Plasma processing apparatus, power system, and method of controlling a source frequency

Abstract

In the plasma processing apparatus of the present invention, a bias power supply supplies an electrical bias having a waveform period to a substrate support. A high-frequency power supply sets the time sequence of the generator source frequency of the high-frequency electrical power within a frequency adjustment period to a maximum frequency at a first specific phase, a minimum frequency at a second specific phase, and a frequency obtained by interpolation at at least two specific phases other than the first and second specific phases. The phase difference between the frequency adjustment period and the waveform period is set to suppress the reflection of the generator source high-frequency electrical power. The high-frequency power supply varies the maximum frequency at the first specific phase and the minimum frequency at the second specific phase in opposite directions within the time sequence of the generator source frequency within the frequency adjustment period to suppress the reflection of the generator source high-frequency electrical power.

Description

Technical Field

[0001] The exemplary embodiments of the present invention relate to plasma processing apparatus, power supply system, and frequency control method. Background Technology

[0002] A plasma processing apparatus is used to perform plasma processing on a substrate. The plasma processing apparatus generates plasma from gas within a chamber by supplying high-frequency electrical power to a generation source. To attract ions from the plasma generated within the chamber to the substrate, the plasma processing apparatus uses a bias high-frequency electrical power. Patent Document 1 below discloses a plasma processing apparatus that modulates the power level and frequency of the bias high-frequency electrical power.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-246091 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] This invention provides a technique for reducing the degree of reflection of high-frequency electrical power generated by a source.

[0008] Technical solutions for solving technical problems

[0009] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, a high-frequency power supply, and a bias power supply. The substrate support is disposed within the chamber. The high-frequency power supply is configured to generate high-frequency electrical power having a generation source frequency for generating plasma from gas within the chamber. The bias power supply is configured to supply an electrical bias to the substrate support for attracting ions from the plasma within the chamber. The electrical bias has a waveform period. The high-frequency power supply is configured to set a time sequence of the generation source frequencies within a frequency adjustment period having a time length equal to the waveform period as a maximum frequency at a first specific phase, a minimum frequency at a second specific phase, and a frequency obtained by interpolation at at least two phases other than the first and second specific phases. The high-frequency power supply and the bias power supply are configured to set a phase difference between the frequency adjustment period and the waveform period to suppress the degree of reflection of the generation source high-frequency electrical power, wherein, during the frequency adjustment period, the generation source frequency can be changed according to an initial frequency group specifying initial generation source frequencies at at least two specific phases. The high-frequency power supply is configured such that, after setting the phase difference, in the time series of the generator source frequency within the frequency adjustment period, the generator source frequency at the first specific phase and the generator source frequency at the second specific phase are determined to suppress the reflection of the high-frequency electrical power of the generator source by changing the maximum frequency at the first specific phase and the minimum frequency at the second specific phase in opposite directions.

[0010] Invention Effects

[0011] According to one exemplary implementation, the degree of reflection of the high-frequency electrical power of the generation source can be reduced. Attached Figure Description

[0012] Figure 1 This is a diagram illustrating a structural example of a plasma processing system.

[0013] Figure 2 This is a diagram illustrating a structural example of a capacitively coupled plasma processing device.

[0014] Figure 3 This is a diagram illustrating a structural example of the power supply system in a plasma processing apparatus according to an exemplary embodiment.

[0015] Figure 4 (a) and Figure 4 (b) are examples of waveforms representing electrical bias.

[0016] Figure 5 (a)~ Figure 5 (c) are figures representing examples of time series of the generation source frequencies of a plasma processing apparatus according to an exemplary embodiment.

[0017] Figure 6 (a) and Figure 6 (b) are figures representing examples of time series of the generation source frequencies of a plasma processing apparatus according to an exemplary embodiment.

[0018] Figure 7 This is a diagram illustrating an example of pulses generating high-frequency electrical power and pulses for electrical bias.

[0019] Figure 8 (a)~ Figure 8 (d) are examples of time series of the generation source frequencies of a plasma processing apparatus according to an exemplary embodiment.

[0020] Figure 9 This is a flowchart of a method for controlling the frequency of a generation source according to an exemplary implementation. Detailed Implementation

[0021] Hereinafter, various exemplary embodiments will be described in detail with reference to the accompanying drawings. Furthermore, in each drawing, the same or equivalent parts are labeled with the same reference numerals.

[0022] Figure 1 This is a diagram illustrating a structural example of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. Furthermore, the plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas outlet for discharging gas from the plasma processing space. The gas supply port is connected to the gas supply unit 20 (described later), and the gas outlet is connected to the exhaust system 40 (described later). The substrate support 11 is disposed within the plasma processing space and has a substrate support surface for supporting a substrate.

[0023] The plasma generation unit 12 is configured to generate plasma from at least one processing gas supplied to the plasma processing space. The plasma generated in the plasma processing space can be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR), helicon wave plasma (HWP), or surface wave plasma (SWP), etc.

[0024] The control unit 2 processes computer-executable commands that cause the plasma processing apparatus 1 to perform the various steps (processes) described herein. The control unit 2 is configured to control the various elements of the plasma processing apparatus 1 to perform the various steps described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 is implemented, for example, by a computer 2a. The processing unit 2a1 may be configured to perform various control actions by reading a program from the storage unit 2a2 and executing the read program. The program may be pre-stored in the storage unit 2a2 or retrieved via a medium when needed. The retrieved program is stored in the storage unit 2a2 and read and executed by the processing unit 2a1. The medium may be various storage media readable by the computer 2a, or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a programmable logic device such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array). The storage unit 2a2 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may also communicate with the plasma processing device 1 via a communication line such as a LAN (Local Area Network).

[0025] Hereinafter, a structural example of a capacitively coupled plasma processing device, which is one example of plasma processing device 1, will be described. Figure 2This is a diagram illustrating a structural example of a capacitively coupled plasma processing device.

[0026] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply system 30, and an exhaust system 40. Additionally, the plasma processing apparatus 1 includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet includes a spray head 13. The substrate support 11 is disposed within the plasma processing chamber 10. The spray head 13 is disposed above the substrate support 11. In one embodiment, the spray head 13 constitutes at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the spray head 13, the sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The substrate support 11 is electrically insulated from the housing of the plasma processing chamber 10.

[0027] The substrate support portion 11 includes a main body portion 111 and a ring assembly 112. The main body portion 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body portion 111 surrounds the central region 111a of the main body portion 111 when viewed from above. The substrate W is disposed on the central region 111a of the main body portion 111, and the ring assembly 112 is disposed on the annular region 111b of the main body portion 111 in such a way that it surrounds the substrate W on the central region 111a of the main body portion 111. Therefore, the central region 111a is also referred to as a substrate support surface for supporting the substrate W, and the annular region 111b is also referred to as an annular support surface for supporting the ring assembly 112.

[0028] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive component. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic component 1111a and an electrostatic electrode 1111b disposed within the ceramic component 1111a. The ceramic component 1111a has a central region 111a. In one embodiment, the ceramic component 1111a also has an annular region 111b. Furthermore, other components surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating component, may also have an annular region 111b. In this case, the ring assembly 112 may be disposed on either the annular electrostatic chuck or the annular insulating component, or on both the electrostatic chuck 1111 and the annular insulating component.

[0029] The ring assembly 112 includes one or more annular components. In one embodiment, the one or more annular components include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover ring is formed of an insulating material.

[0030] Additionally, the substrate support 11 may also include a temperature control module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid such as brine or gas flows in the flow path 1110a. In one embodiment, the flow path 1110a is formed within the base 1110, and one or more heaters are disposed within the ceramic component 1111a of the electrostatic chuck 1111. Furthermore, the substrate support 11 may also include a heat transfer gas supply section configured to supply heat transfer gas to the gap between the back surface of the substrate W and the central region 111a.

[0031] The spray head 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The spray head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas inlets 13c. The process gas supplied to the gas supply port 13a is introduced into the plasma processing space 10s through the gas diffusion chamber 13b and the plurality of gas inlets 13c. Additionally, the spray head 13 includes at least one upper electrode. Furthermore, in addition to the spray head 13, the gas inlet unit may also include one or more side gas injectors (SGIs) mounted on one or more openings formed in the sidewall 10a.

[0032] The gas supply unit 20 may also include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one type of process gas from a corresponding gas source 21 to the spray head 13 via a corresponding flow controller 22. Each flow controller 22 may, for example, include a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may also include at least one flow modulation device for modulating or pulsed the flow rate of the at least one type of process gas.

[0033] The exhaust system 40 can be connected, for example, to a gas outlet 10e located at the bottom of the plasma processing chamber 10. The exhaust system 40 may also include a pressure regulating valve and a vacuum pump. The pressure within the plasma processing space 10s is regulated using the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0034] The following, with Figure 2Refer to together Figure 3 . Figure 3 This is a diagram illustrating a structural example of the power supply system in a plasma processing apparatus according to an exemplary embodiment. The power supply system 30 includes a high-frequency power supply 31 and a bias power supply 32. The high-frequency power supply 31 constitutes a plasma generation unit 12 in one embodiment. The high-frequency power supply 31 is configured to generate a generation source high-frequency electrical power HF. The generation source high-frequency electrical power HF has a generation source frequency f. S That is, the high-frequency electrical power HF generated by the source has a frequency f that is the frequency of the source. S A waveform with a sinusoidal shape. The source frequency f. S It can be a frequency in the range of 10MHz to 150MHz.

[0035] The high-frequency power supply 31 is electrically connected to the high-frequency electrode via a matching adapter 33, thereby enabling it to supply high-frequency electrical power HF to the high-frequency electrode. The high-frequency electrode may also be disposed within the substrate support portion 11. The high-frequency electrode may also be at least one electrode disposed within a conductive component or ceramic component 1111a of the base 1110. Alternatively, the high-frequency electrode may be an upper electrode. When the high-frequency electrical power HF is supplied to the high-frequency electrode, plasma is generated from the gas within the chamber 10.

[0036] Matching unit 33 has a variable impedance. The variable impedance of matching unit 33 is set to reduce the reflection of the high-frequency electrical power HF generated from the load. Matching unit 33 can be controlled, for example, by control unit 2.

[0037] In one embodiment, the high-frequency power supply 31 may also include a signal generator 31g and an amplifier 31a. The signal generator 31g generates a signal with a source frequency f. S The high-frequency signal. The signal generator 31g can also be constructed from a programmable processor or a programmable logic device such as an FPGA (Field-Programmable Gate Array).

[0038] The output of signal generator 31g is connected to the input of amplifier 31a. Amplifier 31a amplifies the high-frequency signal from signal generator 31g to generate high-frequency power HF. The amplification rate of amplifier 31a is specified by control unit 2 for high-frequency power supply 31.

[0039] The bias power supply 32 is electrically coupled to the substrate support portion 11. The bias power supply 32 is electrically connected to a bias electrode within the substrate support portion 11, configured to supply an electrical bias EB to the bias electrode. The bias electrode may also be at least one electrode disposed within a conductive component or ceramic component 1111a of the substrate 1110. The bias electrode may also be shared with a high-frequency electrode. When the electrical bias EB is supplied to the bias electrode, ions from the plasma are attracted to the substrate W.

[0040] The following, with Figure 2 and Figure 3 Refer to together Figure 4 (a) and Figure 4 (b) Figure 4 (a) and Figure 4 Figures (b) are examples of waveforms representing electrical bias. The bias power supply 32 is configured to periodically apply an electrical bias EB having a waveform period CY to the bias electrodes. That is, the electrical bias EB is applied to the bias electrodes in each of the multiple waveform periods CY that are repetitions (repetitions) of the waveform period CY. The waveform period CY is defined by the bias frequency. The bias frequency is, for example, a frequency of 50 kHz or higher and 27 MHz or lower. The duration of the waveform period CY is the reciprocal of the bias frequency.

[0041] like Figure 4 As shown in (a), the electrical bias EB can be a bias high-frequency electrical power LF having a bias frequency. That is, the electrical bias EB can have a waveform with a sinusoidal shape whose frequency is the bias frequency. In this case, the bias power supply 32 is electrically connected to the bias electrode via a matching device 34. The variable impedance of the matching device 34 is set to reduce the reflection of the bias high-frequency electrical power LF from the load.

[0042] Or, such as Figure 4 As shown in (b), the electrical bias EB may also include a voltage pulse VP. The voltage pulse VP is applied to the bias electrode within the waveform period CY. The voltage pulse VP is applied periodically to the bias electrode at time intervals of the same length as the waveform period CY. The waveform of the voltage pulse VP can be a rectangular wave, a triangular wave, or any waveform. The polarity of the voltage pulse VP is set to create a potential difference between the substrate W and the plasma, thereby attracting ions from the plasma to the substrate W. The voltage pulse VP can also be a negative voltage pulse or a negative DC voltage pulse. Furthermore, when the electrical bias EB is a voltage pulse VP, the plasma processing apparatus 1 may not include a matching unit 34. In this case, the bias power supply 32 may also include a power supply (e.g., a DC power supply) and a waveform generator that generates the voltage pulse VP by generating a waveform from the voltage from that power supply.

[0043] The following, with Figures 2-3 Together, Figure 5 (a)~ Figure 5 (c) and Figure 6 (a)~ Figure 6 (b) are graphs showing examples of time series of the generation source frequency of a plasma processing apparatus according to an exemplary embodiment. The high-frequency power supply 31 is configured to adjust the generation source frequency f within a frequency adjustment period (hereinafter referred to as "period FC"). SThis is to suppress the reflection of the high-frequency electrical power HF generated by the source. Furthermore, the following description includes the source frequency f in the high-frequency power supply 31. S The adjustment process can be performed by the signal generator 31g. Alternatively, the adjustment process in the high-frequency power supply 31 can also be performed by other control units (e.g., control unit 2).

[0044] The period FC has the same duration as the waveform period CY and repeats (repeated) in the same manner as the waveform period CY. The period FC contains multiple phases. These multiple phases can be discretely set within the period FC. The multiple phases within the period FC include at least two specific phases. These at least two specific phases include a specific phase α. a (First specific phase) and specific phase α b (Second specific phase). Specific phase α b It is a specific phase α within the period FC a The subsequent phase. Specific phase α a With a specific phase α b The phase difference between them is predetermined.

[0045] The high-frequency power supply 31 is configured to generate the source frequency f within the period FC. S The time series is set to a specific phase α a Frequency at a specific point, phase α b The frequency at point FC and the interpolated (subtracted) frequencies at at least two phases other than a specific phase. The source frequency f within the period FC. S Specific phase α in a time series a The frequency at that point is the source frequency f within the period FC. S The maximum frequency in the time series. The source frequency f within the period FC. S Specific phase α in a time series b The frequency at that point is the source frequency f within the period FC. S The minimum frequency in the time series. The high-frequency power supply 31 uses the frequency obtained by linear interpolation of the generation source frequencies of at least two specific phases, as the generation source frequency f at the phase outside the at least two specific phases within the period FC. S Furthermore, the high-frequency power supply 31 generates source frequencies f at the respective phases between the initial phase and the initial specific phase and between the final specific phase and the final phase within the period FC. S Interpolation is also performed to ensure that, in the case of cyclic FC, the generated source frequency f is maintained between the last specific phase within FC and the first specific phase within the next FC. S The continuity or linearity.

[0046] To determine the degree of reflection of the high-frequency electrical power HF generated by the plasma processing apparatus 1, a sensor 35 (see reference) may also be included. Figure 3 Additionally, the plasma processing apparatus 1 may also include an envelope detector 36 and an AD converter 37 (analog-to-digital converter). The plasma processing apparatus 1 may also include an envelope detector 38 and an AD converter 39 (analog-to-digital converter).

[0047] Sensor 35 may also include a directional coupler. The directional coupler branches the reflected wave from the load of the high-frequency electrical power HF generated by the source. The directional coupler inputs the branched reflected wave to envelope detector 36. Envelope detector 36 detects the envelope of the input reflected wave. A / D converter 37 performs analog-to-digital conversion (AD conversion) on the envelope detected by envelope detector 36. The sampling frequency in AD converter 37 can be less than the source frequency f. S For example, the sampling frequency in the AD converter 37 can be below 20MHz.

[0048] The directional coupler can also branch the traveling wave of the high-frequency electrical power HF generated by the source. The directional coupler can also input the branched traveling wave to the envelope detector 38. The envelope detector 38 detects the envelope of the input traveling wave. The AD converter 39 performs analog-to-digital conversion (AD conversion) on the envelope detected by the envelope detector 38. The sampling frequency of the AD converter 39 can be less than the source frequency f. S For example, the sampling frequency of the AD converter 39 can be below 20MHz.

[0049] The high-frequency power supply 31 determines the average power level Prave of the reflected wave of the generated source high-frequency electrical power HF within the period FC by averaging the values ​​sampled by the AD converter 37 within the period FC. The high-frequency power supply 31 may also use the average value Prave as the degree of reflection within the period FC. Alternatively, the high-frequency power supply 31 may use the average reflectivity within the period FC as the degree of reflection within the period FC. Reflectivity is the ratio of the value sampled by the AD converter 37 to the value sampled by the AD converter 39. Furthermore, the high-frequency power supply 31 may also use the degree of reflection of the generated source high-frequency electrical power HF obtained from measurements obtained by other sensors.

[0050] The high-frequency power supply 31 and the bias power supply 32 set the phase difference θ between the period FC of changing the generator source frequency according to the initial frequency group and the waveform period CY to suppress the reflection of the high-frequency electrical power HF of the generator source. Figure 5 (a) or Figure 6 As shown in (a), the initial frequency group is a specified phase α.a and specific phase α b This refers to a data set (also called a dataset) with at least two specific phases at the initial generation source frequency. In one implementation, the bias power supply 32 can adjust the supply timing of the electrical bias EB according to a timing control signal from the high-frequency power supply 31, thereby adjusting the phase difference θ between the period FC and the waveform period CY. Alternatively, the high-frequency power supply 31 can also adjust the phase difference θ between the period FC and the waveform period CY by adjusting the start time of the period FC.

[0051] In one implementation, the high-frequency power supply 31 can also determine the phase difference θ that best suppresses the reflection of the high-frequency electrical power HF generated by the source while changing the phase difference θ between the period FC and the waveform period CY. A The high-frequency power supply 31 can also determine the phase difference θ. A The phase difference θ between the period FC and the waveform period CY is set. In one example, the high-frequency power supply 31 sets the phase difference θ between the period FC and the waveform period CY as the initial phase difference. Then, the high-frequency power supply 31 changes the phase difference θ. Specifically, the high-frequency power supply 31 sets the value obtained by adding a change amount Δθ to the previously used phase difference θ as the phase difference θ. In addition, the high-frequency power supply 31 initially sets the change amount Δθ to a predetermined initial change amount. If the reflection of the high-frequency power HF generated by the generation source decreases due to the change in phase difference θ, the high-frequency power supply 31 sets the value obtained by further adding the change amount Δθ to the current phase difference θ as the phase difference θ to be used next. On the other hand, if the reflection of the high-frequency power HF generated by the generation source increases due to the change in phase difference θ, the high-frequency power supply 31 updates the change amount Δθ to the product of the current change amount Δθ and (-1 / 2), and sets the value obtained by adding the updated change amount Δθ to the current phase difference θ as the phase difference θ to be used next. The high-frequency power supply 31 determines the phase difference θ when the absolute value of the change Δθ is less than a specified value as the phase difference θ that best suppresses the reflection of the high-frequency electrical power HF generated by the source. A On the other hand, when the absolute value of the change Δθ is above a predetermined value, the high-frequency power supply 31 further performs the aforementioned change in phase difference θ.

[0052] In another embodiment, the high-frequency power supply 31 may also set the phase difference between the period FC and the waveform period CY to a predetermined phase difference, so that a specific phase α a Consistent with the first moment, a specific phase α bThe second time point is consistent with the first time point. Furthermore, the first time point is the moment when the voltage of the substrate support portion 11 corresponding to the electrical bias EB switches from negative to positive (also called "timing"). The second time point is the moment following the first time point, and is the time within the period during which the voltage of the substrate support portion 11 corresponding to the electrical bias EB changes from negative to positive.

[0053] After setting the phase difference between the period FC and the waveform period CY, the high-frequency power supply 31 adjusts the generation source frequency f of each phase within the period FC. S This is to suppress the reflection of the high-frequency electrical power HF generated by the source. Specifically, the high-frequency power supply 31 generates the source frequency f within the period FC. S In a time series, make a specific phase α a Maximum frequency and specific phase α at that point b The minimum frequencies at each point change in opposite directions. That is, the high-frequency power supply 31 amplifies and / or reduces the generation source frequency f within the period FC. S The bandwidth between the maximum and minimum frequencies in the time series. The high-frequency power supply 31 expands and / or reduces this bandwidth within the periodic FC sequence, while determining a specific phase α that reduces or most suppresses the reflection of the high-frequency electrical power HF generated by the source. a and specific phase α b The frequency of the source at each location.

[0054] The generation source frequency f of each phase within the periodic FC is achieved by expanding and / or reducing the aforementioned bandwidth. S The adjustment can be sequential processing or inter-pulse processing. The generator source frequency f is determined when the sequence of periodic FCs consists of multiple consecutive periodic FCs. S This adjustment is performed sequentially. On the other hand, the generator frequency f is adjusted when pulses of high-frequency electrical power HF are periodically supplied to the generator source. S This adjustment includes inter-pulse processing, which will be described later. Hereinafter, the first to third embodiments regarding successive processing and inter-pulse processing will be described.

[0055] In the first implementation, the period FC may contain only two specific phases, namely specific phases α. a and specific phase α b As at least two specific phases. In this case, the high-frequency power supply 31 can be used in each of the successive processing and inter-pulse processing processes, such as Figure 5 As shown in (b), a specific phase α a and specific phase α b The generation source frequency f at the phase within the period FC outside the period FC S Set to use linear interpolation from a specific phase α a Maximum frequency and specific phase α at that point aThe frequency obtained from the minimum frequency at that location.

[0056] In the second embodiment, the period FC may also include at least three specific phases, which are at least two specific phases. For example, at least three specific phases may also be as follows: Figure 6 As shown in (a), in addition to including a specific phase α a and specific phase α b In addition, it also includes a specific phase α c Specific phase α c It can be a specific phase α within the period FC b The subsequent phase can also be a specific phase α. a With a specific phase α b The phase between them.

[0057] In the second embodiment, the high-frequency power supply 31 uses the initial frequency as a specific phase α within the period FC in each of the successive processing and inter-pulse processing processes. a and specific phase α b The source frequency for generating a specific phase other than the initial frequency. Furthermore, the initial frequency is used for a specific phase α within the period FC. a and specific phase α b The initial value of the generation source frequency other than a specific phase is predetermined. Furthermore, in the second embodiment, the high-frequency power supply 31, in each of the successive processing and inter-pulse processing processes, uses the generation source frequency f at at least three specific phases outside the period FC as the generation source frequency f. S The frequency is obtained by linear interpolation based on the source frequencies at at least three specific phases.

[0058] In the second embodiment, the high-frequency power supply 31, in each of the successive processing and inter-pulse processing processes, sets a specific phase α... a and specific phase α b With the initial frequency fixed at a specific phase other than the aforementioned bandwidth expansion and / or contraction, the specific phase α determined therefrom will be... a and specific phase α b Their respective source frequencies f S Fixed. Then, in each process of successive processing and inter-pulse processing, the high-frequency power supply 31 makes a specific phase α a and specific phase α b The source frequency f of other specific phases within the period FC outside of the period FC S Changes, such as Figure 6 As shown in (b), the source frequency f of the other specific phase is used to determine the degree of reduction or suppression of reflection of the high-frequency electrical power HF generated by the source. S A specific phase α exists within the period FC. a and specific phase αb In the case of multiple other specific phases besides the one mentioned above, in order to determine the generation source frequency f of multiple other specific phases that reduce or best suppress the reflection of the generation source high-frequency electrical power HF, S It can generate multiple other specific phase source frequencies f S They can change sequentially, or they can change simultaneously.

[0059] In the third embodiment, the high-frequency power supply 31, in each of the successive processing and inter-pulse processing processes, while controlling a specific phase α... a and specific phase α b A specific phase α is set by linear interpolation of the respective source frequencies. a and specific phase α b The frequency of other phases besides period FC is used to expand and / or shrink the bandwidth as described above. Then, the high-frequency power supply 31 will determine the specific phase α by expanding and / or shrinking the bandwidth as described above. a and specific phase α b Their respective source frequencies f S Fixed. Then, the high-frequency power supply 31 makes a specific phase α within the period FC. a and specific phase α b At least one other phase besides (e.g., Figure 5 The specific phase α in (c) d The generation source frequency f at at least one other phase is used to determine the degree to which the reflection of the high-frequency electrical power HF generated by the generation source is reduced or most suppressed (i.e., suppressed to the greatest extent) S A specific phase α exists within the period FC. a and specific phase α b In the case of multiple other specific phases, in order to determine the generation source frequency f of multiple other specific phases that reduce or best suppress the reflection of the generation source high-frequency electrical power HF. S It can generate multiple other specific phase source frequencies f S They can be changed sequentially, or they can be changed simultaneously. Furthermore, in the third embodiment, the high-frequency power supply 31, in each of the successive processing and inter-pulse processing processes, changes a specific phase α... a and specific phase α b Their respective source frequencies f S After being fixed, the specific phase α within the period FC a Specific phase α b and the generation source frequency f at at least one other phase other than the other phase. S Using a specific phase α a Specific phase α bThe frequency is obtained by linear interpolation of the generation source frequency of at least one other phase.

[0060] The following is for reference Figure 7 . Figure 7 This is a diagram illustrating an example of pulses generating high-frequency electrical power from a source and pulses used for electrical bias. In Figure 7 In these diagrams, "ON" for the high-frequency power HF indicates that the high-frequency power HF is supplied to the generator source, while "OFF" indicates that the high-frequency power HF is not supplied. Furthermore, in these diagrams, "ON" for the bias EB indicates that the bias EB is applied to the bias electrode, while "OFF" for the bias EB indicates that the bias EB is not applied to the bias electrode.

[0061] like Figure 7 As shown, the high-frequency power supply 31 can also be configured to periodically supply the high-frequency electrical power HF generated by the source via a pulsed HFP. Furthermore, the bias power supply 32 can be configured to periodically supply the electrical bias EB via a pulsed EBP. The pulsed HFP and pulsed EBP can be supplied during multiple pulse periods PP, i.e., pulse periods PP1, PP2, ..., PP... K The supply occurs during each pulse period. That is, multiple repetition periods OP (i.e., repetition periods OP1, OP2, ..., OP1) of both pulse HFP and pulse EBP are supplied simultaneously. K Alternatively, the duration of the supply pulse HFP and the duration of the supply pulse EBP can partially overlap or offset from each other. In this case, the multiple overlapping periods OP are each a part of the duration of the supply pulse HFP and a part of the duration of the supply pulse EBP.

[0062] Each of the multiple repetition periods OP includes a first period P a Second period P b During the first period, P a This includes the start time of the corresponding repetition period OP. The second period P b It follows the first period P a The period includes the end time of the corresponding repetition period OP. The first period P a Second period P b Each includes repetitions of period FC and waveform period CY. That is, each of the multiple repetition periods OP includes N periods FC, namely period FC1 to period FC2. N In the following explanation, the period FC n It is the nth cycle FC among the multiple cycles FC in each of the multiple repetition periods OP.

[0063] The following is for reference Figure 8 (a)~ Figure 8 of (d). Figure 8 of (a) to Figure 8 Figs. (d) respectively show examples of time series of the generation source frequencies in a plasma processing apparatus representing an exemplary embodiment.

[0064] In the case where pulse HFP and pulse EBP are periodically supplied, the high-frequency power supply 31 also first sets the phase difference between the period FC and the waveform period CY as described above. When setting the phase difference between the period FC and the waveform period CY, as described above, the generation source frequency f within the period FC S of the time series is set according to the initial frequency group. In addition, the initial frequency group applied to the period FC a within the first period P n may be different from or the same as the initial frequency group applied to the period FC b included in the second period P. Additionally, the high-frequency power supply 31 may also determine the phase difference between the period FC and the waveform period CY only based on the degree of reflection in each period FC within the second period P b .

[0065] After setting the phase difference between the period FC and the waveform period CY, the high-frequency power supply 31 adjusts the generation source frequency f within the period FC S to suppress the degree of reflection of the generation source high-frequency electric power HF in the period FC. In the case where pulse HFP and pulse EBP are periodically supplied, the periods FC a within the first period P of each of the plurality of repetition periods OP n constitute the sequence of the period FC n .

[0066] The high-frequency power supply 31 may also use a time series of frequencies that is shifted to the lower frequency side with respect to the time series of the generation source frequency f determined according to the initial frequency group used in the second period P b as the time series of the generation source frequency f S within the period FC a within the first period P. The amount of frequency shift of the time series of the generation source frequency f n within the period FC S within the first period P with respect to the time series of the generation source frequency f a within the period FC n within the second period P S can be determined in advance. Alternatively, as in b Figs. (a) and n the generation source frequency f S within the period FC Figure 8 of (a) and Figure 8As shown in (b), the high-frequency power supply 31 can also operate during the first period P of multiple repetition periods OP. a Their respective periodic FC n In the sequence, the source frequency f will be generated. S The time series is offset towards the lower frequency side by different offsets, thereby determining the frequency offset that best suppresses the reflection of the high-frequency electrical power HF generated by the source.

[0067] Then, the high-frequency power supply 31 pairs the second period P of each of the multiple repetition periods OP. b The above-described successive processing is applied to multiple consecutive FC cycles within the circuit. Additionally, the high-frequency power supply 31 applies the first period P to each of the multiple repetitive periods OP. a The inter-pulse processing described above is applied to multiple consecutive FC cycles within a given period. Inter-pulse processing is applied to periodic FC cycles. n The sequence. Through inter-pulse processing, the first period P a The generation source frequency f within the periodic FC is within the range of FC. S Time series, for example Figure 8 (c) and / or Figure 8 As shown in (d), it is adjusted.

[0068] As explained above, according to the plasma processing apparatus 1, the generation frequency f of the high-frequency electrical power HF generated by the generation source is used to suppress the reflection of the high-frequency electrical power HF generated within a period FC having the same time length as the waveform period CY. S The time series. Therefore, based on the impedance variation of the load of the high-frequency power supply 31 within the period of the electrical bias EB, the reflection degree of the high-frequency electrical power HF generated is reduced. In addition, according to the plasma processing apparatus 1, the phase difference between the period FC and the waveform period CY, and a specific phase α, can be adjusted. a The generation source frequency f S With a specific phase α b The generation source frequency f S Adjusting the bandwidth between them, setting the source frequency f S The time series. Therefore, according to the plasma processing apparatus 1, the generation frequency f of the high-frequency electric power HF of the generation source, which suppresses the reflection of the generation source high-frequency electric power HF within the period FC, can be set through relatively simple processing. S The time series. Additionally, in one embodiment, the degree of reflection of the high-frequency electrical power HF from the generating source can be determined by AD conversion based on relatively low-speed sampling.

[0069] The following is for reference Figure 9 A method for controlling the frequency of the generation source in an exemplary embodiment will be described. Figure 9This is a flowchart illustrating an exemplary implementation of a method for controlling the frequency of a generator source. Figure 9 The method for controlling the frequency of the generated source (hereinafter referred to as "method MT") shown begins at step STa.

[0070] In step STa, the phase difference between the period FC and the waveform period CY is set as described above.

[0071] In one implementation, method MT may include step STb. Step STb can be performed while periodically supplying pulses HFP and EBP. In step STb, the time relative to the first period P is set as described above. a Within the periodic FC n The generation source frequency f within S The frequency offset of the time series.

[0072] In method MT, step STc is then performed. In step STc, a specific phase α... a The generation source frequency f at that location S [α a With a specific phase α b The generation source frequency f at that location S [α b The result of adjusting the bandwidth between [ ] is that the source frequency f can be determined to suppress the reflection of the high-frequency electrical power HF generated by the source. S [α a and the generation source frequency f S [α b For details regarding step STc, please refer to the above explanation of successive processing and inter-pulse processing.

[0073] Method MT may further include step STd. Step STd is performed after step STc. In step STd, as described with respect to the second embodiment, a specific phase α is changed. a and specific phase α b The generation source frequency f at other specific phases besides S The source frequency f at this other specific phase is used to determine the degree of suppression of reflection of the high-frequency electrical power HF generated by the source. S Alternatively, in step STd, as described with respect to the third embodiment, a specific phase α is changed. a and specific phase α b The generation source frequency f at at least one other phase within the period FC outside of the period FC S The generation source frequency f at at least one other phase is used to determine the degree of suppression of reflection of the high-frequency electrical power HF generated by the generation source. S .

[0074] Hereinafter, various exemplary embodiments of the present invention are described in [E1] to [E13].

[0075] [E1]

[0076] A bias power supply, comprising:

[0077] chamber;

[0078] The substrate support portion is disposed within the cavity;

[0079] A high-frequency power supply configured to generate high-frequency electrical power with a generation source frequency to generate plasma from gas within the cavity; and

[0080] A bias power supply, configured to supply an electrical bias to the substrate support to attract ions from the plasma within the cavity, the electrical bias having a waveform period.

[0081] The high-frequency power supply is configured to set the time series of the generated source frequency within a frequency adjustment period having the same time length as the waveform period to a maximum frequency at a first specific phase, a minimum frequency at a second specific phase, and a frequency obtained by interpolation at at least two phases other than the first and second specific phases.

[0082] The high-frequency power supply and the bias power supply are configured to set a phase difference between the frequency adjustment period and the waveform period to suppress the degree of reflection of the high-frequency electrical power generated by the source. During the frequency adjustment period, the source frequency is changed according to an initial frequency group specifying the initial source frequencies at at least two specific phases.

[0083] The high-frequency power supply is configured to, after the phase difference is set, determine the generation source frequency at the first specific phase and the generation source frequency at the second specific phase to suppress the reflection of the high-frequency electrical power of the generation source by changing the maximum frequency at the first specific phase and the minimum frequency at the second specific phase in opposite directions during the time series of the generation source frequency within the frequency adjustment period.

[0084] [E2]

[0085] According to the plasma processing apparatus described in E1, the high-frequency power supply is configured to determine the phase difference that most suppresses the reflection of the high-frequency electrical power of the generation source while changing the phase difference, and set the determined phase difference as the phase difference between the frequency adjustment period and the waveform period.

[0086] [E3]

[0087] According to the plasma processing apparatus described in E1, the phase difference can be set such that a first moment when the voltage of the substrate support corresponding to the electrical bias switches from negative to positive coincides with a first specific phase, and a second specific phase coincides with a second moment after the first moment, the second moment being the moment when the voltage of the substrate support corresponding to the electrical bias changes from negative to positive.

[0088] [E4]

[0089] According to any one of E1 to E3, the plasma processing apparatus wherein the high-frequency power supply is configured to set the generation source frequency of the phase other than the first specific phase and the second specific phase to a frequency obtained by linear interpolation based on the maximum frequency at the first specific phase and the minimum frequency at the second specific phase during the frequency adjustment period.

[0090] [E5]

[0091] According to any one of E1 to E3, in the plasma processing apparatus, the at least two specific phases include at least three specific phases.

[0092] The high-frequency power supply is configured as follows:

[0093] The generator source frequency can be used as an initial frequency for a specific phase other than the first and second specific phases among the at least three specific phases, and as the generator source frequency at a phase other than the at least three specific phases within the frequency adjustment period, using a frequency obtained by linear interpolation based on the generator source frequencies at the at least three specific phases.

[0094] After fixing the source frequency at the first specific phase and the source frequency at the second specific phase to their respective frequencies determined by changing the maximum frequency at the first specific phase and the minimum frequency at the second specific phase in opposite directions, the source frequency at the specific phase other than the first specific phase and the second specific phase among the at least three specific phases is changed to reduce the reflection of the high-frequency electrical power of the source.

[0095] [E6]

[0096] The plasma processing apparatus according to any one of E1 to E3, wherein...

[0097] The high-frequency power supply is configured as follows:

[0098] The generator source frequency at a phase other than the first specific phase and the second specific phase can be set to a frequency obtained by linear interpolation based on the maximum frequency at the first specific phase and the minimum frequency at the second specific phase within the frequency adjustment period.

[0099] After fixing the source frequency at the first specific phase and the source frequency at the second specific phase to their respective frequencies determined by changing the maximum frequency at the first specific phase and the minimum frequency at the second specific phase in opposite directions, the source frequency at the phases other than the first specific phase and the second specific phase within the frequency adjustment period is changed to reduce the degree of reflection of the high-frequency electrical power of the source.

[0100] [E7]

[0101] The plasma processing apparatus according to any one of E1 to E6, wherein...

[0102] The plasma processing device includes:

[0103] A directional coupler is connected between the high-frequency power supply and its load.

[0104] An envelope detection circuit that detects the envelope of the reflected wave of the high-frequency electrical power from the generator source output from the directional coupler; and

[0105] An AD conversion circuit performs analog-to-digital conversion on the envelope.

[0106] The high-frequency power supply is configured to determine the degree of reflection based on the average value of the amplitude of the envelope digitized by the AD conversion circuit within the frequency adjustment period.

[0107] [E8]

[0108] According to the plasma processing apparatus described in E7, the sampling frequency of the AD conversion circuit is lower than the generation source frequency of the high-frequency electrical power of the generation source.

[0109] [E9]

[0110] The plasma processing apparatus according to any one of E1 to E8, wherein...

[0111] The high-frequency power supply is configured to periodically supply pulses of high-frequency electrical power to the generator source.

[0112] The bias power supply is configured to periodically supply pulses for the electrical bias.

[0113] The period during which the pulses of the high-frequency electrical power of the generation source and the pulses of the electrical bias are supplied simultaneously includes a first period and a second period following the first period.

[0114] The high-frequency power supply is configured to use a time series of frequencies that have shifted towards a lower frequency direction relative to a time series of the generated source frequency determined according to the initial frequency group used in the second period, as a time series of the generated source frequency within the frequency adjustment period in the first period.

[0115] [E10]

[0116] According to the plasma processing apparatus described in E9, wherein...

[0117] The high-frequency power supply is configured to determine the phase difference that best suppresses the reflection of the high-frequency electrical power of the generating source, based solely on the degree of reflection during the second period, while changing the phase difference.

[0118] [E11]

[0119] The plasma processing apparatus according to any one of E1 to E10, wherein...

[0120] The electrical bias is a bias high-frequency electrical power having a bias frequency that is the reciprocal of the time length of the waveform period, or it includes voltage pulses supplied periodically at time intervals equal to the time length of the waveform period.

[0121] [E12]

[0122] A power supply system comprising:

[0123] A high-frequency power supply, configured to generate high-frequency electrical power with a generation source frequency to generate plasma from gas within a plasma processing apparatus chamber; and

[0124] A bias power supply, configured to supply electrical bias to a substrate support within the cavity to attract ions from the plasma within the cavity, the bias power supply having a waveform period.

[0125] The high-frequency power supply is configured to set the time series of the generated source frequency within a frequency adjustment period having the same time length as the waveform period to a maximum frequency at a first specific phase, a minimum frequency at a second specific phase, and a frequency obtained by interpolation at at least two phases other than the first and second specific phases.

[0126] The high-frequency power supply and the bias power supply are configured to set a phase difference between the frequency adjustment period and the waveform period to suppress the degree of reflection of the high-frequency electrical power generated by the source. During the frequency adjustment period, the source frequency is changed according to an initial frequency group specifying the initial source frequencies at at least two specific phases.

[0127] The high-frequency power supply is configured to, after the phase difference is set, determine the generation source frequency at the first specific phase and the generation source frequency at the second specific phase to suppress the reflection of the high-frequency electrical power of the generation source by changing the maximum frequency at the first specific phase and the minimum frequency at the second specific phase in opposite directions during the time series of the generation source frequency within the frequency adjustment period.

[0128] [E13]

[0129] A method for controlling the frequency of a generated source, comprising:

[0130] (a) Step, supplying high-frequency electrical power with a generation source frequency from a high-frequency power source to generate plasma from gas within the chamber of the plasma processing apparatus; and

[0131] (b) Step, supplying an electrical bias from a bias power source to the substrate support within the cavity to attract ions from the plasma within the cavity, wherein the electrical power bias has a waveform period.

[0132] In step (a), the high-frequency power supply sets the time series of the generated source frequencies within a frequency adjustment period having the same time length as the waveform period as the maximum frequency at a first specific phase, the minimum frequency at a second specific phase, and the interpolated frequencies at at least two specific phases other than the first and second specific phases.

[0133] The method also includes:

[0134] (c) Step, setting a phase difference between the frequency adjustment period and the waveform period to suppress the degree of reflection of the high-frequency electrical power of the generated source, wherein, during the frequency adjustment period, the generated source frequency is changed according to an initial frequency group specifying the initial generated source frequencies at at least two specific phases; and

[0135] (d) Step: After the phase difference is set, while making the maximum frequency at the first specific phase and the minimum frequency at the second specific phase change in opposite directions in the time series of the generator source frequency within the frequency adjustment period, the generator source frequency at the first specific phase and the generator source frequency at the second specific phase are determined to suppress the reflection of the high-frequency electrical power of the generator source to a certain extent.

[0136] Based on the above description, it should be understood that various embodiments of the present invention have been described in this specification for illustrative purposes, and various changes can be made without departing from the scope and spirit of the invention. Therefore, the various embodiments described in this specification are not intended to limit the invention, and the true scope and spirit are indicated by the claims.

[0137] Explanation of reference numerals in the attached figures

[0138] 1…Plasma processing device, 10…Cavity, 11…Substrate support, 31…High-frequency power supply, 32…Bias power supply.

Claims

1. A plasma processing device, characterized in that, include: Chamber; The substrate support portion is disposed within the cavity; A high-frequency power supply configured to generate high-frequency electrical power with a generation source frequency to generate plasma from gas within the cavity. and A bias power supply, configured to supply an electrical bias to the substrate support to attract ions from the plasma within the cavity, the electrical bias having a waveform period. The high-frequency power supply is configured to set the time series of the generated source frequency within a frequency adjustment period having the same time length as the waveform period to the maximum frequency at a first specific phase, the minimum frequency at a second specific phase, and the interpolated frequencies at phases other than at least two specific phases including the first and second specific phases. The high-frequency power supply and the bias power supply are configured to set a phase difference between the frequency adjustment period and the waveform period to suppress the degree of reflection of the high-frequency electrical power generated by the source. During the frequency adjustment period, the source frequency can be changed according to an initial frequency group specifying the initial source frequencies at at least two specific phases. The high-frequency power supply is configured to, after the phase difference is set, determine the generation source frequency at the first specific phase and the generation source frequency at the second specific phase, respectively, the degree of suppression of the reflection of the high-frequency electrical power of the generation source, in the time series of the generation source frequency within the frequency adjustment period, while making the maximum frequency at the first specific phase and the minimum frequency at the second specific phase change in opposite directions.

2. The plasma processing apparatus as described in claim 1, characterized in that: The high-frequency power supply is configured to determine the phase difference that best suppresses the reflection of the high-frequency electrical power generated by the source while changing the phase difference, and to set the determined phase difference as the phase difference between the frequency adjustment period and the waveform period.

3. The plasma processing apparatus as described in claim 1, characterized in that: The phase difference can be set such that the first moment when the voltage of the substrate support corresponding to the electrical bias switches from negative to positive coincides with the first specific phase, and the second specific phase coincides with the second moment after the first moment, which is the moment when the voltage of the substrate support corresponding to the electrical bias changes from negative to positive.

4. The plasma processing apparatus according to any one of claims 1 to 3, characterized in that: The high-frequency power supply is configured to set the generation source frequency at a phase other than the first specific phase and the second specific phase to a frequency obtained by linear interpolation based on the maximum frequency at the first specific phase and the minimum frequency at the second specific phase within the frequency adjustment period.

5. The plasma processing apparatus according to any one of claims 1 to 3, characterized in that: The at least two specific phases include at least three specific phases. The high-frequency power supply is configured as follows: The generator source frequency can be used as an initial frequency at a specific phase other than the first and second specific phases among the at least three specific phases, and as the generator source frequency at a phase other than the at least three specific phases within the frequency adjustment period, using a frequency obtained by linear interpolation based on the generator source frequencies at the at least three specific phases. After fixing the source frequency at the first specific phase and the source frequency at the second specific phase to their respective frequencies determined by changing the maximum frequency at the first specific phase and the minimum frequency at the second specific phase in opposite directions, it is possible to change the source frequency at specific phases other than the first specific phase and the second specific phase among the at least three specific phases to reduce the reflection of the high-frequency electrical power of the source.

6. The plasma processing apparatus according to any one of claims 1 to 3, characterized in that: The high-frequency power supply is configured as follows: The generator source frequency at a phase other than the first specific phase and the second specific phase can be set to a frequency obtained by linear interpolation based on the maximum frequency at the first specific phase and the minimum frequency at the second specific phase within the frequency adjustment period. After fixing the source frequency at the first specific phase and the source frequency at the second specific phase to their respective frequencies determined by changing the maximum frequency at the first specific phase and the minimum frequency at the second specific phase in opposite directions, the source frequency at phases other than the first specific phase and the second specific phase within the frequency adjustment period can be varied to reduce the degree of reflection of the high-frequency electrical power of the source.

7. The plasma processing apparatus according to any one of claims 1 to 3, characterized in that, include: A directional coupler is connected between the high-frequency power supply and its load. An envelope detection circuit that detects the envelope of the reflected wave of the high-frequency electrical power generated from the directional coupler. and An AD conversion circuit performs analog-to-digital conversion on the envelope. The high-frequency power supply is configured to determine the degree of reflection based on the average value of the amplitude of the envelope digitized by the AD conversion circuit within the frequency adjustment period.

8. The plasma processing apparatus as described in claim 7, characterized in that: The sampling frequency of the AD conversion circuit is lower than the generation source frequency of the high-frequency electrical power of the generation source.

9. The plasma processing apparatus according to any one of claims 1 to 3, characterized in that: The high-frequency power supply is configured to periodically supply pulses of high-frequency electrical power to the generator source. The bias power supply is configured to periodically supply pulses for the electrical bias. The period during which the pulses of the high-frequency electrical power of the generation source and the pulses of the electrical bias are supplied simultaneously includes a first period and a second period following the first period. The high-frequency power supply is configured to use a time series of frequencies that have shifted towards a lower frequency direction relative to the time series of the generated source frequency determined according to the initial frequency group used in the second period, as the time series of the generated source frequency within the frequency adjustment period in the first period.

10. The plasma processing apparatus as described in claim 9, characterized in that: The high-frequency power supply is configured to determine the phase difference that best suppresses the reflection of the high-frequency electrical power of the generating source, based solely on the degree of reflection during the second period, while changing the phase difference.

11. The plasma processing apparatus according to any one of claims 1 to 3, characterized in that: The electrical bias is a bias high-frequency electrical power having a bias frequency that is the reciprocal of the time length of the waveform period, or it includes voltage pulses supplied periodically at time intervals equal to the time length of the waveform period.

12. A power supply system, characterized in that, include: A high-frequency power supply, configured to generate high-frequency electrical power with a generation source frequency to generate plasma from gas within the chamber of a plasma processing device. and A bias power supply, configured to supply electrical bias to a substrate support within the cavity to attract ions from the plasma within the cavity, the bias power supply having a waveform period. The high-frequency power supply is configured to set the time series of the generated source frequency within a frequency adjustment period having the same time length as the waveform period to the maximum frequency at a first specific phase, the minimum frequency at a second specific phase, and the interpolated frequencies at phases other than at least two specific phases including the first and second specific phases. The high-frequency power supply and the bias power supply are configured to set a phase difference between the frequency adjustment period and the waveform period to suppress the degree of reflection of the high-frequency electrical power generated by the source. During the frequency adjustment period, the source frequency can be changed according to an initial frequency group specifying the initial source frequencies at at least two specific phases. The high-frequency power supply is configured to, after the phase difference is set, determine the generation source frequency at the first specific phase and the generation source frequency at the second specific phase, respectively, the degree of suppression of the reflection of the high-frequency electrical power of the generation source, in the time series of the generation source frequency within the frequency adjustment period, while making the maximum frequency at the first specific phase and the minimum frequency at the second specific phase change in opposite directions.

13. A method for controlling the frequency of a generation source, characterized in that, include: (a) Step: High-frequency electrical power with a generation source frequency is supplied from a high-frequency power source to generate plasma from gas in the chamber of the plasma processing apparatus. and (b) Step, supplying an electrical bias from a bias power source to the substrate support within the cavity to attract ions from the plasma within the cavity, wherein the electrical power bias has a waveform period. In step (a), the high-frequency power supply sets the time series of the generated source frequencies within a frequency adjustment period having the same time length as the waveform period as the maximum frequency at a first specific phase, the minimum frequency at a second specific phase, and the interpolated frequencies at phases other than at least two specific phases including the first and second specific phases. The method also includes: (c) Step, setting a phase difference between the frequency adjustment period and the waveform period to suppress the degree of reflection of the high-frequency electrical power of the generated source, wherein, during the frequency adjustment period, the generated source frequency can be changed according to an initial frequency group specifying the initial generated source frequencies at at least two specific phases; and (d) After the phase difference is set, in the time series of the source frequency within the frequency adjustment period, while changing the maximum frequency at the first specific phase and the minimum frequency at the second specific phase in opposite directions, the source frequency at the first specific phase and the source frequency at the second specific phase are determined to suppress the reflection of the high-frequency electrical power of the source.

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