Radio-frequency control circuit, radio-frequency power supply and control method therefor, and semiconductor process device

Abstract

The present application provides a radio-frequency control circuit, a method, a radio-frequency power supply, and a semiconductor process device, which are applied in the technical field of semiconductors. The circuit comprises a first control circuit, a second control circuit, a signal conversion circuit, and a direct-current power supply. On the basis of a forward power set value and a forward power feedback value, the first control circuit outputs a first target control quantity and a second target control quantity. On the basis of the first target control quantity, the signal conversion circuit generates a pulse driving signal and outputs the pulse driving signal to a power amplification circuit. On the basis of a control quantity deviation between the first target control quantity and a control quantity threshold, the second control circuit outputs a third target control quantity. On the basis of the third target control quantity, the direct-current power supply adjusts a direct-current voltage signal outputted to the power amplification circuit. The present application provides two radio-frequency power adjustment modes, thereby offering more adjustment modes. The response time for adjusting the duty cycle of the pulse driving signal is much shorter than that for adjusting the direct-current voltage. The coordination of the two adjustment modes can effectively improve the adjustment efficiency of the radio-frequency power supply.

Description

Radio frequency control circuits, radio frequency power supplies and their control methods, semiconductor process equipment Technical Field

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

[0002] 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 the equipment. As semiconductor processes continue to improve and equipment upgrades, the requirements for RF power supply control are becoming increasingly stringent.

[0003] Referring to the RF power supply shown in Figure 1, the main controller outputs a control signal to the signal conversion circuit. The signal conversion circuit converts the control signal into a pulse drive signal and outputs it to the power amplifier circuit. The DC power supply provides a DC voltage to the power amplifier circuit. The power amplifier circuit converts the DC voltage into an RF signal according to the duty cycle of the pulse drive signal, thus completing the RF power output. Furthermore, the main controller configures a power setpoint to the control circuit. The control circuit obtains the forward power feedback value through a sampling circuit. Based on the deviation between the forward power feedback value and the power setpoint, it outputs a voltage control quantity for the DC power supply. This allows the DC power supply to adjust its output DC voltage based on the voltage control quantity, thereby adjusting the RF power output by the power amplifier circuit.

[0004] Existing RF power supplies can only adjust RF power by regulating DC voltage. Due to the long response time of DC power supplies, the efficiency of RF power adjustment is low, making it difficult to meet the application requirements of rapid RF power adjustment in practical applications. Summary of the Invention

[0005] In view of this, this application aims to provide a radio frequency control circuit, a radio frequency power supply and its control method, and a semiconductor process equipment to solve the problem of low radio frequency power regulation efficiency in the prior art.

[0006] In a first aspect, this application provides a radio frequency (RF) control circuit for adjusting the RF power of an RF power supply. The RF control circuit is connected to a power amplifier circuit of the RF power supply and provides a pulse drive signal and a DC voltage signal to the power amplifier circuit, so that the power amplifier circuit generates an RF signal based on the pulse drive signal and the DC voltage signal. The RF control circuit includes: a first control circuit, a second control circuit, a signal conversion circuit, and a DC power supply.

[0007] The first control circuit is used to output a first target control quantity and a second target control quantity based on the forward power setpoint and the forward power feedback value;

[0008] The signal conversion circuit is used to generate a pulse drive signal according to the first target control quantity and output it to the power amplifier circuit.

[0009] The second control circuit is used to receive the second target control quantity and a preset control quantity threshold, and output a third target control quantity according to the second target control quantity and the control quantity threshold;

[0010] The DC power supply is used to adjust the DC voltage signal output to the power amplifier circuit according to the third target control quantity.

[0011] In some embodiments, when the first target control quantity is greater than the control quantity threshold, the signal conversion circuit is used to output a pulse drive signal according to a preset duty cycle; when the first target control quantity is less than the control quantity threshold, the signal conversion circuit is used to output a pulse drive signal according to a duty cycle that is proportional to the first target control quantity.

[0012] The second control circuit is used to output a third target control quantity based on the control quantity deviation between the second target control quantity and the control quantity threshold.

[0013] The DC power supply is used to output a DC voltage signal that is proportional to the deviation of the control quantity according to the third target control quantity.

[0014] In some embodiments, the first control circuit includes: a forward feedback control circuit, a reflected power protection circuit, and a comparator circuit, wherein...

[0015] The forward feedback control circuit is used to receive the forward power setpoint and the forward power feedback value, and output a first control quantity based on the forward power deviation between the forward power setpoint and the forward power feedback value;

[0016] The reflected power protection circuit is used to receive a reflected power threshold and a reflected power feedback value, and output a second control quantity based on the reflected power deviation between the reflected power threshold and the reflected power feedback value;

[0017] The comparison circuit is used to select the control quantity that is smaller between the first control quantity and the second control quantity as the first target control quantity and the second target control quantity.

[0018] In some embodiments, when the reflected power feedback value is less than the reflected power threshold, the second control quantity is greater than the first control quantity;

[0019] When the reflected power feedback value is greater than or equal to the reflected power threshold, the second control quantity is less than the first control quantity.

[0020] In some embodiments, the first control circuit further includes: a power dissipation protection circuit, wherein...

[0021] The power dissipation protection circuit is used to receive the power dissipation threshold and the power dissipation feedback value, and output a third control quantity based on the power dissipation deviation between the power dissipation threshold and the power dissipation feedback value;

[0022] The comparison circuit is used to select the smallest control quantity among the first control quantity, the second control quantity, and the third control quantity as the first target control quantity, and to select the smallest control quantity among the first control quantity and the second control quantity as the second target control quantity.

[0023] In some embodiments, if the power dissipation feedback value is less than the power dissipation threshold, the third control quantity is greater than the first control quantity;

[0024] When the dissipated power feedback value is greater than or equal to the dissipated power threshold, the third control quantity is less than the first control quantity.

[0025] In some embodiments, the first control circuit includes: a forward feedback control circuit, a power dissipation protection circuit, and a comparator circuit, wherein...

[0026] The forward feedback control circuit is used to receive the forward power setpoint and the forward power feedback value, and output a first control quantity based on the forward power setpoint and the forward power feedback value;

[0027] The power dissipation protection circuit is used to receive the power dissipation threshold and the power dissipation feedback value, and output a third control quantity based on the power dissipation deviation between the power dissipation threshold and the power dissipation feedback value;

[0028] The comparison circuit is used to select the control quantity that is smaller between the first control quantity and the third control quantity as the first target control quantity, and to select the first control quantity as the second target control quantity.

[0029] In some embodiments, it further includes: a power dissipation calculation circuit, wherein,

[0030] The power dissipation calculation circuit is used to determine the power dissipation feedback value based on the reflected power feedback value, the forward power feedback value, and the voltage and current values ​​of the DC voltage signal.

[0031] Secondly, this application provides an radio frequency (RF) power supply, comprising: a power amplifier circuit, a sampling circuit, and an RF control circuit as described in any one of the first aspects of this application, wherein...

[0032] The sampling circuit is connected to the power amplifier circuit and the radio frequency control circuit respectively, and is used to collect the forward power feedback value and the reflected power feedback value.

[0033] The radio frequency control circuit is used to receive the forward power feedback value and the reflected power feedback value provided by the sampling circuit, and to generate the pulse drive signal and the DC voltage signal;

[0034] The power amplifier circuit is used to generate a radio frequency signal based on the pulse drive signal and the DC voltage signal.

[0035] Thirdly, this application provides a radio frequency power supply control method, applied to the radio frequency power supply provided in this application, the radio frequency power supply control method comprising:

[0036] Obtain the forward power setpoint, forward power feedback value, and control threshold of the power amplifier circuit;

[0037] Based on the forward power setpoint and the forward power feedback value, a first target control quantity and a second target control quantity are generated;

[0038] A pulse drive signal is generated based on the first target control quantity;

[0039] A third target control quantity is output based on the second target control quantity and the control quantity threshold.

[0040] Adjust the DC voltage signal according to the third target control quantity;

[0041] The power amplifier circuit adjusts the output radio frequency signal according to the DC voltage signal and the pulse drive signal.

[0042] In some embodiments, generating a first target control quantity and a second target control quantity based on the forward power setpoint and the forward power feedback value includes:

[0043] Obtain the reflected power threshold and the reflected power feedback value;

[0044] A first control quantity is generated based on the forward power deviation between the forward power setpoint and the forward power feedback value;

[0045] A second control quantity is generated based on the reflection power deviation between the reflection power threshold and the reflection power feedback value;

[0046] The smaller of the first control quantity and the second control quantity is determined as the first target control quantity and the second target control quantity.

[0047] In some embodiments, generating a first target control quantity and a second target control quantity based on the forward power setpoint and the forward power feedback value includes:

[0048] Obtain the power dissipation threshold, power dissipation feedback value, reflected power threshold, and reflected power feedback value;

[0049] A first control quantity is generated based on the forward power deviation between the forward power setpoint and the forward power feedback value;

[0050] A second control quantity is generated based on the reflection power deviation between the reflection power threshold and the reflection power feedback value;

[0051] A third control quantity is generated based on the power dissipation deviation between the power dissipation threshold and the power dissipation feedback value;

[0052] The smallest of the first control quantity, the second control quantity, and the third control quantity is determined as the first target control quantity;

[0053] Furthermore, the smaller of the first control quantity and the second control quantity is determined as the second target control quantity.

[0054] In some embodiments, generating a first target control quantity and a second target control quantity based on the forward power setpoint and the forward power feedback value includes:

[0055] Obtain the power dissipation threshold and the power dissipation feedback value;

[0056] A first control quantity is generated based on the forward power deviation between the forward power setpoint and the forward power feedback value;

[0057] A third control quantity is generated based on the power dissipation deviation between the power dissipation threshold and the power dissipation feedback value;

[0058] The control quantity that is smaller between the first control quantity and the third control quantity is determined as the first target control quantity, and the first control quantity is determined as the second target control quantity.

[0059] Fourthly, this application provides an radio frequency power supply, including: a radio frequency control circuit, a power amplifier circuit, and a sampling circuit, wherein,

[0060] The radio frequency control circuit includes: a main controller, a signal conversion circuit, and a DC power supply, wherein,

[0061] The sampling circuit is connected to the power amplifier circuit;

[0062] The main controller is connected to the signal conversion circuit, the DC power supply, and the sampling circuit, respectively.

[0063] The main controller is used to execute the radio frequency control method provided in any of the third aspects of this application.

[0064] Fifthly, this application provides a semiconductor process apparatus, comprising: a process chamber and at least one radio frequency power supply provided in the second or fourth aspect of this application, wherein...

[0065] 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.

[0066] Based on the above, the radio frequency (RF) control circuit provided in this application is used to connect to a power amplifier circuit and provide the power amplifier circuit with a pulse drive signal and a DC voltage signal, so that the power amplifier circuit generates an RF signal according to the pulse drive signal and the DC voltage signal. The RF control circuit includes a first control circuit, a second control circuit, a signal conversion circuit, and a DC power supply. The first control circuit outputs a first target control quantity and a second target control quantity based on the forward power setpoint and the forward power feedback value's forward power deviation. The signal conversion circuit generates a pulse drive signal based on the first target control quantity and outputs it to the power amplifier circuit. The second control circuit receives the second target control quantity and a preset control quantity threshold, and outputs a third target control quantity based on the second target control quantity and the control quantity threshold. The DC power supply adjusts the DC voltage signal output to the power amplifier circuit according to the third target control quantity. Compared with the single control method of adjusting the RF power by adjusting the DC voltage in the prior art, this application provides two ways to adjust the RF power: adjusting the duty cycle of the pulse drive signal by adjusting the signal conversion circuit by the first target control quantity, and adjusting the output DC voltage by adjusting the DC power supply by the third target control quantity. The more control methods make the adjustment process of the RF power supply more flexible. Furthermore, the response time of adjusting the duty cycle of the pulse drive signal is much shorter than the response time of adjusting the DC voltage. The combination of the two adjustment methods can shorten the overall response time required to adjust the RF power, effectively improve the adjustment efficiency of the RF power supply, and meet the needs of practical applications. Attached Figure Description

[0067] 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.

[0068] Figure 1 is a block diagram of the radio frequency power supply provided by the prior art.

[0069] Figure 2 is a structural block diagram of a radio frequency control circuit provided in an embodiment of the present invention.

[0070] Figure 3 is a structural block diagram of another radio frequency control circuit provided in an embodiment of the present invention.

[0071] Figure 4 is a structural block diagram of another radio frequency control circuit provided in an embodiment of the present invention.

[0072] Figure 5 is a structural block diagram of another radio frequency control circuit provided in an embodiment of the present invention.

[0073] Figure 6 is a structural block diagram of an RF power supply provided in an embodiment of the present invention.

[0074] Figure 7 is a flowchart of an RF power supply control method provided in an embodiment of the present invention.

[0075] Figure 8 is a flowchart of another radio frequency power supply control method provided by an embodiment of the present invention.

[0076] Figure 9 is a flowchart of another radio frequency power supply control method provided in an embodiment of the present invention.

[0077] Figure 10 is a schematic diagram of the structure of the semiconductor process equipment provided in an embodiment of the present invention. Detailed Implementation

[0078] 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. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0079] Referring to Figure 1, which shows a structural block diagram of an RF power supply in the related art, the RF power supply includes a main controller, a signal conversion circuit, a power amplifier circuit, a sampling circuit, a control circuit, and a DC power supply. Based on the connection relationships between the components shown in Figure 1, the main controller outputs a control signal to the signal conversion circuit. The signal conversion circuit converts the control signal into a pulse drive signal capable of driving the switching action in the power amplifier circuit, and outputs the pulse drive signal to the power amplifier circuit. The DC power supply provides a DC voltage to the power amplifier circuit, which converts the DC voltage into an RF signal according to the duty cycle of the pulse drive signal, thus completing the RF signal output.

[0080] Furthermore, the main controller configures a power setting value to the control circuit. Ideally, the RF power supply should output RF power according to this power setting value. The control circuit obtains the forward power feedback value by sampling the RF signal output by the power amplifier circuit. Based on the deviation between the forward power feedback value and the power setting value, it outputs a voltage control quantity for the DC power supply. This allows the DC power supply to adjust its output DC voltage based on the voltage control quantity, thereby adjusting the RF power output by the power amplifier circuit until the deviation between the RF power and the power setting value is within a preset deviation range.

[0081] This RF power supply can only adjust the output RF power by adjusting the DC voltage. Because the DC power supply has a long response time for adjusting the output voltage, the efficiency of the RF power supply in adjusting the RF power is low, making it difficult to meet the application requirements of rapid adjustment of RF power in practical applications.

[0082] To address the aforementioned issues, this application provides an RF control circuit that employs two methods to adjust RF power. This makes the adjustment process of the RF power supply more flexible. Furthermore, the response time for adjusting the duty cycle of the pulse drive signal is much shorter than the response time for adjusting the DC voltage. The combination of these two adjustment methods can shorten the overall response time required to adjust the RF power, effectively improving the adjustment efficiency of the RF power supply and meeting practical application requirements.

[0083] The radio frequency (RF) control circuit provided in this application is used to adjust the RF power of an RF power supply. This RF control circuit is connected to a power amplifier circuit and provides the power amplifier circuit with a pulse drive signal and a DC voltage signal, so that the power amplifier circuit generates an RF signal based on the obtained pulse drive signal and DC voltage signal. Referring to Figure 2, the RF control circuit 200 provided in this application includes: a first control circuit 10, a second control circuit 20, a signal conversion circuit 30, and a DC power supply 40. It should be noted that Figure 2 also shows other internal modules of the RF power supply containing the RF control circuit 200, including a power amplifier circuit 50 and a sampling circuit 60. Of course, in practical applications, the RF power supply may also include other functional modules, which are not listed here. Specific implementations can be found in related technologies. It should also be noted that the structural block diagram shown in Figure 2 can also be considered as an implementation of the RF power supply provided in this application.

[0084] As shown in Figure 2, the input terminal of the sampling circuit 60 is connected to the output terminal of the power amplifier circuit 50. The output terminal of the sampling circuit 60 is connected to one input terminal of the first control circuit 10, providing a forward power feedback value to the first control circuit 10. The other input terminal of the first control circuit 10 is used to receive the forward power setpoint. The output terminal of the first control circuit 10 is connected to the positive input terminal of the second control circuit 20 and the input terminal of the signal conversion circuit 30. The inverting input terminal of the second control circuit 20 is used to receive a preset control threshold value. The output terminal of the second control circuit 20 is connected to the DC power supply 40. The signal conversion circuit 30 and the DC power supply 40 are respectively connected to the power amplifier circuit 50. Based on relevant technologies, it is known that the signal conversion circuit 30 provides a pulse drive signal for the operation of the power amplifier circuit 50, and the DC power supply 40 provides a DC voltage signal for the operation of the power amplifier circuit 50. The power amplifier circuit 50 then converts the DC voltage signal into an RF signal output according to the duty cycle of the pulse drive signal.

[0085] Based on the above connection relationship, the sampling circuit 60 can acquire the forward power during the operation of the RF power supply, and after performing signal processing operations such as frequency calibration, send the acquired forward power as a forward power feedback value to the first control circuit 10. The first control circuit generates a first target control quantity and a second target control quantity based on the forward power deviation between the acquired forward power setpoint and the forward power feedback value fed back by the sampling circuit 60. Then, it sends the first target control quantity to the signal conversion circuit 30 and provides the second target control quantity to the second control circuit 20. It should be noted that the first target control quantity and the second target control quantity can be the same control quantity or different control quantities. The specific differences between the first target control quantity and the second target control quantity will be elaborated in subsequent embodiments and will not be detailed here.

[0086] As mentioned earlier, the forward power setting is mainly used to configure the RF power provided during the operation of the RF power supply, i.e., the RF power required by the user. In practical applications, 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 and the reflection power threshold and dissipation power threshold mentioned later. For specific implementation, please refer to relevant technologies, which will not be detailed here.

[0087] It should be noted that the first target control quantity and the second target control quantity provided by the first control circuit 10 are essentially pure numerical values ​​without any physical units. Their functions will vary depending on the specific application scenario. In this embodiment, the first target control quantity can be used to control the signal conversion circuit 30 to adjust the duty cycle of the pulse drive signal. That is, the first target control quantity can correspond to the duration of the high level in the pulse drive signal, which is also the duration of the switching transistor in the power amplifier circuit 50 being in the on state. At the same time, the second target control quantity serves as the input parameter of the second control circuit 20 to realize the output of the third target control quantity. This process will be elaborated in the following content and will not be described in detail here.

[0088] The inverting input of the second control circuit 20 receives a control threshold value. Similar to the aforementioned forward power setting value, the control threshold value can be configured by the host computer or the slave computer, which will not be repeated here. In this application, the control threshold value is used to determine the third target control value provided by the second control circuit 20. Specifically, the second control circuit 20 calculates the control deviation between the second target control value and the control threshold value in real time, and uses this deviation as input to generate and output the third target control value. Similar to the first target control value and the second target control value provided by the first control circuit 10, the essence of the third target control value described in this embodiment is also a pure numerical value without any physical quantity unit. In this embodiment, the third target control value is used to control the voltage amplitude of the DC voltage signal output by the DC power supply of the RF power supply.

[0089] It should be noted that the third target control quantity and the control quantity deviation also have a preset correspondence. The magnitude of the control quantity deviation will affect the actual value of the third target control quantity. In practical applications, the changing trends of the control quantity deviation and the third target control quantity may be the same or opposite, mainly depending on how the subsequent circuit applies the third target control quantity. In this application, the second control circuit 20 outputs the third target control quantity with the control quantity deviation between the second target control quantity and the control quantity threshold within a preset range as the target, thereby cooperating with the first target control quantity to jointly adjust the RF power output by the power amplifier circuit.

[0090] In one implementation, the second control circuit 20 in the embodiment shown in Figure 2 is based on a PID (Proportion-Integration-Differentiation) circuit. In this embodiment, the second control circuit 20 takes the control quantity deviation (i.e., the deviation between the second target control quantity and the preset control quantity threshold) as input, determines the third target control quantity increment (which can be positive or negative), and uses the sum of the third target control quantity increment and the third target control quantity of the previous control cycle as the third target control quantity of the current control cycle, which is then output to the DC power supply 40 in the subsequent stage. The specific implementation and calculation process of the PID circuit can be implemented with reference to relevant technologies, and will not be detailed here.

[0091] In summary, in the RF control circuit 200 provided in this embodiment, the first control circuit outputs a first target control quantity and a second target control quantity based on the forward power deviation of the forward power setpoint and the forward power feedback value. The signal conversion circuit generates a pulse drive signal based on the first target control quantity and outputs it to the power amplifier circuit. The second control circuit receives the second target control quantity and a preset control quantity threshold, and outputs a third target control quantity based on the second target control quantity and the control quantity threshold. The DC power supply adjusts the DC voltage signal output to the power amplifier circuit based on the third target control quantity. Compared with the single control method of adjusting RF power by adjusting DC voltage in the prior art, this application provides two ways to adjust RF power: adjusting the duty cycle of the pulse drive signal by adjusting the signal conversion circuit by the first target control quantity, and adjusting the output DC voltage by adjusting the DC power supply by the third target control quantity. This provides more control methods and makes the adjustment process of the RF power supply more flexible. Furthermore, the response time of adjusting the duty cycle of the pulse drive signal is much shorter than the response time of adjusting the DC voltage. The combination of the two adjustment methods can shorten the overall response time required to adjust the RF power, effectively improve the adjustment efficiency of the RF power supply, and meet the needs of practical applications.

[0092] In some embodiments, based on the RF control circuit 200 provided in the embodiment shown in FIG2, when the first target control quantity provided by the first control circuit is greater than the control quantity threshold, the first target control quantity is used to control the signal conversion circuit to output a pulse drive signal according to a preset duty cycle. In practical applications, the signal conversion circuit can be configured so that when the signal conversion circuit receives the first target control quantity greater than the control quantity threshold, the signal conversion circuit directly outputs the pulse drive signal according to the preset duty cycle. That is, the duty cycle of the pulse drive signal no longer changes with the change of the first target control quantity. Furthermore, the third target control quantity is used to control the DC power supply output to have a DC voltage signal that is proportional to the deviation of the control quantity (i.e., the deviation between the second target control quantity and the control quantity threshold). In this case, the DC voltage signal of the DC power supply will change with the change of the third target control quantity. The RF control circuit 200 only adjusts the DC voltage signal output by the DC power supply to the power amplifier circuit and no longer adjusts the duty cycle of the pulse drive signal.

[0093] Correspondingly, when the first target control quantity is less than the control quantity threshold, the first target control quantity is used to control the signal conversion circuit to output a pulse drive signal according to a duty cycle that is proportional to the first target control quantity. The third target control quantity is used to control the DC power supply to output a DC voltage signal that is proportional to the deviation of the control quantity (i.e., the deviation between the second target control quantity and the control quantity threshold). In this case, the duty cycle of the pulse drive signal changes with the change of the first target control quantity, and the DC voltage signal of the DC power supply will change with the change of the third target control quantity.

[0094] Of course, when the first target control quantity is less than the control quantity threshold, the first target control quantity can also be used to control the signal conversion circuit to output a pulse drive signal according to a duty cycle that is proportional to the first target control quantity, and the third target control quantity can be used to control the DC power supply to output a preset DC voltage signal. That is, the DC power supply only provides the preset DC voltage signal, and the output of the DC power supply no longer changes with the change of the third target control quantity. In some embodiments, when the second control circuit 20 outputs a fixed value, such as 0, the third target control quantity when the second target control quantity is less than the control quantity threshold, and the DC power supply is configured to output a preset DC voltage signal after receiving the third target control quantity.

[0095] Regarding the specific values ​​of the preset duty cycle, preset DC voltage signal, and control threshold mentioned above, in practical applications, they need to be set in conjunction with the specific configuration parameters of the signal conversion circuit and DC power supply, as well as the control requirements. This application does not limit the specific values ​​of the preset duty cycle, preset DC voltage signal, and control threshold.

[0096] Based on the RF control circuit 200 provided in the above embodiments, differentiated control at different power stages can be achieved. When the RF power supply operates in a low power range, the duty cycle of the pulse drive signal can be adjusted by regulating the signal conversion circuit through the first target control quantity, and the output DC voltage signal can be adjusted by regulating the DC power supply through the third target control quantity. That is, the RF power is adjusted by regulating the duty cycle of the pulse drive signal and the DC voltage. When the RF power supply operates in a high power range, the duty cycle of the pulse drive signal can be maximized by regulating the signal conversion circuit through the first target control quantity, and the output DC voltage signal can be adjusted by regulating the DC power supply through the third target control quantity. That is, the RF power is adjusted by adjusting the DC voltage.

[0097] Based on the above, this application also provides another radio frequency control circuit 200'. As shown in Figure 3, in the radio frequency control circuit 200' provided in this embodiment, the first control circuit 10 includes: a forward feedback control circuit 110, a reflection power protection circuit 120, and a comparison circuit 130.

[0098] The forward feedback control circuit 110 includes a first input terminal, a second input terminal, and an output terminal. The first input terminal receives the aforementioned forward power setpoint. The second input terminal is connected to the sampling circuit 60 and receives the forward power feedback value from the sampling circuit 60. The output terminal is connected to the first input terminal of the comparator circuit 130. The forward feedback control circuit 110 outputs a first control quantity based on the forward power deviation between the forward power setpoint and the forward power feedback value. In one implementation, the forward feedback control circuit 110 is based on a PID circuit. In this embodiment, the forward feedback control circuit 110 uses the forward power deviation as input to determine the increment of the first control quantity (which can be positive or negative), and the sum of the increment of the first control quantity and the first control quantity of the previous control cycle is used as the first control quantity of the current control cycle, which is then output to the subsequent comparator circuit 130. The specific implementation and calculation process of the PID circuit can be implemented with reference to relevant technologies and will not be detailed here.

[0099] Similar to the forward feedback control circuit 110, the reflected power protection circuit 120 also includes a first input terminal, a second input terminal, and an output terminal. The first input terminal of the reflected power protection circuit 120 receives the reflected power threshold, and the second input terminal is connected to the sampling circuit 60 to receive the reflected power feedback value fed back by the sampling circuit 60. The output terminal of the reflected power protection circuit 120 is connected to the second input terminal of the comparator circuit 130. The reflected power protection circuit 120 outputs a second control quantity based on the reflected power deviation between the reflected power threshold and the reflected power feedback value. 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, it can easily cause thermal damage to the matching circuit of the semiconductor process equipment and RF cables due to excessive reflected power. In practical applications, the reflected power threshold needs to be set in conjunction 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 value of the reflected power threshold. The configuration method of the reflected power threshold can be referred to the aforementioned relevant content, and will not be repeated here.

[0100] In the embodiment shown in Figure 3, the reflected power protection circuit 120 is implemented based on a PID circuit. The reflected power protection circuit 120 takes the reflected power deviation as input, determines the second control quantity increment (which can be positive or negative), and uses the sum of the second control quantity increment and the second control quantity of the previous control cycle as the second control quantity of the current control cycle, which is then output to the subsequent comparison circuit 130. As for the specific implementation method and calculation process of the PID circuit, they can be implemented with reference to relevant technologies, and will not be described in detail here.

[0101] The comparator circuit 130 is used to determine a target control quantity based on a first control quantity and a second control quantity. Specifically, the comparator circuit 130 selects the control quantity that is smaller between the first control quantity and the second control quantity as the first target control quantity and the second target control quantity. In some embodiments, the comparator circuit 130 can be implemented based on a multiplexer.

[0102] It should be noted that, similar to the first control quantity mentioned above, the second control quantity provided in this embodiment is essentially a pure numerical value without any physical unit. Its setting rules can be found in the aforementioned content and will not be detailed here. The difference lies in the fact that the basic principle of the second control quantity changing with the reflected power deviation is to ultimately reduce the reflected power feedback value to below the reflected power threshold, thereby ensuring the safe operation of the RF power supply.

[0103] In summary, the radio frequency control circuit provided in this embodiment not only considers the impact of forward power on circuit operation, but also has the function of reflected power protection. The reflected power protection circuit can effectively avoid excessive reflected power, which helps semiconductor devices to start up quickly and improves device performance.

[0104] Furthermore, in practical applications of RF power supplies, dissipation losses are inevitable during operation. Excessive dissipation losses may lead to thermal breakdown, affecting the safe operation of semiconductor process equipment. Therefore, it is necessary to control the dissipation power of RF power supplies and provide corresponding protection mechanisms.

[0105] To meet the above application requirements, this application provides another radio frequency control circuit 200”. As shown in Figure 4, based on the embodiment shown in Figure 3, the radio frequency control circuit 200” provided in this embodiment further includes the first control circuit 10 as follows: a power dissipation protection circuit 140 and a power dissipation calculation circuit 150.

[0106] The first input terminal of the power dissipation protection circuit 140 receives the power dissipation threshold, the second input terminal is connected to the output terminal of the power dissipation calculation circuit 150 and receives the power dissipation feedback value provided by the power dissipation calculation circuit 150, and the output terminal of the power dissipation protection circuit 140 is connected to the third input terminal of the comparator circuit 130. Based on the power dissipation deviation between the power dissipation threshold and the power dissipation feedback value, the power dissipation protection circuit 140 outputs a third control quantity to the comparator circuit 130. The power dissipation threshold corresponds to the maximum allowable power dissipation of the RF power supply. When the power dissipation exceeds the threshold, the RF power supply is prone to thermal breakdown due to excessive power dissipation. In practical applications, the power dissipation threshold needs to be set in conjunction with the performance parameters of the RF power supply, the specific conditions of the power load, and control requirements. This application does not limit the specific value of the power dissipation threshold. The configuration method of the power dissipation threshold can be referred to the aforementioned relevant content and will not be repeated here.

[0107] In the embodiment shown in Figure 4, the power dissipation protection circuit 140 is implemented based on a PID circuit. The power dissipation protection circuit 140 takes the power dissipation deviation as input, determines the third control quantity increment (which can be positive or negative), and uses the sum of the third control quantity increment and the third control quantity of the previous control cycle as the third control quantity of the current control cycle, outputting it to the subsequent comparison circuit 130. The specific implementation and calculation process of the PID circuit can be referenced from relevant technologies and will not be detailed here.

[0108] As mentioned above, the dissipated power feedback value is provided by the dissipated power calculation circuit 150. As shown in Figure 4, the input terminals of the dissipated power calculation circuit 150 are connected to the DC power supply 40 and the sampling circuit 60, respectively. It receives the forward power feedback value and the reflected power feedback value provided by the sampling circuit 60, and simultaneously acquires the DC voltage and DC current of the DC power supply 40. First, the dissipated power calculation circuit 150 determines the product of the DC voltage and DC current to obtain the total output power. Then, it calculates the difference between the total output power and the forward power feedback value, and finally determines the sum of the obtained difference and the reflected power feedback value as the dissipated power feedback value. In practical applications, the aforementioned addition and subtraction calculation process can be implemented using adders and subtractors, while multiplication can be implemented using a multiplier. Of course, the dissipated power feedback value can also be determined in other ways, such as through a microcontroller capable of executing calculation programs. As long as it does not exceed the core concept scope of this application, it also falls within the scope of protection of this application.

[0109] The output of the comparator circuit 130 is connected to the positive input of the second control circuit 20 and the signal conversion circuit 30, respectively. The inverting input of the second control circuit 20 is used to receive the control threshold value, and the output of the second control circuit 20 is connected to the DC power supply 40.

[0110] Considering that the response time required for DC power supply to regulate DC voltage signal is relatively long, and the time required to calculate the third control quantity based on the dissipated power feedback value is also relatively long compared to the first and second control quantities, it is possible that adjusting DC power supply based on the third control quantity may significantly reduce the regulation efficiency of DC voltage signal. Therefore, as a preferred implementation, the comparator circuit 130 selects the smallest control quantity among the first, second, and third control quantities as the first target control quantity, and selects the smallest control quantity among the first and second control quantities as the second target control quantity. This setting can meet the requirements of practical application while satisfying the need for flexible adjustment of radio frequency signal.

[0111] As for the connection relationship of other components in the embodiment shown in Figure 4, please refer to the aforementioned relevant content and Figure 4 for details, which will not be repeated here.

[0112] It should be noted that, similar to the first control quantity mentioned above, the third control quantity provided in this embodiment is essentially a pure numerical value without any physical unit. Its setting rules can be referred to the aforementioned content and will not be detailed here. The difference is that the basic principle of the third control quantity changing with the dissipation power deviation is to eventually reduce the dissipation power feedback value to less than the dissipation power threshold in order to ensure the safe operation of the RF power supply.

[0113] As shown in Figure 4 and the above content, the control circuit provided in this embodiment includes four control loops: forward power control loop, reflected power control loop, dissipated power control loop, and DC power supply control loop. Among them, the control loop with the smallest output control quantity among the forward power control loop, reflected power control loop, and dissipated power control loop can be determined as the control loop currently in the control state by the comparison circuit.

[0114] Understandably, in practical applications, the forward power control loop, reflected power control loop, and dissipated power control loop should meet the following control rules: the reflected power protection mechanism is triggered only when the reflected power is abnormal, i.e., the reflected power control loop is in control mode; the dissipated power protection mechanism is triggered only when the dissipated power is abnormal, i.e., the dissipated power control loop is in control mode; when both reflected power and dissipated power are normal, only the forward power control loop is in control mode, controlling the RF power supply to output RF power according to the forward power set value.

[0115] To achieve the above objectives, the reflected power protection circuit and the first control circuit should be configured such that: when the reflected power feedback value is less than the reflected power threshold, the second control quantity provided by the reflected power protection circuit is greater than the first control quantity provided by the forward feedback control circuit; when the reflected power feedback value is greater than or equal to the reflected power threshold, the second control quantity is less than the first control quantity.

[0116] Accordingly, the power dissipation protection circuit and the forward feedback control circuit are configured such that: when the power dissipation feedback value is less than the power dissipation threshold, the third control quantity output by the power dissipation protection circuit is greater than the first control quantity provided by the forward feedback control circuit; when the power dissipation feedback value is greater than or equal to the power dissipation threshold, the third control quantity is less than the first control quantity.

[0117] Based on the above configuration, assuming the comparator circuit selects the smallest of the first, second, and third control quantities as the target control quantity, 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, then both the second and third control quantities are greater than the first control quantity. This ensures that the target control quantity output by the comparator circuit is the first control quantity, and the forward power control loop is in a controlled state. Correspondingly, in a protection trigger scenario, the protection circuit in a controlled state will provide the minimum control quantity to ensure that the RF power supply operates under the control of the protection circuit and recovers to normal as quickly as possible. Taking the reflected power control loop as an example, when the reflected power feedback value is greater than the reflected power threshold, the second control quantity is less than both the first and third control quantities, ensuring that the comparator circuit can output the second control quantity as the target control quantity, thereby keeping the reflected power control loop in a controlled state.

[0118] When the forward feedback control circuit, the reflected power protection circuit, and the dissipated power protection circuit are all implemented based on PID circuits, the above control rules can be implemented based on the closed-loop control mode of the PID circuit itself. Under normal circumstances, neither the reflected power nor the dissipated power has reached the corresponding power threshold. The second and third control quantities will always be in an accumulating state, and the final output will be the maximum value that the PID circuit can provide. After a certain period of closed-loop control, the forward feedback control circuit will gradually stabilize near the forward power setpoint. Its first control quantity will be much smaller than the second and third control quantities, thereby ensuring that the forward power control loop is in a controlled state.

[0119] In summary, the RF control circuit provided in this embodiment adjusts the duty cycle of the pulse drive signal by adjusting the signal conversion circuit with the first target control quantity, and adjusts the output DC voltage signal by adjusting the DC power supply with the third target control quantity. It has more control methods, which makes the adjustment process of the RF power supply more flexible. The combination of the two adjustment methods can shorten the overall response time required to adjust the RF power, effectively improve the adjustment efficiency of the RF power supply, and meet the needs of practical applications.

[0120] Furthermore, the reflected power protection circuit can protect the power supply in case of abnormal reflected power, and the dissipated power protection circuit can protect the power supply in case of abnormal dissipated power, effectively improving the safety of the RF power supply. Moreover, both the reflected power protection circuit and the dissipated power protection circuit output control quantities to adjust the duty cycle of the pulse drive signal, that is, to control the on / off time of the switching transistor in the power amplifier circuit. This enables rapid adjustment of the RF power, rapid activation of the protection mechanism, shorter response time, and prevention of further escalation of the abnormality, thus contributing to further improving the safety of the RF power supply.

[0121] It is understandable that in practical applications, different RF power supplies have different application scenarios, and the probability of abnormal reflected power and abnormal dissipated power will also vary. Therefore, control circuits with only dissipated power protection function can be provided based on application requirements.

[0122] As shown in Figure 5, the RF control circuit 200”' provided in this embodiment includes a first control circuit 10, a second control circuit 20, a signal conversion circuit 30, and a DC power supply 40. The first control circuit 10 includes a forward feedback control circuit 110, a comparator circuit 130, a power dissipation protection circuit 140, and a power dissipation calculation circuit 150. In addition, Figure 5 also shows other related components of the RF power supply, including a power amplifier circuit 50 and a sampling circuit 60.

[0123] Based on the foregoing, the forward feedback control circuit 110 provides a first control quantity, the power dissipation protection circuit 140 provides a third control quantity, the comparison circuit 130 selects the control quantity with the smallest value between the first control quantity and the third control quantity as the first target control quantity, outputs it to the signal conversion circuit 30, and uses the first control quantity as the second target control quantity, outputs it to the second control circuit 20.

[0124] When the dissipated power feedback value is less than the dissipated power threshold, the third control quantity is greater than the first control quantity. The comparator circuit outputs the first control quantity as the target control quantity to the subsequent circuit, and the forward feedback control circuit is in control state. Correspondingly, when the dissipated power feedback value is greater than or equal to the dissipated power threshold, the third control quantity is less than the first control quantity. The comparator circuit outputs the third control quantity as the target control quantity to the subsequent circuit. In this case, the dissipated power control loop is in control state, providing abnormal dissipated power protection for the RF power supply.

[0125] Based on the above, it can be seen that the control circuit provided in the embodiment shown in Figure 5 can only provide power dissipation abnormality protection function, and is suitable for application scenarios where power dissipation abnormalities frequently or easily occur.

[0126] It should be noted that for the radio frequency control circuit 200”' provided in the embodiment shown in Figure 5, the parts not elaborated in detail can be referred to the relevant content of any of the foregoing embodiments, and will not be repeated here.

[0127] It should also be noted that the RF control circuit, signal conversion circuit, DC power supply, power amplifier circuit, and sampling circuit provided in any of the above embodiments can all be implemented with reference to related technologies, and this application does not impose specific limitations on them. Taking the signal conversion circuit as an example, in practical applications, the signal conversion circuit may include a DDS (Direct Digital Synthesizer) module and a driving circuit. The DDS module is used to generate a corresponding control signal according to the duty cycle corresponding to the target control quantity, while the driving circuit is used to convert the control signal into a pulse driving signal that can drive the switching transistor in the power amplifier circuit. As another implementation, the DDS module can also be replaced by a fast-response DAC (Digital to Analog Converter) module. The DDS module is implemented through an integrated chip. The control quantity is directly input into the integrated chip, and the integrated chip outputs a sine wave. Then, the sine wave and the comparison threshold are used as the positive and negative input terminals of the comparator, respectively. After comparison, the comparator outputs a control signal in the form of a rectangular wave. The alternative high-speed DAC module generates discrete signal points. The discrete signal points form a sine wave, which is compared with the back-end comparator to output a rectangular wave. Of course, other modules also include various implementation methods, which will not be detailed here.

[0128] It should also be noted that the radio frequency control circuit provided in any of the above embodiments can operate according to a preset control cycle, that is, perform processes such as forward power control, reflected power abnormality protection, dissipated power abnormality protection, and DC voltage control according to the preset control cycle. In some embodiments, the preset control cycle of the control circuit can be configured by a host computer. Furthermore, considering that dissipated power requires the acquisition of DC voltage and DC current of the DC power supply, which takes a long time, the control cycle of the dissipated power protection circuit is generally longer than the control cycles of the first control circuit, the second control circuit, and the reflected power protection circuit.

[0129] Based on any of the above embodiments, this application provides an radio frequency power supply, including: a power amplifier circuit, a sampling circuit, and a radio frequency control circuit provided in any of the foregoing embodiments, wherein,

[0130] The sampling circuit is connected to both the power amplifier circuit and the RF control circuit, and is used to acquire the forward power feedback value and the reflected power feedback value. The RF control circuit receives the forward power feedback value and the reflected power feedback value provided by the sampling circuit, and generates a pulse drive signal and a DC voltage signal. The power amplifier circuit generates an RF signal based on the pulse drive signal and the DC voltage signal. The specific implementation of the RF power supply provided in this application can be referred to the relevant descriptions of the RF control circuits in the embodiments of Figures 2 to 5 above, and will not be detailed here.

[0131] This application also provides an RF power supply control method, applied to another RF power supply provided in this application, specifically, applied to the main controller of the RF power supply setting. Specifically, as shown in Figure 6, the RF power supply provided in this application includes a main controller 100, a signal conversion circuit 30, a DC power supply 40, a power amplifier circuit 50, and a sampling circuit 60.

[0132] As shown in Figure 6, the signal conversion circuit 30 and the DC power supply 40 are respectively connected to the power amplifier circuit 50. The signal conversion circuit 30 is used to provide a pulse drive signal to the power amplifier circuit 50, and the DC power supply 40 is used to provide a DC voltage to the power amplifier circuit 50. The power amplifier circuit 50 converts the DC voltage into an RF signal output according to the duty cycle corresponding to the pulse drive signal.

[0133] The sampling circuit 60 is connected to the output of the power amplifier circuit 50. 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 100.

[0134] The main controller 100 is connected to the signal conversion circuit 30, the DC power supply 40 and the sampling circuit 60 respectively. Based on the reflected power feedback value and the forward power feedback value provided by the sampling circuit 60, the main controller 100 will also obtain the DC voltage and DC current of the DC power supply 40, and then output the first target control quantity and the third target control quantity according to the radio frequency power supply control method provided in the subsequent embodiments of this application.

[0135] Of course, in some cases, it can also be applied to other controllers that are independent of the RF power supply, such as the host computer in semiconductor process equipment.

[0136] The following uses the RF power supply shown in Figure 6 as an example to describe the RF power supply control method provided in this application. Referring to Figure 7, the RF power supply protection method provided in this application includes the following steps.

[0137] S100: Obtain the forward power setpoint, forward power feedback value, and control threshold of the power amplifier circuit.

[0138] Both the forward power setpoint and the control threshold are pre-configured by the user. In practical applications, their specific values ​​can be determined by considering the performance parameters of the RF power supply, the process formulation, and specific control requirements, which will not be detailed here. In one possible implementation, the main controller communicates with a host computer, allowing the user to configure the forward power setpoint and control threshold via the host computer.

[0139] The forward power feedback value is directly fed back by the sampling circuit, which will not be elaborated here.

[0140] For the specific definitions of the forward power setpoint and the control threshold, please refer to the aforementioned content, which will not be repeated here.

[0141] S110. Generate the first target control quantity and the second target control quantity based on the forward power setpoint and the forward power feedback value.

[0142] The first and second target control quantities are essentially pure numerical values ​​without any physical units. Their functions vary depending on the specific application scenario. In this embodiment, the first target control quantity can be used to control the signal conversion circuit to adjust the duty cycle of the pulse drive signal. That is, the first target control quantity can correspond to the duration of the high level in the pulse drive signal, which is also the duration of the switching transistor in the power amplifier circuit being in the on state. The specific function of the second target control quantity will be elaborated in subsequent embodiments and will not be detailed here.

[0143] In some embodiments, the main controller further acquires a reflected power threshold and a reflected power feedback value, generates a first control quantity based on the forward power deviation between the forward power setpoint and the forward power feedback value, and generates a second control quantity based on the reflected power deviation between the reflected power threshold and the reflected power feedback value. The control quantity that is smaller between the first and second control quantities is determined as the first target control quantity and the second target control quantity. The first and second control quantities are essentially pure numerical values ​​without any physical units. In this embodiment, the first and second control quantities have the same function: to control the signal conversion circuit to adjust the duty cycle of the pulse drive signal.

[0144] In some embodiments, the first control quantity and the second control quantity are calculated based on a PID algorithm. Specifically, taking the first control quantity as an example, the deviation between the forward power setpoint and the forward power feedback value, i.e., the forward power deviation, is first calculated. Then, using the forward power deviation as input, the increment of the first control quantity is determined (which can be positive or negative). The sum of the increment of the first control quantity and the first control quantity of the previous control cycle is taken as the first control quantity of the current control cycle. Both the first control quantity and the second control quantity can be output based on the PID algorithm. The specific implementation process can be found in the relevant content of the foregoing embodiments, and will not be repeated here.

[0145] S120. Generate a pulse drive signal based on the first target control quantity.

[0146] In this embodiment, the first target control quantity can be used to control the signal conversion circuit 30 to adjust the duty cycle of the pulse drive signal. That is, the first target control quantity can correspond to the duration of the high level in the pulse drive signal, which is also the duration of the switching transistor in the power amplifier circuit 50 being in the on state. As shown in Figure 6, the main controller is connected to the signal conversion circuit and provides the first target control quantity to the signal conversion circuit. The signal conversion circuit generates the pulse drive signal based on the obtained first target control quantity. The specific process of the signal conversion circuit generating the pulse drive signal can be implemented with reference to relevant technologies, and will not be described in detail here.

[0147] S130. Based on the control quantity deviation between the second target control quantity and the control quantity threshold, output the third target control quantity.

[0148] In some embodiments, the third target control quantity is also calculated based on a PID algorithm. Specifically, firstly, the control quantity deviation between the second target control quantity and the control quantity threshold is calculated. Then, using the previous control quantity deviation as input, the increment of the third target control quantity is determined (which can be positive or negative). The sum of the increment of the third target control quantity and the third target control quantity of the previous control cycle is used as the third target control quantity of the current control cycle and output to the DC power supply of the subsequent stage. As for the specific implementation method and calculation process of the PID algorithm, they can be implemented with reference to relevant technologies and will not be detailed here.

[0149] Similar to the first target control quantity, the third target control quantity described in this embodiment is also essentially a pure numerical value without any physical quantity units.

[0150] S140. Adjust the DC voltage signal according to the third target control quantity.

[0151] In this embodiment, the third target control quantity is used to control the amplitude of the DC voltage signal output by the DC power supply of the RF power supply. The specific implementation process of the DC power supply adjusting the DC voltage signal based on the third target control quantity can be referred to relevant technologies, and will not be described in detail here.

[0152] S150, the power amplifier circuit outputs radio frequency signals based on DC voltage signals and pulse drive signals.

[0153] In practical applications, the power amplifier circuit periodically turns on and off according to the duty cycle of the pulse drive signal. When on, it outputs a DC voltage signal (high level), and when off, it outputs a low level, thus converting the DC voltage signal into an radio frequency (RF) signal. The frequency of the RF signal is the same as the frequency of the pulse drive signal, and naturally, their duty cycles are also the same. The specific implementation process of the power amplifier circuit outputting the RF signal can be found in relevant technologies and will not be detailed here.

[0154] In summary, the RF power supply control method provided in this embodiment outputs a first target control quantity and a second target control quantity based on the forward power deviation between the forward power setpoint and the forward power feedback value, and outputs a third target control quantity based on the control quantity deviation between the second target control quantity and the control quantity threshold. Compared with the single control method of adjusting RF power by adjusting DC voltage in the prior art, this application provides two ways to adjust RF power: adjusting the duty cycle of the pulse drive signal by adjusting the signal conversion circuit by the first target control quantity, and adjusting the output DC voltage by adjusting the DC power supply by the third target control quantity. This provides more control methods and makes the adjustment process of RF power supply more flexible. Furthermore, the response time of adjusting the duty cycle of the pulse drive signal is much shorter than the response time of adjusting the DC voltage. The combination of the two adjustment methods can shorten the overall response time required to adjust RF power, effectively improve the adjustment efficiency of RF power supply, and meet the needs of practical applications.

[0155] Furthermore, based on the foregoing embodiments, this application also provides another method for outputting a first target control quantity and a second target control quantity. As shown in FIG8, the control method provided in this embodiment includes the following steps.

[0156] S200: Obtain the forward power setpoint, forward power feedback value, reflected power threshold, reflected power feedback value, dissipated power threshold, dissipated power feedback value, and control quantity threshold.

[0157] As mentioned earlier, both the forward power feedback value and the reflected power feedback value can be obtained through the sampling circuit. The forward power setpoint, reflected power threshold, dissipated power threshold, and control quantity threshold can all be configured by the host computer. For the acquisition of the above parameters, please refer to the foregoing content, which will not be repeated here.

[0158] The dissipated power feedback value can be calculated. Specifically, while obtaining the forward power feedback value and the reflected power feedback value provided by the sampling circuit, the DC voltage and DC current of the DC power supply are acquired. Based on the obtained data, the product of the DC voltage and DC current is first calculated to obtain the total output power. Then, the difference between the total output power and the forward power feedback value is calculated. Finally, the sum of the obtained difference and the reflected power feedback value is determined as the dissipated power feedback value.

[0159] S210: Based on the forward power deviation between the forward power setpoint and the forward power feedback value, output the first control quantity.

[0160] In some embodiments, S210 can be implemented with reference to the relevant content of S110 in the embodiment shown in FIG7, which will not be repeated here.

[0161] S220: Based on the reflection power deviation between the reflection power threshold and the reflection power feedback value, output the second control quantity.

[0162] The second control quantity is essentially a pure numerical value without any physical quantity units. Its function will vary depending on the specific application scenario. In this embodiment, the second control quantity has the same function as the first control quantity. It can be used to control the signal conversion circuit to adjust the duty cycle of the pulse drive signal. Furthermore, it can also be used to calculate the third target control quantity (details will be elaborated in the following content).

[0163] In some embodiments, the second control quantity is calculated based on a PID algorithm. Specifically, first, the deviation between the reflected power threshold and the reflected power feedback value, i.e., the reflected power deviation, is calculated. Then, using the reflected power deviation as input, the increment of the second control quantity is determined (which can be positive or negative). The sum of the increment of the second control quantity and the second control quantity of the previous control cycle is taken as the second control quantity of the current control cycle. Other information involved in the specific implementation of the PID algorithm can be found in relevant technical implementations and will not be detailed here.

[0164] S230: Based on the dissipation power deviation between the dissipation power threshold and the dissipation power feedback value, output the third control quantity.

[0165] The third control quantity is essentially a pure numerical value without any physical quantity unit. In this embodiment, the third control quantity has the same function as the first control quantity and can be used to control the signal conversion circuit to adjust the duty cycle of the pulse drive signal.

[0166] In some embodiments, the third control quantity is calculated based on the PID algorithm. Specifically, firstly, the deviation between the dissipated power threshold and the dissipated power feedback value, i.e., the dissipated power deviation, is calculated. Then, using the dissipated power deviation as input, the increment of the third control quantity is determined (which can be positive or negative). The sum of the increment of the third control quantity and the third control quantity of the previous control cycle is used as the third control quantity of the current control cycle.

[0167] S240. Determine the minimum control quantity among the first control quantity, the second control quantity, and the third control quantity as the first target control quantity.

[0168] For the purpose of using the smallest of the first, second, and third control variables as the first target control variable and its effect in practical applications, please refer to the relevant content in the foregoing embodiments, which will not be repeated here.

[0169] S250. Determine the smaller of the first and second control variables as the second target control variable.

[0170] For the purpose of using the minimum control quantity among the first and second control quantities as the second target control quantity and its effect in practical applications, please refer to the relevant content in the foregoing embodiments, which will not be repeated here.

[0171] Furthermore, the main controller can continue to execute S120-S150 in the embodiment shown in Figure 7 to adjust the pulse drive signal and the DC voltage signal, so that the power amplifier circuit outputs the radio frequency signal. For the specific control process, please refer to the relevant content of the aforementioned embodiment, which will not be repeated here.

[0172] In summary, the RF power supply control method provided in this embodiment adjusts the duty cycle of the pulse drive signal by adjusting the signal conversion circuit with a first target control quantity, and adjusts the output DC voltage by adjusting the DC power supply with a third target control quantity. This provides more control methods, making the RF power supply adjustment process more flexible. The combination of the two adjustment methods can shorten the overall response time required to adjust the RF power, effectively improve the adjustment efficiency of the RF power supply, and meet the needs of practical applications.

[0173] Furthermore, power supply protection under abnormal power dissipation conditions can be implemented, effectively improving the safety of the RF power supply. In other words, the RF power supply control method provided in the embodiment shown in Figure 8 can be decomposed to obtain a control method that provides dissipation power protection separately. The specific implementation process is explained below using the control method that provides abnormal dissipation power protection separately as an example.

[0174] Referring to Figure 9, the radio frequency power supply control method provided in this embodiment includes the following steps.

[0175] S300: Obtain the forward power setpoint, forward power feedback value, dissipated power threshold, dissipated power feedback value, and control quantity threshold.

[0176] In some embodiments, S300 can be implemented with reference to the relevant content of S200 in the embodiment shown in FIG8, which will not be repeated here.

[0177] S310: Based on the forward power deviation between the forward power setpoint and the forward power feedback value, output the first target control quantity.

[0178] In some embodiments, S310 can be implemented with reference to the relevant content of S210 in the embodiment shown in FIG8, which will not be repeated here.

[0179] S320: Based on the dissipation power deviation between the dissipation power threshold and the dissipation power feedback value, output a second control quantity.

[0180] In some embodiments, S320 can be implemented with reference to the relevant content of S230 in the embodiment shown in FIG8, which will not be repeated here.

[0181] S330. Determine the minimum control quantity among the first control quantity and the third control quantity as the first target control quantity, and determine the first control quantity as the second target control quantity.

[0182] For the purpose and effect of using the minimum control quantity among the first and third control quantities as the target control quantity, as well as the purpose and effect of using the first control quantity as the second target control quantity, please refer to the relevant content in the foregoing embodiments, which will not be repeated here.

[0183] Furthermore, the main controller can continue to execute S120-S150 in the embodiment shown in Figure 7 to adjust the pulse drive signal and the DC voltage signal, so that the power amplifier circuit outputs the radio frequency signal. For the specific control process, please refer to the relevant content of the aforementioned embodiment, which will not be repeated here.

[0184] It should be noted that the radio frequency power control method and radio frequency control circuit provided in this application are derived from the same inventive concept, and the difference is only in the specific implementation method. Therefore, for the contents that are not explained in detail in the various embodiments related to the radio frequency power control method, they can be implemented by referring to the relevant contents of the radio frequency control circuit provided in the foregoing embodiments, and will not be repeated here.

[0185] 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.

[0186] In some embodiments, FIG10 is a schematic diagram of the structure of a semiconductor process apparatus according to an embodiment of the present application. As shown in FIG10, the semiconductor process apparatus includes a process chamber 300, an air intake assembly 301, an air extraction assembly (not shown in the figure), an upper electrode assembly 300A, and a lower electrode assembly 300B.

[0187] The air intake assembly 301 is used to introduce the corresponding process gas into the process chamber 300 and to control the flow rate of the process gas. The air extraction assembly is used to extract air from the process chamber 300 to control the pressure inside the process chamber 300 and to remove reaction byproducts.

[0188] The upper electrode assembly 300A includes an RF coil 302, an upper RF power supply 304, and an upper matching unit 305. The upper RF power supply 304 provides upper electrode power to the RF coil 302 through the upper matching unit 305, so that the RF coil 302 excites the process gas inside the process chamber 300 to generate plasma.

[0189] The lower electrode assembly 300B includes a wafer carrier 303, a lower RF power supply 306, and a lower matching unit 307. The lower RF power supply 306 provides lower electrode power to the lower electrode of the wafer carrier 303 through the lower matching unit 307, thereby providing an RF bias voltage to the lower electrode of the wafer carrier 303 to attract plasma above the wafer 308 and bombard the wafer 308.

[0190] At least one of the upper RF power supply 304 and the lower RF power supply 306 described above can be an RF power supply as provided in the foregoing embodiments.

[0191] 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.

[0192] 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 perform the radio frequency power control method described above. For specific implementation details, please refer to the foregoing description; further elaboration is not provided here.

[0193] In addition to the methods and apparatus 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 of the radio frequency power control methods according to various embodiments of this application as described above.

[0194] 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.

[0195] 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.

[0196] 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.

[0197] 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.

[0198] 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.

[0199] 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.

[0200] 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 radio frequency control circuit for adjusting the radio frequency power of a radio frequency power supply, wherein, The radio frequency control circuit is used to connect to the power amplifier circuit of the radio frequency power supply and to provide the power amplifier circuit with a pulse drive signal and a DC voltage signal, so that the power amplifier circuit generates a radio frequency signal according to the pulse drive signal and the DC voltage signal; The radio frequency control circuit includes: a first control circuit, a second control circuit, a signal conversion circuit, and a DC power supply, wherein, The first control circuit is used to output a first target control quantity and a second target control quantity based on the forward power setpoint and the forward power feedback value; The signal conversion circuit is used to generate the pulse drive signal according to the first target control quantity and output it to the power amplifier circuit; The second control circuit is used to receive the second target control quantity and a preset control quantity threshold, and output a third target control quantity according to the second target control quantity and the control quantity threshold; The DC power supply is used to adjust the DC voltage signal output to the power amplifier circuit according to the third target control quantity.

2. The radio frequency control circuit according to claim 1, wherein, When the first target control quantity is greater than the control quantity threshold, the signal conversion circuit is used to output a pulse drive signal according to a preset duty cycle; when the first target control quantity is less than the control quantity threshold, the signal conversion circuit is used to output a pulse drive signal according to a duty cycle that is proportional to the first target control quantity. The second control circuit is used to output a third target control quantity based on the control quantity deviation between the second target control quantity and the control quantity threshold. The DC power supply is used to output a DC voltage signal that is proportional to the deviation of the control quantity according to the third target control quantity.

3. The radio frequency control circuit according to claim 1 or 2, wherein, The first control circuit includes: a forward feedback control circuit, a reflected power protection circuit, and a comparator circuit, wherein, The forward feedback control circuit is used to receive the forward power setpoint and the forward power feedback value, and output a first control quantity based on the forward power deviation between the forward power setpoint and the forward power feedback value; The reflected power protection circuit is used to receive a reflected power threshold and a reflected power feedback value, and output a second control quantity based on the reflected power deviation between the reflected power threshold and the reflected power feedback value; The comparison circuit is used to select the control quantity that is smaller between the first control quantity and the second control quantity as the first target control quantity and the second target control quantity.

4. The radio frequency control circuit according to claim 3, wherein, If the reflected power feedback value is less than the reflected power threshold, the second control quantity is greater than the first control quantity; When the reflected power feedback value is greater than or equal to the reflected power threshold, the second control quantity is less than the first control quantity.

5. The radio frequency control circuit according to claim 3 or 4, wherein, The first control circuit further includes: a power dissipation protection circuit, wherein, The power dissipation protection circuit is used to receive the power dissipation threshold and the power dissipation feedback value, and output a third control quantity based on the power dissipation deviation between the power dissipation threshold and the power dissipation feedback value; The comparison circuit is used to select the smallest control quantity among the first control quantity, the second control quantity, and the third control quantity as the first target control quantity, and to select the smallest control quantity among the first control quantity and the second control quantity as the second target control quantity.

6. The radio frequency control circuit according to claim 5, wherein, If the power dissipation feedback value is less than the power dissipation threshold, the third control quantity is greater than the first control quantity; When the dissipated power feedback value is greater than or equal to the dissipated power threshold, the third control quantity is less than the first control quantity.

7. The radio frequency control circuit according to any one of claims 1-6, wherein, The first control circuit includes: a forward feedback control circuit, a power dissipation protection circuit, and a comparator circuit, wherein, The forward feedback control circuit is used to receive the forward power setpoint and the forward power feedback value, and output a first control quantity based on the forward power setpoint and the forward power feedback value; The power dissipation protection circuit is used to receive the power dissipation threshold and the power dissipation feedback value, and output a third control quantity based on the power dissipation deviation between the power dissipation threshold and the power dissipation feedback value; The comparison circuit is used to select the control quantity that is smaller between the first control quantity and the third control quantity as the first target control quantity, and to select the first control quantity as the second target control quantity.

8. The radio frequency control circuit according to any one of claims 5 to 7, wherein, Also includes: The power dissipation calculation circuit, in which, The power dissipation calculation circuit is used to determine the power dissipation feedback value based on the reflected power feedback value, the forward power feedback value, and the voltage and current values ​​of the DC voltage signal.

9. A radio frequency power supply, wherein, include: The power amplifier circuit, the sampling circuit, and the radio frequency control circuit as described in any one of claims 1 to 8, wherein, The sampling circuit is connected to the power amplifier circuit and the radio frequency control circuit respectively, and is used to collect the forward power feedback value and the reflected power feedback value. The radio frequency control circuit is used to receive the forward power feedback value and the reflected power feedback value provided by the sampling circuit, and to generate the pulse drive signal and the DC voltage signal; The power amplifier circuit is used to generate a radio frequency signal based on the pulse drive signal and the DC voltage signal.

10. A radio frequency power supply control method, wherein, The radio frequency power supply control method, applied to the radio frequency power supply of claim 9, comprises: Obtain the forward power setpoint, forward power feedback value, and control threshold of the power amplifier circuit; Based on the forward power setpoint and the forward power feedback value, a first target control quantity and a second target control quantity are generated; A pulse drive signal is generated based on the first target control quantity; A third target control quantity is output based on the second target control quantity and the control quantity threshold. Adjust the DC voltage signal according to the third target control quantity; The power amplifier circuit adjusts the output radio frequency signal according to the DC voltage signal and the pulse drive signal.

11. The radio frequency power supply control method according to claim 10, wherein, Based on the forward power setpoint and the forward power feedback value, a first target control quantity and a second target control quantity are generated, including: Obtain the reflected power threshold and the reflected power feedback value; A first control quantity is generated based on the forward power deviation between the forward power setpoint and the forward power feedback value; A second control quantity is generated based on the reflection power deviation between the reflection power threshold and the reflection power feedback value; The smaller of the first control quantity and the second control quantity is determined as the first target control quantity and the second target control quantity.

12. The radio frequency power supply control method according to claim 10 or 11, wherein, Based on the forward power setpoint and the forward power feedback value, a first target control quantity and a second target control quantity are generated, including: Obtain the power dissipation threshold, power dissipation feedback value, reflected power threshold, and reflected power feedback value; A first control quantity is generated based on the forward power deviation between the forward power setpoint and the forward power feedback value; A second control quantity is generated based on the reflection power deviation between the reflection power threshold and the reflection power feedback value; A third control quantity is generated based on the power dissipation deviation between the power dissipation threshold and the power dissipation feedback value; The smallest of the first control quantity, the second control quantity, and the third control quantity is determined as the first target control quantity; Furthermore, the smaller of the first control quantity and the second control quantity is determined as the second target control quantity.

13. The radio frequency power supply control method according to any one of claims 10-12, wherein, Based on the forward power setpoint and the forward power feedback value, a first target control quantity and a second target control quantity are generated, including: Obtain the power dissipation threshold and the power dissipation feedback value; A first control quantity is generated based on the forward power deviation between the forward power setpoint and the forward power feedback value; A third control quantity is generated based on the power dissipation deviation between the power dissipation threshold and the power dissipation feedback value; The control quantity that is smaller between the first control quantity and the third control quantity is determined as the first target control quantity, and the first control quantity is determined as the second target control quantity.

14. A semiconductor process apparatus, wherein, include: The process chamber and at least one radio frequency power supply as described in claim 9, 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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