Multi-pulse driving generation apparatus for radio-frequency power supply

Abstract

A multi-pulse driving generation apparatus for a radio-frequency power supply, which apparatus belongs to the technical field of radio-frequency power supplies, and solves the problem of the stability of an existing radio-frequency power supply being poor during pulse switching. The multi-pulse driving generation apparatus comprises a multi-pulse generator and a switcher, wherein the switcher is connected between the multi-pulse generator and an inverter of a radio-frequency power supply; the multi-pulse generator generates multiple levels of pulse signals on the basis of a reference signal, and the pulse signals at each level are different in terms of output power and frequency; and the switcher switches the multiple levels of pulse signals generated by the multi-pulse generator, and outputs same to the inverter to drive the radio-frequency power supply, so as to switch the output power and frequency of the radio-frequency power supply.

Description

A multi-pulse drive generating device for radio frequency power supply Technical Field

[0001] The present application belongs to the technical field of radio frequency power supply, and specifically relates to a multi-pulse drive generating device of a radio frequency power supply. Background Art

[0002] The overall RF plasma power system architecture consists of an RF power supply, a matching box, and a chamber load. The RF power supply outputs a power signal to the matching box, which performs impedance matching and transfers the power signal to the chamber load. During operation, the RF power supply outputs an AC power signal, which is delivered to the chamber load via pulse excitation with a specific duty cycle. This AC power signal provides sufficient electrical energy to the input gas in the chamber, igniting and ionizing the gas. The magnetic field formed by the electrodes then moves the plasma in the direction of the relevant process.

[0003] During non-pulsed excitation, the chamber load may stall due to insufficient power, so a pulsed excitation that maintains the minimum ionization energy is required.

[0004] Currently, the main modules in conventional RF power supplies include an ADC module, a power amplifier, a VI sensor, and a main control module. The power amplifier primarily comprises an inverter and a transformer, with filters added as needed. The inverter in the power amplifier often uses an H-bridge inverter circuit. However, during pulse switching, the continuous current can cause all of the H-bridge's switches to conduct, causing circuit damage.

[0005] Summary of the Invention

[0006] In view of the above analysis, the present application aims to disclose a multi-pulse drive generating device for a radio frequency power supply, which is used to solve the problem of poor stability of the existing radio frequency power supply during pulse switching.

[0007] The present application discloses a multi-pulse drive generating device for a radio frequency power supply, the multi-pulse drive generating device comprising a multi-pulse generator and a switch; wherein,

[0008] The switch is connected between the multi-pulse generator and the inverter of the radio frequency power supply;

[0009] The multi-pulse generator generates a multi-level pulse signal based on a reference signal, and the output power and frequency of each level of the pulse signal are different;

[0010] The switch switches the multi-level pulse signal generated by the multi-pulse generator and outputs it to the inverter to drive the radio frequency power supply, thereby switching the output power and frequency of the radio frequency power supply.

[0011] Based on the above solution, this application also makes the following improvements:

[0012] Furthermore, the multi-pulse drive generating device further includes a switching enable controller; wherein,

[0013] The switching enable controller is connected between the switch and the inverter of the radio frequency power supply;

[0014] The switching enable controller is used to reset the control signal of the inverter to zero during the switching process of the multi-level pulse signal; and is also used to generate the control signal of the inverter according to the input pulse signal during the non-switching process of the multi-level pulse signal;

[0015] The inverter drives the radio frequency power source based on a control signal of the inverter.

[0016] Furthermore, the switching enable controller includes an encoder, a pulse signal converter and an inverter controller; wherein,

[0017] The encoder is used to output a high potential or a low potential;

[0018] The pulse signal converter converts the pulse signal input by the switch to obtain an inverter control reference signal;

[0019] The inverter controller, during the switching process of the multi-level pulse signal, sets the control signal of the inverter output by the inverter controller to zero according to the low potential of the set time width provided by the encoder, and turns off the switching tube of the inverter; and also during the non-switching process of the multi-level pulse signal, outputs the inverter control reference signal as the control signal of the inverter to the switching tube of the inverter according to the high potential of the set time width provided by the encoder to perform power driving.

[0020] Furthermore, the pulse signal converter includes a DAC module, a first inversion module, a filtering module, a comparison module and a second inversion module arranged in sequence; wherein,

[0021] The switch outputs the input pulse signal in the form of a digital signal;

[0022] The DAC module converts the input pulse signal into an analog signal as a positive phase analog signal;

[0023] The first inversion module inverts the positive-phase analog signal to obtain an inverted-phase analog signal;

[0024] The filtering module filters the positive phase analog signal and the negative phase analog signal respectively;

[0025] The comparison module compares the filtered positive phase analog signal and the negative phase analog signal to obtain a comparison signal as a positive phase comparison signal;

[0026] The second inverting module inverts the positive comparison signal to obtain an inverted comparison signal;

[0027] The positive phase comparison signal and the negative phase comparison signal are combined to obtain the inverter control reference signal.

[0028] Furthermore, the inverter is an H-bridge inverter, H1 / H2 is a half-bridge control path of the H-bridge, and H3 / H4 is the other half-bridge control path of the H-bridge;

[0029] The multi-pulse generator includes N levels of pulse generators for generating pulse signals with levels from LV1 to LVN; wherein,

[0030] The pulse generator of level LVn includes LVn-H1 / H2 module and LVn-H3 / H4 module; LVn-H1 / H2 module and LVn-H3 / H4 module respectively generate pulse signals of level LVn for driving H1 / H2 half-bridge control path and H3 / H4 half-bridge control path of H-bridge inverter;

[0031] The value of n is 1 to N.

[0032] Furthermore, the switch includes a linked switch group T1 and a switch group T2;

[0033] The switching switch group T1 includes N switches: switch T1-LV1-H1 / H2 to switch T1-LVN-H1 / H2; among which, switch T1-LVn-H1 / H2 is used to control the operation of the LVn-H1 / H2 module;

[0034] The switching switch group T2 includes N switches: switch T2-LV1-H3 / H4 to switch T2-LVN-H3 / H4; among them, switch T2-LVn-H3 / H4 is used to control the operation of the LVn-H3 / H4 module;

[0035] When switching to the pulse signal of level LVn, the switches T1-LVn-H1 / H2 and T2-LVn-H3 / H4 of the pulse signal of level LVn are linked and closed, and the other switches are opened.

[0036] Furthermore, the DAC module includes a first DAC unit and a second DAC unit; the first inverting module includes a first inverter and a second inverter; the filtering module includes a first filter, a second filter, a third filter and a fourth filter; the comparing module includes a first differential comparator and a second differential comparator; the second inverting module includes a third inverter and a fourth inverter;

[0037] The output end of the switching switch group T1 is connected to the input end of the first DAC unit; one output end of the first DAC unit is connected to the input end of the first filter, and the other output end is connected to the input end of the second filter after being inverted by the first inverter. The output ends of the first filter and the second filter are respectively connected to the non-inverting input end and the inverting input end of the first differential comparator; the output end of the first differential comparator is connected to the input end of the third inverter;

[0038] The output end of the switching switch group T2 is connected to the input end of the second DAC unit; one output end of the second DAC unit is connected to the input end of the third filter, and the other output end is connected to the input end of the fourth filter after being inverted by the second inverter. The output ends of the third filter and the fourth filter are respectively connected to the non-inverting input end and the inverting input end of the second differential comparator; the output end of the second differential comparator is connected to the input end of the fourth inverter;

[0039] The four signals outputted from the output terminal of the first differential comparator, the output terminal of the third inverter, the output terminal of the second differential comparator and the output terminal of the fourth inverter are combined to form the inverter control reference signal.

[0040] Furthermore, the inverter controller includes a first AND gate, a second AND gate, a third AND gate and a fourth AND gate; wherein,

[0041] The output end of the first differential comparator is connected to the first input end of the first AND gate, the output end of the third inverter is connected to the first input end of the second AND gate, the output end of the second differential comparator is connected to the first input end of the third AND gate, and the output end of the fourth inverter is connected to the first input end of the fourth AND gate;

[0042] The second input ends of the first AND gate, the second AND gate, the third AND gate and the fourth AND gate are respectively connected to the output end of the encoder;

[0043] The output ends of the first AND gate, the second AND gate, the third AND gate and the fourth AND gate are connected to the control ends of H1, H2, H3 and H4 respectively.

[0044] Furthermore, among the multi-level pulse signals generated by the multi-pulse generator, at least two levels of pulse signals are enabled; and simultaneously, during the switching process of the multi-level pulse signals, only the enabled pulse signals at each level are switched.

[0045] Furthermore, within one cycle of the reference signal, the sum of the total operating time of the enabled pulse signals of each level and the total operating time during which the encoder maintains a low level is less than the operating time of one cycle of the reference signal.

[0046] This application can achieve one of the following beneficial effects:

[0047] The multi-pulse drive generator for an RF power supply provided in this application can achieve multi-level pulse signal switching to correspondingly switch the RF power supply's output power and frequency. Furthermore, by setting the inverter's control signal to zero during the multi-level pulse signal switching process, this effectively prevents the inverter's H-bridge from fully conducting. This allows the RF power supply to maintain stable operation during pulse switching overshoots, effectively resolving the issue of poor stability during pulse switching in existing RF power supplies. The device is applicable to various forms of RF power supplies or combinations of RF power supplies.

[0048] In addition, this application also provides a specific structure of a switching enable controller with a simple circuit structure and rigorous control logic, which provides a guarantee for providing reliable and stable inverter control signals and provides technical guidance for technical personnel in this field to implement this solution.

[0049] Finally, when using a multi-pulse signal with three or more levels, the number of levels can be flexibly selected based on actual needs. When using a two-level pulse signal, ionization and processing are performed during the high-excitation period of the pulse, while the plasma ionization state is maintained during the low-excitation period, allowing stable operation during pulse switching.

[0050] In this application, the above-mentioned technical solutions can be combined with each other to achieve more preferred combination solutions. Other features and advantages of this application will be described in the subsequent description, and some advantages will become apparent from the description or be understood by practicing this application. The objectives and other advantages of this application can be achieved and obtained through the contents particularly pointed out in the description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not to be considered as limiting the present application. Throughout the drawings, the same reference symbols denote the same components.

[0052] FIG1 is a first structural diagram of a multi-pulse drive generating device of a radio frequency power supply provided in an embodiment of the present application;

[0053] FIG2 is a second structural diagram of a multi-pulse drive generating device of a radio frequency power supply provided in an embodiment of the present application;

[0054] FIG3 is a third structural diagram of a multi-pulse drive generating device of a radio frequency power supply provided in an embodiment of the present application;

[0055] FIG4 is a fourth structural diagram of a multi-pulse drive generating device of a radio frequency power supply provided in an embodiment of the present application;

[0056] FIG5 is a fifth structural diagram of a multi-pulse drive generating device of a radio frequency power supply provided in an embodiment of the present application;

[0057] FIG6 is a sixth structural diagram of a multi-pulse drive generating device of a radio frequency power supply provided in an embodiment of the present application;

[0058] FIG7 is a timing diagram of the drive control of the multi-pulse drive generating device of the radio frequency power supply provided in an embodiment of the present application;

[0059] FIG8 is a timing diagram of the drive control output provided by an embodiment of the present application;

[0060] FIG9 is a single-phase power input RF power supply provided in an embodiment of the present application;

[0061] FIG10 is a diagram of a radio frequency power supply with three-phase power input provided in an embodiment of the present application.

[0062] FIG11 is a flow chart of a multi-pulse driving method of an RF power supply provided in an embodiment of the present application. DETAILED DESCRIPTION

[0063] The preferred embodiments of the present application are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present application and are used together with the embodiments of the present application to illustrate the principles of the present application.

[0064] A specific embodiment of the present application discloses a multi-pulse drive generating device for a radio frequency power supply, a structural schematic diagram of which is shown in Figure 1. The multi-pulse drive generating device for the radio frequency power supply includes a multi-pulse generator and a switch; wherein the switch is connected between the multi-pulse generator and the inverter of the radio frequency power supply; the multi-pulse generator generates a multi-level pulse signal based on a reference signal, and the output power and frequency of each level of the pulse signal are different; the switch switches the multi-level pulse signal generated by the multi-pulse generator, and outputs it to the inverter to drive the radio frequency power supply, thereby switching the output power and frequency of the radio frequency power supply.

[0065] Preferably, the multi-pulse drive generating device further includes a switching enable controller. In this case, the structural schematic diagram of the multi-pulse drive generating device of the RF power supply is shown in Figure 2. The switching enable controller is connected between the switch and the inverter of the RF power supply; the switching enable controller is configured to reset the inverter control signal to zero during the switching process of the multi-level pulse signal; and is further configured to generate the inverter control signal based on the input pulse signal during the non-switching process of the multi-level pulse signal; the inverter drives the RF power supply based on the inverter control signal.

[0066] In this embodiment, the multi-level pulse signals generated by the multi-pulse generator are stored in an FPGA, MCU, or similar electronic computing device capable of reading parameters and outputting signals corresponding to those parameters. Switching between the multi-level pulse signals is handled internally by the FPGA, resulting in soft-controlled switching outputs. Alternatively, a standard signal generation circuit or a combined soft-drive and hard-control module can be employed. During implementation, the multi-pulse generator generates at least two levels of pulse signals, including a high-excitation pulse signal and a low-excitation pulse signal. The high-excitation pulse signal is used for ignition, ionization, and process operation, while the low-excitation pulse signal is used to maintain two ionization energy levels.

[0067] Preferably, the switching enable controller includes an encoder (ENC), a pulse signal converter, and an inverter controller. At this time, the structural diagram of the multi-pulse drive generating device of the RF power supply is shown in Figure 3. In Figure 3, the encoder is used to output a high potential (representing a digital signal 1) or a low potential (representing a digital signal 0); the pulse signal converter converts the pulse signal connected to the switch to obtain an inverter control reference signal; the inverter controller, during the switching process of the multi-level pulse signal, sets the control signal of the inverter output by the inverter controller to zero according to the low potential of the set time width provided by the encoder, and turns off the switch tube of the inverter; and during the non-switching process of the multi-level pulse signal, according to the high potential of the set time width provided by the encoder, outputs the inverter control reference signal as the control signal of the inverter to the switch tube of the inverter for power driving.

[0068] Preferably, the pulse signal converter includes a DAC module, a first inverting module, a filtering module, a comparison module and a second inverting module arranged in sequence. At this time, the structural diagram of the multi-pulse drive generating device of the RF power supply is shown in Figure 4. In Figure 4, the switch outputs the connected pulse signal in the form of a digital signal; the DAC module converts the connected pulse signal into an analog signal as a positive-phase analog signal; the first inverting module inverts the positive-phase analog signal to obtain an inverted analog signal; the filtering module filters the positive-phase analog signal and the inverted analog signal respectively; the comparison module compares the filtered positive-phase analog signal and the inverted analog signal to obtain a comparison signal as a positive-phase comparison signal; the second inverting module inverts the positive-phase comparison signal to obtain an inverted comparison signal; the positive-phase comparison signal and the inverted comparison signal are combined to obtain the inverter control reference signal.

[0069] In this embodiment, the inverter is an H-bridge inverter, where H1 / H2 is one half-bridge control path of the H-bridge, and H3 / H4 is the other half-bridge control path of the H-bridge. The multi-pulse generator includes N levels of pulse generators, which are used to generate pulse signals at levels from LV1 to LVN. The pulse generator at level LVn includes an LVn-H1 / H2 module and an LVn-H3 / H4 module. The LVn-H1 / H2 module and the LVn-H3 / H4 module respectively generate pulse signals at level LVn for driving the H1 / H2 half-bridge control path and the H3 / H4 half-bridge control path of the H-bridge inverter. The value of n ranges from 1 to N.

[0070] Preferably, the switch includes a switching switch group T1 and a switching switch group T2 that are linked. In this case, the structural diagram of the multi-pulse drive generating device of the RF power supply is shown in Figure 5. The switching switch group T1 includes N switches: switch T1-LV1-H1 / H2 to switch T1-LVN-H1 / H2; wherein, switch T1-LVn-H1 / H2 is used to control the operation of the LVn-H1 / H2 module; the switching switch group T2 includes N switches: switch T2-LV1-H3 / H4 to switch T2-LVN-H3 / H4; wherein, switch T2-LVn-H3 / H4 is used to control the operation of the LVn-H3 / H4 module; when switching to a pulse signal of level LVn, switches T1-LVn-H1 / H2 and T2-LVn-H3 / H4 of the pulse signal of level LVn are linked and closed, and the remaining switches are all disconnected.

[0071] In Figure 5, the DAC module includes a first DAC unit and a second DAC unit; the first inverting module includes a first inverter and a second inverter; the filtering module includes a first filter, a second filter, a third filter, and a fourth filter; the comparison module includes a first differential comparator and a second differential comparator; the second inverting module includes a third inverter and a fourth inverter; the output end of the switching switch group T1 is connected to the input end of the first DAC unit; the output end of the first DAC unit is connected to the input end of the first filter in one way, and the other way is connected to the input end of the second filter after being inverted by the first inverter, and the output ends of the first filter and the second filter are respectively connected to the non-inverting input end of the first differential comparator. The output of the first differential comparator is connected to the input of the third inverter; the output of the switching switch group T2 is connected to the input of the second DAC unit; one output of the second DAC unit is connected to the input of the third filter, and the other output is connected to the input of the fourth filter after being inverted by the second inverter; the outputs of the third filter and the fourth filter are respectively connected to the non-inverting input and the inverting input of the second differential comparator; the output of the second differential comparator is connected to the input of the fourth inverter; the four signals outputted from the output of the first differential comparator, the output of the third inverter, the output of the second differential comparator, and the output of the fourth inverter are combined to form the inverter control reference signal.

[0072] Preferably, the inverter controller includes a first AND gate, a second AND gate, a third AND gate, and a fourth AND gate; wherein the output of the first differential comparator is connected to the first input of the first AND gate, the output of the third inverter is connected to the first input of the second AND gate, the output of the second differential comparator is connected to the first input of the third AND gate, and the output of the fourth inverter is connected to the first input of the fourth AND gate; the second inputs of the first, second, third, and fourth AND gates are respectively connected to the output of the encoder; and the outputs of the first, second, third, and fourth AND gates are respectively connected to the control terminals of H1, H2, H3, and H4. In this case, the structural schematic diagram of the multi-pulse drive generating device of the RF power supply is shown in Figure 6.

[0073] Preferably, at least two levels of pulse signals are enabled among the multi-level pulse signals generated by the multi-pulse generator; and during the switching process of the multi-level pulse signals, only the enabled pulse signals of each level are switched. That is, when the total number of levels of all pulse signals generated by the multi-pulse generator is N, the number of enabled pulse signals is m, 2≤m≤N; during the switching process of the multi-level pulse signals, only the enabled m-level pulse signals are switched. Furthermore, within one cycle of the reference signal, the sum of the total operating time of the enabled pulse signals of each level and the total operating time during which the encoder remains at a low level is less than the operating time of one cycle of the reference signal.

[0074] Below, assuming that the frequency of the reference signal is 1KHz and the duty cycle is 50% (expressed as REF-1KHz-50%), and taking the dual-stage pulse signal switching as an example, the operation process of the multi-pulse drive generating device of the RF power supply is described.

[0075] The control data of H1 / H2 / H3 / H4 of the corresponding level is selected according to the level of the pulse signal. In this embodiment, the control mode corresponding to H1 / H2 / H3 / H4 and the pulse signal of level LV1 is represented as path A, and the control mode corresponding to H1 / H2 / H3 / H4 and the pulse signal of level LV2 is represented as path B. In this embodiment, with reference to the reference signal, the on-off (or switching) of path A / B and the 0-1 switching process of ENC are driven and controlled, and the timing diagram of the drive control of the multi-pulse drive generating device of the RF power supply is shown in Figure 7. In Figure 7, path A and path B are switched alternately, and ENC is switched during the alternation between path A and path B. Among them, the duty cycle of the ENC startup time does not exceed 1% of the cycle length of the reference signal. In principle, the smaller the better. The timing diagram in Figure 7 is explained as follows:

[0076] (1) When the reference signal switches to a high level (which is a switching process of a multi-level pulse signal), the ENC outputs a low level, so that all the switches of the inverter are turned off and the inverter outputs zero potential;

[0077] (2) When the reference signal remains at a high level (belonging to the non-switching process of the multi-level pulse signal), ENC outputs a high level, so that the on-off state of the switch tube in the inverter matches path A, and the inverter is driven by the pulse signal LV1 of the corresponding level corresponding to path A;

[0078] (3) When the reference signal switches to a low level (which is a switching process of a multi-level pulse signal), the ENC outputs a low level, so that all the switches of the inverter are turned off, and the inverter outputs zero potential;

[0079] (4) When the reference signal remains at a low level (belonging to the non-switching process of the multi-level pulse signal), ENC outputs a high level, so that the on-off state of the switch tube in the inverter matches path B, and the corresponding level pulse signal LV2 corresponding to path B is used to power drive the inverter.

[0080] Specifically, during the alternating switching between paths A and B, the RF power base signal (the output signal of the pulse signal converter) also switches between LV1 and LV2, and the pulse signal converter generates the corresponding power and frequency outputs for LV1 / LV2. Meanwhile, ENC is normally 1, but during the switching between paths A and B, ENC has a very small duty cycle time when it outputs zero power. According to the structure of the multi-pulse drive generator of the RF power supply, the output of ENC first forms an AND gate logic output with the RF power base signal. According to the AND gate truth table, if any input is 0, the output is 0. Therefore, when ENC is 0, regardless of which level of base signal output it is connected to, it is 0. Therefore, during the alternating switching between paths A and B, because the control signals to the inverter are all 0, the inverter does not operate during this period. The timing diagram of the drive control output is shown in Figure 8. In Figure 8, a waveform with a relatively low amplitude illustrates the waveform detail timing diagram of the drive control signal corresponding to the LV2 pulse signal in Figure 7, and a waveform with a relatively high amplitude illustrates the waveform detail timing diagram of the drive control signal corresponding to the LV1 pulse signal in Figure 7. The waveform with an amplitude of nearly 0 between the two waveforms illustrates the waveform detail timing diagram when the drive control signal is 0. Therefore, there is no situation where the H-bridge switch tube is fully turned on. The above method is applicable to single-phase power input and three-phase power input. The RF power supplies with single-phase power input and three-phase power input are shown in Figures 9 and 10, respectively. At the same time, Figures 9 and 10 illustrate the inverter structure in the RF power supply.

[0081] When switching to path A, path A1 (LV1-H1 / H2) and path A2 (LV1-H3 / H4) alternate based on the frequency of pulse signal LV1. This switching can be software or hardware. As shown in Figure 6, when path A1 is active, the FPGA outputs control signal X for H1 / H2 of LV1. Signal X is a digital signal, which is converted to analog signal X' by the DAC. Analog signal X' is split into two paths. One path passes through a NOT gate, generating two positive and negative signals, X1 and X2. These two signals are filtered and input into a differential comparator to generate a control signal Y. The same signal Y is split into two paths. One path passes through a NOT gate, generating two positive and negative signals, Y1 and Y2, which are used to control H1 and H2 of the same half-bridge. Similarly, when path A2 is active, the FPGA outputs control signals for H3 / H4 of LV1 in a similar manner, controlling H3 and H4 of the same half-bridge. In principle, H1 and H3 conduct with the same duty cycle, while H2 and H4 conduct with the same duty cycle. Similarly, when switching to path B, path B1 (LV2-H1 / H2) and path B2 (LV2-H3 / H4) alternate according to frequency, causing H1 / H3 and H2 / H4 in LV2 to alternate. During the aforementioned switching process between paths A / B, if paths A / B are physical circuits, they can also be replaced by path selectors.

[0082] In summary, the multi-pulse drive generating device of the RF power supply provided in this embodiment can realize the switching of multi-level pulse signals to switch the output power and frequency of the RF power supply accordingly. At the same time, by setting the control signal of the inverter to zero during the switching process of the multi-level pulse signal, the full conduction of the H-bridge in the inverter is effectively avoided, so that the RF power supply can still operate stably during the pulse switching overshoot, which well solves the problem of poor stability of the existing RF power supply during pulse switching, and is suitable for various forms of RF power supplies or combinations of RF power supplies. In addition, this embodiment also provides a specific structure of the switching enable controller, which has a simple circuit structure and rigorous control logic, and provides a guarantee for providing a reliable and stable inverter control signal, and provides technical guidance for technical personnel in this field to implement this solution. Finally, when using a multi-pulse signal of more than three levels, the number of levels to be adopted can also be flexibly selected according to actual needs. When a two-level pulse signal is selected, ionization and processing are carried out during the high excitation period of the pulse, and the plasma ionization state is maintained during the low excitation period of the pulse, and stable operation can be achieved during pulse switching.

[0083] In addition, an embodiment of the present application further provides a multi-pulse driving method for an RF power supply, the flow chart of which is shown in FIG11 . The driving method includes the following steps:

[0084] Step S1: before the RF power supply is powered, a reference signal is set, and the total number of pulse signal levels, as well as the output power and frequency of each level of pulse signal are determined according to the reference signal; wherein the output power and frequency of each level of pulse signal are different.

[0085] It should also be noted that in this embodiment, the inverter is an H-bridge inverter, with H1 / H2 forming one half-bridge control path of the H-bridge and H3 / H4 forming the other half-bridge control path of the H-bridge. The multi-pulse generator includes N levels of pulse generators, configured to generate pulse signals at levels LV1 to LVN. The pulse generators at level LVn generate pulse signals at level LVn for driving the H1 / H2 and H3 / H4 half-bridge control paths of the H-bridge inverter, respectively; n ranges from 1 to N.

[0086] Step S2: When the radio frequency power supply is supplied, based on the reference signal, a multi-pulse generator is used to generate pulse signals of various levels.

[0087] Step S3: using a switch to switch the multi-level pulse signal generated by the multi-pulse generator, and output it to the inverter to drive the radio frequency power supply, thereby switching the output power and frequency of the radio frequency power supply.

[0088] Preferably, the specific execution process of step S3 is described as follows:

[0089] Step S31: using a switch to switch the multi-level pulse signal generated by the multi-pulse generator to generate a control signal for the inverter.

[0090] Step S32: the inverter drives the RF power supply based on the control signal of the inverter.

[0091] Specifically, the process of generating the inverter control signal in step S31 can be described as follows: during the switching process of the multi-level pulse signal, the generated inverter control signal is set to zero; during the non-switching process of the multi-level pulse signal, the inverter control signal is generated according to the input pulse signal. In addition, this embodiment also provides a specific implementation method for generating the inverter control signal, which is described as follows:

[0092] Step S311: Determine the current switching state. If it is a switching process of the multi-level pulse signal, the encoder outputs a low potential; if it is a non-switching process of the multi-level pulse signal, the encoder outputs a high potential.

[0093] Step S312: converting the pulse signal input by the switch to generate an inverter control reference signal;

[0094] Step S313: performing an AND operation on the potential output by the encoder and the inverter control reference signal to generate a control signal for the inverter.

[0095] In step S312, the inverter control reference signal may be generated in the following manner:

[0096] Step S3121: converting the pulse signal received by the switch into an analog signal as a positive phase analog signal;

[0097] Step S3122: inverting the positive-phase analog signal to obtain an inverted-phase analog signal;

[0098] Step S3123: filtering the positive phase analog signal and the negative phase analog signal respectively;

[0099] Step S3124: Compare the filtered positive phase analog signal and the negative phase analog signal to obtain a comparison signal as a positive phase comparison signal;

[0100] Step S3125: inverting the positive comparison signal to obtain a negative comparison signal;

[0101] Step S3126: combining the positive phase comparison signal and the negative phase comparison signal to obtain the inverter control reference signal.

[0102] The specific implementation process of the embodiment of the method of the present application can be referred to the above-mentioned device embodiment, and this embodiment will not be repeated here.

[0103] Since the principles of this embodiment are the same as those of the above-mentioned device embodiment, this method also has the corresponding technical effects of the above-mentioned device embodiment.

[0104] Those skilled in the art will appreciate that all or part of the process steps of the above-described embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, such as a magnetic disk, an optical disk, a read-only memory, or a random access memory.

[0105] The above is only a preferred specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the scope of protection of the present application.

Claims

1. A multi-pulse drive generating device of a radio frequency power supply, characterized in that: The multi-pulse drive generating device comprises a multi-pulse generator and a switch; wherein, The switch is connected between the multi-pulse generator and the inverter of the radio frequency power supply; The multi-pulse generator generates a multi-level pulse signal based on a reference signal, and the output power and frequency of each level of the pulse signal are different; The switch switches the multi-level pulse signal generated by the multi-pulse generator and outputs it to the inverter to drive the radio frequency power supply, thereby switching the output power and frequency of the radio frequency power supply.

2. The multi-pulse driving generating device of the radio frequency power supply according to claim 1, characterized in that: The multi-pulse drive generating device also includes a switching enable controller; wherein, The switching enable controller is connected between the switch and the inverter of the radio frequency power supply; The switching enable controller is used to reset the control signal of the inverter to zero during the switching process of the multi-level pulse signal; and is also used to generate the control signal of the inverter according to the connected pulse signal during the non-switching process of the multi-level pulse signal; The inverter drives the radio frequency power source based on a control signal of the inverter.

3. The multi-pulse driving generating device of the radio frequency power supply according to claim 2, characterized in that: The switching enable controller includes an encoder, a pulse signal converter and an inverter controller; wherein, The encoder is used to output a high potential or a low potential; The pulse signal converter converts the pulse signal input by the switch to obtain an inverter control reference signal; The inverter controller, during the switching process of the multi-level pulse signal, sets the control signal of the inverter output by the inverter controller to zero according to the low potential of the set time width provided by the encoder, and turns off the switch tube of the inverter; and also during the non-switching process of the multi-level pulse signal, according to the encoder The high potential of the set time width is provided, and the inverter control reference signal is output to the switch tube of the inverter as the inverter control signal to perform power driving.

4. The multi-pulse driving generating device of the radio frequency power supply according to claim 3, characterized in that: The pulse signal converter comprises a DAC module, a first inversion module, a filtering module, a comparison module and a second inversion module arranged in sequence; wherein, The switch outputs the connected pulse signal in the form of a digital signal; The DAC module converts the input pulse signal into an analog signal as a positive phase analog signal; The first inversion module inverts the positive phase analog signal to obtain an inverted phase analog signal; The filtering module filters the positive phase analog signal and the negative phase analog signal respectively; The comparison module compares the filtered positive phase analog signal and the negative phase analog signal to obtain a comparison signal as a positive phase comparison signal; The second inversion module inverts the positive comparison signal to obtain an inverted comparison signal; The positive phase comparison signal and the negative phase comparison signal are combined to obtain the inverter control reference signal.

5. The multi-pulse driving generating device of the radio frequency power supply according to claim 4, characterized in that: The inverter is an H-bridge inverter, H1 / H2 is a half-bridge control path of the H-bridge, and H3 / H4 is another half-bridge control path of the H-bridge; The multi-pulse generator includes N levels of pulse generators for generating pulse signals with levels from LV1 to LVN; wherein, The pulse generator of level LVn includes LVn-H1 / H2 module and LVn-H3 / H4 module; LVn-H1 / H2 module and LVn-H3 / H4 module respectively generate pulse signals of level LVn for driving H1 / H2 half-bridge control path and H3 / H4 half-bridge control path of H-bridge inverter; The value of n is 1 to N.

6. The multi-pulse driving generating device of the radio frequency power supply according to claim 5, characterized in that: The switch includes a linked switch group T1 and a switch group T2; The switching switch group T1 includes N switches: switch T1-LV1-H1 / H2 to switch T1-LVN-H1 / H2; wherein the switch T1-LVn-H1 / H2 is used to control the operation of the LVn-H1 / H2 module; The switching switch group T2 includes N switches: switch T2-LV1-H3 / H4 to switch T2-LVN-H3 / H4; wherein the switch T2-LVn-H3 / H4 is used to control the operation of the LVn-H3 / H4 module; When switching to a pulse signal of level LVn, switches T1-LVn-H1 / H2 and T2-LVn-H3 / H4 of the pulse signal of level LVn are linked and closed, and the remaining switches are opened.

7. The multi-pulse driving generating device of the radio frequency power supply according to claim 6, characterized in that: The DAC module includes a first DAC unit and a second DAC unit; the first inversion module includes a first inverter and a second inverter; the filtering module includes a first filter, a second filter, a third filter and a fourth filter; the comparison module includes a first differential comparator and a second differential comparator; the second inversion module includes a third inverter and a fourth inverter; The output end of the switching switch group T1 is connected to the input end of the first DAC unit; one path of the output end of the first DAC unit is connected to the input end of the first filter, and the other path is connected to the input end of the second filter after being inverted by the first inverter, and the output ends of the first filter and the second filter are respectively connected to the non-inverting input end and the inverting input end of the first differential comparator; the output end of the first differential comparator is connected to the input end of the third inverter; The output end of the switching switch group T2 is connected to the input end of the second DAC unit; one path of the output end of the second DAC unit is connected to the input end of the third filter, and the other path is connected to the input end of the fourth filter after being inverted by the second inverter, and the output ends of the third filter and the fourth filter are respectively connected to the non-inverting input end and the inverting input end of the second differential comparator; the output end of the second differential comparator is connected to the input end of the fourth inverter; The four-way signal outputted from the output end of the first differential comparator, the output end of the third inverter, the output end of the second differential comparator and the output end of the fourth inverter is combined to form the inverter control reference signal.

8. The multi-pulse driving generating device of the radio frequency power supply according to claim 7, characterized in that: The inverter controller includes a first AND gate, a second AND gate, a third AND gate and a fourth AND gate; wherein, The output end of the first differential comparator is connected to the first input end of the first AND gate, the output end of the third inverter is connected to the first input end of the second AND gate, the output end of the second differential comparator is connected to the first input end of the third AND gate, and the output end of the fourth inverter is connected to the first input end of the fourth AND gate; The second input ends of the first AND gate, the second AND gate, the third AND gate and the fourth AND gate are respectively connected to the output end of the encoder; The output ends of the first AND gate, the second AND gate, the third AND gate and the fourth AND gate are connected to the control ends of H1, H2, H3 and H4 respectively.

9. The multi-pulse drive generating device of the radio frequency power supply according to any one of claims 3 to 8, characterized in that: Among the multi-level pulse signals generated by the multi-pulse generator, at least two levels of pulse signals are enabled; meanwhile, during the switching process of the multi-level pulse signals, only the enabled pulse signals at each level are switched.

10. The multi-pulse driving generating device of the radio frequency power supply according to claim 9, characterized in that: In one cycle of the reference signal, the sum of the total running time of the enabled pulse signals of each level and the total running time of the encoder maintaining a low level is less than the running time of one cycle of the reference signal.

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