Impedance matching method in pulse width of pulse high-frequency ionization device

Abstract

The invention discloses a pulse width internal impedance matching method for a pulse high-frequency ionization device, and the method comprises the following steps: 1, adding an overlapping region between a high-frequency low-power pulse and a low-frequency high-power pulse of the pulse high-frequency ionization device, a low-density plasma background with a certain high-frequency power receiving effect is generated through the superposition area; and 2, finely adjusting the rising edge and the falling edge of the high-power and low-frequency pulse by adopting a double-frequency driving device, and improving the instantaneous impedance matching effect of the rising edge and the falling edge of the low-frequency and high-power pulse. According to the invention, under the double actions, not only is the huge reflection intensity of the power when the low-frequency high-power pulse arrives improved by adopting the superposition area, but also the rising edge and the falling edge of the low-frequency high-power pulse are further finely adjusted by adopting the double-frequency driving device, so that the risk caused by the fact that the reverse high-frequency power generated instantly is very large or even higher is further reduced.

Description

Technical Field

[0001] The invention relates to the field of particle sources and high-frequency technology, in particular to a pulse width internal impedance matching method of a pulse high-frequency ionization device. Background Art

[0002] High-frequency ionization devices are widely used in charged particle accelerators, the semiconductor industry, plasma and materials science research, and neutral beam heating for controlled nuclear fusion. Pulsed high-frequency ionization devices are particularly suitable for applications requiring high-intensity pulsed beams. They can provide instantaneous extraction currents far exceeding those of high-frequency continuous-wave ionization devices and have a service life far exceeding that of filament-driven arc discharge devices, significantly reducing equipment maintenance frequency.

[0003] The key to generating plasma in a high-frequency ionization device is to feed high-frequency power to the load in the system (such as a high-frequency antenna and the plasma material generated by its drive). The necessary and sufficient condition for high-frequency power to be fed to the load in this way is to achieve "impedance matching" between the load and the high-frequency power transmission system, that is, the impedance of the high-frequency power transmission system at its output port connected to the load is exactly close to or equal to the impedance of the load. If the impedance matching fails or the matching effect is poor, the proportion of high-frequency power transmitted to the load will be very low, and the standing wave of high-frequency power will be very high. As a result, not only will plasma not be generated, or the generated plasma density will not meet the standard, but the high-frequency power source may also be damaged due to power reflection protection (stop output).

[0004] High-frequency ionization devices can achieve impedance matching through a vector impedance matching network. Specifically, the device's port connected to the high-frequency power source matches the output impedance of the high-frequency power source, and the device's port connected to the load matches the load. These devices typically incorporate adjustable capacitors. When the load is within a certain range, the aforementioned impedance matching condition can be achieved by adjusting one or more sets of adjustable capacitors within the device.

[0005] However, for pulsed high-frequency ionization devices, the impedance of the load varies greatly before and after the arrival of each high-frequency power pulse, and the impedance matching effect is distorted near the rising edge of the pulse, making instantaneous power reflection inevitable. When the high-frequency power pulse withdraws, the energy stored in the plasma and discharge chamber will be released, and the impedance of the load will be distorted again. Therefore, the reverse high-frequency power generated instantaneously may be equally large or even higher, and its hazards and dangers are self-evident. Summary of the Invention

[0006] To solve the problems existing in the prior art, the present invention proposes a pulse width internal impedance matching method for a pulse high-frequency ionization device. The purpose is to solve the problem that for a pulse high-frequency ionization device, the impedance of the load differs greatly when each high-frequency power pulse arrives and leaves, and the reverse high-frequency power generated instantaneously may be equally large or even higher, which is self-evidently harmful and dangerous.

[0007] The present invention adopts the following technical solutions to solve the technical problems:

[0008] A pulse width internal impedance matching method for a pulsed high-frequency ionization device is based on a dual-frequency drive device. The dual-frequency drive device is provided with, from one side to the other, a dual-frequency signal controller 10, a dual-frequency sine / cosine digital waveform generator 20, a high-frequency high-frequency digital carrier modulation path 30, a low-frequency high-frequency digital carrier modulation path 31, and a dual-high-frequency digital-to-analog conversion output drive module 40.

[0009] The dual-frequency signal controller 10 is used to generate a dual-frequency frequency control signal and a dual-frequency amplitude control signal with an intrinsic dual-frequency delay control characteristic, and send the dual-frequency frequency control signal to the dual-frequency sine / cosine digital waveform generator 20, and send the dual-frequency amplitude control signal with an intrinsic delay characteristic to the high-frequency and high-frequency digital carrier modulation path 30 and the low-frequency and high-frequency digital carrier modulation path 31 respectively;

[0010] The dual-frequency sine / cosine digital waveform generator 20 is used to convert the received dual-frequency frequency control signal into a sine / cosine signal and send it to the high-frequency high-frequency digital carrier modulation path 30 and the low-frequency high-frequency digital carrier modulation path 31 respectively;

[0011] The high-frequency and high-frequency digital carrier modulation path 30 is used to multiply the received sine / cosine signal by the received dual-frequency amplitude control signal with the inherent dual-frequency delay control characteristic to achieve modulation of the high-frequency and high-frequency digital carrier signal; the low-frequency and high-frequency digital carrier modulation path 31 is used to multiply the received sine / cosine signal by the received dual-frequency amplitude control signal with the inherent dual-frequency delay control characteristic to achieve modulation of the low-frequency and high-frequency digital carrier signal;

[0012] The dual high-frequency digital-to-analog conversion output drive module 40 is used to perform digital-to-analog conversion on the modulated high-frequency digital carrier signal and the modulated low-frequency digital carrier signal, and send the continuously output high-frequency drive signal after the digital-to-analog conversion to a third-party low-power high-frequency power source; send the pulse output high-frequency drive signal after the digital-to-analog conversion to a third-party low-power high-frequency power source; and send the pulse output low-frequency drive signal after the digital-to-analog conversion to a third-party high-power high-frequency power source.

[0013] The frequency signals sent by the dual-frequency signal controller 10 to the dual-frequency sine / cosine digital waveform generator 20 are a high-frequency high-frequency control signal FREQ10 and a low-frequency high-frequency control signal FREQ11;

[0014] The amplitude signals sent by the dual-frequency signal controller 10 to the high-frequency high-frequency digital carrier modulation path 30 and the low-frequency high-frequency digital carrier modulation path 31 are: the high-frequency high-frequency path modulation signal AMPL12 and the low-frequency high-frequency path modulation signal AMPL13;

[0015] The modulated signal sent by the high-frequency and high-frequency digital carrier modulation path 30 to the dual high-frequency digital-to-analog conversion output driver module 40 and the modulated signal sent by the low-frequency and high-frequency digital carrier modulation path 31 to the dual high-frequency digital-to-analog conversion output driver module 40 are both digital high-frequency and high-frequency modulated signals DMOD30 and digital low-frequency and high-frequency modulated signals DMOD31.

[0016] The characteristic is that the pulse width internal impedance matching method includes the following steps:

[0017] Step 1: adding an overlapping region between the high-frequency low-power pulse and the low-frequency high-power pulse of the pulse high-frequency ionization device, and generating a low-density background plasma with a certain high-frequency power receiving effect through the overlapping region;

[0018] Step 2: Use a dual-frequency driving device to fine-tune the rising and falling edges of the high-power low-frequency pulse to improve the instantaneous impedance matching effect of the rising and falling edges of the low-frequency high-power pulse.

[0019] Furthermore, the superposition region of step 1, that is, the superposition region is a pre-ionization region relative to the low-frequency high-power pulse, and the pre-ionization region is within this superposition region. The high-frequency low-power pulse generates a low-density plasma in advance for the high-frequency low-power pulse to improve the low-frequency and high-power receiving effect; the low-density plasma is the plasma generated with a density that can just ensure that the low-frequency high-power pulse can be in a stable state when the low-frequency high-power pulse arrives.

[0020] Furthermore, the overlapping region is generated by extending the falling edge of the high-frequency, low-power pulse to a set time after the rising edge of the low-frequency, high-power pulse. The density of the plasma generated at the set time can just ensure that the low-frequency, high-power pulse can be in a stable state when the low-frequency, high-power pulse arrives.

[0021] Furthermore, when the high-frequency low-power pulse is 13.56 MHz and the low-frequency high-power pulse is 2 MHz, the set time is 80 microseconds.

[0022] Furthermore, the dual-frequency driving device is used in step 2 to fine-tune the rising and falling edges of the low-frequency, high-power pulse, thereby improving the instantaneous impedance matching effect of the rising and falling edges of the low-frequency, high-power pulse. Specifically, the frequency and amplitude at the rising and falling edges of the low-frequency, high-power pulse are fine-tuned by the dual-frequency driving device so that the power reflection is minimized when the low-frequency, high-power pulse arrives and is removed.

[0023] Furthermore, the dual-frequency driving device fine-tunes the frequency at the rising and falling edges of the low-frequency, high-power pulse, specifically by using the low-frequency, high-frequency frequency control signal FREQ11 sequence sent by the dual-frequency signal controller 10 to the low-frequency, high-frequency digital carrier modulation path 31 to fine-tune the frequency at the rising and falling edges of the low-frequency, high-power pulse, thereby reducing the reflection at the rising and falling edges of the low-frequency, high-power pulse.

[0024] Furthermore, the dual-frequency driving device fine-tunes the amplitude at the rising and falling edges of the low-frequency, high-power pulse, specifically by using the low-frequency, high-frequency amplitude signal AMPL13 sequence sent by the dual-frequency signal controller 10 to the low-frequency, high-frequency digital carrier modulation path 31 to fine-tune the amplitude at the rising and falling edges of the low-frequency, high-power pulse, thereby further reducing the reflection of the rising and falling edges of the low-frequency, high-power pulse.

[0025] Furthermore, when the frequency A with the lowest instantaneous reflection coefficient corresponding to the arrival of the low-frequency, high-power pulse is compared with the frequency B with the lowest average reflection coefficient in each pulse through a third-party device, and frequency A is lower, the dual-frequency driving device is used to adjust the frequencies of the rising and falling edges of the low-frequency, high-power pulse to A, and restore the frequency of the middle area of ​​the pulse width to B.

[0026] Furthermore, when the frequency A with the lowest instantaneous reflection coefficient corresponding to the arrival of a low-frequency, high-power pulse is compared with the frequency B with the lowest average reflection coefficient in each pulse through a third-party device, and frequency A is higher, a dual-frequency driving device is used to adjust the frequencies of the rising and falling edges of the low-frequency, high-power pulse to A, and the frequency of the middle area of ​​the pulse width to B.

[0027] Furthermore, when the frequency of the low-frequency, high-power pulse is 2 MHz and the frequency corresponding to the lowest impedance in the pulse width region is 1.95 MHz, a dual-frequency driving device is used to adjust the frequencies of the rising and falling edges of the low-frequency, high-power pulse to 1.95 MHz, and the frequency of the middle region of the pulse width is adjusted to 2 MHz.

[0028] Advantages and effects of the present invention

[0029] 1. The present invention chooses to add an 80-microsecond overlapping area between high-frequency low-power and low-frequency high-power. This overlapping area improves the huge reflection intensity of the power when the low-frequency high-power pulse arrives, and reduces the risk of the instantaneous reverse high-frequency power being very large or even higher.

[0030] 2. The present invention adopts a two-pronged approach. Not only does it use the overlapping area to improve the huge reflection intensity of the power when the low-frequency high-power pulse arrives, but it also uses a dual-frequency driving device to further fine-tune the rising and falling edges of the low-frequency high-power pulse, thereby further reducing the risk of the instantaneous reverse high-frequency power being very large or even higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a flow chart of the pulse width internal impedance matching method of the pulse high-frequency ionization device of the present invention;

[0032] Figure 2 This is a schematic diagram of high-frequency power, reflection, and impedance in the prior art;

[0033] Figure 3 A schematic diagram of the present invention showing the addition of an overlapping region to generate a low-density plasma background;

[0034] Figure 4 This is a schematic diagram of the present invention using a dual-frequency drive device to fine-tune the rising and falling edges of a high-power pulse;

[0035] Figure 5 This is a schematic diagram comparing the reflected power before and after the improvement of the present invention;

[0036] Figure 6 Schematic diagram of the relationship between reflection coefficient and frequency;

[0037] Figure 7 This is an application effect diagram of the dual-frequency driving device of the present invention;

[0038] Figure 8 This is a structural diagram of a dual-frequency driving device for a pulsed high-frequency ionization device according to the present invention;

[0039] Figure 9 The present invention is a schematic diagram of an adjustable dual-frequency vector impedance matching structure and device in the prior art. DETAILED DESCRIPTION

[0040] Design principle of the present invention

[0041] 1. Innovation of the present invention: The innovation lies in the use of a multi-pronged approach to reduce the problem of load impedance distortion at the moment of arrival and removal of low-frequency, high-power pulses, and the sudden deterioration of impedance matching near the rising edge of the pulse, which causes huge instantaneous power reflection. The multi-pronged approach is a method that combines adding an overlapping area (the overlapping area between the high-frequency, low-power pulse and the low-frequency, high-power pulse) with fine-tuning the rising and falling edges of the low-frequency, high-power pulse.

[0042] 2. The difference between the present invention and the prior art: The prior art generally does not use a superposition method for dual-frequency pulses because superimposing two frequencies is difficult to handle. Therefore, the two pulses are generally separated into independent time periods without superposition. The present invention, however, takes the opposite approach and increases the superposition area. The method for increasing the superposition area is to use the dual-frequency signal controller 10 of the dual-frequency driving device to generate a dual-frequency amplitude control signal with inherent dual-frequency delay control characteristics, and send the dual-frequency frequency control signal to the dual-frequency sine / cosine digital waveform generator 20. The dual-frequency amplitude control signal with inherent delay characteristics is sent to the high-frequency high-frequency digital carrier modulation path 30 and the low-frequency high-frequency digital carrier modulation path 31, respectively. This achieves "synchronization" of high-frequency low-power pulses and low-frequency high-power pulses, that is, controlling the "early" and "late" arrival of the high-frequency low-power pulses and the low-frequency high-power pulses, thereby achieving orderly and controllable superposition between the high-frequency low-power pulses and the low-frequency high-power pulses.

[0043] 3. Design principle of low-density plasma background: First, the low-density plasma background is used to make up for the defects of low-frequency high-power pulses in the moment of rising edge, such as poor power absorption and large power reflection. Figure 2As shown, when the rising edge of a low-frequency, high-power pulse arrives, the plasma generated by the high-frequency, low-power pulse only matches the high-frequency frequency and is mismatched with the low-frequency frequency. Although the high-frequency, low-power pulse is removed before the low-frequency, high-power pulse arrives, the plasma generated by it still exists at the moment of its removal. Therefore, even without the overlap region, the reflected power at the rising edge of the subsequent low-frequency, high-power pulse will be very high, while the absorbed power will be very low. However, if this overlap region is added, the initial power absorption may be very low, but because the superimposed high-frequency, low-power pulse continues to exist and continuously replenishes it, until enough plasma originally matched to the high-frequency, low-power state is converted to a state matched to the low-frequency, high-power state. Specifically, when the low-frequency, high-power pulse arrives, the present invention uses the high-frequency, low-power pulse to continuously generate a low-density plasma background in the 80-microsecond region that it is about to cover, until this background plasma gradually adapts to receiving the power of the low-frequency, high-power pulse within this 80-microsecond dual-frequency power overlap region. Therefore, the low-density plasma generated within 80 microseconds can improve the situation where the high-frequency, low-power pulse has poor power absorption and large reflected power at the moment of rising edge. The reason is: the low-density plasma in the 80 microsecond region promotes the absorption of power by the low-frequency, high-power pulse at the moment of rising edge. Second, the size of the superposition area must take into account the reduction of reflected power and the cost of extending the pulse width in the superposition area, and find a balance. The cost of extending the pulse width in the superposition area means that the frequency of the high-frequency, low-power pulse is higher, so the electron temperature generated is also higher, and the electrons with higher temperature will destroy the negative hydrogen ions in the ionization process, which is contrary to the original design intention of the high-frequency pulse ionization device. Therefore, as long as it is believed that the 2MHz pulse can be stabilized at the moment of arrival instead of being reflected too much, the 13.56MHz pulse will be quickly removed. Based on this, the superposition area cannot be too long or too short.

[0044] 4. Design principle of fine-tuning the rising and falling edges of high-power low-frequency pulses: Figure 6 As shown, the reflection coefficient is lowest at approximately 1.95MHz, while the reflection coefficients corresponding to other frequencies on both sides are larger. Therefore, by adjusting the power at the rising and falling edges of the low-frequency, high-power signal to the optimal value of 1.95MHz, the reflection coefficient at the rising or falling edge can be reduced to below 0.1. Figure 6 The frequency of 1.95MHz is the lowest reflection coefficient, which is the result of the adjustment of the application number: 2023102699594, invention name: An adjustable dual-frequency vector impedance matching structure and device. The adjustment principle is shown in Figure 9 The present invention makes fine adjustments to the rising and falling edges of the low-frequency, high-power pulse based on the matching of the adjustment result with the 2MHz low-frequency, high-power pulse.

[0045] The present invention will be further explained below with reference to the accompanying drawings:

[0046] A pulse width internal impedance matching method for a pulse high frequency ionization device Figure 1 As shown, the method is based on a dual-frequency drive device as shown in Figure 7 、 Figure 8 As shown, the dual-frequency driving device is provided with, from one side to the other, a dual-frequency signal controller 10, a dual-frequency sine / cosine digital waveform generator 20, a high-frequency high-frequency digital carrier modulation path 30 and a low-frequency high-frequency digital carrier modulation path 31, and a dual high-frequency digital-to-analog conversion output driving module 40;

[0047] The dual-frequency signal controller 10 is used to generate a dual-frequency frequency control signal and a dual-frequency amplitude control signal with an intrinsic dual-frequency delay control characteristic, and send the dual-frequency frequency control signal to the dual-frequency sine / cosine digital waveform generator 20, and send the dual-frequency amplitude control signal with an intrinsic delay characteristic to the high-frequency and high-frequency digital carrier modulation path 30 and the low-frequency and high-frequency digital carrier modulation path 31 respectively;

[0048] The dual-frequency sine / cosine digital waveform generator 20 is used to convert the received dual-frequency frequency control signal into a sine / cosine signal and send it to the high-frequency high-frequency digital carrier modulation path 30 and the low-frequency high-frequency digital carrier modulation path 31 respectively;

[0049] The high-frequency and high-frequency digital carrier modulation path 30 is used to multiply the received sine / cosine signal by the received dual-frequency amplitude control signal with the inherent dual-frequency delay control characteristic to achieve modulation of the high-frequency and high-frequency digital carrier signal; the low-frequency and high-frequency digital carrier modulation path 31 is used to multiply the received sine / cosine signal by the received dual-frequency amplitude control signal with the inherent dual-frequency delay control characteristic to achieve modulation of the low-frequency and high-frequency digital carrier signal;

[0050] The dual high-frequency digital-to-analog conversion output drive module 40 is used to perform digital-to-analog conversion on the modulated high-frequency digital carrier signal and the modulated low-frequency digital carrier signal, and send the continuously output high-frequency drive signal after the digital-to-analog conversion to a third-party low-power high-frequency power source; send the pulse output high-frequency drive signal after the digital-to-analog conversion to a third-party low-power high-frequency power source; and send the pulse output low-frequency drive signal after the digital-to-analog conversion to a third-party high-power high-frequency power source.

[0051] The frequency signals sent by the dual-frequency signal controller 10 to the dual-frequency sine / cosine digital waveform generator 20 are a high-frequency high-frequency control signal FREQ10 and a low-frequency high-frequency control signal FREQ11;

[0052] The amplitude signals sent by the dual-frequency signal controller 10 to the high-frequency high-frequency digital carrier modulation path 30 and the low-frequency high-frequency digital carrier modulation path 31 are: the high-frequency high-frequency path modulation signal AMPL12 and the low-frequency high-frequency path modulation signal AMPL13;

[0053] The modulated signal sent by the high-frequency and high-frequency digital carrier modulation path 30 to the dual high-frequency digital-to-analog conversion output driver module 40 and the modulated signal sent by the low-frequency and high-frequency digital carrier modulation path 31 to the dual high-frequency digital-to-analog conversion output driver module 40 are both digital high-frequency and high-frequency modulated signals DMOD30 and digital low-frequency and high-frequency modulated signals DMOD31.

[0054] The characteristic is that the pulse width internal impedance matching method includes the following steps:

[0055] Step 1: adding an overlapping region between the high-frequency low-power pulse and the low-frequency high-power pulse of the pulse high-frequency ionization device, and generating a low-density background plasma with a certain high-frequency power receiving effect through the overlapping region;

[0056] Step 2: Use a dual-frequency driving device to fine-tune the rising and falling edges of the high-power low-frequency pulse to improve the instantaneous impedance matching effect of the rising and falling edges of the low-frequency high-power pulse.

[0057] The superposition area of ​​step 1 is as follows Figure 3 As shown, the superposition region is a pre-ionization region relative to the low-frequency high-power pulse, and the pre-ionization region is within the superposition region. The high-frequency low-power pulse generates a low-density plasma in advance for the high-frequency low-power pulse to improve the low-frequency and high-power receiving effect; the low-density plasma is the plasma generated with a density that can just ensure that the low-frequency high-power pulse can be in a stable state when the low-frequency high-power pulse arrives.

[0058] like Figure 3 As shown, the superposition area is generated by extending the falling edge of the high-frequency low-power pulse to a set time after the rising edge of the low-frequency high-power pulse. The density of the plasma generated at the set time can just ensure that the low-frequency high-power pulse can be in a stable state when the low-frequency high-power pulse arrives.

[0059] like Figure 3 As shown, when the high-frequency low-power pulse is 13.56 MHz and the low-frequency high-power pulse is 2 MHz, the set time is 80 microseconds.

[0060] The step 2 uses a dual-frequency driving device to fine-tune the rising and falling edges of the low-frequency, high-power pulse, thereby improving the instantaneous impedance matching effect of the rising and falling edges of the low-frequency, high-power pulse. Specifically, the dual-frequency driving device is used to fine-tune the frequency and amplitude at the rising and falling edges of the low-frequency, high-power pulse so that the power reflection is minimized when the low-frequency, high-power pulse arrives and when it is removed.

[0061] like Figure 8 and Figure 4 As shown in the frequency-time diagram, the dual-frequency driving device fine-tunes the frequencies at the rising and falling edges of the low-frequency, high-power pulse. Specifically, the dual-frequency signal controller 10 sends a low-frequency, high-frequency frequency control signal FREQ11 sequence to the low-frequency, high-frequency digital carrier modulation path 31 to fine-tune the frequencies at the rising and falling edges of the low-frequency, high-power pulse, thereby reducing reflections at the rising and falling edges of the low-frequency, high-power pulse.

[0062] like Figure 8 and Figure 4 As shown in the amplitude-time diagram, further, the dual-frequency driving device fine-tunes the amplitude at the rising edge and falling edge of the low-frequency high-power pulse, specifically: the low-frequency high-frequency amplitude signal AMPL13 sequence sent by the dual-frequency signal controller 10 to the low-frequency high-frequency digital carrier modulation path 31 is used to fine-tune the amplitude at the rising edge and falling edge of the low-frequency high-power pulse, thereby further reducing the reflection of the rising edge and falling edge of the low-frequency high-power pulse.

[0063] Additional notes:

[0064] like Figure 4 As shown, the present invention can also further reduce the reflection of the rising edge and the falling edge by amplitude modulation. However, the amplitude cannot be reduced too much, otherwise, for the rising edge, a longer overlapping segment will be required to achieve the conversion of plasma matching low-frequency high-power pulses, so that there will be less negative hydrogen and more electronic load on the anode; for the falling edge, the pulse width for generating instantaneous high-current negative hydrogen is also compressed.

[0065] like Figure 5 、 Figure 6 As shown, when the frequency A with the lowest instantaneous reflection coefficient corresponding to the arrival of a low-frequency, high-power pulse is compared with the frequency B with the lowest average reflection coefficient in each pulse through a third-party device, when frequency A is lower, the dual-frequency driving device is used to adjust the frequencies of the rising and falling edges of the low-frequency, high-power pulse to A, and restore the frequency of the middle area of ​​the pulse width to B.

[0066] Furthermore, when the frequency A with the lowest instantaneous reflection coefficient corresponding to the arrival of a low-frequency, high-power pulse is compared with the frequency B with the lowest average reflection coefficient in each pulse through a third-party device, and frequency A is higher, a dual-frequency driving device is used to adjust the frequencies of the rising and falling edges of the low-frequency, high-power pulse to A, and the frequency of the middle area of ​​the pulse width to B.

[0067] like Figure 5 、 Figure 6 As shown, when the frequency of the low-frequency high-power pulse is 2 MHz and the frequency corresponding to the lowest impedance in the pulse width region is 1.95 MHz, a dual-frequency driving device is used to adjust the frequencies of the rising and falling edges of the low-frequency high-power pulse to 1.95 MHz, and the frequency of the middle region of the pulse width is adjusted to 2 MHz.

[0068] It should be emphasized that the above specific embodiments are merely explanations of the present invention and are not limitations of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the above embodiments as needed, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A pulse width internal impedance matching method for a pulse high-frequency ionization device, the method being based on a dual-frequency driving device, the dual-frequency driving device being provided with, from one side to the other, a dual-frequency signal controller (10), a dual-frequency sine / cosine digital waveform generator (20), a high-frequency high-frequency digital carrier modulation path (30) and a low-frequency high-frequency digital carrier modulation path (31), and a dual-high-frequency digital-to-analog conversion output driving module (40); The dual-frequency signal controller (10) is used to generate a dual-frequency frequency control signal and a dual-frequency amplitude control signal with an intrinsic dual-frequency delay control characteristic, and send the dual-frequency frequency control signal to a dual-frequency sine / cosine digital waveform generator (20), and send the dual-frequency amplitude control signal with an intrinsic delay characteristic to a high-frequency high-frequency digital carrier modulation path (30) and a low-frequency high-frequency digital carrier modulation path (31). The dual-frequency sine / cosine digital waveform generator (20) is used to convert the received dual-frequency frequency control signal into a sine / cosine signal and send it to a high-frequency high-frequency digital carrier modulation path (30) and a low-frequency high-frequency digital carrier modulation path (31) respectively; The high-frequency and high-frequency digital carrier modulation path (30) is used to multiply the received sine / cosine signal by the received dual-frequency amplitude control signal with an intrinsic dual-frequency time delay control characteristic, thereby realizing modulation of the high-frequency and high-frequency digital carrier signal; the low-frequency and high-frequency digital carrier modulation path (31) is used to multiply the received sine / cosine signal by the received dual-frequency amplitude control signal with an intrinsic dual-frequency time delay control characteristic, thereby realizing modulation of the low-frequency and high-frequency digital carrier signal; The dual high-frequency digital-analog conversion output drive module (40) is used to perform digital-analog conversion on a modulated high-frequency high-frequency digital carrier signal and a modulated low-frequency high-frequency digital carrier signal, and send the continuously output high-frequency drive signal after digital-analog conversion to a third-party low-power high-frequency power source; send the pulse output high-frequency drive signal after digital-analog conversion to a third-party low-power high-frequency power source; send the pulse output low-frequency drive signal after digital-analog conversion to a third-party high-power high-frequency power source; The frequency signals sent by the dual-frequency signal controller (10) to the dual-frequency sine / cosine digital waveform generator (20) are a high-frequency high-frequency control signal (FREQ10) and a low-frequency high-frequency control signal (FREQ11); The amplitude signals sent by the dual-frequency signal controller (10) to the high-frequency and high-frequency digital carrier modulation path (30) and the low-frequency and high-frequency digital carrier modulation path (31) are: a high-frequency and high-frequency path modulation signal (AMPL12) and a low-frequency and high-frequency path modulation signal (AMPL13); The modulated signal sent by the high-frequency and high-frequency digital carrier modulation path (30) to the dual-high-frequency digital-to-analog conversion output driving module (40) and the modulated signal sent by the low-frequency and high-frequency digital carrier modulation path (31) to the dual-high-frequency digital-to-analog conversion output driving module (40) are both digital high-frequency and high-frequency modulated signals (DMOD30) and digital low-frequency and high-frequency modulated signals (DMOD31); Features: The pulse width internal impedance matching method comprises the following steps: Step 1: adding an overlapping region between the high-frequency low-power pulse and the low-frequency high-power pulse of the pulse high-frequency ionization device, and generating a low-density plasma background with a certain high-frequency power receiving effect through the overlapping region; Step 2: Use a dual-frequency driving device to fine-tune the rising and falling edges of the high-power low-frequency pulse to improve the instantaneous impedance matching effect of the rising and falling edges of the low-frequency high-power pulse.

2. A pulse width internal impedance matching method for a pulse high frequency ionization device according to claim 1, Features: The superposition area of ​​step one, that is, the superposition area is a pre-ionization area relative to the low-frequency high-power pulse, and the pre-ionization area is in this superposition area. The high-frequency low-power pulse generates a low-density plasma in advance for improving the low-frequency and high-power receiving effect of the high-frequency low-power pulse; the low-density plasma is the plasma generated so that the density can just ensure that when the low-frequency high-power pulse arrives, the low-frequency high-power pulse can be in a stable state.

3. The pulse width internal impedance matching method of a pulse high frequency ionization device according to claim 1, characterized in that: The overlapping area is generated by extending the falling edge of the high-frequency low-power pulse to a set time after the rising edge of the low-frequency high-power pulse. The density of the plasma generated at the set time can just ensure that the low-frequency high-power pulse can be in a stable state when the low-frequency high-power pulse arrives.

4. The pulse width internal impedance matching method of a pulse high frequency ionization device according to claim 3, characterized in that: When the high-frequency low-power pulse is 13.56 MHz and the low-frequency high-power pulse is 2 MHz, the set time is 80 microseconds.

5. The pulse width internal impedance matching method of a pulse high frequency ionization device according to claim 1, characterized in that: The step 2 adopts a dual-frequency driving device to fine-tune the rising edge and falling edge of the low-frequency high-power pulse, and improve the instantaneous impedance matching effect of the rising edge and falling edge of the low-frequency high-power pulse. Specifically, the frequency and amplitude at the rising edge and falling edge of the low-frequency high-power pulse are fine-tuned by the dual-frequency driving device, so that the power reflection of the low-frequency high-power pulse when it arrives and when it is removed is minimized.

6. A pulse width internal impedance matching method for a pulse high frequency ionization device according to claim 5, characterized in that: The dual-frequency driving device fine-tunes the frequencies at the rising and falling edges of the low-frequency high-power pulses, specifically by using a low-frequency high-frequency frequency control signal (FREQ11) sequence sent by a dual-frequency signal controller (10) to a low-frequency high-frequency digital carrier modulation path (31) to fine-tune the frequencies at the rising and falling edges of the low-frequency high-power pulses, thereby reducing reflections at the rising and falling edges of the low-frequency high-power pulses.

7. The pulse width internal impedance matching method of a pulse high frequency ionization device according to claim 5, characterized in that: The dual-frequency driving device fine-tunes the amplitude at the rising edge and the falling edge of the low-frequency high-power pulse, specifically: a low-frequency high-frequency amplitude signal (AMPL13) sequence is sent to the low-frequency high-frequency digital carrier modulation path (31) by the dual-frequency signal controller (10), so as to fine-tune the amplitude at the rising edge and the falling edge of the low-frequency high-power pulse, and further reduce the reflection at the rising edge and the falling edge of the low-frequency high-power pulse.

8. The pulse width internal impedance matching method of a pulse high frequency ionization device according to claim 6, characterized in that: When the frequency A with the lowest instantaneous reflection coefficient corresponding to the arrival of a low-frequency high-power pulse is lower than the frequency B with the lowest average reflection coefficient in each pulse through a third-party device, a dual-frequency driving device is used to adjust the frequencies of the rising and falling edges of the low-frequency high-power pulse to A, and restore the frequency of the middle area of ​​the pulse width to B.

9. The pulse width internal impedance matching method of a pulse high frequency ionization device according to claim 6, characterized in that: When the frequency A with the lowest instantaneous reflection coefficient corresponding to the arrival of a low-frequency high-power pulse is higher than the frequency B with the lowest average reflection coefficient in each pulse through a third-party device, the frequency of the rising and falling edges of the low-frequency high-power pulse is adjusted to A by a dual-frequency driving device, and the frequency of the middle area of ​​the pulse width is adjusted to B.

10. The pulse width internal impedance matching method of a pulse high frequency ionization device according to claim 8, characterized in that: When the frequency of the low-frequency high-power pulse is 2 MHz and the frequency corresponding to the lowest impedance in the pulse width region is 1.95 MHz, a dual-frequency driving device is used to adjust the frequencies of the rising and falling edges of the low-frequency high-power pulse to 1.95 MHz, and the frequency of the middle region of the pulse width is adjusted to 2 MHz.

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