Impedance matcher and plasma generating device

Abstract

The utility model discloses an impedance matcher and a plasma generating device, and relates to the impedance matching technology field, the impedance matcher comprises a noise detection circuit, a first filter circuit, a main control circuit and an impedance matching circuit, the input end of the first filter circuit is electrically connected with the positive electrode of an external power supply; the controlled end of the first filter circuit is electrically connected with the main control circuit, the detection end of the noise detection circuit is electrically connected with the positive electrode of an external power supply, the output end of the noise detection circuit is electrically connected with the detection end of the main control circuit, and the first input end of the impedance matching circuit is electrically connected with the output end of the first filter circuit; the second input end of the impedance matching circuit is electrically connected with the negative electrode of the external power supply, and the output end of the impedance matching circuit is electrically connected with the load; the utility model aims to improve the anti-interference capability of the impedance matcher under various conditions.

Description

Technical Field

[0001] The utility model relates to the technical field of impedance matching, in particular to an impedance matcher and a plasma generating device. Background Art

[0002] In plasma chamber applications, the RF power supply is responsible for providing energy to the plasma. However, due to the nonlinear characteristics of the load in the plasma chamber, its impedance is often not equal to the constant output impedance of the RF power supply. This impedance mismatch will cause a large amount of reflected power on the transmission line between the RF power supply and the plasma chamber, which means that the power generated by the RF power supply cannot be efficiently delivered to the plasma chamber, resulting in significant power loss.

[0003] To this end, an impedance matching network needs to be set up between the RF power supply system and the plasma chamber. By fine-tuning this impedance matching network, it is possible to ensure that the impedance of the matching network is combined with the nonlinear load impedance in the plasma chamber, achieve impedance matching between the RF power supply and the plasma chamber, and achieve maximum output power.

[0004] In order to eliminate the interference signal in the power signal emitted by the RF power supply, a low-pass filter circuit is usually added between the RF power supply and the impedance matching network. However, the interference signal will change when the RF power supply is used in different environments. The interference signals emitted by RF power supplies of different qualities are also different. At present, most low-pass filters have fixed bandwidths and cannot adapt to changes in interference signals. Low-pass filters with very low bandwidth can be used to adapt to the interference signals emitted by RF power supplies in most cases, but this will make the power signal incomplete, affect the quality of the power signal, and result in poor matching effect of the impedance matching network. Utility Model Content

[0005] The main purpose of the utility model is to provide an impedance matcher and a plasma generating device, aiming to improve the anti-interference ability of the impedance matcher in various situations.

[0006] In order to achieve the above-mentioned object, the utility model proposes an impedance matching device, which is characterized by comprising:

[0007] A noise detection circuit, wherein a detection end of the noise detection circuit is electrically connected to a positive electrode of an external power supply, and the noise detection circuit is used to detect a high-frequency noise frequency of a power signal output by the external power supply, and output a corresponding noise detection signal;

[0008] a first filter circuit, the first filter circuit comprising: an RC filter circuit, a first amplifier circuit, an adjustable capacitor circuit and an adjustable resistor circuit, the first end of the RC filter circuit being electrically connected to the positive electrode of an external power supply, the second end of the RC filter circuit being electrically connected to the inverting end of the first amplifier circuit, the non-inverting end of the first amplifier circuit being grounded, the first end of the adjustable resistor circuit being electrically connected to the third end of the RC filter circuit, the first end of the adjustable capacitor circuit being electrically connected to the inverting end of the first amplifier circuit, and the second end of the adjustable capacitor circuit and the second end of the adjustable resistor circuit being electrically connected to the output end of the first amplifier circuit;

[0009] A main control circuit, wherein the output end of the noise detection circuit is electrically connected to the detection end of the main control circuit, and the control end of the main control circuit is electrically connected to the controlled end of the adjustable capacitor circuit and the controlled end of the adjustable resistor circuit; the main control circuit is used to adjust the equivalent impedance of the adjustable capacitor circuit and the equivalent impedance of the adjustable resistor circuit according to the noise detection signal;

[0010] An impedance matching circuit, wherein a controlled end of the impedance matching circuit is electrically connected to a control end of the main control circuit, a first input end of the impedance matching circuit is electrically connected to an output end of the first amplifier circuit, a second input end of the impedance matching circuit is electrically connected to a negative electrode of an external power supply, and an output end of the impedance matching circuit is electrically connected to a load.

[0011] In one embodiment, the adjustable capacitance circuit includes:

[0012] A capacitor string and a plurality of first switch tubes, wherein the capacitor string is a circuit formed by sequentially connecting a plurality of capacitors in series, a first end of the capacitor string is electrically connected to an inverting end of the first amplifier circuit, a second end of the capacitor string is electrically connected to an output end of the first amplifier circuit, a plurality of the first switch tubes are connected in parallel with a plurality of the capacitors one by one, and controlled ends of the plurality of the first switch tubes are electrically connected to a control end of the main control circuit;

[0013] The adjustable resistance circuit comprises:

[0014] A resistor string and a plurality of second switch tubes, wherein the resistor string is a circuit formed by a plurality of resistors connected in series in sequence, a first end of the resistor string is electrically connected to an inverting end of the first amplifier circuit, a second end of the resistor string is electrically connected to an output end of the first amplifier circuit, a plurality of the second switch tubes are connected in parallel with a plurality of the resistors one by one, and controlled ends of the plurality of the second switch tubes are all electrically connected to a control end of the main control circuit.

[0015] In one embodiment, the RC filter circuit includes:

[0016] A first resistor, a second resistor and a first capacitor, wherein the first end of the first resistor is electrically connected to the positive electrode of an external power supply, the second end of the first resistor is electrically connected to the first end of the second resistor, the first end of the first capacitor and the first end of the adjustable resistance circuit respectively, the second end of the first capacitor is grounded, and the second end of the second resistor is electrically connected to the inverting end of the first amplifier circuit.

[0017] In one embodiment, the impedance matcher further includes:

[0018] A common-mode inductor, a first TVS tube and a second TVS tube, wherein the first input end of the common-mode inductor is electrically connected to the positive electrode of an external power supply, the second input end of the common-mode inductor is electrically connected to the negative electrode of the external power supply, the first output end of the common-mode inductor is electrically connected to the first end of the RC filter circuit and the first end of the first TVS tube respectively, the second end of the first TVS tube is grounded, the second output end of the common-mode inductor is electrically connected to the second input end of the impedance matching circuit and the first end of the second TVS tube respectively, and the second end of the second TVS tube is grounded.

[0019] In one embodiment, the impedance matcher further includes:

[0020] A voltage detection circuit and a current detection circuit, wherein the detection end of the voltage detection circuit and the detection end of the current detection circuit are both electrically connected to the first input end of the impedance matching circuit, and the output end of the voltage detection circuit and the output end of the current detection circuit are both electrically connected to the detection end of the main control circuit, the voltage detection circuit is used to detect the voltage of the first input end of the impedance matching circuit and output a corresponding voltage detection signal, and the current detection circuit is used to detect the current of the first input end of the impedance matching circuit and output a corresponding current detection signal.

[0021] In one embodiment, the voltage detection circuit includes:

[0022] a voltage divider circuit, a second amplifier circuit, and a second filter circuit, wherein a first end of the voltage divider circuit is electrically connected to a first input end of the impedance matching circuit, a second end of the voltage divider circuit is electrically connected to an input end of the second amplifier circuit, an output end of the second amplifier circuit is electrically connected to an input end of the second filter circuit, and an output end of the second filter circuit is electrically connected to a detection end of the main control circuit;

[0023] The current detection circuit comprises:

[0024] A current sensor, a third amplifier circuit and a third filter circuit, wherein the detection end of the current sensor is electrically connected to the first input end of the impedance matching circuit, the output end of the current sensor is electrically connected to the input end of the third amplifier circuit, the output end of the third amplifier circuit is electrically connected to the input end of the third filter circuit, and the output end of the third filter circuit is electrically connected to the detection end of the main control circuit.

[0025] In one embodiment, the voltage divider circuit includes:

[0026] A third resistor and a fourth resistor, wherein a first end of the third resistor is electrically connected to the first input end of the impedance matching circuit, a second end of the third resistor is electrically connected to the input end of the second amplifier circuit and the first end of the fourth resistor respectively, and a second end of the fourth resistor is grounded.

[0027] In one embodiment, the first filtering circuit further includes:

[0028] A voltage follower circuit, wherein an input end of the voltage follower circuit is electrically connected to a positive electrode of an external power supply, and an output end of the voltage follower circuit is electrically connected to a first end of the RC filter circuit.

[0029] The utility model also provides a plasma generating device, comprising any one of the impedance matching devices described above.

[0030] The technical scheme of the utility model includes a noise detection circuit, a first filtering circuit, a main control circuit and an impedance matching circuit. The first filtering circuit includes an RC filtering circuit, a first amplifier circuit, an adjustable capacitor circuit and an adjustable resistor circuit. The RC filtering circuit is used to filter out high-frequency signals in a power supply signal output by a power supply. The first amplifier circuit, the adjustable capacitor circuit and the adjustable resistor circuit form an amplifier circuit. The RC filtering circuit and the first amplifier circuit form a second-order low-pass filtering circuit (first filtering circuit). Compared with a first-order filter, the second-order low-pass filtering circuit can provide a steeper transition band, that is, a faster roll-off speed near a cut-off frequency, thereby more effectively removing high-frequency noise. The noise detection circuit is used to detect high-frequency noise in the power supply signal. When the frequency of the high-frequency noise reaches a preset value, the main control circuit outputs a corresponding control signal to adjust the equivalent impedance of the adjustable capacitor circuit and the adjustable resistor circuit, thereby adjusting the cut-off frequency of the first filtering circuit. The smaller the equivalent impedance of the adjustable capacitor circuit or the equivalent impedance of the adjustable circuit is, the larger the cut-off frequency of the first filtering circuit will be. On the contrary, the equivalent impedance of the adjustable capacitor circuit or the adjustable resistor circuit is The larger the equivalent impedance is, the smaller the cutoff frequency of the first filtering circuit will be. With this arrangement, the impedance matcher of the utility model can adapt to various usage scenarios and various power supplies. In practical applications, when the plasma generating device to which the impedance matcher of the utility model is applied works in a complex electromagnetic environment, or uses a power supply of poor quality, the high-frequency noise frequency in the power supply signal output by the power supply is relatively high. The impedance matcher of the utility model can increase the cutoff frequency of its own filtering, thereby better filtering out the high-frequency noise. When used in a better environment or using a power supply of better quality, the high-frequency noise frequency in the power supply signal is relatively low. The utility model can reduce the cutoff frequency of its own filtering, thereby avoiding the impedance matching circuit in the utility model from receiving an incomplete power supply signal due to an excessively high cutoff frequency, thereby ensuring that the impedance of the impedance matching circuit is combined with the nonlinear load impedance in the plasma chamber, and realizing impedance matching between the radio frequency power supply and the plasma chamber, so that the plasma generating device has a strong anti-interference ability, and can maintain good performance and stability in various usage environments or when using power supplies of various different qualities. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0032] Figure 1 A schematic diagram of a module of an embodiment of the utility model is provided;

[0033] Figure 2 A circuit structure diagram of another embodiment of the present invention is provided;

[0034] Figure 3 A schematic diagram of the circuit structure of another embodiment of the utility model is provided;

[0035] Figure 4 A circuit structure diagram of another embodiment of the utility model is provided;

[0036] Figure 5 The present invention provides a circuit structure diagram of another embodiment.

[0037] Description of Figure Numbers:

[0038] 10. Noise detection circuit; 20. First filter circuit; 21. RC filter circuit; 22. Adjustable resistance circuit; 23. Adjustable capacitance circuit; 30. Main control circuit; 40. Impedance matching circuit; 50. Voltage detection circuit; 60. Current detection circuit.

[0039] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0041] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0042] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0043] In plasma chamber applications, the RF power supply is responsible for providing energy to the plasma. However, due to the nonlinear characteristics of the load in the plasma chamber, its impedance is often not equal to the constant output impedance of the RF power supply. This impedance mismatch will cause a large amount of reflected power on the transmission line between the RF power supply and the plasma chamber, which means that the power generated by the RF power supply cannot be efficiently delivered to the plasma chamber, resulting in significant power loss.

[0044] To this end, an impedance matching network needs to be set up between the RF power supply system and the plasma chamber. By fine-tuning this impedance matching network, it is possible to ensure that the impedance of the matching network is combined with the nonlinear load impedance in the plasma chamber, achieve impedance matching between the RF power supply and the plasma chamber, and achieve maximum output power.

[0045] In order to eliminate the interference signal in the power signal emitted by the RF power supply, a low-pass filter circuit is usually added between the RF power supply and the impedance matching network. However, the interference signal will change when the RF power supply is used in different environments. The interference signals emitted by RF power supplies of different qualities are also different. At present, most low-pass filters have fixed bandwidths and cannot adapt to changes in interference signals. Low-pass filters with very low bandwidth can be used to adapt to the interference signals emitted by RF power supplies in most cases, but this will make the power signal incomplete, affect the quality of the power signal, and result in poor matching effect of the impedance matching network.

[0046] To this end, the utility model proposes an impedance matcher and a plasma generating device, aiming to improve the anti-interference capability of the impedance matcher in various situations.

[0047] refer to Figure 1 In one embodiment of the present invention, an impedance matcher includes:

[0048] A noise detection circuit 10, wherein the detection end of the noise detection circuit 10 is electrically connected to the positive electrode of the external power supply, and the noise detection circuit 10 is used to detect the high-frequency noise frequency of the power signal output by the external power supply, and output a corresponding noise detection signal;

[0049] A first filter circuit 20, the first filter circuit 20 includes: an RC filter circuit 21, a first amplifier circuit U1, an adjustable capacitor circuit 23 and an adjustable resistor circuit 22, a first end of the RC filter circuit 21 is electrically connected to the positive electrode of the external power supply, a second end of the RC filter circuit 21 is electrically connected to the inverting end of the first amplifier circuit U1, a non-inverting end of the first amplifier circuit U1 is grounded, a first end of the adjustable resistor circuit 22 is electrically connected to the third end of the RC filter circuit 21, a first end of the adjustable capacitor circuit 23 is electrically connected to the inverting end of the first amplifier circuit U1, and a second end of the adjustable capacitor circuit 23 and a second end of the adjustable resistor circuit 22 are both electrically connected to the output end of the first amplifier circuit U1;

[0050] The main control circuit 30, the output end of the noise detection circuit 10 is electrically connected to the detection end of the main control circuit 30, and the control end of the main control circuit 30 is electrically connected to the controlled end A2 of the adjustable capacitor circuit 23 and the controlled end A1 of the adjustable resistor circuit 22; the main control circuit 30 is used to adjust the equivalent impedance of the adjustable capacitor circuit 23 and the equivalent impedance of the adjustable resistor circuit 22 according to the noise detection signal;

[0051] The impedance matching circuit 40, the controlled end A3 of the impedance matching circuit 40 is electrically connected to the control end of the main control circuit 30, the first input end of the impedance matching circuit 40 is electrically connected to the output end of the first amplifier circuit U1, the second input end of the impedance matching circuit 40 is electrically connected to the negative pole of the external power supply, and the output end of the impedance matching circuit 40 is electrically connected to the load.

[0052] In this embodiment, the noise detection circuit 10 can use a bandpass filter to select a specific high-frequency noise frequency band, and use a detector (such as an envelope detector or a square-law detector) to extract the amplitude information of the bandpass filter output signal. The output of the detector can be compared with a preset threshold by a comparator to determine whether the high-frequency noise has reached a preset value. A peak detector can also be used. The peak detector can capture the maximum or minimum amplitude value in the signal. In high-frequency noise detection, an appropriate time window can be set to capture the peak value of the high-frequency noise, and output the corresponding noise detection signal to the main control circuit 30.

[0053] In this embodiment, the main control circuit 30 can be implemented by a main controller, such as MCU (Microcontroller Unit), DSP (Digital Signal Process), FPGA (Field Programmable Gate Array), SOC (System On Chip), etc.

[0054] In this embodiment, the first amplifier circuit U1 is composed of at least one amplifier.

[0055] In this embodiment, in this embodiment, the impedance matching circuit 40 can adopt one of an L-type impedance matching circuit, a T-type impedance matching circuit or a Π-type impedance matching circuit. The L-type matching circuit is usually composed of an inductor and a capacitor, and these two elements can be connected in series or in parallel; the T-type network impedance matching circuit is composed of two series-connected inductors and a parallel-connected capacitor; the Π-type network impedance matching circuit is composed of a parallel-connected capacitor and two series-connected inductors. By adjusting the values ​​of the inductor and the capacitor, the impedance of the signal source (RF power supply) and the impedance of the load (plasma chamber) can be converted into matching impedances, thereby achieving maximum power transmission and minimum reflection loss.

[0056] In this embodiment, specifically, the technical solution of the utility model includes a noise detection circuit 10, a first filter circuit 20, a main control circuit 30 and an impedance matching circuit 40, the first filter circuit 20 includes an RC filter circuit 21, a first amplifier circuit U1, an adjustable capacitor circuit 23 and an adjustable resistor circuit 22, the RC filter circuit 21 is used to filter out the high-frequency signal in the power signal output by the power supply, the first amplifier circuit U1, the adjustable capacitor circuit 23 and the adjustable resistor circuit 22 constitute an amplifier circuit, and the RC filter circuit 21 and the first amplifier circuit U1 constitute a second-order low-pass filter circuit (the first filter The second-order low-pass filter circuit can provide a steeper transition band than the first-order filter, that is, it has a faster roll-off speed near the cut-off frequency, thereby more effectively removing high-frequency noise; the noise detection circuit 10 is used to detect the high-frequency noise in the power supply signal. When the frequency of the high-frequency noise reaches a preset value, the main control circuit 30 outputs a corresponding control signal to adjust the equivalent impedance of the adjustable capacitor circuit 23 and the adjustable resistor circuit 22, thereby adjusting the cut-off frequency of the first filter circuit 20. The smaller the equivalent impedance of the adjustable capacitor circuit 23 or the equivalent impedance of the adjustable resistor circuit 22, the lower the first filter circuit 20. The larger the cut-off frequency will be, on the contrary, the larger the equivalent impedance of the adjustable capacitor circuit 23 or the equivalent impedance of the adjustable resistor circuit 22, the smaller the cut-off frequency of the first filter circuit 20 will be. With this arrangement, the impedance matcher of the utility model can adapt to various usage scenarios and adapt to various power supplies. In practical applications, when the plasma generating device applied by the impedance matcher of the utility model works in a complex electromagnetic environment, or uses a power supply of poor quality, the high-frequency noise frequency in the power supply signal output by the power supply is relatively high. The impedance matcher of the utility model can increase the cut-off frequency of its own filtering, thereby better filtering out the high-frequency noise. When used in a better environment or using a power supply of better quality, the high-frequency noise frequency in the power supply signal is relatively low. The utility model can reduce the cut-off frequency of its own filtering to avoid incomplete power supply signals received by the impedance matching circuit 40 of the utility model, thereby ensuring that the impedance of the impedance matching circuit 40 is combined with the nonlinear load impedance in the plasma chamber to achieve impedance matching between the RF power supply and the plasma chamber, so that the plasma generating device has a strong anti-interference ability and can maintain good performance and stability under various usage environments or using power supplies of various qualities.

[0057] refer to Figure 2 In one embodiment of the present utility model, the adjustable capacitance circuit 23 includes:

[0058] A capacitor string and a plurality of first switch tubes Q1, wherein the capacitor string is a circuit formed by a plurality of capacitors connected in series in sequence, wherein a first end of the capacitor string is electrically connected to an inverting end of a first amplifier circuit U1, a second end of the capacitor string is electrically connected to an output end of the first amplifier circuit U1, a plurality of first switch tubes Q1 are connected in parallel to a plurality of capacitors one by one, and a controlled end A1 of the plurality of first switch tubes Q1 is electrically connected to a control end of a main control circuit 20;

[0059] The adjustable resistance circuit 22 comprises:

[0060] A resistor string and multiple second switch tubes Q2, the resistor string is a circuit formed by multiple resistors connected in series in sequence, the first end of the resistor string is electrically connected to the inverting end of the first amplifier circuit U1, the second end of the resistor string is electrically connected to the output end of the first amplifier circuit U1, the multiple second switch tubes Q2 are connected in parallel with the multiple resistors one by one, and the controlled ends A2 of the multiple second switch tubes Q2 are all electrically connected to the control end of the main control circuit 20.

[0061] In this embodiment, the first switch tube Q1 and the second switch tube Q2 are both NMOS tubes. When one or more first switch tubes Q1 are turned on, the corresponding one or more capacitors in parallel are short-circuited to reduce the equivalent impedance of the capacitor string; when one or more first switch tubes Q1 are turned off, the corresponding one or more capacitors in parallel are turned on to increase the equivalent impedance of the capacitor string. The technical effect of the resistor string is the same as that of the capacitor string, which will not be repeated here.

[0062] In this embodiment, the RC filter circuit 21 includes:

[0063] A first resistor R1, a second resistor R2 and a first capacitor C1, the first end of the first resistor R1 is electrically connected to the positive electrode of an external power supply, the second end of the first resistor R1 is electrically connected to the first end of the second resistor R2, the first end of the first capacitor C1 and the first end of the adjustable resistance circuit 22 respectively, the second end of the first capacitor C1 is grounded, and the second end of the second resistor R2 is electrically connected to the inverting end of the first amplifier circuit U1.

[0064] In this embodiment, assuming that the resistance of the first resistor R1 is R1, the resistance of the second resistor R2 is R2, and the capacitance of the first capacitor C1 is C1, the equivalent impedance of the resistor string is R3, and the equivalent impedance of the capacitor string is C2, the cutoff frequency of the first filter circuit 20 is It can be seen from the formula that when the equivalent impedance of the resistor string or the equivalent impedance of the capacitor string is larger, the cut-off frequency of the first filter circuit 20 is smaller, and vice versa.

[0065] In this embodiment, when the frequency of the high-frequency noise in the power supply signal is relatively high, the main control circuit 30 outputs a corresponding turn-on signal to one or more first switch tubes Q1 or second switch tubes Q2 according to the noise detection signal output by the noise detection circuit 10, so that the corresponding first switch tube Q1 or second switch tube Q2 is turned on, and the corresponding capacitor or resistor is also short-circuited, so that the equivalent impedance of the capacitor string or resistor string becomes smaller, thereby increasing the cut-off frequency of the first filter circuit 20; when the high-frequency noise in the power supply signal is relatively small, the main control circuit 30 outputs a corresponding turn-off signal to one or more first switch tubes Q1 or second switch tubes Q2 according to the noise detection signal output by the noise detection circuit 10, and the corresponding capacitor or resistor is also short-circuited. The first filter circuit 20 is turned on to increase the equivalent impedance of the capacitor string or the resistor string, thereby reducing the cutoff frequency of the first filter circuit 20. With such a configuration, in practical applications, when the plasma generating device applied by the impedance matcher of the utility model works in a complex electromagnetic environment, or uses a power supply of poor quality, the high-frequency noise frequency in the power signal output by the power supply is relatively high. The impedance matcher of the utility model can increase the cutoff frequency of its own filtering, thereby better filtering out the high-frequency noise; when used in a better environment, or using a power supply of better quality, the high-frequency noise frequency in the power signal is relatively low. The utility model can reduce the cutoff frequency of its own filtering, thereby avoiding that the power signal received by the impedance matching circuit 40 in the utility model is incomplete.

[0066] refer to Figure 3 In one embodiment of the present utility model, the impedance matcher further includes:

[0067] Common-mode inductor L1, first TVS tube D1 and second TVS tube D2, the first input end of the common-mode inductor L1 is electrically connected to the positive electrode of the external power supply, the second input end of the common-mode inductor L1 is electrically connected to the negative electrode of the external power supply, the first output end of the common-mode inductor L1 is electrically connected to the first end of the RC filter circuit 21 and the first end of the first TVS tube D1 respectively, the second end of the first TVS tube D1 is grounded, the second output end of the common-mode inductor L1 is electrically connected to the second input end of the impedance matching circuit 40 and the first end of the second TVS tube D2 respectively, and the second end of the second TVS tube D2 is grounded.

[0068] In this embodiment, the common mode inductor L1 is used to filter out the common mode interference in the power supply signal, and the first TVS tube D1 and the second TVS tube D2 are used to protect the circuit from transient voltages such as static electricity. When a transient high voltage appears in the circuit, the TVS tube will quickly turn on and shunt the excessive voltage to the ground to protect other circuit components from damage. This arrangement can improve the anti-interference ability of the impedance matcher of the utility model and the plasma generating device used therein.

[0069] refer to Figure 4 In one embodiment of the present utility model, the impedance matcher further includes:

[0070] The voltage detection circuit 50 and the current detection circuit 60, the detection end of the voltage detection circuit 50 and the detection end of the current detection circuit 60 are both electrically connected to the first input end of the impedance matching circuit 40, the output end B1 of the voltage detection circuit 50 and the output end B2 of the current detection circuit 60 are both electrically connected to the detection end of the main control circuit 30, the voltage detection circuit 50 is used to detect the voltage of the first input end of the impedance matching circuit 40 and output a corresponding voltage detection signal, and the current detection circuit 60 is used to detect the current of the first input end of the impedance matching circuit 40 and output a corresponding current detection signal.

[0071] In this embodiment, the voltage detection circuit 50 and the current detection circuit 60 are used to check the voltage and current on the power transmission line. The main control circuit 30 calculates the reflected power on the power transmission line based on the detection results, and determines whether the output impedance of the power supply and the input impedance of the load (such as the plasma chamber) match based on the reflected power. When the reflected power is zero, the output impedance of the power supply and the input impedance of the load match. Conversely, when the reflected power is not zero, the output impedance of the power supply and the input impedance of the load are mismatched. The main control circuit 30 adjusts the impedance of the impedance matching circuit 40 to match the output impedance of the power supply and the input impedance of the load.

[0072] In this embodiment, the voltage detection circuit 50 includes:

[0073] A voltage divider circuit, a second amplifier circuit and a second filter circuit, wherein a first end of the voltage divider circuit is electrically connected to a first input end of the impedance matching circuit 40, a second end of the voltage divider circuit is electrically connected to an input end of the second amplifier circuit, an output end of the second amplifier circuit is electrically connected to an input end of the second filter circuit, and an output end B1 of the second filter circuit is electrically connected to a detection end of the main control circuit 30;

[0074] The current detection circuit 60 includes:

[0075] A current sensor, a third amplifier circuit and a third filter circuit, the detection end of the current sensor is electrically connected to the first input end of the impedance matching circuit 40, the output end of the current sensor is electrically connected to the input end of the third amplifier circuit, the output end of the third amplifier circuit is electrically connected to the input end of the third filter circuit, and the output end B2 of the third filter circuit is electrically connected to the detection end of the main control circuit 30.

[0076] The voltage divider circuit includes:

[0077] A third resistor R3 and a fourth resistor R4, a first end of the third resistor R3 is electrically connected to the first input end of the impedance matching circuit 40, a second end of the fourth resistor R4 is electrically connected to the input end of the second amplifier circuit and the first end of the fourth resistor R4 respectively, and a second end of the fourth resistor R4 is grounded.

[0078] In the present embodiment, the voltage divider circuit collects the voltage of the power supply in the form of resistor voltage division. For example, the voltage divider circuit includes a third resistor R3 and a fourth resistor R4. The inverting end of the second amplifier circuit obtains the voltage of the power supply through the fourth resistor R4. The second amplifier circuit is used to amplify the collected voltage so that the output voltage detection signal reaches the working voltage of the main control circuit 30. The second filter circuit is used to filter out the high-frequency noise of the signal output by the second amplifier circuit. The current sensor can adopt any one of a resistor shunt, a current transformer or a Hall current sensor to detect the current signal output by the power supply. The third amplifier circuit and the third filter circuit have the same circuit structure as the second amplifier circuit and the second filter circuit, and the technical effects they play are also the same. They will not be described one by one here. In this way, the amplifier circuit is used to amplify the collected detection signal to avoid the voltage of the detection signal not reaching the working voltage of the main control circuit 30. The filter circuit is used to filter out the high-frequency noise of the detection signal to make the detection signal purer. In practical applications, the anti-interference ability of the impedance matcher of the utility model and the plasma generating device thereof can be improved.

[0079] refer to Figure 5 In one embodiment of the present utility model, the first filtering circuit 20 further includes:

[0080] The voltage follower circuit U2 has an input end electrically connected to the positive electrode of the external power supply, and an output end electrically connected to the first end of the RC filter circuit 21 .

[0081] In this embodiment, the voltage follower circuit U2 uses at least one voltage follower, and the voltage follower circuit U2 has the characteristics of high input impedance and low output impedance, thereby isolating the power supply and the subsequent circuit, eliminating the mutual influence between the two, and ensuring that the stable voltage of the power supply is accurately transmitted to the first amplifier circuit U1. Such a setting can improve the anti-interference ability of the impedance matcher of the utility model and the plasma generating device using it in practical applications.

[0082] The utility model also provides a plasma generating device, comprising the impedance matching device as described above.

[0083] It is worth noting that, since the plasma generating device of the present invention is based on the above-mentioned impedance matching device, the embodiments of the plasma generating device of the present invention include all technical solutions of all the embodiments of the above-mentioned impedance matching device, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0084] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An impedance matching device, characterized in that: include: A noise detection circuit, wherein a detection end of the noise detection circuit is electrically connected to a positive electrode of an external power supply, and the noise detection circuit is used to detect a high-frequency noise frequency of a power signal output by the external power supply, and output a corresponding noise detection signal; a first filter circuit, the first filter circuit comprising: an RC filter circuit, a first amplifier circuit, an adjustable capacitor circuit and an adjustable resistor circuit, the first end of the RC filter circuit being electrically connected to the positive electrode of an external power supply, the second end of the RC filter circuit being electrically connected to the inverting end of the first amplifier circuit, the non-inverting end of the first amplifier circuit being grounded, the first end of the adjustable resistor circuit being electrically connected to the third end of the RC filter circuit, the first end of the adjustable capacitor circuit being electrically connected to the inverting end of the first amplifier circuit, and the second end of the adjustable capacitor circuit and the second end of the adjustable resistor circuit being electrically connected to the output end of the first amplifier circuit; A main control circuit, wherein the output end of the noise detection circuit is electrically connected to the detection end of the main control circuit, and the control end of the main control circuit is electrically connected to the controlled end of the adjustable capacitor circuit and the controlled end of the adjustable resistor circuit; the main control circuit is used to adjust the equivalent impedance of the adjustable capacitor circuit and the equivalent impedance of the adjustable resistor circuit according to the noise detection signal; An impedance matching circuit, wherein a controlled end of the impedance matching circuit is electrically connected to a control end of the main control circuit, a first input end of the impedance matching circuit is electrically connected to an output end of the first amplifier circuit, a second input end of the impedance matching circuit is electrically connected to a negative electrode of an external power supply, and an output end of the impedance matching circuit is electrically connected to a load.

2. The impedance matching device according to claim 1, wherein: The adjustable capacitance circuit comprises: A capacitor string and a plurality of first switch tubes, wherein the capacitor string is a circuit formed by sequentially connecting a plurality of capacitors in series, a first end of the capacitor string is electrically connected to an inverting end of the first amplifier circuit, a second end of the capacitor string is electrically connected to an output end of the first amplifier circuit, a plurality of the first switch tubes are connected in parallel with a plurality of the capacitors one by one, and controlled ends of the plurality of the first switch tubes are electrically connected to a control end of the main control circuit; The adjustable resistance circuit comprises: A resistor string and a plurality of second switch tubes, wherein the resistor string is a circuit formed by a plurality of resistors connected in series in sequence, a first end of the resistor string is electrically connected to an inverting end of the first amplifier circuit, a second end of the resistor string is electrically connected to an output end of the first amplifier circuit, a plurality of the second switch tubes are connected in parallel with a plurality of the resistors one by one, and controlled ends of the plurality of the second switch tubes are all electrically connected to a control end of the main control circuit.

3. The impedance matching device according to claim 1, wherein: The RC filter circuit comprises: A first resistor, a second resistor and a first capacitor, wherein the first end of the first resistor is electrically connected to the positive electrode of an external power supply, the second end of the first resistor is electrically connected to the first end of the second resistor, the first end of the first capacitor and the first end of the adjustable resistance circuit respectively, the second end of the first capacitor is grounded, and the second end of the second resistor is electrically connected to the inverting end of the first amplifier circuit.

4. The impedance matching device according to any one of claims 1 to 3, characterized in that: The impedance matcher also includes: A common-mode inductor, a first TVS tube and a second TVS tube, wherein the first input end of the common-mode inductor is electrically connected to the positive electrode of an external power supply, the second input end of the common-mode inductor is electrically connected to the negative electrode of the external power supply, the first output end of the common-mode inductor is electrically connected to the first end of the RC filter circuit and the first end of the first TVS tube respectively, the second end of the first TVS tube is grounded, the second output end of the common-mode inductor is electrically connected to the second input end of the impedance matching circuit and the first end of the second TVS tube respectively, and the second end of the second TVS tube is grounded.

5. The impedance matching device according to claim 1, wherein: The impedance matcher also includes: A voltage detection circuit and a current detection circuit, wherein the detection end of the voltage detection circuit and the detection end of the current detection circuit are both electrically connected to the first input end of the impedance matching circuit, and the output end of the voltage detection circuit and the output end of the current detection circuit are both electrically connected to the detection end of the main control circuit, the voltage detection circuit is used to detect the voltage of the first input end of the impedance matching circuit and output a corresponding voltage detection signal, and the current detection circuit is used to detect the current of the first input end of the impedance matching circuit and output a corresponding current detection signal.

6. The impedance matching device according to claim 5, characterized in that: The voltage detection circuit comprises: a voltage divider circuit, a second amplifier circuit, and a second filter circuit, wherein a first end of the voltage divider circuit is electrically connected to a first input end of the impedance matching circuit, a second end of the voltage divider circuit is electrically connected to an input end of the second amplifier circuit, an output end of the second amplifier circuit is electrically connected to an input end of the second filter circuit, and an output end of the second filter circuit is electrically connected to a detection end of the main control circuit; The current detection circuit comprises: A current sensor, a third amplifier circuit and a third filter circuit, wherein the detection end of the current sensor is electrically connected to the first input end of the impedance matching circuit, the output end of the current sensor is electrically connected to the input end of the third amplifier circuit, the output end of the third amplifier circuit is electrically connected to the input end of the third filter circuit, and the output end of the third filter circuit is electrically connected to the detection end of the main control circuit.

7. The impedance matching device according to claim 6, wherein: The voltage divider circuit comprises: A third resistor and a fourth resistor, wherein a first end of the third resistor is electrically connected to the first input end of the impedance matching circuit, a second end of the third resistor is electrically connected to the input end of the second amplifier circuit and the first end of the fourth resistor respectively, and a second end of the fourth resistor is grounded.

8. The impedance matching device according to claim 1, wherein: The first filtering circuit further includes: A voltage follower circuit, wherein an input end of the voltage follower circuit is electrically connected to a positive electrode of an external power supply, and an output end of the voltage follower circuit is electrically connected to a first end of the RC filter circuit.

9. A plasma generating device, characterized in that: The invention comprises the impedance matching device as claimed in any one of claims 1 to 8.

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