が目標値に達した場合は、追従制御回数Ｆｃｎｔ（ｎ）の値を０にリセットし（Ｓ２９）、Ｓ１０に戻る。尚、ＶＳ（ｔ）が目標値に達した場合は、一定時間、周波数制御を停止してもよい。 If VS (t) has reached the target value, the value of the follow-up control count Fcnt (n) is reset to 0 (S29), and the process returns to S10. When VS (t) reaches the target value, the frequency control may be stopped for a certain time.
　次いで、図８に示す整合器制御の動作について説明する。図８に示す処理は、図７に示す処理と同時に（並行して）実行される。整合器制御では、先ず、整合器制御フラグがＯＮか否か判断する（Ｓ５０）。この整合器制御フラグは、ＯＮのときに整合器制御の実行を許可するもので、整合器制御フラグがＯＮでないときは以降の処理をスキップする。
前述したように、整合器制御フラグは、初期値がＯＦＦであると共に、図７に示す処理で周波数制御フラグがＯＦＦされるのと同時にＯＮに設定される。そのため、高周波電源装置１の起動時には整合器制御は実行されず、周波数制御から整合器制御に切り替えられることになる。
周波数制御から整合器制御に切り替えられた際、発振器１０の発振周波数は、周波数制御で設定された最新のＦ（ｔ）に維持される。 Next, the operation of the matching unit control shown in FIG. 8 will be described. The process shown in FIG. 8 is executed simultaneously (in parallel) with the process shown in FIG. In the matching unit control, first, it is determined whether or not the matching unit control flag is ON (S50). The matching unit control flag permits execution of matching unit control when it is ON. When the matching unit control flag is not ON, the subsequent processing is skipped.
As described above, the matching unit control flag has the initial value OFF, and is set to ON simultaneously with the frequency control flag being turned OFF in the process shown in FIG. Therefore, the matching device control is not executed when the high frequency power supply device 1 is started, and the frequency control is switched to the matching device control.
When switching from frequency control to matching device control, the oscillation frequency of the oscillator 10 is maintained at the latest F (t) set by the frequency control.
整合器制御フラグがＯＮのときはＶＳ（ｔ）を算出し（Ｓ５１）、定数変更方向（ｄｏｗｎまたはＵＰ）の決定処理が行われる（Ｓ５２）。
整合器制御が初回であるときは、定数の変更方向は特定の方向（本実施例ではｕｐ方向）に決定される。一方、整合器制御が２回目以降であるときは、前回の整合器制御を行う前のＶＳＷＲであるＶＳ（ｔ－ｘ）と今回値ＶＳ（ｔ）に基づいて変更方向を決定する。具体的には、ＶＳ（ｔ－ｘ）がＶＳ（ｔ）以上、即ち、前回の整合器制御によってＶＳＷＲが改善している場合には、前回と同一方向とする。逆に、ＶＳ（ｔ－ｘ）がＶＳ（ｔ）を下回っている、即ち、前回の整合器制御によってＶＳＷＲが悪化している場合には、前回と逆方向とする。 When the matcher control flag is ON, VS (t) is calculated (S51), and the constant change direction (down or UP) is determined (S52).
When the matcher control is the first time, the constant changing direction is determined to be a specific direction (up direction in this embodiment). On the other hand, when the matcher control is performed for the second time or later, the change direction is determined based on VS (t−x), which is VSWR before the previous matcher control, and the current value VS (t). Specifically, when VS (t−x) is equal to or higher than VS (t), that is, when the VSWR is improved by the previous matcher control, the direction is the same as the previous time. On the other hand, when VS (t−x) is lower than VS (t), that is, when VSWR has deteriorated due to the previous matcher control, the reverse direction is set.
次いで、定数の変更幅ΔＣを決定する（Ｓ５３）。変更幅ΔＣは、ΔＦ同様、ＶＳ（ｔ）に応じて決定される。具体的には、ＶＳ（ｔ）が大きいほど（目標値から離れているほど）、変更幅ΔＣを大きくする。これにより、ＶＳ（ｔ）をより速やかに目標値に近づけることができると共に、目標値近傍では精度良く目標値に追従させることができる。尚、整合器制御で制御する定数は、具体的には可変コンデンサの容量であり、ΔＣの単位は、例えばｐＦ（ピコ・ファラッド）とする。 Next, a constant change width ΔC is determined (S53). The change width ΔC is determined according to VS (t), similarly to ΔF. Specifically, the change width ΔC is increased as VS (t) increases (away from the target value). As a result, VS (t) can be brought closer to the target value more quickly, and the target value can be accurately followed in the vicinity of the target value. The constant controlled by the matching unit control is specifically the capacitance of the variable capacitor, and the unit of ΔC is, for example, pF (pico farad).
　定数の変更方向と変更幅ΔＣを決定すると、現在の定数であるＣ（ｔ）にΔＣを加算あるいは減算して、Ｃ（ｔ）を更新する（Ｓ５４）。そして、ＶＳ（ｔ）を上述のＶＳ（ｔ－ｘ）として記憶し（Ｓ５５）、定数をＳ５４で更新した新たなＣ（ｔ）に制御する（Ｓ５６）。 When the constant change direction and change width ΔC are determined, ΔC is added to or subtracted from the current constant C (t) to update C (t) (S54). Then, VS (t) is stored as VS (t−x) described above (S55), and the constant is controlled to the new C (t) updated in S54 (S56).
　次いで、定数が変更された後のＶＳ（ｔ）を算出し、当該ＶＳ（ｔ）が目標値（ＶＳＷＲ＝１）に達しているか否か判断する（Ｓ５７）。 Next, VS (t) after the constant is changed is calculated, and it is determined whether or not the VS (t) has reached the target value (VSWR = 1) (S57).
　ＶＳ（ｔ）が目標値に達していない場合は、整合器制御回数Ｃｃｎｔ（ｎ）をカウントアップし（Ｓ５８）、このＣｃｎｔ（ｎ）が所定回数（例えば５回）を超えているか否か判断する（Ｓ５９）。Ｃｃｎｔ（ｎ）が所定回数を超えていない、即ち、整合器制御によるＶＳ（ｔ）の改善がまだ見込まれるときは、Ｓ５０に戻って整合器制御を継続する。
一方、Ｃｃｎｔ（ｎ）が所定回数を超えているときは、整合器制御をこれ以上継続してもＶＳ（ｔ）の改善が期待できないため、周波数制御フラグをＯＮにすると共に、整合器制御フラグをＯＦＦに設定し（Ｓ６０）、Ｓ５０に戻る。また、ＶＳ（ｔ）が目標値に達した場合は、整合器制御回数Ｃｃｎｔ（ｎ）の値を０にリセットし（Ｓ６１）、Ｓ５０に戻る。尚、ＶＳ（ｔ）が目標値に達した場合は、一定時間、整合器制御を停止してもよい。 If VS (t) has not reached the target value, the matching unit control count Ccnt (n) is counted up (S58), and it is determined whether or not this Ccnt (n) exceeds a predetermined number (for example, 5 times). (S59). When Ccnt (n) does not exceed the predetermined number of times, that is, when improvement of VS (t) by the matching device control is still expected, the process returns to S50 and the matching device control is continued.
On the other hand, when Ccnt (n) exceeds the predetermined number of times, improvement of VS (t) cannot be expected even if the matching unit control is continued further. Therefore, the frequency control flag is turned ON and the matching unit control flag is set. Is set to OFF (S60), and the process returns to S50. When VS (t) reaches the target value, the value of the matching unit control count Ccnt (n) is reset to 0 (S61), and the process returns to S50. When VS (t) reaches the target value, the matching unit control may be stopped for a certain time.
Ｓ６０で整合器制御フラグがＯＦＦに設定されると、次回のループにおいてＳ５０で否定されるため、整合器制御が実行されないことになる。逆に、周波数制御フラグがＯＮにされると、図７に示す処理で周波数制御が実行される。即ち、整合器制御から周波数制御に切り替えられる。このとき、整合器２の定数は、整合器制御で設定された最新のＣ（ｔ）に維持される。尚、整合器制御から周波数制御に切り替えられたときは、図７のＳ１２で肯定され、追従制御が実行されるものとする。 If the matcher control flag is set to OFF in S60, the matcher control is not executed because the result in S50 is negative in the next loop. Conversely, when the frequency control flag is turned ON, frequency control is executed by the processing shown in FIG. In other words, the matching device control is switched to the frequency control. At this time, the constant of the matching unit 2 is maintained at the latest C (t) set by the matching unit control. When the matching device control is switched to the frequency control, it is affirmed in S12 of FIG. 7 and the follow-up control is executed.
図９は、図７に示す周波数制御と図８に示す整合器制御を実行したときの整合状態を示すタイムチャートである。
図９に示すように、周波数制御で整合しきれなかった場合、周波数制御で設定した周波数を維持しつつ整合器制御に切り替えることで、整合を取ることができる。また、整合器制御でも整合しきれなかった場合は、当該整合器制御で設定した定数を維持しつつ、再度、周波数制御に切り替えて整合を試みることで、徐々に目標値に近づけることができる。
尚、図９では、理解の便宜上、整合器制御の開始後、しばらくして定数が変更されるように示したが、実際には、設定した定数に徐々に近づいていく。 FIG. 9 is a time chart showing a matching state when the frequency control shown in FIG. 7 and the matching unit control shown in FIG. 8 are executed.
As shown in FIG. 9, when the frequency control cannot be matched, matching can be achieved by switching to the matching device control while maintaining the frequency set by the frequency control. In addition, when the matching cannot be achieved even by the matching unit control, it is possible to gradually approach the target value by switching to the frequency control again and attempting the matching while maintaining the constant set by the matching unit control.
In FIG. 9, for convenience of understanding, the constant is shown to be changed after a while after the start of the matching unit control. However, in actuality, the constant gradually approaches the set constant.
以上のように、本発明の第１の実施の形態に係る高周波電源装置にあっては、周波数制御と整合器制御とを切り替えて実行すると共に、周波数制御から整合器制御に切り替えるとき、周波数制御の制御結果（最新のＦ（ｎ））を維持したまま整合器制御を行い、整合器制御から周波数制御に切り替えるとき、整合器制御の制御結果（最新のＣ（ｔ））を維持したまま周波数制御を実行するようにした。また、周波数制御（追従制御）を所定回数実行してもＶＳ（ｔ）が目標値に達しないときは周波数制御から整合器制御に切り替え、整合器制御を所定回数実行してもＶＳ（ｔ）が目標値に達しないときは整合器制御から周波数制御（追従制御）に切り替えるようにした。
このように、周波数制御と整合器制御とを連携して行うことで、整合範囲を広げることができる。 As described above, in the high frequency power supply device according to the first embodiment of the present invention, the frequency control and the matching device control are switched and executed, and when the frequency control is switched to the matching device control, the frequency control is performed. When the matcher control is performed while maintaining the control result (latest F (n)) and switching from the matcher control to the frequency control, the frequency is maintained while maintaining the matcher control result (latest C (t)). Control was executed. Further, if VS (t) does not reach the target value even if frequency control (follow-up control) is executed a predetermined number of times, switching from frequency control to matching device control is performed, and VS (t) is executed even if matching device control is executed a predetermined number of times. When the value does not reach the target value, switching from matcher control to frequency control (follow-up control) is performed.
As described above, the matching range can be expanded by performing the frequency control and the matching unit control in cooperation.
　次いで、第２の実施の形態に係る高周波電源装置について説明する。第１の実施の形態との相違点は周波数制御と整合器制御にあるので、それについて説明する。
　図１０は、本発明の第２の実施の形態に係る周波数制御と整合器制御の処理の前半部分を示すフローチャートであり、図１１は、図１０に示す処理の後半部分を示すフローチャートである。 Next, a high frequency power supply device according to a second embodiment will be described. The difference from the first embodiment is in frequency control and matching unit control, which will be described.
FIG. 10 is a flowchart showing the first half of the frequency control and matching unit control processing according to the second embodiment of the present invention, and FIG. 11 is a flowchart showing the second half of the processing shown in FIG.
　図１０の処理について説明すると、先ず、ＶＳ（ｔ）と、周波数制御によるＶＳＷＲの変化率Ｆｖｓとを算出する（Ｓ１００）。ＶＳ（ｔ）の算出には上述の式１を用いる。Ｆｖｓの単位はパーセントであり、その算出には以下の式２を用いる。
Ｆｖｓ＝（（ＶＳ（ｔ－１）／ＶＳ（ｔ））×１００）－１００　　式２ The processing of FIG. 10 will be described. First, VS (t) and the VSWR change rate Fvs by frequency control are calculated (S100). For calculating VS (t), the above Equation 1 is used. The unit of Fvs is percent, and the following formula 2 is used for the calculation.
Fvs = ((VS (t−1) / VS (t)) × 100) −100 Equation 2
　次いで、Ｓ１０１からＳ１１６、Ｓ１１８において、第１の実施の形態で説明した図７のＳ１２からＳ２７、Ｓ２９と同様の処理を行う。これらの処理については説明を省略する。 Next, in S101 to S116 and S118, the same processing as S12 to S27 and S29 in FIG. 7 described in the first embodiment is performed. Description of these processes is omitted.
　図１０において、Ｓ１１６で肯定された場合は、Ｆｖｓの絶対値が所定値Ｆｖｓｒｅｆ（例えば５％）を下回っているか否か、即ち、周波数制御によるＶＳＷＲの変化が少ないか否か判断する（Ｓ１１７）。周波数制御によるＶＳＷＲの変化が大きく、周波数制御によるＶＳ（ｔ）の改善が見込まれる場合は、Ｓ１００に戻って周波数制御（追従制御）を継続する。尚、Ｓ１１７において、所定回数連続してＦｖｓの絶対値が所定値Ｆｖｓｒｅｆを下回っているか否か判断するようにしてもよい。 In FIG. 10, when the result in S116 is affirmative, it is determined whether or not the absolute value of Fvs is below a predetermined value Fvsref (for example, 5%), that is, whether or not the change in VSWR due to frequency control is small (S117). . When the change in VSWR due to the frequency control is large and the improvement of VS (t) due to the frequency control is expected, the process returns to S100 and the frequency control (follow-up control) is continued. In S117, it may be determined whether or not the absolute value of Fvs is lower than the predetermined value Fvsref for a predetermined number of times.
　一方、周波数制御によるＶＳＷＲの変化が小さく、周波数制御によるＶＳ（ｔ）の改善が期待できない場合は、図１１のＳ１１９からＳ１２３において、第１の実施の形態で説明した図８のＳ５２からＳ５６と同様の整合器制御を行う。周波数制御から整合器制御に切り替えられた際、発振器１０の発振周波数は周波数制御で設定された最新のＦ（ｔ）が維持される。 On the other hand, when the change in VSWR due to frequency control is small and improvement of VS (t) due to frequency control cannot be expected, in S119 to S123 in FIG. 11, S52 to S56 in FIG. 8 described in the first embodiment are used. Similar matching unit control is performed. When the frequency control is switched to the matching device control, the latest F (t) set by the frequency control is maintained as the oscillation frequency of the oscillator 10.
　図１１において、Ｓ１２３の処理の後、定数変更が完了したか否か判断する（Ｓ１２４）。前述したように、整合器制御において、可変コンデンサの定数の変更には時間を要する。Ｓ１２４では、例えば、可変コンデンサの駆動を開始してからの経過時間をカウントしたり、可変コンデンサの容量を検出したりすることにより、定数変更が完了したか否かを判断する。
　定数の変更が完了していない場合は、定数の変更が完了するまでＳ１２４の処理を繰り返す。一方、定数の変更が完了した場合は、Ｓ１０１の処理に戻って周波数制御（追従制御）を実行する。整合器制御から周波数制御に切り替えられた際、整合器２の定数は整合器制御で設定された最新のＣ（ｔ）が維持される。 In FIG. 11, after the process of S123, it is determined whether or not the constant change has been completed (S124). As described above, it takes time to change the constant of the variable capacitor in the matching unit control. In S124, for example, it is determined whether or not the constant change has been completed by counting the elapsed time from the start of driving the variable capacitor or detecting the capacitance of the variable capacitor.
If the change of the constant is not completed, the process of S124 is repeated until the change of the constant is completed. On the other hand, when the change of the constant is completed, the process returns to S101 to execute frequency control (follow-up control). When the matching device control is switched to the frequency control, the constant of the matching device 2 is maintained at the latest C (t) set by the matching device control.
図１２は、図１０、図１１に示す周波数制御と整合器制御を実行したときの整合状態を示すタイムチャートである。
図１２に示すように、周波数制御で整合しきれなかった場合、周波数制御で設定した周波数を維持しつつ整合器制御に切り替える。そして、整合器制御で定数を所定回数（本実施例では１回）変更し、定数の変更が完了した時点で再度周波数制御に戻って整合を試みる。尚、整合器制御を連続して複数回実行した後、周波数制御に戻るようにしてもよい。 FIG. 12 is a time chart showing a matching state when the frequency control and matching unit control shown in FIGS. 10 and 11 are executed.
As shown in FIG. 12, when the frequency control fails to match, switching to the matching device control is performed while maintaining the frequency set by the frequency control. Then, the constant is changed a predetermined number of times (one time in the present embodiment) by the matching unit control, and when the change of the constant is completed, the frequency control is returned again to try the matching. Note that the matching unit control may be continuously performed a plurality of times and then returned to the frequency control.
このように、本発明の第２の実施の形態に係る高周波電源装置にあっては、周波数制御と整合器制御とを連携して行うことで、整合範囲を広げることができる。また、動作に時間を要する整合器制御を所定回数実行して周波数制御に移行するようにしたので、整合器制御で整合が取りきれないと判断されるまで整合器制御を継続する第１の実施の形態に比し、整合時間の短縮が期待できる。また、整合器制御の回数が減少すれば、機械的動作部品を有する整合器の寿命を延ばすことができる。 Thus, in the high frequency power supply device according to the second embodiment of the present invention, the matching range can be expanded by performing the frequency control and the matching unit control in cooperation. In addition, since matching device control that requires time for operation is executed a predetermined number of times to shift to frequency control, the matching device control is continued until it is determined that matching cannot be achieved by the matching device control. Compared to this form, shortening of the matching time can be expected. Further, if the number of times of matching device control is reduced, the life of the matching device having mechanically operating parts can be extended.
　次いで、第３の実施の形態に係る高周波電源装置について説明する。従前の実施の形態との相違点は周波数制御と整合器制御にあるので、それについて説明する。
　図１３は、本発明の第３の実施の形態に係る周波数制御と整合器制御の処理の前半部分を示すフローチャートであり、図１４は、図１３に示す処理の後半部分を示すフローチャートである。 Next, a high frequency power supply device according to a third embodiment will be described. The difference from the previous embodiment is in frequency control and matching device control, which will be described.
FIG. 13 is a flowchart showing the first half of the frequency control and matching unit control processing according to the third embodiment of the present invention, and FIG. 14 is a flowchart showing the second half of the processing shown in FIG.
　図１３の処理について説明すると、先ず、ＶＳ（ｔ）と、Ｆｖｓと、整合器制御によるＶＳＷＲの変化率Ｃｖｓとを算出する（Ｓ２００）。ＶＳ（ｔ）の算出には上述の式１を用い、Ｆｖｓの算出には上述の式２を用いる。Ｃｖｓの単位はパーセントであり、その算出には以下の式３を用いる。
Ｃｖｓ＝（（ＶＳ（ｔ－ｘ）／ＶＳ（ｔ））×１００）－１００　　式３ The processing of FIG. 13 will be described. First, VS (t), Fvs, and the VSWR change rate Cvs by the matching unit control are calculated (S200). The above equation 1 is used for calculating VS (t), and the above equation 2 is used for calculating Fvs. The unit of Cvs is percent, and the following formula 3 is used for the calculation.
Cvs = ((VS (t−x) / VS (t)) × 100) −100 Equation 3
　次いで、今回の処理が、高周波電源装置１が起動してから初回の処理であるか否か判断する（Ｓ２０１）。今回の処理が初回であれば、整合器制御初回フラグをＯＮに設定すると共に、中断中フラグをＯＦＦに設定する（Ｓ２０２）。今回の処理が初回でなければ、Ｓ２０２の処理は行わない。 Next, it is determined whether or not the current process is the first process after the high frequency power supply device 1 is activated (S201). If this process is the first time, the matching unit control initial flag is set to ON and the interrupting flag is set to OFF (S202). If this process is not the first time, the process of S202 is not performed.
　次いで、Ｓ２０３からＳ２１７において、第２の実施の形態で説明した図１０のＳ１０１からＳ１１４、Ｓ１１８と同様な処理を行う。
　図１３において、Ｓ２１６で否定された場合は、整合器制御初回フラグがＯＮに設定されているか否か判断する（Ｓ２１８）。整合器制御初回フラグは、高周波電源装置１の起動後に整合器制御が未実施か否かを示すフラグである。 Next, in S203 to S217, processing similar to S101 to S114 and S118 of FIG. 10 described in the second embodiment is performed.
In FIG. 13, when the result in S216 is negative, it is determined whether or not the matcher control initial flag is set to ON (S218). The matcher control initial flag is a flag indicating whether or not matcher control is not performed after the high frequency power supply device 1 is started.
整合器制御初回フラグがＯＮの場合、即ち、まだ整合器制御を実行していないときは、Ｓ２１９からＳ２２１において、図１０のＳ１１５からＳ１１７と同様な処理を行う。一方、整合器制御初回フラグがＯＮに設定されていないとき、即ち、整合器制御が既に実行されているときは、Ｓ２１９からＳ２２１の処理をスキップする。 When the matcher control initial flag is ON, that is, when matcher control is not yet executed, the same processing as S115 to S117 in FIG. 10 is performed in S219 to S221. On the other hand, when the matching unit control initial flag is not set to ON, that is, when matching unit control has already been executed, the processing from S219 to S221 is skipped.
　次いで、図１４の処理に進み、定数を変更中か否か、具体的には、可変コンデンサを駆動している最中か否か判断する（Ｓ２２２）。この処理は、図１１のＳ１２４と同様に、可変コンデンサの駆動を開始してからの経過時間をカウントしたり、可変コンデンサの容量を検出したりすることで判断する。
　Ｓ２２２で否定されるときは、中断中フラグがＯＮに設定されているか否か判断する（Ｓ２２３）。中断中フラグがＯＮに設定されていなければ、Ｃｖｓの絶対値が第１の所定値Ｃｖｓｒｅｆ１（例えば５％）を下回っているか否か、即ち、整合器制御によるＶＳ（ｔ）の変化が少ないか否か判断する（Ｓ２２４）。尚、Ｓ２２４において、所定回数連続してＣｖｓの絶対値が第１の所定値Ｃｖｓｒｅｆ１を下回っているか否か判断するようにしてもよい。 Next, the process proceeds to the process of FIG. 14 to determine whether or not the constant is being changed, specifically, whether or not the variable capacitor is being driven (S222). This process is determined by counting the elapsed time from the start of driving of the variable capacitor or detecting the capacitance of the variable capacitor, as in S124 of FIG.
When the result in S222 is negative, it is determined whether or not the interrupting flag is set to ON (S223). If the suspension flag is not set to ON, whether or not the absolute value of Cvs is below a first predetermined value Cvsref1 (for example, 5%), that is, whether the change in VS (t) due to matching device control is small It is determined whether or not (S224). In S224, it may be determined whether or not the absolute value of Cvs is below the first predetermined value Cvsref1 for a predetermined number of times.
　Ｃｖｓの絶対値が第１の所定値Ｃｖｓｒｅｆ１を下回っておらず、整合器制御によるＶＳ（ｔ）の改善が見込まれる場合は、Ｓ２２５からＳ２２９において、図１１のＳ１１９からＳ１２３と同様の整合器制御を行う。
そして、Ｓ２２９の処理の後、整合器制御初回フラグをＯＦＦに設定し（Ｓ２３０）、Ｓ２００に戻って周波数制御（追従制御）を実行する。 When the absolute value of Cvs is not lower than the first predetermined value Cvsref1 and the improvement of VS (t) by the matching unit control is expected, matching unit control similar to S119 to S123 of FIG. 11 is performed in S225 to S229. I do.
After the process of S229, the matching device control initial flag is set to OFF (S230), and the process returns to S200 to execute frequency control (follow-up control).
　一方、Ｓ２２２で肯定されるとき、即ち、可変コンデンサを駆動しているときは、以降の整合器制御に関わる処理をスキップしてＳ２００に戻り、周波数制御（追従制御）を実行する。即ち、整合器制御によって整合器２の可変コンデンサを駆動している間も、周波数制御は実行し続ける。従って、周波数制御の実行中、整合器２の定数は、整合器制御で設定した最新のＣ（ｔ）に変更（更新）し続けられる。また、整合器制御の実行中、周波数発振器１０の発振周波数は、周波数制御で設定した最新のＦ（ｔ）に変更（更新）し続けられる。 On the other hand, when the result in S222 is affirmative, that is, when the variable capacitor is driven, the processing related to the matching unit control is skipped and the process returns to S200 to execute frequency control (follow-up control). That is, the frequency control continues to be executed while the variable capacitor of the matching device 2 is driven by the matching device control. Therefore, during execution of the frequency control, the constant of the matching device 2 is continuously changed (updated) to the latest C (t) set by the matching device control. Further, during execution of the matching unit control, the oscillation frequency of the frequency oscillator 10 is continuously changed (updated) to the latest F (t) set by the frequency control.
　また、Ｓ２２４で肯定されるとき、即ち、Ｃｖｓの絶対値が第１の所定値Ｃｖｓｒｅｆ１を下回っており、整合器制御によるＶＳ（ｔ）の改善が期待できない場合は、中断中フラグをＯＮに設定する（Ｓ２３１）。中断中フラグは、整合器制御を中断するか否かを示すフラグである。 When the result in S224 is affirmative, that is, when the absolute value of Cvs is below the first predetermined value Cvsref1 and improvement of VS (t) by matching unit control cannot be expected, the interrupting flag is set to ON. (S231). The suspension flag is a flag indicating whether or not to match the matching unit control.
　中断中フラグがＯＮに設定されると、次回のループにおいてＳ２２３で肯定され、Ｃｖｓが第２の所定値Ｃｖｓｒｅｆ２を下回っているか否か判断する（Ｓ２３２）。第２の所定値Ｃｖｓｒｅｆ２は、例えば－２０％に設定する。上記の式（３）からわかるように、Ｃｖｓが負の値であることはＶＳ（ｔ）が大きくなったことを意味する。即ち、Ｓ２３２の判断は、整合器制御の中断中にＶＳ（ｔ）が所定の割合以上に悪化したか否かを判断することに相当する。Ｃｖｓが第２の所定値Ｃｖｓｒｅｆ２を下回っていなければ、即ち、ＶＳ（ｔ）が悪化していなければ、以降の整合器制御の処理をスキップしてＳ２２２に戻る。
　一方、Ｃｖｓが第２の所定値Ｃｖｓｒｅｆ２を下回っている、即ち、ＶＳ（ｔ）が悪化していれば、中断中フラグをＯＦＦに設定し（Ｓ２３３）、Ｓ２２５に進んで整合器制御を実行する。 When the interrupting flag is set to ON, it is affirmed in S223 in the next loop, and it is determined whether Cvs is below a second predetermined value Cvsref2 (S232). The second predetermined value Cvsref2 is set to −20%, for example. As can be seen from the above equation (3), a negative value of Cvs means that VS (t) has increased. That is, the determination in S232 corresponds to determining whether or not VS (t) has deteriorated to a predetermined rate or more during interruption of the matching unit control. If Cvs is not lower than the second predetermined value Cvsref2, that is, if VS (t) has not deteriorated, the subsequent matching unit control process is skipped and the process returns to S222.
On the other hand, if Cvs is lower than the second predetermined value Cvsref2, that is, if VS (t) is deteriorated, the interruption flag is set to OFF (S233), and the flow proceeds to S225 to execute the matching unit control. .
　また、前述のＳ２１８において、整合器制御初回フラグがＯＮのとき、即ち、整合器制御をまだ実行していないときは、Ｓ２１９からＳ２２１の処理により、周波数制御によるＶＳ（ｔ）の改善が見込まれないと判断されるまで整合器制御は実施しない。
一方、整合器制御が実行されてＳ２３０で整合器制御フラグがＯＦＦに設定されると、その後はＳ２１６で整合が取れたと判断されるか、Ｓ２３１で中断中フラグがＯＮに設定されない限り、周波数制御と整合器制御を同時に実行する。 In S218 described above, when the matching unit control initial flag is ON, that is, when matching unit control is not yet executed, the processing from S219 to S221 is expected to improve VS (t) by frequency control. Matching device control is not performed until it is determined that there is no.
On the other hand, if matching unit control is executed and the matching unit control flag is set to OFF in S230, then it is determined that matching has been achieved in S216, or unless the suspension flag is set to ON in S231, frequency control is performed. And matcher control are executed simultaneously.
図１５は、図１３、図１４に示す周波数制御と整合器制御を実行したときの整合状態を示すタイムチャートである。
図１５に示すように、追従制御に移行した後、整合器制御において定数を変更しながら周波数制御も同時に実行するため、整合時間を短縮することができる。尚、周波数制御と整合器制御を同時に実行するにあたり、ハンチングを防止するには各制御の整合動作速度に差を設ければよい。即ち、一方の制御が他方の制御よりも整合速度が十分に速ければ、ハンチングは発生しない。例えば、周波数整合の整合動作速度（周波数の変更周期）が１ｍｓであるとすると、整合器制御の整合動作速度（定数の変更周期）を１０ｍｓ以上とすればよい。 FIG. 15 is a time chart showing a matching state when the frequency control and matching unit control shown in FIGS. 13 and 14 are executed.
As shown in FIG. 15, after shifting to the follow-up control, the frequency control is simultaneously performed while changing the constant in the matching unit control, so that the matching time can be shortened. In order to prevent hunting when performing frequency control and matching unit control at the same time, a difference may be provided in the matching operation speed of each control. That is, if one control has a matching speed sufficiently higher than the other control, hunting does not occur. For example, if the matching operation speed (frequency change period) of frequency matching is 1 ms, the matching operation speed (constant change period) of the matcher control may be 10 ms or more.
このように、本発明の第３の実施の形態に係る高周波電源装置にあっては、周波数制御と整合器制御とを連携して行うことで、整合範囲を広げることができる。さらに、周波数制御と整合器制御を同時に実行する（整合器２の定数の変更中も周波数制御を実行する）ようにしたので、整合時間を短縮することができる。
また、周波数制御は、可変コンデンサを動作させる整合器制御に比し、動作速度と分解能が高い。そのため、整合器制御と同時に周波数制御も実行することで、インピーダンスの小さな変化に対してより精度良く追従することができる。 As described above, in the high frequency power supply device according to the third embodiment of the present invention, the matching range can be expanded by performing the frequency control and the matching unit control in cooperation. Furthermore, since the frequency control and the matching device control are executed simultaneously (the frequency control is executed even when the constant of the matching device 2 is changed), the matching time can be shortened.
Further, the frequency control has a higher operation speed and resolution than the matching unit control that operates the variable capacitor. Therefore, by executing the frequency control simultaneously with the matching unit control, it is possible to follow a small change in impedance more accurately.
　次いで、第４の実施の形態に係る高周波電源装置について説明する。従前の実施の形態との相違点は周波数制御と整合器制御にあるので、それについて説明する。
　図１６は、本発明の第４の実施の形態に係る周波数制御と整合器制御の処理の前半部分を示すフローチャートであり、図１７は、図１６に示す処理の後半部分を示すフローチャートである。 Next, a high frequency power supply device according to a fourth embodiment will be described. The difference from the previous embodiment is in frequency control and matching device control, which will be described.
FIG. 16 is a flowchart showing the first half of the frequency control and matching unit control processing according to the fourth embodiment of the present invention, and FIG. 17 is a flowchart showing the second half of the processing shown in FIG.
　図１６に示す処理について説明すると、先ず、前述の式（１）に従い、ＶＳ（ｔ）を算出する（Ｓ３００）。次いで、Ｓ３０１からＳ３０５において、図１１のＳ１１９からＳ１２３と同様な整合器制御を行う。そして、Ｓ３０５の処理の後、定数が変更された後のＶＳ（ｔ）を算出し、当該ＶＳ（ｔ）が目標値（ＶＳＷＲ＝１）に達しているか否か判断する（Ｓ３０６）。 16 will be described. First, VS (t) is calculated according to the above-described equation (1) (S300). Next, in S301 to S305, matching unit control similar to S119 to S123 in FIG. 11 is performed. Then, after the process of S305, VS (t) after the constant is changed is calculated, and it is determined whether or not the VS (t) has reached the target value (VSWR = 1) (S306).
　ＶＳ（ｔ）が目標値に達していない場合は、整合器制御回数Ｃｃｎｔ（ｎ）をカウントアップし（Ｓ３０７）、このＣｃｎｔ（ｎ）が所定回数（例えば５回）を超えているか否か判断する（Ｓ３０８）。Ｃｃｎｔ（ｎ）が所定回数を超えていない、即ち、整合器制御によるＶＳ（ｔ）の改善がまだ見込まれるときは、Ｓ３００に戻って整合器制御を継続する。 If VS (t) has not reached the target value, the matching unit control number Ccnt (n) is counted up (S307), and it is determined whether or not this Ccnt (n) exceeds a predetermined number (for example, five times). (S308). When Ccnt (n) does not exceed the predetermined number of times, that is, when improvement of VS (t) due to matching device control is still expected, the processing returns to S300 and matching device control is continued.
一方、Ｃｃｎｔ（ｎ）が所定回数を超えているときは、整合器制御をこれ以上継続してもＶＳ（ｔ）の改善が期待できないため、図１７のＳ３０９からＳ３１８において、図１０のＳ１０９からＳ１１６、Ｓ１１８と同様な周波数制御を行う。整合器制御から周波数制御に切り替えられた際、整合器２の定数は整合器制御で設定された最新のＣ（ｔ）が維持される。
尚、Ｃｃｎｔ（ｎ）の確認に加え、第３の実施の形態と同様に、ＶＳＲＷの変化率も確認するようにしてもよい。 On the other hand, when Ccnt (n) exceeds the predetermined number of times, improvement in VS (t) cannot be expected even if the matcher control is continued any more, so in S309 to S318 in FIG. 17, from S109 in FIG. Frequency control similar to S116 and S118 is performed. When the matching device control is switched to the frequency control, the constant of the matching device 2 is maintained at the latest C (t) set by the matching device control.
In addition to confirming Ccnt (n), the rate of change of VSRW may be confirmed as in the third embodiment.
Ｓ３１７において、Ｆｃｎｔ（ｎ）が所定回数を上回ったとき、即ち、周波数整合を所定回数行っても整合が取れない場合は、Ｓ３００に戻って整合器制御を行う。
周波数制御から整合器制御に切り替えられた際、発振器１０の発振周波数は周波数制御で設定された最新のＦ（ｔ）が維持される。
一方、Ｆｃｎｔ（ｎ）が所定回数を上回っていないときは、Ｓ３０９に戻って周波数制御を継続する。尚、Ｆｃｎｔ（ｎ）の回数判断に加え、第３の実施の形態と同様に、ＶＳＲＷの変化率も確認するようにしてもよい。 In S317, when Fcnt (n) exceeds the predetermined number of times, that is, when the frequency matching is not performed even after the predetermined number of times, the process returns to S300 to perform the matching unit control.
When the frequency control is switched to the matching device control, the latest F (t) set by the frequency control is maintained as the oscillation frequency of the oscillator 10.
On the other hand, if Fcnt (n) does not exceed the predetermined number, the process returns to S309 and the frequency control is continued. In addition to the determination of the number of times of Fcnt (n), the rate of change of the VSRW may be confirmed as in the third embodiment.
また、Ｓ３１５においてＶＳ（ｔ）が目標値に達したと判断されるときは、Ｆｃｎｔ（ｎ）を０にリセットした後、Ｓ３１０に戻って周波数制御を継続する。
また、図１６のＳ３０６においてＶＳ（ｔ）が目標値に達したと判断されるときは、Ｃｃｎｔ（ｎ）を０にリセットした後、Ｓ３１０に進んで周波数制御を実行する。このときも、整合器２の定数は整合器制御で設定された最新のＣ（ｔ）が維持される。 If it is determined in S315 that VS (t) has reached the target value, Fcnt (n) is reset to 0, and then the process returns to S310 to continue the frequency control.
When it is determined in S306 of FIG. 16 that VS (t) has reached the target value, Ccnt (n) is reset to 0, and then the process proceeds to S310 to execute frequency control. Also at this time, the latest C (t) set by the matcher control is maintained as the constant of the matcher 2.
図１８は、図１６、図１７に示す周波数制御と整合器制御を実行したときの整合状態を示すタイムチャートである。
図１８に示すように、整合器制御で整合を取った後、周波数制御を実行する。これは、整合後のインピーダンスの小さな変化に対し、動作速度と分解能が整合器制御よりも高い周波数制御で追従するためである。 FIG. 18 is a time chart showing a matching state when the frequency control and matching device control shown in FIGS. 16 and 17 are executed.
As shown in FIG. 18, after matching is performed by the matching unit control, frequency control is executed. This is because the operation speed and resolution follow a small change in impedance after matching with frequency control higher than matching device control.
このように、本発明の第４の実施の形態に係る高周波電源装置にあっては、周波数制御と整合器制御とを連携して行うことで、整合範囲を広げることができる。さらに、整合器制御で整合を取った後、周波数制御を実行することで、整合後のインピーダンスの小さな変化に対して精度良く追従することができる。 Thus, in the high frequency power supply device according to the fourth embodiment of the present invention, the matching range can be expanded by performing the frequency control and the matching unit control in cooperation. Furthermore, after matching is performed by matching device control, frequency control is executed, so that it is possible to accurately follow small changes in impedance after matching.
　尚、上記の各実施例では、整合状態を示す値としてＶＳＷＲを算出したが、インピーダンスを算出しても良い。また、それらに代え、反射の度合いを示す係数など、整合状態を示すものであれば他の指標を用いてもよい。 In each of the above embodiments, VSWR is calculated as a value indicating the matching state, but impedance may be calculated. Instead of these, other indicators may be used as long as they indicate the matching state, such as a coefficient indicating the degree of reflection.
　本発明は、プラズマ処理装置等に電源を供給する高周波電源装置に利用することができる。 The present invention can be used in a high-frequency power supply device that supplies power to a plasma processing apparatus or the like.
１・・・高周波電源装置
１０・・・周波数発振器
１１・・・ＲＦ増幅器
１２・・・方向性結合器
１３・・・検出回路
１４・・・制御部
２・・・整合器
３・・・負荷 DESCRIPTION OF SYMBOLS 1 ... High frequency power supply device 10 ... Frequency oscillator 11 ... RF amplifier 12 ... Directional coupler 13 ... Detection circuit 14 ... Control part 2 ... Matching device 3 ... Load

Claims (13)

  1. 定数が可変である整合器を介して高周波電力を負荷に供給する高周波電源装置において、
    発振周波数が可変である周波数発振器と、
    前記周波数発振器の出力を増幅して前記整合器に出力する増幅器と、
    前記高周波電源装置と前記負荷との間の整合状態を示す整合状態値を検出する検出部と、
    前記整合状態値に基づいて前記周波数発振器の発振周波数を制御する第１の制御と、前記整合状態値に基づいて前記整合器の定数を制御する第２の制御とを同時に実行する制御部と、
    を備えることを特徴とする高周波電源装置。     In a high-frequency power supply device that supplies high-frequency power to a load via a matching unit having a variable constant,
    A frequency oscillator whose oscillation frequency is variable;
    An amplifier that amplifies the output of the frequency oscillator and outputs it to the matching unit;
    A detection unit for detecting a matching state value indicating a matching state between the high-frequency power supply device and the load;
    A control unit that simultaneously executes a first control for controlling the oscillation frequency of the frequency oscillator based on the matching state value and a second control for controlling a constant of the matching unit based on the matching state value;
    A high frequency power supply device comprising:
  2. 前記制御部は、前記第２の制御で前記定数を変更している間も、前記第１の制御によって前記発振周波数を変更し続けることを特徴とする請求項１に記載の高周波電源装置。 2. The high-frequency power supply device according to claim 1, wherein the control unit continues to change the oscillation frequency by the first control even while the constant is being changed by the second control.
  3. 前記第１の制御によって前記発振周波数が変更される周期と、前記第２の制御によって前記定数が変更される周期とが異なることを特徴とする請求項１または２に記載の高周波電源装置。 3. The high frequency power supply device according to claim 1, wherein a cycle in which the oscillation frequency is changed by the first control is different from a cycle in which the constant is changed by the second control.
  4. 前記制御部は、前記第１の制御で前記整合状態値が目標値に到達しなかったとき、前記第２の制御も実行することを特徴とする請求項１から３のいずれかに記載の高周波電源装置。 4. The high frequency according to claim 1, wherein the control unit also executes the second control when the matching state value does not reach a target value in the first control. 5. Power supply.
  5. 定数が可変である整合器を介して高周波電力を負荷に供給する高周波電源装置において、
    発振周波数が可変である周波数発振器と、
    前記周波数発振器の出力を増幅して前記整合器に出力する増幅器と、
    前記高周波電源装置と前記負荷との間の整合状態を示す整合状態値を検出する検出部と、
    前記整合状態値に基づいて前記周波数発振器の発振周波数を制御する第１の制御と、前記整合状態値に基づいて前記整合器の定数を制御する第２の制御とを切り替えて実行する制御部と、を備えると共に、
    前記制御部は、前記第１の制御から前記第２の制御に切り替えるとき、前記第１の制御の制御結果を維持したまま前記第２の制御を行い、前記第２の制御から前記第１の制御に切り替えるとき、前記第２の制御の制御結果を維持したまま前記第１の制御を行うことを特徴とする高周波電源装置。     In a high-frequency power supply device that supplies high-frequency power to a load via a matching unit having a variable constant,
    A frequency oscillator whose oscillation frequency is variable;
    An amplifier that amplifies the output of the frequency oscillator and outputs it to the matching unit;
    A detection unit for detecting a matching state value indicating a matching state between the high-frequency power supply device and the load;
    A control unit that switches between a first control for controlling the oscillation frequency of the frequency oscillator based on the matching state value and a second control for controlling a constant of the matching unit based on the matching state value; And having
    When the control unit switches from the first control to the second control, the control unit performs the second control while maintaining a control result of the first control, and from the second control to the first control. When switching to control, the first control is performed while maintaining the control result of the second control.
  6. 前記制御部は、前記第１の制御で前記整合状態値が目標値に到達しなかったとき、前記第２の制御に切り替えることを特徴とする請求項５に記載の高周波電源装置。 The high frequency power supply device according to claim 5, wherein the control unit switches to the second control when the matching state value does not reach a target value in the first control.
  7. 前記制御部は、前記第２の制御で前記整合状態値が目標値に到達しなかったとき、前記第１の制御に切り替えることを特徴とする請求項５または６に記載の高周波電源装置。 7. The high-frequency power supply device according to claim 5, wherein the control unit switches to the first control when the matching state value does not reach a target value in the second control. 8.
  8. 前記制御部は、前記第１の制御から前記第２の制御に切り替えた後、前記第２の制御による定数の変更を所定回数行って前記第１の制御に戻ることを特徴とする請求項５または６に記載の高周波電源装置。 6. The control unit, after switching from the first control to the second control, changes a constant by the second control a predetermined number of times and returns to the first control. Or the high frequency power supply device of 6.
  9. 前記制御部は、前記第２の制御で前記整合状態値が目標値に到達したとき、前記第１の制御に切り替えることを特徴とする請求項５または６に記載の高周波電源装置。 The high frequency power supply device according to claim 5 or 6, wherein the control unit switches to the first control when the matching state value reaches a target value in the second control.
  10. 前記制御部は、前記第１の制御において、前記整合状態値とその目標値との差分に応じて前記発振周波数の変更幅を決定することを特徴とする請求項１から９のいずれかに記載の高周波電源装置。 The said control part determines the change width | variety of the said oscillation frequency according to the difference of the said matching state value and its target value in the said 1st control. High frequency power supply.
  11. 前記制御部は、前記第２の制御において、前記整合状態値とその目標値との差分に応じて前記定数の変更幅を決定することを特徴とする請求項１から１０のいずれかに記載の高周波電源装置。 The said control part determines the change width | variety of the said constant according to the difference of the said matching state value and its target value in said 2nd control, The Claim 1 characterized by the above-mentioned. High frequency power supply.
  12. 整合器の定数と周波数発振器の発振周波数が可変である高周波電源装置の整合方法において、
    前記高周波電源装置とその電力供給先である負荷との間の整合状態を示す整合状態値を検出し、
    前記整合状態値に基づいて前記周波数発振器の発振周波数を制御する第１の制御と、前記整合状態値に基づいて前記整合器の定数を制御する第２の制御とを同時に実行することを特徴とする高周波電源装置の整合方法。     In the matching method of the high-frequency power supply device in which the constant of the matching unit and the oscillation frequency of the frequency oscillator are variable,
    Detecting a matching state value indicating a matching state between the high frequency power supply device and a load that is a power supply destination thereof,
    A first control for controlling the oscillation frequency of the frequency oscillator based on the matching state value and a second control for controlling a constant of the matching unit based on the matching state value are executed simultaneously. Matching method of high frequency power supply device.
  13. 整合器の定数と周波数発振器の発振周波数が可変である高周波電源装置の整合方法において、
    前記高周波電源装置とその電力供給先である負荷との間の整合状態を示す整合状態値を検出し、
    前記整合状態値に基づいて前記周波数発振器の発振周波数を制御する第１の制御と、前記整合状態値に基づいて前記整合器の定数を制御する第２の制御とを切り替えて実行すると共に、前記第１の制御から前記第２の制御に切り替えるとき、前記第１の制御の制御結果を維持したまま前記第２の制御を行い、前記第２の制御から前記第１の制御に切り替えるとき、前記第２の制御の制御結果を維持したまま前記第１の制御を行うことを特徴とする高周波電源装置の整合方法。     In the matching method of the high-frequency power supply device in which the constant of the matching unit and the oscillation frequency of the frequency oscillator are variable,
    Detecting a matching state value indicating a matching state between the high frequency power supply device and a load that is a power supply destination thereof,
    The first control for controlling the oscillation frequency of the frequency oscillator based on the matching state value and the second control for controlling a constant of the matching unit based on the matching state value are switched and executed, and When switching from the first control to the second control, performing the second control while maintaining the control result of the first control, and when switching from the second control to the first control, A matching method for a high frequency power supply apparatus, wherein the first control is performed while maintaining a control result of the second control.
PCT/JP2012/055653 2012-03-06 2012-03-06 High frequency power source device and matching method therefor WO2013132591A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2014503319A JP6045118B2 (en) 2012-03-06 2012-03-06 High frequency power supply device and matching method thereof
PCT/JP2012/055653 WO2013132591A1 (en) 2012-03-06 2012-03-06 High frequency power source device and matching method therefor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2012/055653 WO2013132591A1 (en) 2012-03-06 2012-03-06 High frequency power source device and matching method therefor

Publications (1)

Publication Number Publication Date
WO2013132591A1 true WO2013132591A1 (en) 2013-09-12

Family

ID=49116107

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2012/055653 WO2013132591A1 (en) 2012-03-06 2012-03-06 High frequency power source device and matching method therefor

Country Status (2)

Country Link
JP (1) JP6045118B2 (en)
WO (1) WO2013132591A1 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017126290A (en) * 2016-01-15 2017-07-20 株式会社リコー High-frequency power supply device, image forming apparatus, and power supply control method
KR20170107545A (en) 2015-02-27 2017-09-25 가부시키가이샤 히다치 고쿠사이 덴키 Matching device and matching method
US9876482B2 (en) 2014-02-28 2018-01-23 Hitachi Kokusai Electric Inc. Matching unit and matching method
KR20180010239A (en) 2015-06-30 2018-01-30 가부시키가이샤 히다치 고쿠사이 덴키 Matching device and matching method
JP2018504864A (en) * 2015-01-06 2018-02-15 北京北方華創微電子装備有限公司Ｂｅｉｊｉｎｇ Ｎａｕｒａ Ｍｉｃｒｏｅｌｅｃｔｒｏｎｉｃｓ Ｅｑｕｉｐｍｅｎｔ Ｃｏ．， Ｌｔｄ． Impedance matching method and apparatus for pulse high frequency power supply
JP2019515429A (en) * 2016-04-20 2019-06-06 エーイーエス グローバル ホールディングス， プライベート リミテッド Device for frequency tuning in an RF generator
CN110942970A (en) * 2018-09-21 2020-03-31 阿德特克等离子技术公司 Impedance matching device arranged in high-frequency power supply system

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06243992A (en) * 1993-02-16 1994-09-02 Tokyo Electron Ltd Plasma processing device
JPH1187097A (en) * 1997-09-10 1999-03-30 Adtec:Kk Impedance matching and power control system for high frequency plasma processing device
JP2008130398A (en) * 2006-11-22 2008-06-05 Pearl Kogyo Co Ltd High frequency power supply device and high frequency power supplying method
JP2008181846A (en) * 2006-12-29 2008-08-07 Daihen Corp High frequency device
JP2011519115A (en) * 2008-02-01 2011-06-30 エム ケー エス インストルメンツ インコーポレーテッド Radio frequency power distribution system
JP2011217482A (en) * 2010-03-31 2011-10-27 Daihen Corp High-frequency power supply device

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007336148A (en) * 2006-06-14 2007-12-27 Daihen Corp Electrical property adjusting device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06243992A (en) * 1993-02-16 1994-09-02 Tokyo Electron Ltd Plasma processing device
JPH1187097A (en) * 1997-09-10 1999-03-30 Adtec:Kk Impedance matching and power control system for high frequency plasma processing device
JP2008130398A (en) * 2006-11-22 2008-06-05 Pearl Kogyo Co Ltd High frequency power supply device and high frequency power supplying method
JP2008181846A (en) * 2006-12-29 2008-08-07 Daihen Corp High frequency device
JP2011519115A (en) * 2008-02-01 2011-06-30 エム ケー エス インストルメンツ インコーポレーテッド Radio frequency power distribution system
JP2011217482A (en) * 2010-03-31 2011-10-27 Daihen Corp High-frequency power supply device

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9876482B2 (en) 2014-02-28 2018-01-23 Hitachi Kokusai Electric Inc. Matching unit and matching method
JP2018504864A (en) * 2015-01-06 2018-02-15 北京北方華創微電子装備有限公司Ｂｅｉｊｉｎｇ Ｎａｕｒａ Ｍｉｃｒｏｅｌｅｃｔｒｏｎｉｃｓ Ｅｑｕｉｐｍｅｎｔ Ｃｏ．， Ｌｔｄ． Impedance matching method and apparatus for pulse high frequency power supply
US10643822B2 (en) 2015-01-06 2020-05-05 Beijing Naura Microelectronics Equipment Co., Ltd. Impedance matching method and device for pulsed radio frequency power supply
KR20170107545A (en) 2015-02-27 2017-09-25 가부시키가이샤 히다치 고쿠사이 덴키 Matching device and matching method
KR20180010239A (en) 2015-06-30 2018-01-30 가부시키가이샤 히다치 고쿠사이 덴키 Matching device and matching method
US10812036B2 (en) 2015-06-30 2020-10-20 Hitachi Kokusai Electric Inc. Matching box and matching method
JP2017126290A (en) * 2016-01-15 2017-07-20 株式会社リコー High-frequency power supply device, image forming apparatus, and power supply control method
JP2019515429A (en) * 2016-04-20 2019-06-06 エーイーエス グローバル ホールディングス， プライベート リミテッド Device for frequency tuning in an RF generator
CN110942970A (en) * 2018-09-21 2020-03-31 阿德特克等离子技术公司 Impedance matching device arranged in high-frequency power supply system
KR20200034554A (en) 2018-09-21 2020-03-31 가부시키가이샤 아도테쿠 프라즈마 테쿠노로지 Mpedance matching device provided in high frequency power system
CN110942970B (en) * 2018-09-21 2022-03-25 阿德特克等离子技术公司 Impedance matching device arranged in high-frequency power supply system
US11651938B2 (en) 2018-09-21 2023-05-16 Adtec Plasma Technology Co., Ltd. Impedance matching device provided in high-frequency power system

Also Published As

Publication number Publication date
JPWO2013132591A1 (en) 2015-07-30
JP6045118B2 (en) 2016-12-14

Similar Documents

Publication Publication Date Title
JP6045118B2 (en) High frequency power supply device and matching method thereof
US10643822B2 (en) Impedance matching method and device for pulsed radio frequency power supply
US9378931B2 (en) Pulse plasma apparatus and drive method thereof
US9408288B2 (en) Edge ramping
US9627182B2 (en) Tuning a parameter associated with plasma impedance
US10291198B2 (en) Matching device and matching method
JP4887197B2 (en) High frequency equipment
US10475624B2 (en) High-frequency power supply device, and control method for high-frequency power supply device
US20200126762A1 (en) Impedance matching method, impedance matching device and plasma generating apparatus
JP2008181846A5 (en)
JP5327785B2 (en) Impedance matching device and impedance matching method
JP2020156043A (en) Impedance matching device and impedance matching method
JP5210659B2 (en) Plasma processing equipment
WO2020083340A1 (en) Power transmission method for radio frequency power supply
KR102194601B1 (en) Plasma power supply system having a electronic variable impedance matching box
KR102348338B1 (en) The Driving Frequency Control Method of The Pulsed Frequency Variable RF Generator
US10812036B2 (en) Matching box and matching method
US20200098546A1 (en) Impedance matching device provided in high-frequency power system
US20220392746A1 (en) Plasma processing device
JPH10112625A (en) Tracking circuit for matched tuner circuit of transmitter and tracking method for matched tuner circuit
CN112447479A (en) Plasma processing system and plasma ignition assisting method
CN113066712A (en) Impedance matching method and semiconductor process equipment
JP2011023356A (en) Plasma processing device, and substrate processing method
US20230253185A1 (en) Systems and Methods for Radiofrequency Signal Generator-Based Control of Impedance Matching System
KR20210084264A (en) Impedance adjustment device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12870509

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2014503319

Country of ref document: JP

Kind code of ref document: A

122 Ep: pct application non-entry in european phase

Ref document number: 12870509

Country of ref document: EP

Kind code of ref document: A1