Phase synchronization method, phase calibration method and calibration device of radio frequency power supply

Abstract

The invention provides a radio frequency power supply phase synchronization method, a phase calibration method and a calibration device thereof. In one embodiment, the radio frequency power supply phase synchronization calibration method comprises the steps of obtaining a phase of a co-excitation input signal, obtaining a phase of a sampling signal, calculating a first phase difference between the sampling signal and the co-excitation input signal, obtaining a phase of a forward wave signal in a load signal, and calculating a second phase difference between the sampling signal and the co-excitation input signal. A second phase difference between the forward wave signal and the co-excitation input signal is calculated, a third phase difference between the forward wave signal and the load signal is calculated, and the third phase difference is calculated based on the load signal and the forward wave signal and the reflected wave signal in the load signal; and calculating a fixed phase difference based on the first phase difference, the second phase difference and the third phase difference, wherein the fixed phase difference serves as a phase synchronization calibration parameter of the radio frequency power supply. The phase synchronization calibration method can realize phase synchronization of the radio frequency power supply output signal and the co-excitation input signal under any load impedance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor equipment, and in particular, to a phase synchronization method of a radio frequency power supply, a phase synchronization calibration method and a device thereof. BACKGROUND

[0002] Plasma processing equipment is used in various industries for manufacturing chips, including semiconductors, magnetic read / write, magnetic storage, and micro-electro-mechanical systems. Using radio frequency power supplies or radio frequency systems to excite plasma has been widely applied in the field of plasma processing.

[0003] With the maturity of technology and the needs of the industry, plasma processing equipment becomes more and more complex, for example, using multiple radio frequency power supplies to provide radio frequency power for multiple electrodes in the same or different vacuum chambers, so as to achieve complex process effects and improve production efficiency. When multiple radio frequency power supplies work independently, the difference between the output radio frequency and phase of each power supply may cause mutual interference between the power supplies, thereby adversely affecting the system. Using the Common Exciter (CEX) function, also known as the phase synchronization function, of the radio frequency power supply can lock two or more power supplies to the same output phase, thereby effectively reducing the interference between the power supplies and eliminating the problems related thereto. Therefore, this function is widely used in plasma processing equipment containing multiple radio frequency power supplies. Usually, the CEX synchronization input signal from the main radio frequency power supply or signal generator is connected to the CEX input end of the slave radio frequency power supply, so that the radio frequency output signal of the slave radio frequency power supply is expected to maintain the same phase as the CEX input signal. However, the output signal of the radio frequency power supply has a phase difference with the CEX input signal. Moreover, when the impedance in the chamber of the plasma processing equipment changes, the phase difference will also change accordingly.

[0004] Therefore, there is a need for a radio frequency power supply phase synchronization method that can control the phase difference between the radio frequency power supply output signal and the CEX input signal under various dynamic wide impedance load conditions, so as to achieve phase synchronization and locking of the radio frequency power supply output signal and the CEX input signal. The present application is suitable for solving this demand. SUMMARY

[0005] One purpose of an embodiment of the present application is to provide a radio frequency power supply phase synchronization method, a phase calibration method, and a phase calibration device, to solve the problem of how to lock the phase of the radio frequency power supply.

[0006] In a first aspect, the embodiments of the present application provide a method for calibrating phase synchronization of a radio frequency power supply, which is suitable for calibrating a phase difference between a co-excitation input signal input to the radio frequency power supply and a forward wave signal output from the radio frequency power supply. The method comprises: receiving the co-excitation input signal by the radio frequency power supply and obtaining a phase of the co-excitation input signal; sampling a load signal output from the radio frequency power supply and obtaining a phase of the sampled signal; calculating a first phase difference between the sampled signal and the co-excitation input signal; obtaining a phase of the forward wave signal in the load signal; calculating a second phase difference between the forward wave signal and the co-excitation input signal; calculating a third phase difference between the forward wave signal and the load signal, wherein the third phase difference is calculated based on the load signal, the forward wave signal and a reflected wave signal in the load signal; and calculating a fixed phase difference based on the first phase difference, the second phase difference and the third phase difference, wherein the fixed phase difference is taken as a phase synchronization calibration parameter of the radio frequency power supply.

[0007] Optionally, the obtaining of the phase of the co-excitation input signal and the obtaining of the phase of the forward wave signal in the load signal comprise: connecting a first port of an oscilloscope and a co-excitation input signal input end of the radio frequency power supply by using a first cable to detect the phase of the co-excitation input signal; and connecting an input end of a double directional coupler and a radio frequency power output end of the radio frequency power supply, and connecting a second port of the oscilloscope and a coupling end of the double directional coupler by using a second cable to detect the phase of the forward wave signal.

[0008] Optionally, the first cable and the second cable have the same material and length.

[0009] Optionally, the calculating of the third phase difference between the forward wave signal and the load signal comprises: obtaining a load voltage and a load current in the load signal; calculating a forward wave power and a reflected wave power; calculating a forward wave voltage amplitude, a reflected wave voltage amplitude and a phase difference between the forward wave voltage and the reflected wave voltage; and calculating the third phase difference between the forward wave signal and the load signal based on the forward wave voltage amplitude, the reflected wave voltage amplitude, the phase difference between the forward wave voltage and the reflected wave voltage and the load voltage.

[0010] In a second aspect, the embodiments of the present application provide a device for calibrating phase synchronization of a radio frequency power supply, characterized in that the device comprises: a radio frequency power supply configured to receive a co-excitation input signal at a co-excitation input end and output a load signal at a radio frequency output end; a sensor configured to sample the load signal to obtain a sample signal; a double directional coupler connected to the radio frequency power supply and configured to receive the load signal output by the radio frequency power supply and output the load signal to a load unit at an output end and output a forward wave signal at a coupling end; an oscilloscope connected to the co-excitation input end of the radio frequency power supply through a first cable and connected to the coupling end of the double directional coupler through a second cable and configured to detect the phase of the co-excitation input signal and the phase of the forward wave signal in the load signal; and a controller configured to calculate a first phase difference between the sample signal and the co-excitation input signal and calculate a third phase difference between the forward wave signal and the load signal, wherein the third phase difference is calculated based on the load signal, the forward wave signal and a reflected wave signal in the load signal.

[0011] Optionally, the first cable and the second cable have the same material and length.

[0012] Optionally, the controller is configured to obtain a load voltage and a load current in the load signal, calculate a forward wave power and a reflected wave power, calculate a forward wave voltage amplitude, a reflected wave voltage amplitude and a phase difference between the forward wave voltage and the reflected wave voltage, and calculate the third phase difference between the forward wave signal and the load signal based on the forward wave voltage amplitude, the reflected wave voltage amplitude, the phase difference between the forward wave voltage and the reflected wave voltage and the load voltage.

[0013] Optionally, the resistance value of the load unit is 50 ohms.

[0014] In a third aspect, the embodiments of the present application provide a method for phase synchronization of a radio frequency power supply, which is suitable for controlling the phase difference between a co-excitation input signal input to a radio frequency power supply and a forward wave signal output from the radio frequency power supply. The method comprises: the radio frequency power supply receiving the co-excitation input signal and obtaining the phase of the co-excitation input signal, sampling a load signal output from the radio frequency power supply and obtaining the phase of the sampling signal, calculating the first phase difference between the sampling signal and the co-excitation input signal, obtaining the phase of the forward wave signal in the load signal, calculating the second phase difference between the forward wave signal and the co-excitation input signal, calculating the third phase difference between the forward wave signal and the load signal, wherein the third phase difference is calculated based on the load signal, the forward wave signal and the reflected wave signal in the load signal, calculating the fixed phase difference based on the first phase difference, the second phase difference and the third phase difference, and adjusting the radio frequency power supply during the operation of the radio frequency power supply so that the sum of the first phase difference and the third phase difference is equal to the fixed phase difference.

[0015] The method for phase synchronization of the radio frequency power supply provided by the present application can maintain the phase synchronization and locking between the forward wave signal output from the radio frequency power supply and the CEX input signal when the plasma load impedance changes, thereby avoiding the crosstalk between multiple radio frequency power supplies. BRIEF DESCRIPTION OF DRAWINGS

[0016] One or more embodiments are illustrated by way of example in the figures that form a part of this patent document, these example are not intended to limit the embodiments, elements having the same reference numbers in the figures indicate like elements unless otherwise expressly stated, the figures in the drawings are not to scale.

[0017] Figure 1 A flow chart of the method for phase synchronization calibration of the radio frequency power supply provided by an embodiment of the present application is shown;

[0018] Figure 2 A schematic diagram of the device for phase synchronization calibration of the radio frequency power supply provided by an embodiment of the present application is shown;

[0019] Figure 3 A schematic diagram of the device for phase synchronization test of the radio frequency power supply provided by another embodiment of the present application is shown;

[0020] Figure 4 A waveform diagram of the forward wave signal and the co-excitation input signal under the 50-ohm load impedance provided by an embodiment of the present application is shown; and

[0021] Figure 5 A waveform diagram of the forward wave signal and the co-excitation input signal under the non-50-ohm load impedance provided by an embodiment of the present application is shown. DETAILED DESCRIPTION

[0022] In order to make the purposes, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0023] It should be noted that the various features of the embodiments of the present application can be combined with each other, and all fall within the scope of protection of the present application, if there is no conflict. In addition, although the functional modules are divided in the device schematic diagram, and the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order from the module division in the device or the order in the flowchart. Furthermore, the "first", "second", "third" and the like used in the present application do not limit the data and execution order, but only distinguish the same items or similar items with basically the same function and effect.

[0024] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the present application are only for the purpose of describing specific embodiments of the present application and are not used to limit the present application. The term "and / or" used in the present application includes any and all combinations of one or more related listed items. In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as there is no conflict.

[0025] As technology develops and different process requirements, a plasma processing apparatus can include multiple radio frequency power sources. In one example, the plasma processing apparatus includes a main radio frequency power source and a slave radio frequency power source. The main radio frequency power source generates a radio frequency signal to deliver the signal to an input of a main impedance matcher. An output of the main matcher is used to deliver the radio frequency signal to a plasma processing chamber having multiple loads therein for receiving the radio frequency signal generated by the radio frequency power source. The plasma processing apparatus can also include a radio frequency delivery component for delivering radio frequency power into a plasma of the chamber. The main radio frequency power source can deliver the radio frequency signal to the chamber directly or indirectly via an intermediate component.

[0026] A main RF power source provides a first RF signal to a load in a chamber to excite and sustain a plasma in the chamber for wafer processing or chamber cleaning, etc. The main RF power source can also provide RF power at different frequencies. The output of the main RF power source is provided with a sensor that samples and detects the output load signal of the main RF power source to obtain a sampled signal. The sampled signal has a fixed phase difference with the actual load signal. The sampled signal can be an RF current signal or an RF voltage signal. As an example, the sensor can be a voltage-current sensor.

[0027] A main impedance matching circuit is provided between the main RF power source and the chamber. The matching circuit is used to match the output impedance of the main RF power source to the input impedance of the chamber. The input impedance can vary with the frequency of the applied voltage by the main RF power source, the chamber pressure, the gas composition, and the target material or substrate material. The main matching circuit includes electrical elements such as variable capacitance and variable inductance to dynamically match the output impedance of the main RF power source to the input impedance of the chamber. Most RF sources have an output impedance of 50 ohms. The main matching circuit can adjust for the mismatch between the input impedance and the output impedance (50 ohms) of the RF source.

[0028] The chamber can be used for various semiconductor processing steps such as etching, deposition, cleaning, etc. The chamber has multiple loads. Among them, a first load is connected to the main RF power source through a cable to receive the RF signal, and a second load is connected to the slave RF power source through a cable to receive the RF signal. The load can be a capacitive load such as an electrode plate. The load can also be an inductive load such as a coil. Therefore, the chamber can be any of the following chambers: a capacitive-coupled plasma (CCP) chamber, an inductive-coupled plasma (ICP) chamber, a transformer-coupled plasma (TCP) chamber, a through-silicon via (TSV) chamber, and a remote plasma source (RPS) chamber.

[0029] The slave RF power source is connected to the slave matching circuit, and the slave matching circuit is connected to the load in the chamber. The slave RF power source is used to generate a second RF signal to the load. The slave RF power source and the slave matching circuit have the same functions as the main RF power source and the main matching circuit described above, and are not described here. The output of the slave RF power source is provided with a sensor such as a voltage-current sensor.

[0030] The main RF power source and the slave RF power source are connected to transmit a synchronization signal, also known as a co-excitation input signal. Specifically, the main RF power source generates a co-excitation input signal, which is transmitted to the co-excitation input end of the slave RF power source through a cable, to synchronize the phase of the RF power signals of the main RF power source and the slave RF power source.

[0031] The master RF power supply and the slave RF power supply can also be connected to a signal generator. The signal generator outputs a common excitation input signal to the master RF power supply and the slave RF power supply, respectively, to synchronize the phase of the RF power signals of the master RF power supply and the slave RF power supply.

[0032] The load signal output by the RF power supply is the superposition of the forward wave signal and the reverse wave signal. For the RF power supply, the target of phase synchronization is to make the phase of the forward wave signal output by the RF power supply always follow the phase of the common excitation input signal CEX_IN received by the power supply, and the phase difference remains zero. The load signal, the forward wave signal, the reverse wave signal and the sampling signal mentioned above can be voltage signals or current signals, and the following description takes voltage signals as an example.

[0033] The voltage current sensor arranged at the output of the RF power supply directly samples the output load voltage V L The signal sampling, the sampled sampling voltage V s The signal and the load voltage V L There is a fixed phase difference between the signal and the load voltage V Wherein And Respectively represent the phase of V L And V s . Therefore, when the control unit inside the RF power supply makes phase-locked control, by adjusting the internal phase-locked circuit to change the phase of V s Signal, the phase synchronization of the load voltage V L Output by the power supply and the common excitation input signal CEX_IN signal can be realized. In addition, the load voltage V L Is the superposition of the forward wave voltage V fwd Signal and the reverse wave voltage V rfl Signal. When the load impedance is constant, the phase difference between the load voltage V L And the forward wave voltage V fwd Remains unchanged, then changing the phase of V s Signal, the phase synchronization of the signal V fwd And the common excitation input signal CEX_IN signal can also be realized.

[0034] However, in the process of impedance matching adjustment of the RF power supply, the load impedance will change in real time and not always 50Ω. Since the phase of the forward wave voltage V fwd Changes, the phase difference between the sampling voltage V s Signal and the forward wave voltage V fwd Signal will change with the change of the load impedance. Therefore, the forward wave voltage V s Cannot be realized by controlling the lock of V fwdsignal. Therefore, the inventor believes that it is necessary to find a new voltage V + signal, whose phase has a fixed phase difference with the forward wave voltage V fwd signal, and the phase difference will not change with the change of the load impedance.

[0035] Voltage V + Signal

[0036] signal, as described above, is sampled by the voltage current sensor. s signal. When the load impedance changes, V L signal is only sampled from the load voltage V s signal. Therefore, it is necessary to find a V L signal, whose phase difference with the V fwd signal has a variable phase difference. Therefore, it is necessary to find a V + signal, whose phase difference with the V + signal can still keep a fixed phase difference. The forward wave voltage V fwd signal is defined as the load voltage V fwd signal, whose phase difference with the load voltage V L signal is signal is known as the load voltage V s signal. Therefore, it is necessary to find a V L signal, whose phase difference with the V signal is a fixed phase difference. Therefore, it is necessary to find a new signal V s signal, whose phase difference with the V + signal is a fixed phase difference fwd signal.

[0037]

[0038] signal, whose phase difference with the V fwd signal is a fixed phase difference, and the phase difference will not change with the change of the load impedance. + signal, whose phase difference with the V s signal is a fixed phase difference, and the phase difference will not change with the change of the load impedance. signal, whose phase difference with the V + signal is a fixed phase difference, and the phase difference will not change with the change of the load impedance. fwd signal. In the control unit, the V s signal sampled by the voltage current sensor is known, so it is only necessary to calculate α in real time to obtain the V + signal.

[0039] Phase difference a between forward wave signal and load signal

[0040] The load voltage V can be obtained from the sampled values ​​acquired by the voltage and current sensors. L Load current I L and V L with I L phase difference between By V L I L , The load impedance Z can be calculated. L Power reflection coefficient and forward power P fwd Reflection power P rfl Load power P L .

[0041] And because By P fwd and P rfl The amplitude |V of the forward wave can be calculated. fwd |, Amplitude of the reflected wave|V rfl | and V ref With V fwd phase difference between

[0042] According to the definition above, Represents forward wave voltage V fwd With load voltage V L The phase difference between them, and the load voltage can be expressed as the superposition of the forward wave and the reflected wave, that is...

[0043]

[0044] The obtained V L 、|V rfl |、|V fwd |、 Substituting into equation (2), we can obtain α.

[0045] After obtaining the phase difference α, the sampled voltage V s Adding the phase difference α yields V. + The signal. Therefore, when performing phase-locked control, the control unit inside the RF power supply only needs to adjust V. s The phase of the signal can be used to realize the forward wave voltage V of the power supply output under any load. fwd It is phase-synchronized with the common excitation input CEX_IN signal.

[0046] Phase synchronization calibration method

[0047] According to equation (1) above, V + Forward wave voltage V of signal and power supply output fwd There is a fixed phase difference between them and this fixed phase difference does not change with the change of load impedance. Then

[0048]

[0049] The target of phase synchronization is the forward wave voltage V fwd in phase with the co-excitation input CEX IN signal, i.e. Substituting (4), we get

[0050]

[0051] From (5), since and can be measured by a sensor and obtained by a signal generator, and α is calculated by the above formula (2), then if the value of V can be obtained, the phase difference between V fwd and CEX IN is 0. And since does not change with the change of load impedance, it can be measured at any load (preferably 50 Ω standard load) and written into the phase-locked loop as a calibration parameter to achieve 0 phase locking. And V + is the output of the power supply, the fixed phase difference between the V fwd signal and the V s signal of the power supply output can be obtained by formula (4), i.e.

[0052]

[0053] wherein, is the phase difference between the sampling voltage and the co-excitation input signal, and α is the phase difference between the forward wave voltage and the load voltage, is the phase difference between the forward wave voltage and the co-excitation input signal.

[0054] Based on this, in one embodiment, the present application provides a phase synchronization calibration method for a radio frequency power supply, Figure 1 a flowchart of the phase synchronization calibration method is shown, which is suitable for calibrating the phase difference between the co-excitation input signal of the input radio frequency power supply and the forward wave signal output from the radio frequency power supply. Figure 1 The flowchart shown is only an example, which should not improperly limit the scope of the claims. Those of ordinary skill in the art will recognize many variations, alternatives, and modifications. For example, Figure 1 Various steps shown in the flowchart can be added, removed, replaced, rearranged, and repeated.

[0055] In one embodiment, the phase synchronization calibration method for a radio frequency power supply includes the following steps:

[0056] At step 102, the RF power supply receives a co-excitation input signal and obtains a phase of the co-excitation input signal. The RF power supply receives the co-excitation input signal from a main RF power supply. In another embodiment, the RF power supply receives the co-excitation input signal from a signal generator.

[0057] At step 104, a load signal outputted by the RF power supply is sampled by a voltage current sensor and a phase of the sampled signal is obtained.

[0058] At step 106, a first phase difference between the sampled signal and the co-excitation input signal is calculated.

[0059] At step 108, a phase of a forward wave signal in the load signal is obtained by a dual directional coupler connected to an output of the RF power supply.

[0060] At step 110, a second phase difference between the forward wave signal and the co-excitation input signal is calculated.

[0061] At step 112, a third phase difference between the forward wave signal and the load signal is calculated, wherein the third phase difference is calculated based on the load signal and the forward wave signal and a reflected wave signal in the load signal.

[0062] At step 114, a fixed phase difference is calculated based on the first phase difference, the second phase difference and the third phase difference, and the fixed phase difference is used as a phase synchronization calibration parameter of the RF power supply. The phase synchronization calibration parameter is written into a phase locked loop inside the RF power supply for phase locked control. By adjusting the phase locked circuit, the phase of the V s signal is changed so that the forward wave voltage V fwd outputted by the RF power supply is synchronized with the phase of the co-excitation input CEX_IN signal.

[0063] In an embodiment, the phase of the co-excitation input signal and the phase of the forward wave signal in the load signal are obtained by connecting a first port of an oscilloscope to a co-excitation input signal input of the RF power supply using a first cable to detect the phase of the co-excitation input signal, connecting an input of a dual directional coupler to a RF power output of the RF power supply, and connecting a second port of the oscilloscope to a coupled end of the dual directional coupler using a second cable to detect the phase of the forward wave signal.

[0064] In an embodiment, the first cable and the second cable have the same material and length so that no additional phase difference is introduced.

[0065] In an embodiment, the third phase difference between the forward wave signal and the load signal is calculated by obtaining a load voltage and a load current in the load signal, calculating a forward wave power and a reflected wave power, calculating a forward wave voltage amplitude, a reflected wave voltage amplitude and a phase difference between the forward wave voltage and the reflected wave voltage, and calculating the third phase difference between the forward wave signal and the load signal based on the forward wave voltage amplitude, the reflected wave voltage amplitude, the phase difference between the forward wave voltage and the reflected wave voltage, and the load voltage.

[0066] Phase synchronization calibration device

[0067] Figure 2 A schematic diagram of a radio frequency power source phase synchronization calibration device is shown. As shown, the phase calibration device includes a radio frequency power source 10, a sensor 20, a dual directional coupler 30, an oscilloscope 40 and a controller 40. Figure 2

[0068] The radio frequency power source 10 is connected with the sensor 20, the dual directional coupler 30 and the 50 ohm load unit 50 in sequence. During the operation of the radio frequency power source 10, the common excitation input signal input end of the radio frequency power source 10 receives a common excitation input signal, and outputs a load signal at the radio frequency output end. The common excitation input signal can be output by a master radio frequency power source to achieve phase synchronization of the master radio frequency power source and the slave radio frequency power source. The common excitation input signal can be output by a signal generator to achieve phase synchronization of the master and slave radio frequency power sources controlled by the signal generator. The sensor 20 is arranged at the radio frequency output end of the radio frequency power source 10, and is used to sample the output load signal to obtain a sampling signal. The dual directional coupler 30 is configured to receive the load signal output by the radio frequency power source 10 and output the load signal to the load unit 50 at its output end. The load signal includes a forward wave signal and a reflected wave signal. The coupling end of the dual directional coupler 30 outputs the forward wave signal. The oscilloscope 40 is connected with the common excitation input end of the radio frequency power source 10 through a first cable and connected with the coupling end of the dual directional coupler 30 through a second cable. The oscilloscope 40 is used to detect the phase of the common excitation input signal and the phase of the forward wave signal in the load signal. The controller 60 calculates a first phase difference between the sampling signal and the common excitation input signal, and a third phase difference between the forward wave signal and the load signal, wherein the third phase difference is calculated based on the load signal, the forward wave signal and the reflected wave signal in the load signal.

[0069] In an embodiment, the first cable and the second cable have the same material and length, so as not to introduce additional phase difference.

[0070] ​In an embodiment, the controller is configured to obtain a load voltage and a load current in the load signal, to calculate a forward wave power and a reflected wave power, to calculate a forward wave voltage amplitude, a reflected wave voltage amplitude, and a phase difference between the forward wave voltage and the reflected wave voltage, and to calculate a third phase difference between the forward wave signal and the load signal based on the forward wave voltage amplitude, the reflected wave voltage amplitude, the phase difference between the forward wave voltage and the reflected wave voltage, and the load voltage.

[0071] In an embodiment, the present application provides a method for phase synchronization of a radio frequency power source, which is suitable for controlling a phase difference between a co-excitation input signal input to a radio frequency power source and a forward wave signal output from the radio frequency power source, and the method comprises the following steps:

[0072] receiving the co-excitation input signal and obtaining a phase of the co-excitation input signal,

[0073] sampling a load signal output from the radio frequency power source and obtaining a phase of the sampled signal,

[0074] calculating a first phase difference between the sampled signal and the co-excitation input signal,

[0075] obtaining a phase of a forward wave signal in the load signal,

[0076] calculating a second phase difference between the forward wave signal and the co-excitation input signal,

[0077] calculating a third phase difference between the forward wave signal and the load signal, wherein the third phase difference is calculated based on the load signal and the forward wave signal and a reflected wave signal in the load signal,

[0078] calculating a fixed phase difference based on the first phase difference, the second phase difference, and the third phase difference,

[0079] during operation of the radio frequency power source, the first phase difference is adjusted by adjusting a phase of a driving signal of a power amplifier circuit of the radio frequency power source, so that a sum of the first phase difference and the third phase difference is equal to the fixed phase difference.

[0080] Figure 3 A schematic diagram of a phase synchronization test device of an embodiment of the present application is shown. The phase synchronization test device is different from the phase synchronization calibration device shown in Figure 2 in that the phase synchronization test device further comprises an impedance transformer 70 connected between the bidirectional coupler 20 and the 50-ohm load unit 50. The impedance transformer 70 is used to adjust the load impedance to an arbitrary impedance value to simulate the load impedance when the radio frequency power source 10 is actually operating.

[0081] Figure 4Fig. 2 shows a waveform diagram of the forward wave signal and the co-excitation input signal under a 50-ohm load impedance according to an embodiment of the present application, Figure 5 Fig. 3 shows a waveform diagram of the forward wave signal and the co-excitation input signal under a non-50-ohm load impedance according to an embodiment of the present application. As shown in Fig. 3, Figure 4 and Figure 5 the yellow line represents the co-excitation input CEX_IN signal, and the red line represents the forward wave voltage V fwd signal. When the load impedance is any value, the phase of the co-excitation input CEX_IN signal and the forward wave voltage V fwd signal can be locked, and the phase difference is 0. During the process of adjusting the load impedance, the CEX_IN signal can always be locked. fwd

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; under the idea of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above, which are not provided in detail for simplicity; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.​

Claims

1. A method for calibrating the phase synchronization of an RF power supply, applicable to calibrating the phase difference between a common-excitation input signal of an input RF power supply and a forward wave signal output from the RF power supply, the method comprising: The radio frequency power supply receives the common excitation input signal and obtains the phase of the common excitation input signal. The load signal output by the radio frequency power supply is sampled to obtain the phase of the sampled signal. Calculate the first phase difference between the sampled signal and the common-excitation input signal. Obtain the phase of the forward wave signal in the load signal. Calculate the second phase difference between the forward wave signal and the co-excitation input signal. Calculate the third phase difference between the forward wave signal and the load signal, wherein the third phase difference is calculated based on the load signal and the forward wave signal and reflected wave signal in the load signal. A fixed phase difference is calculated based on the first phase difference, the second phase difference, and the third phase difference, and the fixed phase difference is used as the phase synchronization calibration parameter of the RF power supply.

2. The phase synchronization calibration method according to claim 1, characterized in that, The process of obtaining the phase of the common-excitation input signal and obtaining the phase of the forward wave signal in the load signal includes: Connect the first port of the oscilloscope to the common excitation input signal input terminal of the RF power supply using the first cable to detect the phase of the common excitation input signal. Connect the input of the dual directional coupler to the RF power output of the RF power supply, and Use a second cable to connect the second port of the oscilloscope to the coupling end of the dual directional coupler to detect the phase of the forward wave signal.

3. The phase synchronization calibration method according to claim 2, characterized in that, The first cable and the second cable have the same material and length.

4. The phase synchronization calibration method according to claim 1, characterized in that, The calculation of the third phase difference between the forward wave signal and the load signal includes: Obtain the load voltage and load current from the load signal. Calculate the forward wave power and the reflected wave power. Calculate the amplitude of the forward wave voltage, the amplitude of the reflected wave voltage, and the phase difference between the forward wave voltage and the reflected wave voltage. The third phase difference between the forward wave signal and the load signal is calculated based on the forward wave voltage amplitude, the reflected wave voltage amplitude, the phase difference between the forward wave voltage and the reflected wave voltage, and the load voltage.

5. A radio frequency power supply phase synchronization calibration device, characterized in that, The device includes: The RF power supply is configured to receive a common excitation input signal at the common excitation input signal input terminal and output a load signal at the RF output terminal. The sensor is configured to sample the load signal to obtain a sampled signal. A dual directional coupler, connected to an RF power supply, is configured to receive a load signal output from the RF power supply and output a load signal to a load unit at its output terminal, and output a positive wave signal at the coupling terminal. An oscilloscope, connected via a first cable to the common excitation input of an RF power supply and via a second cable to the coupling terminal of a dual directional coupler, is configured to detect the phase of the common excitation input signal and the phase of the forward wave signal in the load signal. The controller is configured to calculate a first phase difference between the sampled signal and the common-excitation input signal, and to calculate a third phase difference between the forward wave signal and the load signal, wherein the third phase difference is calculated based on the load signal and the forward wave signal and the reflected wave signal in the load signal.

6. The phase synchronization calibration device according to claim 5, characterized in that, The first cable and the second cable have the same material and length.

7. The phase synchronization calibration device according to claim 5, characterized in that, The controller is configured to acquire the load voltage and load current in the load signal, calculate the forward wave power and reflected wave power, calculate the forward wave voltage amplitude, the reflected wave voltage amplitude and the phase difference between the forward wave voltage and the reflected wave voltage, and calculate a third phase difference between the forward wave signal and the load signal based on the forward wave voltage amplitude, the reflected wave voltage amplitude, the phase difference between the forward wave voltage and the reflected wave voltage and the load voltage.

8. The phase synchronization calibration device according to claim 5, characterized in that, The resistance of the load unit is 50 ohms.

9. A radio frequency power supply phase synchronization method, applicable to controlling the phase difference between a common excitation input signal of an input radio frequency power supply and a forward wave signal output from the radio frequency power supply, the method comprising: The radio frequency power supply receives the common excitation input signal and obtains the phase of the common excitation input signal. The load signal output by the radio frequency power supply is sampled to obtain the phase of the sampled signal. Calculate the first phase difference between the sampled signal and the common-excitation input signal. Obtain the phase of the forward wave signal in the load signal. Calculate the second phase difference between the forward wave signal and the co-excitation input signal. Calculate the third phase difference between the forward wave signal and the load signal, wherein the third phase difference is calculated based on the load signal and the forward wave signal and reflected wave signal in the load signal, and a fixed phase difference is calculated based on the first phase difference, the second phase difference, and the third phase difference. During the operation of the radio frequency power supply, the radio frequency power supply is adjusted so that the sum of the first phase difference and the third phase difference is equal to the fixed phase difference.

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