Radio frequency driving circuit and radio frequency power supply

Abstract

The application provides a radio frequency driving circuit and a radio frequency power supply, wherein the radio frequency driving circuit comprises a driving module and a control module; the driving module is used for providing a driving signal to the gate of a radio frequency transistor, so as to drive the radio frequency transistor to periodically turn on and turn off, and make the power amplifier circuit perform radio frequency output; and the control module is used for superimposing an amplified adjusting signal on the gate of the radio frequency transistor, so as to adjust the driving signal, and thus control the drain-source current of the radio frequency transistor. The scheme can effectively improve the driving efficiency of the power amplifier circuit.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and in particular to a radio frequency (RF) drive circuit and an RF power supply. Background Technology

[0002] A radio frequency (RF) power supply is an energy conversion device used to convert power input from mains frequency AC to RF power. It is commonly used in semiconductor processes such as plasma etching, vapor deposition, and sputtering. For example... Figure 1 As shown, the RF power supply 10 of the related technology includes a power amplifier circuit 11 and an RF drive circuit 12, which is used to drive the power amplifier circuit 11 to output RF signals. Summary of the Invention

[0003] This application provides an RF driving circuit and an RF power supply to solve the technical problems existing in related technologies.

[0004] The first aspect of this application provides a radio frequency (RF) driving circuit for driving a power amplifier circuit. The power amplifier circuit has an RF transistor. The RF driving circuit includes a driving module and a control module. The driving module provides a driving signal to the gate of the RF transistor to drive the RF transistor to periodically turn on and off, so that the power amplifier circuit can output RF signals. The control module amplifies an adjustment signal and superimposes it on the gate of the RF transistor to adjust the driving signal, thereby controlling the drain-source current of the RF transistor.

[0005] In one embodiment, the control module includes a controller, an adjustment signal generation submodule, and a signal amplification submodule; the controller is used to determine and control the adjustment signal generation submodule to generate a corresponding adjustment signal based on a preset radio frequency power and the radio frequency power fed back by the power amplification circuit; the signal amplification submodule is used to amplify the adjustment signal and transmit it to the gate of the radio frequency transistor.

[0006] In one embodiment, the signal amplification submodule includes a differential operation subcircuit and an integral operation subcircuit. The differential operation subcircuit is used to differentially amplify the adjustment signal; the integral operation subcircuit is used to stabilize the differentially amplified adjustment signal and then transmit the differentially amplified adjustment signal to the gate of the radio frequency transistor after inverting proportional amplification.

[0007] In one embodiment, the differential operational sub-circuit includes a first operational amplifier, a first resistor, a second resistor, a third resistor, and a fourth resistor. The first resistor is connected between the adjustment signal generation sub-module and the inverting input terminal of the first operational amplifier. The second resistor is connected between the inverting input terminal and the output terminal of the first operational amplifier. The first terminal of the third resistor is used to connect to a reference voltage signal, and the second terminal of the third resistor is connected to the non-inverting input terminal of the first operational amplifier. The non-inverting input terminal of the first operational amplifier is grounded through the fourth resistor.

[0008] And / or, the integral operation sub-circuit includes a second operational amplifier, a fifth resistor, a sixth resistor, and a first capacitor. The fifth resistor is connected between the output terminal of the differential operation sub-circuit and the inverting input terminal of the second operational amplifier. The first capacitor is connected between the inverting input terminal and the output terminal of the second operational amplifier. The sixth resistor is connected between the inverting input terminal of the second operational amplifier and the gate of the RF transistor. The non-inverting input terminal of the second operational amplifier is grounded, so that the differentially amplified adjustment signal is transmitted to the gate of the RF transistor after being inverted and proportionally amplified by the fifth and sixth resistors.

[0009] In one embodiment, the control module further includes a voltage clamping submodule, which is connected between the signal amplification submodule and the gate of the RF transistor, and is used to clamp the gate voltage of the RF transistor within the preset voltage range when the drive signal exceeds the preset voltage range.

[0010] In one embodiment, the voltage clamping submodule includes: a first clamping transistor, the gate of which is connected to the signal amplification submodule, the source of which is connected to the gate of the RF transistor, and the drain of which is connected to a first preset voltage, and a parasitic diode is connected between the drain and the source of the first clamping transistor; and / or, a second clamping transistor, the gate of which is connected to the output terminal of the signal amplification submodule, the source of which is connected to the gate of the RF transistor, the drain of which is connected to a second preset voltage, and a parasitic diode is connected between the source and the drain of the second clamping transistor.

[0011] In one embodiment, the control module further includes a voltage protection submodule, which is connected between the signal amplification submodule and the gate of the RF transistor and is connected to the controller. The voltage protection submodule is used to disconnect the connection between the signal amplification submodule and the gate of the RF transistor and control the RF transistor to turn off when a protection command is received from the controller.

[0012] In one embodiment, the voltage protection submodule has a first input terminal, a second input terminal, a control terminal, and an output terminal. The first input terminal is connected to the signal amplification submodule, the second input terminal is used to connect to a third preset voltage, the control terminal is connected to the controller, and the output terminal is connected to the gate of the RF transistor. The controller is used to send a protection command to the control terminal when it is determined that a fault has occurred in the RF drive circuit, so that the first input terminal is disconnected from the output terminal and the second input terminal is connected to the output terminal.

[0013] In one embodiment, the control module further includes a transformer, the input side of which is connected to the drive module, the first end of the output side of which is connected to the control module, and the second end of the output side of which is connected to the gate of the radio frequency transistor, so as to superimpose the amplified adjustment signal after the drive signal is transformed.

[0014] In one embodiment, the control module further includes a voltage generation submodule and a second capacitor. The voltage generation submodule is used to provide a first voltage signal to a first terminal of the output side of the transformer, and the second capacitor is connected between the voltage generation submodule and the first terminal of the output side of the transformer.

[0015] In one implementation, the control module further includes a digital isolator connected between the controller and the regulation signal generation submodule.

[0016] A second aspect of this application provides an RF power supply, including a power amplifier circuit and an RF driving circuit of any of the above-described embodiments, wherein the RF driving circuit is used to drive the power amplifier circuit to perform RF output.

[0017] The advantages or beneficial effects of the above technical solution include at least the following: In the process of the driving module providing a driving signal to the gate of the RF transistor and using the driving signal to control the RF transistor to periodically turn on and off, so that the power amplifier circuit can output RF power, the control module can amplify the rate of change of the gate-source voltage of the RF transistor by amplifying the small adjustment signal and superimposing it on the gate of the RF transistor, thereby increasing the control speed of the source-drain current of the RF transistor output, and thus improving the control efficiency of the RF power output of the power amplifier circuit, which can effectively improve the driving efficiency of the power amplifier circuit. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Furthermore, these drawings and textual descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this application to those skilled in the art through reference to specific embodiments.

[0019] Figure 1 The diagram shows a partial structural schematic of a radio frequency power supply in a related technology.

[0020] Figure 2 The diagram shown is a schematic representation of the connection between the radio frequency driving circuit and the power amplifier circuit according to an embodiment of this application.

[0021] Figure 3 The figure shown is a schematic diagram of the output characteristic curve of an RF transistor.

[0022] Figure 4 As shown Figure 2 A structural diagram of the middle section.

[0023] Figure 5A The diagram shows the effect of adjusting the gate-source voltage of a radio frequency transistor.

[0024] Figure 5BThe diagram shows another effect of adjusting the gate-source voltage of an RF transistor.

[0025] Figure 6 The diagram shown is a schematic representation of the connection relationship between the radio frequency driving circuit and the power amplifier circuit according to another embodiment of this application. Detailed Implementation

[0026] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0027] Figure 1 The diagram shows a partial structural schematic of a radio frequency power supply in a related technology.

[0028] like Figure 1 As shown in the related technology, the RF power supply 10 includes a power amplifier circuit 11 and an RF drive circuit 12. The power amplifier circuit 11 includes an RF transistor M1, a first inductor L1, a second inductor L2, and a first capacitor C11. The RF drive circuit 12 includes a drive module 12A and a control module 12B. The control module 12B includes a controller 121 and a voltage generation submodule 122. The drive module 12A provides a drive signal Vin to the gate G of the RF transistor M1 to drive the RF transistor M1 to turn on or off. The controller 121 in the control module 12B controls the voltage generation submodule 122 to provide a first voltage signal -U to the first terminal of the RF transistor M1 and a second voltage signal +U to the first terminal of the first inductor L1 to control the magnitude of the source-drain current output by the RF transistor M1. When the RF transistor M1 is turned on, the first inductor L1 is charged by the drain-source current of the RF transistor M1. The second terminal of the first inductor L1 generates a first half-power signal with a waveform in the negative half-cycle. The first half-power signal is filtered by the filter circuit composed of the second inductor L2 and the first capacitor C11 and then output. When the RF transistor M1 is turned off, the first inductor L1 discharges, and the second terminal of the first inductor L1 generates a second half-power signal with a waveform in the positive half-cycle. The second half-power signal is filtered by the filter circuit composed of the second inductor L2 and the first capacitor C11 and then output, so that the power amplifier circuit 11 outputs the RF signal Vout, realizing RF output.

[0029] In related technologies, the controller 121 adjusts the source-drain current of the RF transistor M1 by controlling the magnitude of the first voltage signal -U output to the first terminal and the second voltage signal +U output to the second terminal of the voltage generation submodule 122. The RF transistor M1 can be an NMOS transistor, with the first terminal being the source and the second terminal being the drain D. That is, by adjusting the drain-source voltage of the RF transistor M1, the drain-source current of the RF transistor M1 is adjusted, thereby regulating the RF power output of the power amplifier circuit 11. For example, a 10V change in either the first voltage signal -U or the second voltage signal +U corresponds to a 50W change in the RF power output of the power amplifier circuit 11. However, due to the relatively long response time of the voltage generation submodule 122 (e.g., a 10V change in the output voltage signal requires several hundred microseconds), the change rate of the source-drain current of the RF transistor M1 is slow, resulting in low driving efficiency of the power amplifier circuit 11.

[0030] Based on this, embodiments of this application provide a radio frequency driving circuit and a radio frequency power supply, which can effectively solve the technical problems existing in related technologies. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0031] Figure 2 The diagram shown is a schematic diagram of the connection relationship between the radio frequency driving circuit and the power amplifier circuit according to an embodiment of this application, that is, a partial schematic diagram of the radio frequency power supply.

[0032] like Figure 2 As shown, the RF drive circuit 12 drives the power amplifier circuit 11, which has an RF transistor M1. The RF drive circuit 12 includes a drive module 12A and a control module 12B. The drive module 12A provides a drive signal Vin to the gate G of the RF transistor M1, causing the RF transistor M1 to periodically turn on and off, enabling the power amplifier circuit 11 to output RF signals. The control module 12B amplifies the adjustment signal VDAC and superimposes it onto the gate G of the RF transistor M1 to adjust the drive signal Vin, thereby controlling the drain-source current output by the RF transistor M1.

[0033] For example, such as Figure 3As shown, there is a positive correlation between the gate-source voltage VGS of the RF transistor M1 and its output drain-source current IDS. That is, when the gate-source voltage VGS of the RF transistor M1 increases, the conduction angle between the drain D and the source S of the RF transistor M1 increases, and the drain-source current IDS of the RF transistor M1 increases accordingly. Furthermore, there is a positive correlation between the drain-source current IDS output by the RF transistor M1 and the RF power output by the power amplifier circuit 11. Therefore, when the source voltage of the RF transistor M1 remains constant, the gate-source voltage VGS of the RF transistor M1 can be adjusted by adjusting the magnitude of the drive signal Vin applied to the gate G of the RF transistor M1, thereby adjusting the drain-source current IDS output by the RF transistor M1. This allows the RF power output by the power amplifier circuit 11 to change with the drain-source current IDS of the RF transistor M1, thus achieving the adjustment of the RF power output by the power amplifier circuit 11.

[0034] During the adjustment process, the range of the adjustment signal VDAC can be 0V to 3V (including the endpoint value), and the range of the amplified adjustment signal VBIas can be -11V to 4V (including the endpoint value). For every 1V change in the adjustment signal VDAC, the amplified adjustment signal VBIas will change by 5V, which in turn causes the gate voltage of the RF transistor M1 to change by 5V accordingly. This achieves a 5V change in the gate-source voltage VGS of the RF transistor M1 for every 1V change in the adjustment signal VDAC, thereby accelerating the change rate of the gate-source voltage VGS and drain-source current IDS of the RF transistor M1 and improving the control speed of the output RF power of the power amplifier circuit 11.

[0035] In the above scheme, when the driving module 12A provides a driving signal Vin to the gate G of the RF transistor M1 and uses the driving signal Vin to control the RF transistor M1 to periodically turn on and off, enabling the power amplifier circuit 11 to output RF power, the control module 12B amplifies the smaller adjustment signal VDAC and superimposes it on the gate G of the RF transistor M1. This amplifies the rate of change of the gate-source voltage VGS of the RF transistor M1, increases the control speed of the source-drain current IDS output by the RF transistor M1, thereby improving the control efficiency of the RF power output by the power amplifier circuit 11 and effectively improving the driving efficiency of the power amplifier circuit 11.

[0036] In one implementation, such as Figure 2 and Figure 4As shown, the control module 12B includes a controller 121, a modulation signal generation submodule 123, and a signal amplification submodule 124. The controller 121 determines and controls the modulation signal generation submodule 123 to generate a corresponding modulation signal VDAC based on a preset RF power and the RF power fed back from the power amplifier circuit 11. The signal amplification submodule 124 amplifies the modulation signal VDAC and transmits it to the gate G of the RF transistor M1, that is, it amplifies the modulation signal VDAC to obtain an amplified modulation signal VBIas, and transmits the amplified modulation signal VBIas to the gate G of the RF transistor M1.

[0037] For example, the adjustment signal generation submodule 123 can be a digital-to-analog converter (DAC). The controller 121 compares the preset RF power with the RF power fed back from the power amplifier circuit 11, and determines the adjustment signal VDAC based on the comparison result. This controls the DAC to generate the corresponding adjustment signal VDAC, which is then amplified by the signal amplification submodule 124 and transmitted to the gate G of the RF transistor M1. This adjustment regulates the RF power output by the power amplifier circuit 11 by adjusting the gate-source voltage VGS of the RF transistor M1. The adjustment signal generation submodule 123 can be an external, independent chip of the controller 121, or it can be a module integrated within the controller 121. This embodiment does not limit the configuration of the adjustment signal generation submodule 123.

[0038] In practical applications, when the controller 121 controls the voltage generation submodule 122 to provide a first voltage signal -U to the first terminal of the RF transistor M and a second voltage signal +U to the first terminal of the first inductor L1, if voltage ripple is generated due to large variations in the first voltage signal -U and the second voltage signal +U, it will cause instability in the RF power output of the power amplifier circuit 11. The above-mentioned adjustment method can effectively improve the impact of voltage ripple on the power amplifier circuit 11 and effectively improve the stability of the RF power output of the power amplifier circuit 11.

[0039] Preferably, the control period for the controller 121 to control the digital-to-analog converter to generate the adjustment signal VDAC is several μs, for example, 5 μs, and the signal amplification submodule 124 is an analog circuit with a fast response speed, so that the drive signal Vin can be adjusted within tens of μs, for example, 10 μs, which can effectively improve the adjustment efficiency of the control module 12B on the drive signal Vin, thereby improving the control speed of the RF power output by the power amplifier circuit 11.

[0040] In one implementation, such as Figure 2 and Figure 4As shown, the signal amplification submodule 124 includes a differential operation subcircuit 124A and an integral operation subcircuit 124B. The differential operation subcircuit 124A is used to differentially amplify the adjustment signal VDAC, and the integral operation subcircuit 124B is used to stabilize the differentially amplified adjustment signal V2 and then perform an inverting proportional amplification of the differentially amplified adjustment signal V2 before transmitting it to the gate G of the RF transistor M1, that is, to transmit the amplified adjustment signal VBIas to the gate G of the RF transistor M1.

[0041] For example, the differential operation sub-circuit 124A and the integral operation sub-circuit 124B are connected in series between the adjustment signal generation sub-module 123 and the gate G of the RF transistor M1. This allows the adjustment signal VDAC to be differentially amplified by the differential operation sub-circuit 124A and then inverted proportionally amplified by the integral operation sub-circuit 124B before being transmitted to the gate G of the RF transistor M1. This enables the output of the amplified adjustment signal VBIas to the gate G of the RF transistor M1 to adjust the drive signal Vin. Furthermore, the integral operation sub-circuit 124B is also used to stabilize the differentially amplified adjustment signal V2 output by the differential operation sub-circuit 124A, preventing the differentially amplified adjustment signal V2 from rising or falling too quickly, thus making the adjustment process of the drive signal Vin smoother and more stable.

[0042] Among them, such as Figure 2 and Figure 4 As shown, the differential operational sub-circuit 124A includes a first operational amplifier OP1, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4. The first resistor R1 is connected between the adjustment signal generation sub-module 123 and the inverting input terminal of the first operational amplifier OP1. The second resistor R2 is connected between the inverting input terminal and the output terminal of the first operational amplifier OP1. The first terminal of the third resistor R3 is used to connect to the reference voltage signal VREF, and the second terminal of the third resistor R3 is connected to the non-inverting input terminal of the first operational amplifier OP1. The non-inverting input terminal of the first operational amplifier OP1 is grounded through the fourth resistor R4.

[0043] Based on the characteristics of the operational amplifier, the relationship between the adjustment signal VDAC, the voltage signal V1 at the non-inverting input of the first operational amplifier OP1, and the differentially amplified voltage signal V2 output from the output can be expressed by the following formula (1):

[0044]

[0045] The relationship between the voltage signal V1 at the inverting input terminal of the first operational amplifier OP1 and the reference voltage signal VREF can be expressed by the following formula (2):

[0046]

[0047] According to formulas (1) and (2), the relationship between the differential discharge adjustment signal V2 and the adjustment signal VDAC output by the first operational amplifier OP1 can be expressed by the following formula (3):

[0048]

[0049] Based on this, the adjustment signal VDAC can be differentially amplified to obtain the differentially amplified adjustment signal V2.

[0050] Among them, such as Figure 2 and Figure 4 As shown, the integral operation sub-circuit 124B includes a second operational amplifier OP2, a fifth resistor R5, a sixth resistor R6, and a first capacitor C21. The fifth resistor R5 is connected between the output terminal of the differential operation sub-circuit 124A and the inverting input terminal of the second operational amplifier OP2. The first capacitor C21 is connected between the inverting input terminal and the output terminal of the second operational amplifier OP2. The sixth resistor R6 is connected between the inverting input terminal of the second operational amplifier OP2 and the gate G of the RF transistor M1. The non-inverting input terminal of the second operational amplifier OP2 is grounded, so that the differentially amplified adjustment signal V2 is transmitted to the gate G of the RF transistor M1 after being inverted and proportionally amplified by the fifth resistor R5 and the sixth resistor R6.

[0051] In this embodiment, the sixth resistor R6 is connected between the inverting input and output of the second operational amplifier OP2, which is equivalent to the feedback resistor of the integral operation sub-circuit 124B. It provides a feedback loop for the first capacitor C21, which can prevent the first capacitor C21 from endlessly charging or discharging, ensuring that the voltage on the first capacitor C21 is 0V, so that the second operational amplifier OP2 maintains the virtual short characteristic, that is, the voltage at the non-inverting input of the second operational amplifier OP2 is equal to the voltage at the inverting input. According to the virtual short characteristic of the operational amplifier, the relationship between the final amplified adjustment signal VBIas and the differentially amplified adjustment signal V2 can be expressed by the following formula (4):

[0052]

[0053] As can be seen from formula (4), the integral operation sub-circuit 124B can perform inverted proportional amplification on the differential amplified adjustment signal V2 and output it to the gate G of the RF transistor M1.

[0054] Preferably, the integral operation sub-circuit 124B may further include a third capacitor C23, which is connected in parallel across the sixth resistor R6 to filter the signal fed back to the inverting input of the second operational amplifier OP2, thereby further reducing the impact on the differentially amplified adjustment signal V2.

[0055] Furthermore, based on formulas (3) and (4), the amplified adjustment signal can also be expressed by the following formula (5):

[0056]

[0057] As can be seen from formula (5), there is a positive correlation between the adjustment signal VDAC and the amplified adjustment signal BVIas.

[0058] Based on this, the differentially amplified adjustment signal V2 can be amplified by an inverting amplifier to obtain the amplified adjustment signal VBIas, and the amplified adjustment signal VBIas can be transmitted to the gate G of the RF transistor M1 to adjust the drive signal Vin.

[0059] In one implementation, such as Figure 2 and Figure 4 As shown, the control module 12B also includes a voltage clamping submodule 125, which is connected between the signal amplification submodule 124 and the gate G of the RF transistor M1. It is used to clamp the drive signal Vin within the preset voltage range when the drive signal Vin exceeds the preset voltage range.

[0060] For example, such as Figure 2 and Figure 4 As shown, the voltage clamping submodule 125 includes a first clamping transistor P1. The gate G of the first clamping transistor P1 is connected to the signal amplification submodule 124, specifically, the gate G of the first clamping transistor P1 is connected to the output terminal of the integration operation subcircuit 124B. The source S of the first clamping transistor P1 is connected to the gate G of the RF transistor M1. The drain D of the first clamping transistor P1 is connected to a first preset voltage -VCC1. A parasitic diode is connected between the drain D and the source S of the first clamping transistor P1. When the driving signal Vin is less than the minimum value of the preset voltage range, the parasitic diode of the first clamping transistor P1 is turned on, connecting the first preset voltage -VCC1 to the gate G of the RF transistor M1, clamping the driving signal Vin to the first preset voltage -VCC1. The first clamping transistor P1 can be a PMOS transistor. Both the minimum value of the preset voltage range and the first preset voltage -VCC1 are negative voltages, and the minimum value of the preset voltage range is less than the first preset voltage -VCC1. The first preset voltage -VCC1 can be -8V.

[0061] In addition, the voltage clamping submodule 125 also includes a second clamping transistor M2. The gate G of the second clamping transistor M2 is connected to the output terminal of the integration operation subcircuit 124B, the source S of the second clamping transistor M2 is connected to the gate G of the RF transistor M1, and the drain D of the second clamping transistor M2 is connected to a second preset voltage VCC1. A parasitic diode is connected between the source S and the drain D of the second clamping transistor M2. When the driving signal Vin is greater than the maximum value of the preset voltage range, the parasitic diode of the second clamping transistor M2 is turned on, connecting the second preset voltage VCC1 to the gate G of the RF transistor M1, clamping the driving signal Vin to the second preset voltage VCC1. The second clamping transistor M2 can be an NMOS transistor. Both the maximum value of the preset voltage range and the second preset voltage VCC1 are positive voltages, and the maximum value of the preset voltage range is greater than the second preset voltage VCC1. The second preset voltage VCC1 can be 8V.

[0062] The voltage clamping submodule 125 also includes a seventh resistor R7, which is connected between the gate G and source S of the first clamping transistor P1 and between the gate G and source S of the second clamping transistor M2, so as to provide bias voltage to the first clamping transistor P1 and the second clamping transistor M2, ensuring that the first clamping transistor P1 and the second clamping transistor M2 can work normally when the drive signal Vin is within the preset voltage range.

[0063] The above solution involves setting a voltage clamping submodule 125 between the signal amplification submodule 124 and the gate G of the RF transistor M1. This voltage clamping submodule 125 clamps the drive signal Vin within a preset voltage range when the drive signal Vin exceeds this range. This way, when the drive signal Vin becomes uncontrolled, it can be clamped within a certain range, which helps improve the stability of the drive signal Vin regulation.

[0064] In one implementation, such as Figure 2 and Figure 4 As shown, the control module 12B also includes a voltage protection submodule 126. The voltage protection submodule 126 is connected between the signal amplification submodule 124 and the gate G of the RF transistor M1, and is connected to the controller 121. It is used to disconnect the connection between the signal amplification submodule 124 and the gate G of the RF transistor M1 and control the RF transistor M1 to turn off when it receives a protection command sent by the controller 121.

[0065] For example, the voltage protection submodule 126 has a first input terminal 1261, a second input terminal 1262, a control terminal 1263, and an output terminal 1264. The first input terminal 1261 is connected to the signal amplification submodule 124, the second input terminal 1262 is used to connect a third preset voltage -VCC2, the control terminal 1263 is connected to the controller 121, and the output terminal 1264 is connected to the gate G of the RF transistor M1. The controller 121 is used to determine whether the RF drive circuit 12 has malfunctioned. If the controller 121 determines that the RF drive circuit 12 has malfunctioned, the controller 121 sends a protection command to the control terminal 1263 of the voltage protection submodule 126, causing the first input terminal 1261 to disconnect from the output terminal 1264 and connecting the second input terminal 1262 to the output terminal 1264. This allows the third preset voltage -VCC2 to be transmitted to the gate G of the RF transistor M1, controlling the RF transistor M1 to turn off, thereby disconnecting the connection between the RF drive circuit 12 and the power amplification circuit 11, thus providing a shutdown protection function. If the controller 121 determines that the RF drive circuit 12 is not faulty, the controller 121 sends a working command to the control terminal of the voltage protection submodule 126, connecting the first input terminal 1261 and the output terminal 1264, and disconnecting the second input terminal 1262 and the output terminal 1264, thereby controlling the disconnection between the RF drive circuit 12 and the power amplifier circuit 11, so that the RF drive circuit 12 can drive the power amplifier circuit 11. The third preset voltage -VCC2 can be -11V.

[0066] In one application scenario, the controller 121 can periodically control the connection and disconnection between the signal amplification submodule 124 and the gate G of the RF transistor M1, so that the power amplifier circuit 11 generates pulsed RF power.

[0067] In one example, the voltage protection submodule 126 can be composed of an analog switch, for example, the first input terminal 1261 and the output terminal 1264 of the voltage protection submodule 126 are connected by a first analog switch (see attached diagram). Figure 4 (Unmarked in the text) is connected, and the second input terminal 1262 and output terminal 1264 of the voltage protection submodule 126 are connected via a second analog switch (attached). Figure 4 (Unmarked) The control terminals of both the first and second analog switches are connected to the controller 121. Thus, the controller 121 can achieve the above control by controlling the on / off state of the first and second analog switches. In another example, the first and second analog switches in the voltage protection submodule 126 can also be replaced one-to-one with a first relay and a second relay, achieving a similar control as described above.

[0068] Preferably, the first input terminal 1261 of the voltage protection submodule 126 can be connected to the output terminal of the integration sub-circuit 124B in the signal amplification submodule 124 via the eighth resistor R8. The output terminal 1264 of the voltage protection submodule 126 can be connected to the seventh resistor R7 in the voltage clamping submodule 125 via the ninth resistor R9. The seventh resistor R7 is connected to the gate G of the RF transistor M1 via the tenth resistor R10, so that the voltage protection submodule 126 is connected between the signal amplification submodule 124 and the gate G of the RF transistor M1. The resistance values ​​of the eighth resistor R8, the ninth resistor R9, and the tenth resistor R10 are all small and can be ignored.

[0069] In one implementation, such as Figure 2 As shown, the control module 12B also includes a transformer T1. The input side of the transformer T1 is connected to the drive module 12A, the first end of the output side of the transformer T1 is connected to the control module 12B, and the second end of the output side of the transformer T1 is connected to the gate G of the radio frequency transistor M1, so as to superimpose the amplified adjustment signal VBIas after the drive signal Vin is transformed.

[0070] For example, the driving module 12A is used to provide a square wave signal to the input side of the transformer T1. The transformer T1 is used to transform the square wave signal to obtain a driving signal Vin, and output the driving signal Vin from the output side, so that the driving signal Vin is superimposed with the amplified adjustment signal BVIas to adjust the amplitude of the driving signal Vin, thereby adjusting the drain-source current of the radio frequency transistor M1 by adjusting the amplitude of the gate voltage of the radio frequency transistor M1.

[0071] For example, the drive signal Vin output by transformer T1 can be a square wave signal with a maximum value of 12.5V, a minimum value of -12.5V, a frequency of 13.56MHz, a duty cycle of 50%, and a phase difference of 180°. Figure 5A As shown, when the amplified adjustment signal VBIas = 0V, the superimposed signal is a square wave signal with equal amplitudes in the positive and negative half-cycles, i.e., the waveform of the gate-source voltage VGS of the RF transistor M1 is as follows. Figure 5A As shown; Figure 5B As shown, when the amplified adjustment signal VBIas = -3V, the superimposed signal is a square wave signal with a positive half-cycle amplitude smaller than the negative half-cycle amplitude, i.e., the waveform of the gate-source voltage VGS of the RF transistor M1 is as follows. Figure 5B As shown. Thus, the drain-source current of RF transistor M1 can be adjusted by regulating the amplitude of the positive half-cycle of the gate-source voltage VGS of RF transistor M1.

[0072] In one implementation, such as Figure 2As shown, the control module 12B also includes a voltage generation submodule 122 and a second capacitor C22. The voltage generation submodule 122 provides a first voltage signal -U to the first terminal of the output side of the transformer T1, and the second capacitor C22 is connected between the voltage generation submodule 122 and the first terminal of the output side of the transformer T1. Thus, when the voltage generation submodule 122 provides the first voltage signal -U to the first terminal of the output side of the transformer T1, the second capacitor C22 can filter out the ripple of the first voltage signal -U, preventing sudden changes in the gate voltage of the RF transistor M1 caused by abrupt changes in the first voltage signal -U.

[0073] Preferably, such as Figure 2 As shown, the power amplifier circuit 11 also includes a first inductor L1, a second inductor L2 and a first capacitor C11. The first end of the first inductor L1 is connected to the voltage generation submodule 122 to receive the second voltage signal +U. The second end of the first inductor L1 is connected to the second terminal of the radio frequency transistor M1 and the first end of the second inductor L2, respectively. The second end of the second inductor L2 is connected to the first capacitor C11.

[0074] In this circuit, the radio frequency (RF) transistor M1 is an NMOS transistor, with its first terminal being the source (S) and its second terminal being the drain (D). The voltage generation submodule 122 provides a first voltage signal -U to the source (S) of the RF transistor M1 and a second voltage signal +U to the first terminal of the first inductor L1. The voltage values ​​of both the first voltage signal -U and the second voltage signal +U can be fixed. When the first voltage signal -U and the second voltage signal +U supply power to the power amplifier circuit 11, the amplified adjustment signal VBIas controls the RF transistor M1 to turn on and off, thereby outputting an RF signal Vout. This RF signal Vout is filtered by a filter circuit composed of the second inductor L2 and the first capacitor C11 before being output, thus achieving RF output.

[0075] It should be noted that the magnitudes of the first voltage signal -U and the second voltage signal +U can be selected and adjusted according to the actual needs of the radio frequency transistor M1. In this embodiment, the magnitudes of the first voltage signal -U and the second voltage signal +U are not limited.

[0076] In one implementation, such as Figure 6As shown, the control module 12B also includes a digital isolator 127, which is connected between the controller 121 and the adjustment signal generation submodule 123. For example, when the controller 121 and the adjustment signal generation submodule 123 are connected to different grounds, by setting the digital isolator 127 between the controller 121 and the adjustment signal generation submodule 123, the digital isolator 127 can isolate the controller 121 and the adjustment signal generation submodule 123, avoiding mutual interference between them and ensuring the safe and stable operation of the RF drive circuit 12. When the controller 121 and the adjustment signal generation submodule 123 are connected to the same ground, the digital isolator 127 is not required.

[0077] Furthermore, when the control module 12B includes a digital isolator 127, the control module 12B may also include an isolated power supply (not shown in the figures), which supplies power to the digital isolator 127, the regulating signal generation submodule 123, the signal amplification submodule 124, the voltage clamping submodule 125, and the voltage protection submodule 126. When the control module 12B does not include a digital isolator 127, the isolated power supply can be replaced with a linear power supply for power supply.

[0078] like Figure 2 and Figure 6 As shown, this application embodiment also provides an RF power supply 10, including a power amplifier circuit 11 and an RF drive circuit 12 of any of the above embodiments. The RF drive circuit 12 is used to drive the power amplifier circuit 11 to perform RF output. The specific structure of the RF power supply 10 is as described in the above embodiments. Since the RF power supply 10 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0079] In practical applications, because the RF power supply 10 of this embodiment changes RF power rapidly, its response time is fast and its control precision is high. For example, the time required for the RF power supply 10 to go from 0W to full power output is short. Based on this, when the RF power supply 10 is applied to semiconductor process equipment, it helps to improve the process performance and control precision of the semiconductor process. For example, in the etching process, it can improve the uniformity and control precision of etching.

[0080] Furthermore, in this application, unless otherwise expressly specified and limited, the terms "connected," "linked," "stacked," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0081] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A radio frequency driving circuit, characterized in that, For driving a power amplifier circuit, the power amplifier circuit having a radio frequency transistor, the radio frequency driving circuit comprising: A driving module is used to provide a driving signal to the gate of the radio frequency transistor to drive the radio frequency transistor to periodically turn on and off, so that the power amplifier circuit can output radio frequency. The control module is used to amplify the adjustment signal and superimpose it on the gate of the radio frequency transistor to adjust the drive signal, thereby controlling the drain-source current of the radio frequency transistor.

2. The radio frequency driving circuit according to claim 1, characterized in that, The control module includes a controller, a regulation signal generation submodule, and a signal amplification submodule; The controller is used to determine and control the adjustment signal generation submodule to generate a corresponding adjustment signal based on the preset radio frequency power and the radio frequency power fed back by the power amplifier circuit. The signal amplification submodule is used to amplify the adjustment signal and transmit it to the gate of the radio frequency transistor.

3. The radio frequency driving circuit according to claim 2, characterized in that, The signal amplification submodule includes: A differential operation sub-circuit is used to differentially amplify the adjustment signal; An integral operation sub-circuit is used to stabilize the differentially amplified adjustment signal and then transmit the differentially amplified adjustment signal to the gate of the radio frequency transistor after inverting proportional amplification.

4. The radio frequency driving circuit according to claim 3, characterized in that, The differential operational sub-circuit includes a first operational amplifier, a first resistor, a second resistor, a third resistor, and a fourth resistor. The first resistor is connected between the adjustment signal generation sub-module and the inverting input terminal of the first operational amplifier. The second resistor is connected between the inverting input terminal and the output terminal of the first operational amplifier. The first terminal of the third resistor is used to connect to a reference voltage signal, and the second terminal of the third resistor is connected to the non-inverting input terminal of the first operational amplifier. The non-inverting input terminal of the first operational amplifier is grounded through the fourth resistor. And / or, the integral operation sub-circuit includes a second operational amplifier, a fifth resistor, a sixth resistor, and a first capacitor. The fifth resistor is connected between the output terminal of the differential operation sub-circuit and the inverting input terminal of the second operational amplifier. The first capacitor is connected between the inverting input terminal and the output terminal of the second operational amplifier. The sixth resistor is connected between the inverting input terminal of the second operational amplifier and the gate of the RF transistor. The non-inverting input terminal of the second operational amplifier is grounded, so that the differentially amplified adjustment signal is transmitted to the gate of the RF transistor after being inverted and proportionally amplified by the fifth resistor and the sixth resistor.

5. The radio frequency driving circuit according to claim 2, characterized in that, The control module also includes: A voltage clamping submodule is connected between the signal amplification submodule and the gate of the radio frequency transistor, and is used to clamp the gate voltage of the radio frequency transistor within the preset voltage range when the driving signal exceeds the preset voltage range.

6. The radio frequency driving circuit according to claim 5, characterized in that, The voltage clamping submodule includes: The first clamping transistor has its gate connected to the signal amplification submodule, its source connected to the gate of the radio frequency transistor, and its drain connected to a first preset voltage. A parasitic diode is connected between the drain and source of the first clamping transistor. And / or, the second clamping transistor has its gate connected to the output terminal of the signal amplification submodule, its source connected to the gate of the RF transistor, its drain connected to a second preset voltage, and a parasitic diode connected between the source and drain of the second clamping transistor.

7. The radio frequency driving circuit according to claim 2, characterized in that, The control module also includes: A voltage protection submodule is connected between the signal amplification submodule and the gate of the RF transistor, and is connected to the controller. It is used to disconnect the connection between the signal amplification submodule and the gate of the RF transistor and control the RF transistor to turn off when a protection command is received from the controller.

8. The radio frequency driving circuit according to claim 7, characterized in that, The voltage protection submodule has a first input terminal, a second input terminal, a control terminal, and an output terminal. The first input terminal is connected to the signal amplification submodule, the second input terminal is used to connect to a third preset voltage, the control terminal is connected to the controller, and the output terminal is connected to the gate of the RF transistor. When the controller determines that a fault has occurred in the RF drive circuit, it sends the protection command to the control terminal to disconnect the first input terminal from the output terminal and connect the second input terminal to the output terminal.

9. The radio frequency driving circuit according to any one of claims 1 to 8, characterized in that, The control module also includes: The transformer has its input side connected to the drive module, its first output end connected to the control module, and its second output end connected to the gate of the radio frequency transistor, so as to transform the drive signal and then superimpose the amplified adjustment signal.

10. The radio frequency driving circuit according to claim 9, characterized in that, The control module further includes a voltage generation submodule and a second capacitor. The voltage generation submodule is used to provide a first voltage signal to the first terminal of the output side of the transformer, and the second capacitor is connected between the voltage generation submodule and the first terminal of the output side of the transformer.

11. The radio frequency driving circuit according to claim 2, characterized in that, The control module also includes: A digital isolator is connected between the controller and the regulation signal generation submodule.

12. A radio frequency power supply, characterized in that, It includes a power amplifier circuit and a radio frequency driving circuit according to any one of claims 1 to 11, wherein the radio frequency driving circuit is used to drive the power amplifier circuit to perform radio frequency output.

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