Radio frequency power supply control method and apparatus, radio frequency power supply, and semiconductor process device

Abstract

The present application provides a radio frequency power supply control method and apparatus, a radio frequency power supply, and a semiconductor process device, applied to the technical field of semiconductor process devices. The method is applied to a radio frequency power supply that provides at least one pulse signal in each work cycle, wherein among the at least one pulse signal in each work cycle of the radio frequency power supply, one pulse signal is controlled according to a first control mode, and the first control mode comprises: on the basis of a forward power feedback value, reflected power feedback value, dissipated power feedback value and bus voltage threshold of the current radio frequency power supply, regulating a bus voltage outputted to the radio frequency power supply, and keeping a bias voltage outputted to the radio frequency power supply unchanged. Compared with protection circuits constructed on the basis of electronic components in the prior art, the present application provides a software protection mechanism, and the execution process would be less affected by factors such as ambient temperature and electromagnetic interference, making the protection mechanism more reliable, and ensuring the safety of the radio frequency power supply during operation.

Description

RF power supply control methods, devices, RF power supplies and semiconductor process equipment Technical Field

[0001] This application relates to the field of radio frequency power supply technology, specifically to a control method, device, radio frequency power supply, and semiconductor process equipment for a radio frequency power supply. Background Technology

[0002] Currently, radio frequency (RF) power supplies are one of the core components of semiconductor process equipment, primarily used to provide high-frequency plasma excitation sources for these equipment. However, with continuous improvements in semiconductor processes and upgrades to semiconductor equipment, the safety requirements for RF power supplies during operation are becoming increasingly stringent.

[0003] To improve the safety of radio frequency (RF) power supply operation, existing technologies include protection circuits in RF power supplies. These protection circuits collect the forward power and reflected power during RF power supply operation. When the forward power exceeds a preset forward power setting value, a forward power control quantity is provided to control the forward power within a preset range. Similarly, when the reflected power exceeds a preset reflected power threshold, a reflected power control quantity is provided to control the reflected power within a preset range.

[0004] The inventors discovered that existing technologies for protecting radio frequency power supplies rely on analog circuits. The electronic components in these protection circuits are frequently affected by factors such as ambient temperature and electromagnetic interference, leading to unstable performance, malfunctions, or even failures of the protection mechanism. This makes it difficult to effectively protect the safety requirements of the radio frequency power supply during operation. Summary of the Invention

[0005] In view of this, this application aims to provide a control method, apparatus, RF power supply, and semiconductor process equipment for an RF power supply, so as to solve the problem that protection circuits in the prior art are unable to effectively protect the operational safety of the RF power supply.

[0006] In a first aspect, this application provides a method for controlling a radio frequency (RF) power supply, wherein the RF power supply provides at least one pulse signal in each operating cycle, the control method comprising:

[0007] Within each of the said working cycles, one of the at least one pulse signal is controlled according to a first control method;

[0008] The first control method is to adjust the bus voltage output to the RF power supply according to the forward power feedback value, reflected power feedback value, dissipated power feedback value and bus voltage threshold of the current RF power supply, and maintain the bias voltage output to the RF power supply unchanged.

[0009] In some embodiments, the radio frequency power supply provides at least two pulse signals in each of the duty cycles;

[0010] Among the at least two pulse signals, the pulse signal with the largest forward power setting value is controlled according to the first control method, and the other pulse signals besides the pulse signal with the largest forward power setting value are controlled according to the second control method.

[0011] The second control method is to adjust the bias voltage output to the RF power supply according to the current forward power feedback value and reflected power feedback value of the RF power supply, and maintain the bus voltage of the RF power supply unchanged.

[0012] In some embodiments, adjusting the bus voltage output to the RF power supply based on the current forward power feedback value, reflected power feedback value, dissipated power feedback value, and bus voltage threshold includes:

[0013] Obtain the current forward power setting value, reflected power threshold, dissipated power threshold, forward power feedback value, reflected power feedback value, dissipated power feedback value, and bus voltage threshold of the RF power supply.

[0014] The forward power control amount is determined based on the forward power deviation between the forward power setpoint and the forward power feedback value;

[0015] The reflection power control amount is determined based on the reflection power deviation between the reflection power threshold and the reflection power feedback value;

[0016] The dissipation power control quantity is determined based on the dissipation power deviation between the dissipation power threshold and the dissipation power feedback value;

[0017] The first target control quantity is determined based on the forward power control quantity, the reflected power control quantity, the dissipated power control quantity, and the bus voltage threshold.

[0018] Adjust the bus voltage output to the RF power supply according to the first target control quantity.

[0019] In some embodiments, determining a first target control quantity based on the forward power control quantity, the reflected power control quantity, the dissipated power control quantity, and the bus voltage threshold includes:

[0020] The smallest value among the forward power control quantity, the reflected power control quantity, the dissipated power control quantity, and the bus voltage threshold is determined as the first target control quantity.

[0021] In some embodiments, obtaining the bus voltage threshold includes:

[0022] The current scaling factor is determined based on the ratio of the reflected power feedback value to the forward power feedback value;

[0023] The bus voltage threshold is determined based on the current proportional coefficient and the pre-determined correspondence between the bus voltage threshold and the proportional coefficient.

[0024] In some embodiments, the predetermined correspondence between the bus voltage threshold and the proportional coefficient includes:

[0025] When the proportional coefficient is less than or equal to the first threshold, the bus voltage threshold corresponding to the proportional coefficient is the first voltage value;

[0026] When the proportional coefficient is greater than or equal to the second threshold, the bus voltage threshold corresponding to the proportional coefficient is the second voltage value, and the second threshold is greater than the first threshold;

[0027] When the proportional coefficient is greater than the first threshold and less than the second threshold, the proportional coefficient is inversely proportional to the bus voltage threshold.

[0028] In some embodiments, adjusting the bias voltage of the radio frequency power supply based on the forward power and reflected power of the radio frequency power supply includes:

[0029] Obtain the forward power setting value, reflected power threshold, forward power feedback value, and reflected power feedback value of the radio frequency power supply;

[0030] The forward power control amount is determined based on the forward power deviation between the forward power setpoint and the forward power feedback value;

[0031] The reflection power control amount is determined based on the reflection power deviation between the reflection power threshold and the reflection power feedback value;

[0032] The smallest control quantity among the forward power control quantity and the reflected power control quantity is selected as the second target control quantity;

[0033] Adjust the bias voltage of the RF power supply according to the second target control value.

[0034] Secondly, this application provides a control device for a radio frequency power supply, wherein the radio frequency power supply provides at least one pulse signal in each operating cycle, and the control device includes:

[0035] The main control unit is used to control one of the at least one pulse signals according to a first control method during each working cycle.

[0036] The first control method is to adjust the bus voltage output to the RF power supply according to the forward power feedback value, reflected power feedback value, dissipated power feedback value and bus voltage threshold of the current RF power supply, and maintain the bias voltage output to the RF power supply unchanged.

[0037] In some embodiments, the radio frequency power supply provides at least two pulse signals in each of the duty cycles;

[0038] The main control unit is configured to control the pulse signal with the largest forward power setting value among the at least two pulse signals according to the first control method, and control the remaining pulse signals other than the pulse signal with the largest forward power setting value according to the second control method.

[0039] The second control method is to adjust the bias voltage output to the RF power supply according to the current forward power feedback value and reflected power feedback value of the RF power supply, and maintain the bus voltage of the RF power supply unchanged.

[0040] In some embodiments, the main control unit includes: a forward power control quantity calculation unit, a reflected power control quantity calculation unit, a dissipated power control quantity calculation unit, a comparison unit, and a control unit, wherein,

[0041] The forward power control calculation unit is used to obtain the current forward power setting value and forward power feedback value of the RF power supply, and determine the forward power control amount based on the forward power deviation between the forward power setting value and the forward power feedback value.

[0042] The reflected power control quantity calculation unit is used to obtain the reflected power threshold and reflected power feedback value of the current radio frequency power supply, and determine the reflected power control quantity based on the reflected power deviation between the reflected power threshold and the reflected power feedback value.

[0043] The power dissipation control calculation unit is used to obtain the current power dissipation threshold and power dissipation feedback value of the radio frequency power supply, and determine the power dissipation control amount based on the power dissipation deviation between the power dissipation threshold and the power dissipation feedback value.

[0044] The comparison unit is used to determine a first target control quantity based on the forward power control quantity, the reflected power control quantity, the dissipated power control quantity, and the bus voltage threshold.

[0045] The control unit is used to adjust the bus voltage output to the radio frequency power supply according to the first target control quantity.

[0046] In some embodiments, the comparison unit is further configured to determine the minimum control quantity among the forward power control quantity and the reflected power control quantity as the second target control quantity;

[0047] The control unit is also configured to adjust the bias voltage of the radio frequency power supply according to the second target control quantity.

[0048] Thirdly, this application provides an radio frequency power supply, including: a main controller, a power amplifier circuit, and a sampling circuit, wherein,

[0049] The sampling circuit is connected to the power amplifier circuit;

[0050] The main controller is connected to the power amplifier circuit and the sampling circuit respectively;

[0051] The main controller is used to execute the control method of the radio frequency power supply as described in any of the first aspects of this application.

[0052] Fourthly, this application provides a semiconductor process apparatus, comprising: a process chamber and at least one radio frequency power supply as described in the third aspect of this application, wherein...

[0053] The radio frequency power supply is used to provide radio frequency power to the process chamber to excite the process gas in the process chamber to generate plasma.

[0054] Based on the above, the control method provided in this application is applied to an RF power supply that provides at least one pulse signal in each working cycle. In this method, one of the pulse signals in each working cycle of the RF power supply is controlled according to a first control mode. The first control mode is: adjusting the bus voltage output to the RF power supply according to the current forward power feedback value, reflected power feedback value, dissipated power feedback value and bus voltage threshold of the RF power supply, and maintaining the bias voltage output to the RF power supply unchanged. Compared with the protection circuit built based on electronic components in the prior art, the control method of the RF power supply provided in this application provides a software protection mechanism for the RF power supply. The execution process is not easily affected by factors such as ambient temperature and electromagnetic interference. The protection mechanism is more reliable and can effectively ensure the safety of the RF power supply during operation. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figures 1a and 1b are schematic diagrams of the waveforms of the output pulse signals of the RF power supply.

[0057] Figure 2 is a flowchart of a radio frequency power supply control method provided in an embodiment of the present invention.

[0058] Figure 3 is a voltage diagram of the power switch provided in an embodiment of the present invention.

[0059] Figure 4 is a flowchart of a bus current calculation method provided by an embodiment of the present invention.

[0060] Figure 5 is a schematic diagram of the mapping relationship between the proportional coefficient and the bus voltage threshold provided in the embodiment of the present invention.

[0061] Figure 6 is a graph showing the variation of forward power control, dissipated power control, and reflected power control provided in an embodiment of the present invention.

[0062] Figure 7 is a flowchart of a control quantity calculation method provided by an embodiment of the present invention.

[0063] Figure 8 is a flowchart of another control quantity calculation method provided by an embodiment of the present invention.

[0064] Figure 9 is a structural block diagram of a radio frequency power supply control device provided in an embodiment of the present invention.

[0065] Figure 10 is a structural block diagram of another radio frequency power supply control device provided in an embodiment of the present invention.

[0066] Figure 11 is a waveform diagram of another pulse signal output by the RF power supply.

[0067] Figure 12 is a structural block diagram of an RF power supply provided in an embodiment of the present invention. Detailed Implementation

[0068] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0069] As mentioned earlier, existing technologies, in order to improve the safety of RF power supply operation, incorporate protection circuits. These circuits provide forward power control to keep the forward power within a preset range when the forward power exceeds a preset value, and similarly, provide reflected power control to keep the reflected power within a preset range when the reflected power exceeds a preset threshold. However, existing RF power supply protection mechanisms are implemented using analog circuits. The electronic components in these protection circuits are frequently affected by factors such as ambient temperature and electromagnetic interference, leading to unstable circuit performance, malfunctions, or even complete failure of the protection mechanism. This makes it difficult to effectively ensure the safety requirements of the RF power supply during operation.

[0070] To address the aforementioned issues, this application provides a control method for an RF power supply. Compared to the protection circuits built with electronic components in the prior art, this application provides a software protection mechanism for the RF power supply. The execution process is less susceptible to factors such as ambient temperature and electromagnetic interference, making the protection mechanism more reliable and effectively ensuring the safety of the RF power supply during operation.

[0071] The RF power supply control method provided in this application utilizes an electronic device. This electronic device can be a main controller built into the RF power supply itself, or it can be a controller independent of the RF power supply, such as a host computer in semiconductor process equipment. Of course, in some cases, it can also be a server located at a remote location. The RF power supply control method provided in this application provides a protection mechanism for the RF power supply during operation. The RF power supply can provide at least one pulse signal in each working cycle. For example, when the RF power supply provides one pulse signal, its output pulse signal can be seen in Figure 1a, that is, within the same working cycle, the RF power supply provides the same type of pulse signal. As another example, when the RF power supply provides two or more pulse signals, its output pulse signals can be seen in Figure 1b (Figure 1b takes providing four types of pulse signals as an example). That is, within the same working cycle, the RF power supply outputs pulse signal 1, pulse signal 2, pulse signal 3, and pulse signal 4 sequentially according to the preset output rules of the pulse signals.

[0072] Based on the above, and referring to Figure 2, the radio frequency power supply control method provided in this application includes the following steps.

[0073] S100. In each working cycle, one of the pulse signals is controlled according to a first control method.

[0074] In practical applications, the output of a pulse signal by an RF power supply during any operating cycle can be divided into two implementation methods. In some embodiments, the RF power supply outputs only one pulse signal during any operating cycle. In this case, the method controls the pulse signal according to the first control method. Taking Figure 1a as an example, if the RF power supply only provides one pulse signal as shown in Figure 1a, the pulse signal is controlled according to the first control method.

[0075] In another implementation, the RF power supply outputs two or more pulse signals in any operating cycle. For example, the RF power supply can provide multiple pulse signals as shown in Figure 1b, namely pulse signal 1, pulse signal 2, pulse signal 3 and pulse signal 4.

[0076] Understandably, in practical applications, the RF power supply outputs pulse signals based on a forward power setting. This forward power setting is primarily used to configure the RF power provided during operation, which is also the RF power required by the user. In practice, the forward power setting can be provided by a host computer or slave computer connected to the RF power supply to control its operation. This application does not limit the specific configuration method of the forward power setting, or the reflection power threshold and dissipation power threshold mentioned later; these can be implemented using relevant technologies and will not be detailed here. More importantly, each pulse signal corresponds to one forward power setting, meaning there is a one-to-one correspondence between the pulse signal and the forward power setting.

[0077] Based on the above, among the at least two pulse signals provided by the RF power supply, this application controls the pulse signal with the largest forward power setting value according to the first control method, and controls the remaining pulse signals according to the second control method. Taking Figure 1b as an example, among the four pulse signals provided by the RF power supply, pulse signal 4 has the largest forward power setting value, so the output of pulse signal 4 is controlled according to the first control method. For the remaining pulse signals, the second control method is used.

[0078] Furthermore, the first control method described above specifically involves adjusting the bus voltage output to the RF power supply based on the current forward power feedback value, reflected power feedback value, dissipated power feedback value, and bus voltage threshold, while maintaining the bias voltage output to the RF power supply unchanged. The second control method specifically involves adjusting the bias voltage output to the RF power supply based on the current forward power feedback value and reflected power feedback value, while maintaining the bus voltage of the RF power supply unchanged.

[0079] It should be noted that the RF power supply in this application includes a power amplifier circuit composed of a power switching transistor. As shown in Figure 3, the voltage between the source (S) and drain (D) of the power switching transistor Q0 is the bus voltage V mentioned in this application. bus Correspondingly, the voltage between the gate (G) and source (S) of the power switch Q0 is the bias voltage V mentioned in this application. bias .

[0080] Understandably, for an RF power supply that provides multiple pulse signals in the same operating cycle, accurately identifying the current output pulse signal is a fundamental prerequisite for ensuring the reliability of the protection mechanism.

[0081] As mentioned earlier, the RF power supply outputs each pulse signal according to a preset output rule. This preset output rule includes the output order of each pulse signal and the preset duration of each pulse signal (or the preset number of pulses included in each pulse signal). Taking Figure 1b as an example, in any operating cycle, the RF power supply first outputs pulse signal 1. Based on this, the duration of the RF power supply outputting pulse signal 1 is counted. When the counted duration reaches the preset duration of pulse signal 1, it is confirmed that the output of pulse signal 1 is complete. During the period from when the RF power supply starts outputting pulse signal 1 until the counted duration reaches the preset duration, pulse signal 1 is the pulse signal currently provided by the RF power supply. After the output of pulse signal 1 is completed, the output of pulse signal 2 is monitored according to the aforementioned method. During the output of pulse signal 2, pulse signal 2 is the pulse signal currently provided by the RF power supply. Of course, the above process can also be achieved based on the preset number of pulses for each pulse signal. That is, in any operating cycle, the RF power supply first outputs pulse signal 1. Based on this, the number of pulses of the RF power supply outputting pulse signal 1 is counted. When the pulse count reaches the preset number of pulses for pulse signal 1, it is confirmed that the output of pulse signal 1 is complete. During the time period from when the RF power supply starts outputting pulse signal 1 until the pulse count reaches the preset number of pulses, pulse signal 1 is the pulse signal currently provided by the RF power supply. And so on, which will not be repeated here.

[0082] For scenarios where the RF power supply outputs a single pulse signal in any operating cycle, the aforementioned identification process can be omitted.

[0083] In summary, compared with the protection circuits built based on electronic components in the prior art, the control method for the RF power supply provided in this application provides a software protection mechanism for the RF power supply. The execution process is not easily affected by factors such as ambient temperature and electromagnetic interference, and the protection mechanism is more reliable, which can effectively ensure the safety of the RF power supply during operation.

[0084] By setting the bus voltage threshold, the DC voltage output of the DC power supply in the RF power supply can be limited, ensuring that the DC voltage provided by the DC power supply does not exceed the maximum withstand voltage of the switching transistor in the power amplifier circuit. This effectively ensures the safe operation of the power amplifier circuit and improves the overall operational safety of the RF power supply.

[0085] The following describes the specific implementation of the first control method provided in this application. The specific process of adjusting the bus voltage output to the RF power supply based on the forward power feedback value, reflected power feedback value, dissipated power feedback value and bus voltage threshold of the current RF power supply may include the following steps.

[0086] First, obtain the forward power setting value, reflected power threshold, dissipated power threshold, forward power feedback value, reflected power feedback value, and dissipated power feedback value corresponding to the pulse signal output by the current RF power supply.

[0087] Specifically, the forward power setting is mainly used to configure the RF power provided during the output pulse signal of the RF power supply, which is also the RF power required by the user. As mentioned earlier, in practical applications, the forward power setting is different for different pulse signals output by the RF power supply. The reflected power threshold corresponds to the maximum allowed reflected power of the RF power supply. When the reflected power exceeds the reflected power threshold, the RF power supply may cause thermal damage to the matching circuit of the semiconductor process equipment and RF cables due to excessive reflected power. Correspondingly, the dissipation power threshold corresponds to the maximum allowed dissipation power of the RF power supply. When the dissipation power exceeds the reflected power threshold, the RF power supply may cause thermal breakdown due to excessive dissipation power. In practical applications, the reflected power threshold and dissipation power threshold need to be set in combination with the performance parameters of the RF power supply, the specific conditions of the power supply load, and the control requirements. This application does not limit the specific values ​​of the reflected power threshold and dissipation power threshold.

[0088] Similar to the forward power setting, the reflected power threshold and dissipated power threshold of the RF power supply are also different when outputting different pulse signals. In practical applications, it is necessary to obtain the forward power setting, reflected power threshold, and dissipated power threshold corresponding to the pulse signal currently output by the RF power supply. Furthermore, the forward power setting, reflected power threshold, and dissipated power threshold can all be provided by a host computer or slave computer connected to the RF power supply for controlling its operation. This application does not limit the specific configuration method of the forward power setting, reflected power threshold, and dissipated power threshold; specific implementations can be found in relevant technologies, which will not be detailed here.

[0089] In one implementation, the RF power supply is equipped with a sampling circuit. The input terminal of the sampling circuit is connected to the output terminal of the power amplifier circuit in the RF power supply. The sampling circuit can collect the forward power and reflected power during the operation of the RF power supply. After the obtained forward power and reflected power are processed by signal processing operations such as frequency calibration, they are output as forward power feedback value and reflected power feedback value. The electronic device executing this method is connected to the output terminal of the sampling circuit, and the forward power feedback value and reflected power feedback value of the corresponding pulse signal can be obtained.

[0090] In some embodiments, the duration of the RF power supply output pulse signal can be counted. If the counted duration does not reach the preset duration corresponding to the pulse signal, multiple forward power feedback values ​​and reflected power feedback values ​​provided by the sampling circuit are collected according to a preset sampling period. Then, the average value of each forward power feedback value is calculated, and the obtained average forward power is used as the final forward power feedback value. Correspondingly, the average value of each reflected power feedback value is calculated, and the obtained average reflected power is used as the final reflected power feedback value.

[0091] The dissipated power feedback value needs to be calculated. As one implementation method, it is based on the principle of energy conservation: the DC input power of the RF power supply is equal to the sum of its forward output power, reflected power, and internal dissipated power. The specific calculation steps are as follows: First, obtain the current bus voltage of the DC power supply in the RF power supply and the target bus current used to calculate the dissipated power. Calculate the product of the current bus voltage and the target bus current to obtain the first power value (i.e., DC input power). Based on the first power value, the forward power feedback value, and the reflected power feedback value, determine the dissipated power feedback value. Specifically, subtract the forward power feedback value from the first power value, and sum the difference with the reflected power feedback value to obtain the dissipated power feedback value.

[0092] When the RF power supply provides multiple pulse signals, the RF power corresponding to different output pulse signals is different, and the generated dissipation power will naturally be different as well. Based on this, as an implementation method, this embodiment provides a method for determining the target bus current, which can be implemented using the process steps shown in Figure 4.

[0093] S1001: Obtain the current bus current of the DC power supply and the target bus current of the previous cycle.

[0094] It should be noted that the previous cycle mentioned in this embodiment refers to the previous protection cycle in which this method was executed, and the current bus current refers to the bus current of the DC power supply during the current pulse signal output by the DC power supply.

[0095] S1002. Determine whether the current bus current is greater than the target bus current of the previous cycle. If yes, execute S1003; otherwise, execute S1004.

[0096] S1003. Determine the current bus current as the target bus current for the current cycle.

[0097] If the current bus current is greater than the target bus current of the previous cycle, then the current bus current is determined to be the target bus current of the current cycle.

[0098] S1004. Determine the target bus current of the previous cycle as the target bus current of the current cycle.

[0099] If the current bus current is less than or equal to the target bus current of the previous cycle, then the target bus current of the previous cycle will be used as the target bus current of the current cycle.

[0100] As can be seen from the above process, the target bus current determination method provided in the above embodiment takes the largest bus current in each protection cycle as the target bus current. With this setting, the maximum dissipation power feedback value can be calculated. This setting can ensure the effective triggering of the dissipation power protection mechanism, and for radio frequency power supplies, it corresponds to a larger safety margin.

[0101] In another implementation, the average value of the bus current in each protection cycle can be used as the target bus current for the current cycle, which is also feasible. Of course, other methods can also be used to determine the target bus current, which are also within the scope of protection of this application as long as they do not exceed the scope of the present application.

[0102] Based on the above, the forward power control amount can be determined by the forward power deviation between the forward power setpoint and the forward power feedback value; the reflection power control amount can be determined by the reflection power deviation between the reflection power threshold and the reflection power feedback value; and the dissipation power control amount can be determined by the dissipation power deviation between the dissipation power threshold and the dissipation power feedback value. The specific calculation process for the forward power control amount, reflection power control amount, and dissipation power control amount will be elaborated in subsequent sections and will not be detailed here.

[0103] It should be noted that the forward power control quantity, reflection power control quantity, and dissipation power control quantity mentioned in this embodiment are essentially pure numerical values ​​without any physical quantity units. Their functions will vary depending on the specific application scenario. In this application, each control quantity can be used to adjust the operation of the RF power supply. The specific adjustment process will be elaborated in the following content and will not be described in detail here.

[0104] Furthermore, the control method provided in this application also requires obtaining the bus voltage threshold.

[0105] In one possible implementation, the bus voltage threshold can be determined based on the change in the ratio between the aforementioned reflected power feedback value and the forward power feedback value. That is, firstly, the current proportional coefficient is determined based on the ratio of the reflected power feedback value to the forward power feedback value, and then the bus voltage threshold is determined based on the obtained current proportional coefficient and the pre-determined correspondence between the bus voltage threshold and the proportional coefficient.

[0106] Specifically, referring to Figure 5, as an optional implementation, when the proportional coefficient is less than or equal to the first threshold VSWR1, the bus voltage threshold corresponding to the obtained proportional coefficient is the first voltage value (corresponding to curve L1); when the obtained proportional coefficient is greater than or equal to the second threshold VSWR2, the bus voltage threshold corresponding to the obtained proportional coefficient is the second voltage value (corresponding to curve L3); when the obtained proportional coefficient is greater than the first threshold VSWR1 and less than the second threshold VSWR2, the obtained proportional coefficient is inversely proportional to the bus voltage threshold (corresponding to curve L2), wherein the second threshold is greater than the first threshold.

[0107] In one possible implementation, the correspondence shown in Figure 5 can be determined in the following way.

[0108] First, multiple sample coefficients are selected between the first and second thresholds. For each sample coefficient, the forward power feedback value, the reflected power feedback value, and the bus voltage threshold acting on the RF power supply are obtained under that sample coefficient condition. This sample coefficient is the sample point of the aforementioned proportionality coefficient.

[0109] For each sample coefficient, the power ratio corresponding to each sample coefficient can be calculated according to formula (1), that is, the sample coefficient.

[0110] Where KX represents the sample coefficient;

[0111] Rx represents the reflected power feedback value corresponding to KX;

[0112] Fx represents the forward power feedback value corresponding to KX.

[0113] Furthermore, based on the data obtained above, the correspondence between each sample coefficient and the bus voltage threshold of the RF power supply is fitted, and the correspondence between the bus voltage threshold of the RF power supply and the sample coefficients can be obtained as shown in formula (2): AgcOut=A1*(A2-K X ×A2) (2)

[0114] Where AgcOut represents the bus voltage threshold, and A2 and A1 are both fitting coefficients.

[0115] It is understandable that the formula (2) is the one mentioned above used to record the correspondence between different sample coefficients and bus voltage thresholds.

[0116] The first threshold VSWR1 represents the ratio between the reflected power feedback value and the forward power feedback value when reflection protection is triggered. In other words, VSWR1 is the trigger point for reflection power protection; when the ratio of reflected power to forward power reaches this threshold, the control system activates the reflection protection mechanism. The second threshold VSWR2 represents the ratio between the reflected power feedback value and the forward power feedback value when the power amplifier tube fails during testing. VSWR2 is an experimentally determined critical safety boundary for the power amplifier tube nearing failure, and this value is higher than the first threshold VSWR1.

[0117] It should be noted that the above-mentioned bus voltage threshold can be understood as being determined based on a piecewise function. In practical applications, it can also be determined using a quadratic function or other forms, which will not be listed here. As long as it does not exceed the core idea of ​​this application, it also falls within the scope of protection of this application.

[0118] Having completed the aforementioned steps, the forward power control quantity, reflected power control quantity, dissipated power control quantity, and bus voltage threshold of the current RF power supply have been obtained. Based on this, this application further determines the aforementioned first target control quantity according to the obtained forward power control quantity, reflected power control quantity, dissipated power control quantity, and bus voltage threshold.

[0119] In some embodiments, this application determines the minimum value among the forward power control quantity, reflected power control quantity, dissipated power control quantity, and bus voltage threshold as the first target control quantity. This means the control method provided in this embodiment offers a four-dimensional protection mechanism: a forward power protection mechanism, a reflected power protection mechanism, a dissipated power protection mechanism, and an overvoltage protection mechanism. The forward power protection mechanism, reflected power protection mechanism, and dissipated power protection mechanism have mutually restrictive control relationships.

[0120] As shown in Figure 6, in practical applications, the forward power protection mechanism, the reflected power protection mechanism, and the dissipated power protection mechanism should meet the following control rules: when both the reflected power and the dissipated power are normal, only the forward power mechanism is effective, controlling the RF power supply to output RF power according to the forward power setting value.

[0121] To achieve the above objectives, the following conditions must be met: when the reflected power feedback value is less than the reflected power threshold, the reflected power control amount is greater than the forward power control amount; when the reflected power feedback value is greater than or equal to the reflected power threshold, the reflected power control amount is less than the forward power control amount.

[0122] Correspondingly, when the dissipated power feedback value is less than the dissipated power threshold, the dissipated power control quantity is greater than the forward power control quantity; when the dissipated power feedback value is greater than or equal to the dissipated power threshold, the dissipated power control quantity is less than the forward power control quantity.

[0123] Based on the above, the smallest of the three control values ​​should be used as the control value for further comparison with the bus voltage threshold. Therefore, if the reflected power feedback value is less than the reflected power threshold and the dissipated power feedback value is less than the dissipated power threshold, both the reflected power control value and the dissipated power control value are greater than the forward power control value, ensuring that the forward power control value is used as the control value for further comparison with the bus voltage threshold. Correspondingly, in the protection triggering scenario, the reflected power control value or the dissipated power control value is output to reduce the RF power at the RF power supply end and restore normal operation as soon as possible. Taking the reflected power protection mechanism as an example, when the reflected power feedback value is greater than the reflected power threshold, the reflected power control value is less than the dissipated power control value and the forward power control value, ensuring that the reflected power control value can be output as the control value for comparison with the bus voltage threshold, thereby providing reflected power abnormality protection when the voltage is normal.

[0124] After determining the first target control value, the bus voltage output to the RF power supply is further adjusted according to the first target control value, while maintaining the bias voltage of the RF power supply unchanged.

[0125] In some embodiments, the bus voltage regulation process can be achieved by referring to the following formula (3). Out=(A3×,V bus ) 2 / 65535 (3)

[0126] Where A3 represents the bus voltage V bus The conversion factor between A3 and the first target control quantity Out can be obtained by fitting specific circuit parameters and experimental data in practical applications. This application does not limit the specific value of A3. 65535 is a constant in the conversion process, which can be regarded as the full-scale value corresponding to the maximum DC voltage that the DC power supply can output. Of course, the specific value of A3 mentioned above is also related to this full-scale value, and can be determined by combining relevant technologies, which will not be detailed here.

[0127] Formula (3) limits Out and V bus The mapping relationship between them, after determining the first target control quantity through the aforementioned steps, allows the corresponding bus voltage to be calculated according to formula (3), and the bus voltage of the RF power supply to be further adjusted according to the obtained result. As mentioned above, in this scenario, the bias voltage of the DC power supply is kept constant.

[0128] In practical applications, considering that the execution cycle of the bus voltage control method is longer than that of the bias voltage control method, and that the bus voltage control method has higher linearity in the adjustment process under higher RF power than the bias voltage control method, the first control method is preferred when the pulse signal with the largest forward power setting is output, while the second control method is used when other pulse signals are output.

[0129] The following describes the specific implementation of the second control method provided in this application. The specific process of adjusting the bias voltage of the RF power supply according to the forward power and reflected power of the RF power supply in the second control method may include the following steps.

[0130] First, the forward power setpoint, reflected power threshold, forward power feedback value, and reflected power feedback value of the RF power supply are obtained. Then, based on the forward power deviation between the forward power setpoint and the forward power feedback value, the forward power control quantity is determined. Finally, based on the reflected power deviation between the reflected power threshold and the reflected power feedback value, the reflected power control quantity is determined. The specific implementation process of this step can be referred to the relevant content of the foregoing embodiments, and will not be repeated here.

[0131] Furthermore, the smallest control value among the forward power control value and the reflected power control value is selected as the second target control value. It is understandable that when the RF power supply provides at least two pulse signals, it will frequently switch the output pulse signals. Since the dissipation power feedback value needs to be calculated based on the current bus voltage, target bus current, forward power feedback value, and reflected power feedback value, and the sampling period for DC voltage and DC current is relatively long, determining the dissipation power takes a considerable amount of time. If the dissipation power control value is calculated for each output pulse signal, it will consume a significant amount of time and may even cause system malfunctions. Moreover, if the dissipation power of the pulse signal with the largest forward power setting does not cause RF power supply abnormalities, other pulse signals are unlikely to cause RF power supply abnormalities.

[0132] After determining the second target control quantity, the bias voltage of the RF power supply can be adjusted according to the second target control quantity. In practical applications, the mapping relationship between the bias voltage and the second target control quantity is similar to that in formula (3). After determining the second target control quantity, the bias voltage of the RF power supply can be adjusted in a similar manner. As for the specific adjustment process, it can be implemented by referring to relevant technologies, which will not be detailed here.

[0133] In some embodiments, the forward power control amount, the reflected power control amount, and the dissipated power control amount can be determined using the following methods.

[0134] The control methods for the radio frequency power supply provided in the foregoing embodiments all involve the process of determining the forward power control quantity, the reflected power control quantity, and the dissipated power control quantity. These three control quantities can be calculated based on the core idea of ​​the PID algorithm. The following describes several methods provided in this application for calculating each control quantity based on the core idea of ​​the PID algorithm.

[0135] Referring to Figure 7, the control quantity calculation method provided in this embodiment includes the following steps.

[0136] S300. Based on the deviation between the threshold of the target parameter and the feedback value, obtain the control increment corresponding to the target parameter.

[0137] As mentioned above, the three parameters—forward power control, reflected power control, and dissipated power control—can be obtained using the same calculation algorithm. Accordingly, the target parameter mentioned in this embodiment can be any one of forward power, reflected power, and dissipated power. Correspondingly, the threshold of forward power is the forward power threshold mentioned in the aforementioned embodiment, the feedback value of forward power is the forward power feedback value, the threshold of reflected power is the reflected power threshold mentioned in the aforementioned embodiment, the feedback value of reflected power is the reflected power feedback value, the threshold of dissipated power is the dissipated power threshold mentioned in the aforementioned embodiment, and the feedback value of dissipated power is the dissipated power feedback value.

[0138] Based on the above, the control increment corresponding to the parameter is obtained by calculating the deviation between the target parameter threshold and the feedback value. Taking forward power as an example, the deviation between the forward power threshold and the forward power feedback value is calculated to obtain the forward power deviation. Then, the control increment corresponding to the forward power can be determined using the forward power deviation as input. The specific implementation of determining the control increment based on the forward power deviation can be found in the relevant content of the PID algorithm, and will not be detailed here.

[0139] S310. Determine the sum of the control increment and the target control quantity of the previous cycle, which is the current control quantity of the target parameter.

[0140] Taking forward power as the target parameter as an example, after obtaining the control increment of forward power in the current cycle, the sum of the control increment of the current cycle and the smallest control quantity among the multiple control quantities determined in the previous cycle, i.e. the target control quantity, is calculated. The result is used as the control quantity of forward power in the current cycle, i.e., the forward power control quantity.

[0141] As can be seen from the above, when the forward power, reflected power, and dissipated power are all calculated according to the above algorithm, if the reflected power and dissipated power do not exceed their respective thresholds, the control quantities of each parameter will ultimately achieve the effect shown in Figure 6. Here, curve S1 represents the reflected power control quantity, S2 represents the dissipated power control quantity, and S3 represents the forward power control quantity. Specifically, according to the basic principle of the PID algorithm, when neither the reflected power nor the dissipated power reaches the corresponding power threshold, the reflected power control quantity and the dissipated power control quantity will continuously accumulate, and the corresponding control quantities will continue to increase. However, since the PID algorithm requires setting a maximum calculated value for its output during application to avoid the PID algorithm's calculation result increasing indefinitely, the final target control quantity output to the DC power supply will not exceed the maximum calculated value. Therefore, it can also be understood that the reflected power control quantity and the dissipated power control quantity will stabilize after reaching their maximum calculated value and will no longer increase. After a certain period of closed-loop control, the forward power control value gradually stabilizes near the forward power setpoint. At this point, the forward power control value also stabilizes synchronously, causing the entire RF power supply output to enter a stable state. Under these circumstances, the forward power control value will not accumulate further, and therefore will be much smaller than the dissipation power control value and the reflection power control value, thus ensuring that the forward power control value can be used as the target control value to control the DC power supply output. As shown in Figure 8, the forward power setpoint is smaller than the aforementioned maximum calculated value.

[0142] Therefore, the control quantity calculation method provided in this embodiment can meet the relevant rules mentioned in the foregoing embodiment, namely: when the reflected power feedback value is less than the reflected power threshold, the reflected power control quantity is greater than the forward power control quantity; correspondingly, when the dissipated power feedback value is less than the dissipated power threshold, the dissipated power control quantity is greater than the forward power control quantity.

[0143] According to the basic principle of PID algorithm, when the reflected power feedback value is greater than or equal to the reflected power threshold, the reflected power control quantity will become smaller, and thus smaller than the forward power control quantity. Correspondingly, when the dissipated power feedback value is greater than or equal to the dissipated power threshold, the dissipated power control quantity will also be smaller than the forward power control quantity.

[0144] According to the control quantity calculation method provided in this embodiment, the control quantity of each parameter in the current cycle is calculated based on the target control quantity of forward power control quantity, reflected power control quantity, and dissipated power control quantity in the previous cycle. This can more quickly reduce the RF power of the RF power supply in the event of abnormal reflected power or abnormal dissipated power, avoid RF power supply overload, and effectively improve protection efficiency and RF power supply safety.

[0145] The following section uses power dissipation protection as an example to explain the principle behind this method's ability to quickly provide protection.

[0146] First, obtain the dissipated power threshold, current bus voltage, target bus current, forward power feedback value, and reflected power feedback value, and calculate the dissipated power feedback value according to the aforementioned calculation method. Further, calculate the dissipated power deviation between the dissipated power threshold and the dissipated power feedback value, and determine the control increment corresponding to the dissipated power based on the obtained dissipated power deviation. Further, take the minimum value among the dissipated power control quantity, forward power control quantity, and reflected power control quantity of the previous cycle, i.e., the target control quantity, as the control quantity of dissipated power in the previous cycle, and calculate the sum of the dissipated power control increment and the target control quantity to obtain the control quantity corresponding to the dissipated power in the current cycle. The calculation process for the forward power control quantity and reflected power control quantity is similar and will not be detailed further. Determine the target control quantity for the current cycle based on the obtained forward power control quantity, dissipated power control quantity, and reflected power control quantity (which should also include the bus voltage threshold if one is provided). Finally, adjust the DC voltage of the DC power supply and adjust the RF power of the RF power supply according to the obtained target control quantity.

[0147] Based on the above, assuming that the reflected power and dissipated power were normal in the previous cycle, the forward power control was used to control the RF power output, and the resulting forward power control was 1000. The dissipated power control and reflected power control both reached their maximum values, such as 3000. Therefore, the final control value in this cycle is 1000.

[0148] If the dissipated power suddenly increases within the current cycle, exceeding the dissipated power threshold, the dissipated power protection mechanism needs to be executed immediately. This means that the dissipated power control quantity is output as the minimum target control quantity. Assuming that the dissipated power increment calculated in the current cycle is -200, according to the calculation method of relevant technologies, the sum of the dissipated power control quantity calculated in the previous cycle and the control quantity increment of the current cycle is used as the dissipated power control quantity of the current cycle, i.e., 3000 + (-200) = 2800. Obviously, the obtained dissipated power control quantity is still too large to be used as the target control quantity output. Even if it is used as the target control quantity output, it is still difficult to effectively reduce the DC voltage and the corresponding RF power due to the large control quantity value.

[0149] Compared to the above calculation method, this method calculates the sum of the dissipation power control increment and the target control quantity determined in the previous cycle, which is used as the dissipation power control quantity for the current cycle. Following the previous example, this is (-200) + 1000 = 800. Clearly, the method provided in this application can rapidly reduce the dissipation power control quantity, thereby using it as the target control quantity to reduce the DC power supply voltage and control the RF power within a safe range. The triggering process of the reflected power protection mechanism is similar and will not be detailed further.

[0150] Based on the same idea, as shown in Figure 8, this embodiment provides another method for calculating control quantities, which includes the following steps.

[0151] S400. Based on the deviation between the threshold of the target parameter and the feedback value, the control increment is obtained.

[0152] In some embodiments, S400 can be implemented with reference to the relevant content of S300 in the embodiment shown in FIG7, which will not be repeated here.

[0153] S410. Determine the sum of the control increment and the preset baseline control quantity corresponding to the target parameter, which is the current control quantity of the target parameter.

[0154] Compared to the previous embodiment where the control quantity of the current cycle is determined based on the control quantity increment and the target control quantity of the previous cycle, this embodiment provides a preset reference control quantity for the target parameter. It is understood that in order to achieve the goal of quickly reducing the target parameter control quantity, the value of the preset reference control quantity should not be too large. In practical applications, the preset reference control quantity can be determined based on the control quantity corresponding to the safe operation state of the RF power supply, as long as it is less than the control quantity corresponding to the safe operation state of the RF power supply.

[0155] The process of controlling the operation of the radio frequency power supply and providing abnormal reflection power protection and abnormal dissipation power protection according to the method provided in this embodiment can be implemented with reference to the relevant content of the foregoing embodiments, and will not be repeated here.

[0156] Based on the execution process of the RF power supply control methods provided in the above embodiments, it can be seen that the calculation of forward power control, reflected power control, and dissipated power control is performed according to a preset cycle, not in real time. Furthermore, according to the operating characteristics of the DC power supply (slow voltage regulation response speed), the adjustment process of the bus voltage and bias voltage is also performed according to a preset cycle. Therefore, for any of the above embodiments, when regulating the DC power supply bus voltage, the calculation cycle of the reflected power control and forward power control should be consistent with the bus voltage adjustment cycle. Correspondingly, when regulating the DC power supply bias voltage, the calculation cycle of the reflected power control and forward power control should be consistent with the bias voltage adjustment cycle. Because the acquisition cycle of the bus voltage and DC current involved in the calculation of the dissipated power control is relatively long (again, because the process of the DC power supply adjusting the bus voltage and DC current is relatively long), the calculation cycle of the dissipated power control is longer than the calculation cycles of the reflected power control and forward power control in the above two cases. In practical applications, the calculation cycles for forward power control, reflected power control, and dissipated power control can be set by considering the above factors and the performance of the DC power supply.

[0157] It is understood that the RF power supply control method provided in the above embodiments of this application is implemented based on software algorithms. Compared with the hardware protection circuit implemented based on electronic components in related technologies, it is less susceptible to electromagnetic field fluctuations and ambient temperature changes. Furthermore, the relevant parameters involved in the execution of the method can be changed at any time by the host computer, thus making it applicable to different RF power supplies with a wider range of applications and greater flexibility.

[0158] The following describes the control device for the radio frequency power supply provided by this invention. This control device belongs to the same concept as the control method for the radio frequency power supply provided in the embodiments of this application, and can execute the control method for the radio frequency power supply provided in any embodiment of this application. It possesses the corresponding functional modules and beneficial effects for executing the control method for the radio frequency power supply. Technical details not described in detail in this embodiment can be found in the control method for the radio frequency power supply provided in the embodiments of this application, and will not be repeated here.

[0159] Referring to Figure 9, the control device for the radio frequency power supply provided in this embodiment includes a main control unit 10, wherein the main control unit 10 is connected to the DC power supply 20 in the radio frequency power supply, and the DC power supply 20 is connected to the power amplifier circuit 30. The main control unit 10 adopts the control method provided in this application to control the bus voltage and bias voltage provided by the DC power supply 20 to the power amplifier circuit 30.

[0160] Specifically, the main control unit 10 is used to control at least one of the pulse signals according to a first control method in each working cycle.

[0161] First control method: Adjust the bus voltage output to the RF power supply according to the current forward power feedback value, reflected power feedback value, dissipated power feedback value and bus voltage threshold of the RF power supply, and keep the bias voltage output to the RF power supply unchanged.

[0162] Furthermore, when the RF power supply provides at least two pulse signals in each working cycle, the main control unit 10 is also used to control the pulse signal with the largest forward power setting value according to the first control method, and control the other pulse signals except for the pulse signal with the largest forward power setting value according to the second control method.

[0163] The second control method is to adjust the bias voltage output to the RF power supply based on the current forward power feedback value and reflected power feedback value of the RF power supply, and keep the bus voltage of the RF power supply constant.

[0164] Furthermore, referring to Figure 10, this application provides another control device for an RF power supply. Based on the embodiment shown in Figure 9, the main control unit 10 provided in this embodiment specifically includes:

[0165] The forward power control calculation unit 110 is used to obtain the forward power setting value and forward power feedback value of the current RF power supply, and determine the forward power control amount based on the forward power deviation between the forward power setting value and the forward power feedback value.

[0166] The reflection power control calculation unit 120 is used to obtain the reflection power threshold and reflection power feedback value of the current RF power supply, and to determine the reflection power control quantity based on the reflection power deviation between the reflection power threshold and the reflection power feedback value.

[0167] The power dissipation control calculation unit 130 is used to obtain the current power dissipation threshold and power dissipation feedback value of the RF power supply, and determine the power dissipation control amount based on the power dissipation deviation between the power dissipation threshold and the power dissipation feedback value.

[0168] The power dissipation calculation unit 140 is used to calculate the current power dissipation feedback value of the RF power supply and provide this power dissipation control quantity calculation unit 130. It is understood that the RF power supply also includes a sampling circuit 40 for acquiring and feeding back the relevant parameters shown in Figure 10.

[0169] The bus voltage threshold determination unit 150 is used to determine the current bus voltage threshold of the RF power supply.

[0170] Comparison unit 160 is used to determine a first target control quantity based on forward power control quantity, reflected power control quantity, dissipated power control quantity and bus voltage threshold.

[0171] Control unit 170 is used to adjust the bus voltage output to the radio frequency power supply according to the first target control quantity.

[0172] Furthermore, the comparison unit 160 is also used to determine the smallest control quantity among the forward power control quantity and the reflected power control quantity as the second target control quantity.

[0173] The control unit 170 is also used to adjust the bias voltage of the radio frequency power supply according to the second target control quantity.

[0174] The following describes in detail the specific process of the RF power supply outputting the pulse signal shown in Figure 11, using the control device provided in the embodiment shown in Figure 10 as an example. Referring to Figure 11, in any operating cycle, the RF power supply needs to provide two pulse signals, namely pulse signal 1 and pulse signal 2. The forward power setting value of pulse signal 1 is greater than the forward power setting value of pulse signal 2. Based on this, this application controls the RF power supply to output pulse signal 1 according to a first control method and controls the RF power supply to output pulse signal 2 according to a second control method.

[0175] During the output of pulse signal 1, the specific execution process is as follows:

[0176] The forward power control calculation unit 110 acquires the forward power set value of the pulse signal 1 and the forward power feedback value fed back by the sampling circuit 40, and determines the forward power control amount of the pulse signal 1 based on the forward power deviation between the forward power set value and the forward power feedback value.

[0177] The reflection power control calculation unit 120 obtains the reflection power threshold and reflection power feedback value of the pulse signal 1, and determines the reflection power control amount of the pulse signal 1 based on the reflection power deviation between the reflection power threshold and the reflection power feedback value.

[0178] The power dissipation calculation unit 140 collects the DC voltage and DC current of the DC power supply 20. At the same time, it collects the forward power feedback value and reflected power feedback value of the pulse signal 1 through the sampling circuit 40. Based on the obtained parameters, it calculates the power dissipation feedback value corresponding to the pulse signal 1 and finally outputs the obtained power dissipation feedback value to the power dissipation control quantity calculation unit 130.

[0179] The power dissipation control calculation unit 130 obtains the power dissipation threshold and power dissipation feedback value of the pulse signal 1, and determines the power dissipation control amount of the pulse signal 1 based on the power dissipation deviation between the obtained power dissipation threshold and the power dissipation feedback value.

[0180] The bus voltage threshold determination unit 150 determines the bus voltage threshold corresponding to pulse signal 1.

[0181] The comparison unit 160 takes the smallest value among the forward power control quantity, reflected power control quantity, dissipated power control quantity and bus voltage threshold provided by the aforementioned related units as the first target control quantity and outputs it to the control unit 170.

[0182] The control unit 170 adjusts the bus voltage output to the RF power supply according to the first target control quantity, and maintains the bias voltage of the RF power supply unchanged.

[0183] The power amplifier circuit 30 outputs a pulse signal 1 based on the obtained drive signal and the DC voltage provided by the DC power supply 20.

[0184] The specific execution process during the output pulse signal 2 is as follows:

[0185] The forward power control calculation unit 110 acquires the forward power set value of the pulse signal 2 and the forward power feedback value fed back by the sampling circuit 40, and determines the forward power control amount of the pulse signal 2 based on the forward power deviation between the forward power set value and the forward power feedback value.

[0186] The reflection power control calculation unit 120 obtains the reflection power threshold and reflection power feedback value of the pulse signal 2, and determines the reflection power control amount of the pulse signal 2 based on the reflection power deviation between the reflection power threshold and the reflection power feedback value.

[0187] The comparison unit 160 takes the smallest value among the forward power control quantity and the reflection power control quantity provided by the aforementioned related units as the second target control quantity and outputs it to the control unit 170.

[0188] The control unit 170 adjusts the bias voltage output to the RF power supply according to the second target control quantity, and maintains the bus voltage of the RF power supply unchanged.

[0189] The power amplifier circuit 30 outputs a pulse signal 2 based on the obtained drive signal and the DC voltage provided by the DC power supply 20.

[0190] It should be noted that, assuming pulse signal 1 is output before pulse signal 2, when controlling the RF power supply to output pulse signal 2, the bus voltage is kept constant. At this time, the specific value of the bus voltage can be the bus voltage value of the RF power supply during the output of pulse signal 1. Correspondingly, assuming pulse signal 2 is output before pulse signal 1, the bus voltage when outputting pulse signal 2 can be the bus voltage value in the previous control cycle.

[0191] This application also provides an RF power supply, as shown in Figure 12. The RF power supply provided in this application includes a main controller 50, a DC power supply 20, a power amplifier circuit 30, and a sampling circuit 40.

[0192] As shown in Figure 12, the control terminal of the power amplifier circuit 30 receives the drive signal, the DC power supply 20 provides DC voltage to the power amplifier circuit 30, and the power amplifier circuit 30 converts the DC voltage into a pulse signal output according to the duty cycle corresponding to the pulse drive signal.

[0193] The sampling circuit 40 is connected to the output of the power amplifier circuit 30. It can collect the forward power and reflected power of the RF power supply. After signal processing operations such as frequency calibration, it provides the reflected power feedback value and forward power feedback value to the main controller 50.

[0194] The main controller 50 is connected to the DC power supply 20 and the sampling circuit 40 respectively. Based on the reflected power feedback value and forward power feedback value provided by the sampling circuit 40, the main controller 50 will also obtain the bus voltage and DC current of the DC power supply 20.

[0195] The main controller 50 is used to execute the RF power supply control method provided in any of the above embodiments.

[0196] Furthermore, this application also provides a semiconductor process apparatus, which includes a process chamber and at least one radio frequency power supply as provided in the foregoing embodiments. The radio frequency power supply is used to provide radio frequency power to the process chamber to excite the process gas in the process chamber to generate plasma.

[0197] The semiconductor process equipment in this application embodiment can be either an inductively coupled plasma (ICP) device or a capacitively coupled plasma (CCP) device. This application embodiment does not limit the type of semiconductor process equipment.

[0198] In some embodiments, this embodiment also provides a computer-readable storage medium, such as a floppy disk, optical disk, hard disk, flash memory, USB flash drive, SD (Secure Digital Memory Card), MMC (Multimedia Card), etc., in which one or more instructions for implementing the above steps are stored. When these one or more instructions are executed by one or more processors, the processors execute the radio frequency power supply control method described above. For specific implementation details, please refer to the foregoing description; further elaboration is not provided here.

[0199] In addition to the methods and devices described above, embodiments of this application may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps in the radio frequency power supply control methods according to various embodiments of this application as described above.

[0200] Computer program products can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this application. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0201] Those skilled in the art will understand that the contents disclosed herein can be varied and modified in many ways. For example, the various devices or components described above can be implemented in hardware, or in software, firmware, or a combination of some or all of the three.

[0202] Furthermore, while this disclosure makes various references to certain elements of systems according to embodiments of this disclosure, any number of different elements may be used and operated on clients and / or servers. Elements are merely illustrative, and different aspects of the system and method may use different elements.

[0203] This disclosure uses flowcharts to illustrate the steps of a method according to embodiments of this disclosure. It should be understood that the preceding or following steps are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes.

[0204] Those skilled in the art will understand that all or part of the steps in the above methods can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium, such as a read-only memory. Optionally, all or part of the steps in the above embodiments can also be implemented using one or more integrated circuits. Accordingly, each module / unit in the above embodiments can be implemented in hardware or as a software functional module. This disclosure is not limited to any particular combination of hardware and software.

[0205] Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that terms such as those defined in a common dictionary should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0206] The foregoing description is intended to illustrate the present disclosure and should not be construed as limiting it. While several exemplary embodiments of the present disclosure have been described, those skilled in the art will readily understand that many modifications may be made to the exemplary embodiments without departing from the novel teachings and advantages of the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure as defined by the claims. It should be understood that the foregoing description is intended to illustrate the present disclosure and should not be construed as limiting it to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the appended claims. The present disclosure is defined by the claims and their equivalents.

Claims

1. A method for controlling an radio frequency power supply, wherein, The radio frequency power supply provides at least one pulse signal in each operating cycle, and the control method includes: Within each of the said working cycles, one of the at least one pulse signal is controlled according to a first control method; The first control method is to adjust the bus voltage output to the RF power supply according to the forward power feedback value, reflected power feedback value, dissipated power feedback value and bus voltage threshold of the current RF power supply, and maintain the bias voltage output to the RF power supply unchanged.

2. The control method according to claim 1, wherein, The radio frequency power supply provides at least two pulse signals in each of the said duty cycles; Among the at least two pulse signals, the pulse signal with the largest forward power setting value is controlled according to the first control method, and the other pulse signals besides the pulse signal with the largest forward power setting value are controlled according to the second control method. The second control method is to adjust the bias voltage output to the RF power supply according to the current forward power feedback value and reflected power feedback value of the RF power supply, and maintain the bus voltage of the RF power supply unchanged.

3. The control method according to claim 1 or 2, wherein, Adjusting the bus voltage output to the RF power supply based on the forward power feedback value, reflected power feedback value, dissipated power feedback value, and bus voltage threshold of the current RF power supply includes: Obtain the current forward power setting value, reflected power threshold, dissipated power threshold, forward power feedback value, reflected power feedback value, dissipated power feedback value, and bus voltage threshold of the RF power supply. The forward power control amount is determined based on the forward power deviation between the forward power setpoint and the forward power feedback value. The reflection power control amount is determined based on the reflection power deviation between the reflection power threshold and the reflection power feedback value; The dissipation power control quantity is determined based on the dissipation power deviation between the dissipation power threshold and the dissipation power feedback value; The first target control quantity is determined based on the forward power control quantity, the reflected power control quantity, the dissipated power control quantity, and the bus voltage threshold. Adjust the bus voltage output to the RF power supply according to the first target control quantity.

4. The control method according to claim 3, wherein, Determining the first target control quantity based on the forward power control quantity, the reflected power control quantity, the dissipated power control quantity, and the bus voltage threshold includes: The smallest value among the forward power control quantity, the reflected power control quantity, the dissipated power control quantity, and the bus voltage threshold is determined as the first target control quantity.

5. The control method according to claim 3 or 4, wherein, Obtaining the bus voltage threshold includes: The current scaling factor is determined based on the ratio of the reflected power feedback value to the forward power feedback value; The bus voltage threshold is determined based on the current proportional coefficient and the pre-determined correspondence between the bus voltage threshold and the proportional coefficient.

6. The control method according to claim 5, wherein, The predetermined correspondence between the bus voltage threshold and the proportional coefficient includes: When the proportional coefficient is less than or equal to the first threshold, the bus voltage threshold corresponding to the proportional coefficient is the first voltage value; When the proportional coefficient is greater than or equal to the second threshold, the bus voltage threshold corresponding to the proportional coefficient is the second voltage value, and the second threshold is greater than the first threshold; When the proportional coefficient is greater than the first threshold and less than the second threshold, the proportional coefficient is inversely proportional to the bus voltage threshold.

7. The control method according to any one of claims 1-6, wherein, Adjusting the bias voltage of the radio frequency power supply based on its forward power and reflected power includes: Obtain the forward power setting value, reflected power threshold, forward power feedback value, and reflected power feedback value of the radio frequency power supply; The forward power control amount is determined based on the forward power deviation between the forward power setpoint and the forward power feedback value. The reflection power control amount is determined based on the reflection power deviation between the reflection power threshold and the reflection power feedback value; The smallest control quantity among the forward power control quantity and the reflected power control quantity is selected as the second target control quantity; Adjust the bias voltage of the RF power supply according to the second target control value.

8. A control device for a radio frequency power supply, wherein, The radio frequency power supply provides at least one pulse signal in each operating cycle, and the control device includes: The main control unit is used to control one of the at least one pulse signals according to a first control method during each working cycle. The first control method is to adjust the bus voltage output to the RF power supply according to the forward power feedback value, reflected power feedback value, dissipated power feedback value and bus voltage threshold of the current RF power supply, and maintain the bias voltage output to the RF power supply unchanged.

9. The control device according to claim 8, wherein, The radio frequency power supply provides at least two pulse signals in each of the said duty cycles; The main control unit is configured to control the pulse signal with the largest forward power setting value among the at least two pulse signals according to the first control method, and control the remaining pulse signals other than the pulse signal with the largest forward power setting value according to the second control method. The second control method is to adjust the bias voltage output to the RF power supply according to the current forward power feedback value and reflected power feedback value of the RF power supply, and maintain the bus voltage of the RF power supply unchanged.

10. The control device for the radio frequency power supply according to claim 8 or 9, wherein, The main control unit includes: a forward power control quantity calculation unit, a reflected power control quantity calculation unit, a dissipated power control quantity calculation unit, a comparison unit, and a control unit, wherein... The forward power control calculation unit is used to obtain the current forward power setting value and forward power feedback value of the RF power supply, and determine the forward power control amount based on the forward power deviation between the forward power setting value and the forward power feedback value. The reflected power control quantity calculation unit is used to obtain the reflected power threshold and reflected power feedback value of the current radio frequency power supply, and determine the reflected power control quantity based on the reflected power deviation between the reflected power threshold and the reflected power feedback value. The power dissipation control calculation unit is used to obtain the current power dissipation threshold and power dissipation feedback value of the radio frequency power supply, and determine the power dissipation control amount based on the power dissipation deviation between the power dissipation threshold and the power dissipation feedback value. The comparison unit is used to determine a first target control quantity based on the forward power control quantity, the reflected power control quantity, the dissipated power control quantity, and the bus voltage threshold. The control unit is used to adjust the bus voltage output to the radio frequency power supply according to the first target control quantity.

11. The control device for the radio frequency power supply according to claim 10, wherein, The comparison unit is further configured to determine the smallest control quantity among the forward power control quantity and the reflected power control quantity as the second target control quantity; The control unit is also configured to adjust the bias voltage of the radio frequency power supply according to the second target control quantity.

12. A radio frequency power supply, wherein, include: The main controller, power amplifier circuit, and sampling circuit are included. The sampling circuit is connected to the power amplifier circuit; The main controller is connected to the power amplifier circuit and the sampling circuit respectively; The main controller is used to execute the control method of the radio frequency power supply as described in any one of claims 1 to 7.

13. A semiconductor process apparatus, wherein, include: The process chamber and at least one radio frequency power supply as described in claim 12, wherein, The radio frequency power supply is used to provide radio frequency power to the process chamber to excite the process gas in the process chamber to generate plasma.

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