Driving circuit, radio frequency power supply and semiconductor process equipment

Abstract

The invention provides a driving circuit, a radio frequency power supply and semiconductor process equipment, belongs to the technical field of radio frequency, and can solve the problems that an existing radio frequency power supply is low in output precision, not timely in adjustment and poor in anti-interference capability. The driving circuit is applied to a radio frequency power supply, and comprises an inverting module which is configured to generate a first input signal and an inverting signal thereof, and generate a second input signal and an inverting signal thereof; the signal amplification module is configured to amplify the first input signal and the inverted signal thereof, and amplify the second input signal and the inverted signal thereof; the signal processing module is configured to generate a first driving signal and a second driving signal; the first input signal and the second input signal are digital signals, and the first driving signal and the second driving signal are analog signals. The radio frequency power supply based on the driving circuit has the advantages of being rapid in response, timely in adjustment, high in output precision and strong in anti-interference capability.

Description

Technical Field

[0001] The present disclosure belongs to the field of radio frequency technology, and in particular relates to a driving circuit, a radio frequency power supply, and semiconductor process equipment. Background Art

[0002] RF power supplies are high-frequency AC power sources capable of generating frequencies between 300kHz and 300MHz. They are widely used in the semiconductor, photovoltaic, and medical aesthetics industries. In the semiconductor industry, RF power supplies are typically used in various types of semiconductor manufacturing equipment, playing roles in exciting plasma and selecting etching directions during the semiconductor process, thereby completing deposition, etching, and cleaning steps.

[0003] Taking etching equipment as an example, after the etching gas enters the reaction chamber, it is ionized by the high-frequency electric field generated by the RF power supply, generating a glow discharge, completing the transformation from gas molecules to ions and forming a plasma. During this process, the stability and accuracy of the RF power supply are directly related to the plasma concentration, uniformity, and stability in the reaction chamber.

[0004] In recent years, with the rapid development of the microelectronics industry, the size of semiconductor devices has gradually decreased, and the integration of semiconductor circuits has become increasingly higher. The smaller the feature size of transistors, the higher the precision requirements of processes such as etching and deposition. Therefore, as the miniaturization of semiconductor processes continues, semiconductor manufacturing equipment has increasingly stringent requirements for the stability and precision of RF power supplies. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. On the one hand, a driving circuit is provided, which is applied to a radio frequency power supply. The driving circuit includes: an inverting module, which is configured to receive a first input signal and a second input signal, and generate a first signal group based on the first input signal, and generate a second signal group based on the second input signal; the first signal group includes the first input signal and its inverted signal, and the second signal group includes the second input signal and its inverted signal; a signal amplification module, which is configured to amplify the first signal group and the second signal group; a signal processing module, which is configured to generate a first driving signal based on the amplified first signal group and generate a second driving signal based on the amplified second signal group; the first input signal and the second input signal are digital signals, and the first driving signal and the second driving signal are analog signals.

[0006] In some examples, the inverting module includes: a first inverting circuit, including a first inverter and a second inverter; the first inverter is configured to receive the first input signal and generate an inverted signal of the first input signal; the input end of the second inverter is connected to the output end of the first inverter, and the second inverter is configured to receive the inverted signal of the first input signal and generate the first input signal; a second inverting circuit, including a third inverter and a fourth inverter; the third inverter is configured to receive the second input signal and generate an inverted signal of the second input signal; the input end of the fourth inverter is connected to the output end of the third inverter, and the fourth inverter is configured to receive the inverted signal of the second input signal and generate the second input signal.

[0007] In some examples, the signal processing module includes: a first tuning subcircuit, configured to tune the amplified first input signal to generate a first tuning signal; a first transformer, configured to receive the first tuning signal and an inverted signal of the amplified first input signal to generate the first drive signal; a second tuning subcircuit, configured to tune the amplified second input signal to generate a second tuning signal; and a second transformer, configured to receive the second tuning signal and an inverted signal of the amplified second input signal to generate the second drive signal.

[0008] Based on the same inventive concept, in a second aspect, the present invention provides a radio frequency power supply, comprising at least one drive circuit as described in any of the above examples, a control module, and a drive signal processing module corresponding one-to-one to the drive circuit; the control module is configured to provide the first input signal and the second input signal to the drive circuit; the drive signal processing module is configured to process the first drive signal and the second drive signal to generate a radio frequency output signal.

[0009] In some examples, a sampling module and an operation module are further included, each corresponding to the drive signal processing module; the sampling module is configured to collect the RF output signal of the corresponding drive signal processing module to generate a sampling signal; the operation module is configured to generate a compensation signal based on the sampling signal and transmit it to the control module; the control module is further configured to adjust the first input signal and / or the second input signal corresponding to each drive circuit based on the compensation signal corresponding to each drive circuit to change the phase difference between the first input signal and the second input signal.

[0010] In some examples, when the RF power supply includes multiple driving circuits, the RF power supply further includes a first synthesizer; the first synthesizer is configured to synthesize the RF output signals to generate a composite RF signal.

[0011] In some examples, a sampling module and an operation module are further included; the sampling module is configured to collect the composite RF signal and generate a sampling signal; the operation module is configured to generate a compensation signal based on the sampling signal and transmit it to the control module; the control module is also configured to adjust the first input signal and / or the second input signal corresponding to at least some of the driving circuits in the multiple driving circuits based on the compensation signal to change the phase difference between the first input signal and the second input signal.

[0012] In some examples, the drive signal processing module includes: a first power amplification circuit configured to amplify the first drive signal; a second power amplification circuit configured to amplify the second drive signal; and a second synthesizer configured to synthesize the amplified first drive signal and the amplified second drive signal to generate the RF output signal.

[0013] In some examples, the sampling module includes: a first sampling circuit configured to acquire the RF output signal and generate a first sampling voltage signal based on the RF output signal; a second sampling circuit configured to acquire the RF output signal and, based on the RF output signal, obtain a first sampling current signal and convert the first sampling current signal into a second sampling voltage signal.

[0014] In some examples, the sampling module includes: a first sampling circuit configured to acquire the composite RF signal and generate a first sampling voltage signal based on the composite RF signal; a second sampling circuit configured to acquire the composite RF signal and obtain a first sampling current signal based on the composite RF signal, and convert the first sampling current signal into a second sampling voltage signal.

[0015] In some examples, the operation module includes: an adder configured to calculate a sum signal based on the first sampled voltage signal and the second sampled voltage signal; a subtractor configured to calculate a difference signal based on the first sampled voltage signal and the second sampled voltage signal; a multiplier configured to calculate the square of the sum signal and the square of the difference signal; an operational amplifier configured to obtain a forward power signal based on the square of the sum signal and to obtain a reflected power signal based on the square of the difference signal; and a data processing unit configured to obtain the compensation signal based on the forward power signal and the reflected power signal.

[0016] Based on the same inventive concept, in the third aspect, the present invention provides a semiconductor process equipment, characterized in that it includes the RF power supply described in any example of the second aspect above, as well as a RF matcher and a process chamber, wherein the RF matcher is connected between the RF power supply and the process chamber.

[0017] The driving circuit provided by the present disclosure has a digital input signal and an analog output signal. When applied to a radio frequency power supply, the radio frequency power supply can produce the following beneficial effects: since the input signals of the radio frequency power supply are two digital signals and the output is an analog signal, the digital signal has good resistance to the influence of the analog signal to a certain extent due to its discreteness. Therefore, the degree of interference between digital signals and analog signals is weaker than the degree of interference between analog signals, and the generation and phase control of digital signals are relatively simple and precise. Therefore, the radio frequency power supply provided by the present disclosure has better anti-interference ability and output accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the modular structure of the radio frequency power supply in the related art.

[0019] Figure 2 This is a schematic diagram of the module structure of the driving circuit provided by the present disclosure.

[0020] Figure 3 for Figure 2 Schematic diagram of the circuit structure of the driving circuit shown.

[0021] Figure 4 Schematic diagram of the waveforms of the first input signal and the second input signal.

[0022] Figure 5 Schematic diagram of the waveforms of the first input signal and its inverted signal.

[0023] Figure 6 Schematic diagram of waveforms of the first input signal, the second input signal, the first driving signal, and the second driving signal.

[0024] Figure 7 This is a schematic diagram of the first module structure of the radio frequency power supply provided by the present disclosure.

[0025] Figure 8 This is a schematic diagram of the second module structure of the radio frequency power supply provided by the present disclosure.

[0026] Figure 9 It is a structural diagram of the driving signal processing module.

[0027] Figure 10 Schematic diagram of the circuit structure of the sampling module.

[0028] Figure 11 Schematic diagram of the module structure of the operation module.

[0029] Figure 12 This is a schematic diagram of the module structure of the semiconductor process equipment provided by the present disclosure.

[0030] Figure 13 This is an exemplary structure of semiconductor process equipment.

[0031] Figure 14 Another exemplary structure of semiconductor process equipment.

[0032] Figure 15 This is another structural schematic diagram of semiconductor process equipment.

[0033] The accompanying drawings are denoted as follows:

[0034] 100, signal input module; 200, first-stage full-bridge drive amplifier module; 300, main full-bridge drive amplifier module; 400, power amplifier; 500, signal input detection protection circuit; 1, drive circuit; 11, inverter module; 12, signal amplifier module; 13, signal processing module; 111, first inverter circuit; 1111, first inverter; 1112, second inverter; 112, second inverter circuit; 1121, third inverter; 1122, fourth inverter; 121, first driver chip; 122, second driver chip; 123, third driver chip; 124, fourth driver chip; 131, first tuning sub-circuit; 132, first transformer; 133, second tuning sub-circuit; 134, second transformer; 2, Control module; 3. Drive signal processing module; 4. Sampling module; 5. Operation module; 6. First synthesizer; 7. Second synthesizer; 41. First sampling circuit; 42. Second sampling circuit; 51. Adder; 52. Subtractor; 53. First filter; 54. Multiplier; 55. Second filter; 56. Operation amplifier; 57. Data processing unit; 801. RF matcher; 802. Process chamber; 91. Upper RF power supply; 92. Upper matcher; 93. Current distribution unit; 94. Etching chamber; 95. Lower RF power supply; 96. Lower matcher; 97. Phase-locked cable; 941. Base; 942. Wafer; 943. Plasma; 944. Nozzle; 945. Dielectric window; 946. Outer coil; 947. Inner coil. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0036] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by people with ordinary skills in the field to which this disclosure belongs. The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "an" or "the" do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0037] As used herein, "parallel" and "perpendicular" include the conditions described and conditions similar to the conditions described, and the range of the similar conditions is within an acceptable deviation range, wherein the acceptable deviation range is determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range for approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range for approximate perpendicularity can also be, for example, a deviation within 5°.

[0038] As used herein, "electrically connected" includes components connected together via an element having some electrical function. There are no specific limitations on "elements having some electrical function" as long as they enable the transfer of electrical signals between connected components. Examples of "elements having some electrical function" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other components having various functions.

[0039] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0040] Before describing the technical solution of the present disclosure in detail, this article first describes the radio frequency power supply in the related art and the technical problems it has.

[0041] Figure 1 This is a schematic diagram of the modular structure of the RF power supply in the related technology. Figure 1 As shown, the RF power supply includes a signal input module, a first-stage full-bridge drive amplifier module, a main-stage full-bridge drive amplifier module, a power amplifier module, and a signal input detection and protection circuit. The signal input module is configured to provide a first drive signal and a second drive signal to the first-stage full-bridge drive amplifier module, and to provide an initial enable signal to the signal input detection and protection circuit; the first-stage full-bridge drive amplifier module is configured to amplify the first drive signal and the second drive signal; the main-stage full-bridge drive amplifier module is configured to amplify the amplified first drive signal and the second drive signal to generate and output an RF power signal; and the power amplifier module is configured to further amplify the RF power signal to generate an RF output signal, which serves as the output of the RF power supply and provides high-frequency voltage for semiconductor manufacturing equipment. In addition, the signal input detection protection circuit is configured to, during initial operation, turn on the output of the RF power supply based on the simultaneous input of the initial enable signal and the first drive signal and the second drive signal of the signal input module; in the subsequent working stage of the RF power supply, generate a working enable signal based on the detected feedback signal, and replace the initial enable signal with the working enable signal, so that the first-stage full-bridge drive amplifier module works, thereby ensuring that the working enable signal is generated only when the feedback signal is normal, and the RF power supply circuit is shut down in time when the output signal is erroneous, thereby protecting the safety of the circuit.

[0042] The RF power supply provided in the above related technologies has at least one of the following technical problems:

[0043] 1. Typically, the first drive signal and the second drive signal are sinusoidal signals of the same frequency, and the signal type is an analog signal; and the RF output signal is also a sinusoidal signal of the same frequency, and its type is also an analog signal. It is understood by those skilled in the art that, due to the continuity of the two analog signals, compared to a digital signal and an analog signal, they are more likely to interfere with each other, thereby generating noise during the transmission of the input signal, thereby affecting the frequency, amplitude, and phase parameters of the output signal. In addition, because the power of the RF output signal, that is, the signal amplitude, is usually much greater than the signal amplitude of the first drive signal and the second drive signal, the first drive signal and the second drive signal with smaller amplitudes are easily interfered with by the RF output signal with larger amplitudes during the transmission process of the entire circuit, which may cause the amplitude, frequency, and phase characteristics of the first drive signal and the second drive signal to be modulated, thereby causing signal distortion in the output signal.

[0044] 2. In a specific implementation, the phase of the first drive signal and the phase of the second drive signal are usually fixed values ​​preset based on the required power of the RF output signal, so that the power of the RF output signal meets the preset power. However, in actual application, due to changes in load impedance or increased reflected power, it is easy for the actual power of the RF output signal to not meet the preset power. In this case, it is necessary to manually change the phase difference between the first drive signal and the second drive signal or change the parameters of certain devices or circuit structures (such as power amplifiers) to achieve the purpose of adjusting the power of the RF output signal. However, manually adjusting the phase or device parameters of the first drive signal and the second drive signal based on the RF output signal has the problem of untimely adjustment and low efficiency.

[0045] In general, the RF power supply provided by the relevant technology has problems such as severe interference between input and output signals, poor circuit adjustment capability, slow adjustment speed, poor anti-interference ability and low fault tolerance.

[0046] In order to solve at least one of the above technical problems, on the one hand, the present disclosure provides a driving circuit applied to a radio frequency power supply.

[0047] Figure 2 This is a schematic diagram of the module structure of the driving circuit provided by the present disclosure, such as Figure 2 As shown, the driving circuit 1 includes: an inverting module 11, a signal amplifying module 12, and a signal processing module 13 connected in sequence. The inverting module 11 is configured to receive a first input signal S1 and a second input signal S2, and generate a first signal group based on the first input signal S1, and a second signal group based on the second input signal S2; specifically, the first signal group includes the first input signal S1 and its inverted signal S1', and the second signal group includes the second input signal S2 and its inverted signal S2'. The signal amplifying module 12 is configured to amplify the first signal group and the second signal group respectively. The signal processing module 13 is configured to generate a first driving signal D1 based on the amplified first input signal S1 and its inverted signal S1', and to generate a second driving signal D2 based on the amplified S2 and its inverted signal S2'. For the driving circuit 1 provided by the present disclosure, the first input signal S1 and the second input signal S2 are digital square wave signals, and the first driving signal D1 and the second driving signal D2 are analog sine wave signals.

[0048] The input signal of the RF power supply of the related art is an analog sine wave signal, and the RF output signal is also an analog sine wave signal, and the amplitude of the RF output signal is much larger than the amplitude of the input signal. Therefore, the output and input signals interfere with each other seriously, resulting in low anti-interference ability of the RF power supply and poor output accuracy. The driving circuit 1 provided in the present disclosure converts two digital square wave signals into two analog sine wave signals. The RF power supply based on this driving circuit 1 also outputs an analog sine wave signal. In terms of the degree of interference, due to the continuity of the analog signal, it is more susceptible to the influence of the analog signal, resulting in noise and signal distortion. However, due to its discreteness, the digital signal has better resistance to the influence of the analog signal to a certain extent. Therefore, the interference degree between the digital signal and the analog signal is weaker than the interference degree between the analog signal and the analog signal. In other words, the RF power supply based on the driving circuit provided in the present disclosure has better anti-interference ability and output accuracy.

[0049] Next, the optional circuit structure of the driving circuit is provided. Figure 3 It is a circuit structure diagram of a driving circuit.

[0050] like Figure 3 As shown, in some examples, the inverting module 11 includes: a first inverting circuit 111 and a second inverting circuit 112. Specifically, the first inverting circuit 111 includes a first inverter 1111 and a second inverter 1112; wherein the first inverter 1111 is configured to receive a first input signal S1, perform an inverting operation on the first input signal S1, and generate an inverted signal S1' of the first input signal S1; the input end of the second inverter 1112 is connected to the output end of the first inverter 1111, and the second inverter 1112 is configured to receive the inverted signal S1' of the first input signal, perform an inverting operation on the inverted signal S1' of the first input signal, and generate the first input signal S1. Similar to the first inverter circuit 111, the second inverter circuit 112 includes a third inverter 1121 and a fourth inverter 1122; wherein, the third inverter 1121 is configured to receive the second input signal S2, perform an inversion operation on the second input signal S2, and generate an inverted signal S2' of the second input signal; the input end of the fourth inverter 1122 is connected to the output end of the third inverter 1121, and the fourth inverter 1122 is configured to receive the inverted signal S2' of the second input signal, perform an inversion operation on the inverted signal S2' of the second input signal, and generate the second input signal S2.

[0051] Exemplarily, the first inverter 1111, the second inverter 1112, the third inverter 1121 and the fourth inverter 1122 can adopt 74 series inverters, CD4011 series inverters, operational amplifier inverters, BJT inverters, MOSFET inverters, level converter chips, etc. Preferably, SN74ACT14DR model inverters can be used.

[0052] Continue to refer to Figure 3 In some examples, the signal amplification module 12 includes a first driver chip 121, a second driver chip 122, a third driver chip 123, and a fourth driver chip 124. The input terminal of the first driver chip 121 is connected to the output terminal of the first inverter 1111 and is configured to amplify the inverted signal S1' of the first input signal; the input terminal of the second driver chip 122 is connected to the output terminal of the second inverter 1112 and is configured to amplify the first input signal S1; the input terminal of the third driver chip 123 is connected to the output terminal of the third inverter 1121 and is configured to amplify the inverted signal S2' of the second input signal; and the input terminal of the fourth driver chip 124 is connected to the output terminal of the fourth inverter 1122 and is configured to amplify the second input signal S2. The signal amplification factor depends on the power supply voltage VCC of the driver chip. The amplitudes of the amplified first input signal S1, the inverted signal S1' of the first input signal, the second input signal S2, and the inverted signal S2' of the second input signal are equivalent to the amplitudes of the power supply voltage VCC of their respective corresponding driver chips.

[0053] Exemplarily, the first driver chip 121, the second driver chip 122, the third driver chip 123 and the fourth driver chip 124 can be driver chips of the IXYS series, the Texas Instruments (TI) series, the Infineon series, the STMicroelectronics series, the ON Semiconductor series, the Microchip series, or the Analog Devices series; preferably, the IXDD630MYI model driver chip in the IXYS series can be used.

[0054] Continue to refer to Figure 3In some examples, the signal processing module 13 includes: a first tuning subcircuit 131, a first transformer 132, a second tuning subcircuit 133, and a second transformer 134. The first tuning subcircuit 131 is configured to tune the amplified first input signal S1 to generate a first tuning signal. The first tuning circuit 131 may include a first inductor L1 and a first capacitor C1 connected in series, wherein a first end of the first inductor L1 is connected to the output end of the second driver chip 122, and a second end of the first capacitor C1 is connected to an input end of the first transformer 132. The first transformer 132 has two input ends and one output end. The other input end of the first transformer 132 is connected to the output end of the first driver chip 121. The first transformer 132 is configured to receive the first tuning signal and an inverted signal S1' of the amplified first input signal to generate a first drive signal D1. The second tuning subcircuit 133 is configured to tune the amplified second input signal S2 to generate a second tuning signal. Specifically, the second tuning circuit 133 may include a second inductor L2 and a second capacitor C2 connected in series. The first end of the second inductor L2 is connected to the output end of the fourth driver chip 124, and the second end of the second capacitor C2 is connected to an input end of the second transformer 134. The second transformer 134 has two input ends and one output end. The other input end of the second transformer 134 is connected to the output end of the third driver chip 123. The second transformer 134 is configured to receive the second tuning signal and an inverted signal S2' of the amplified second input signal to generate the second drive signal D2.

[0055] Exemplarily, the magnetic cores of the first transformer 132 and the second transformer 134 may be made of ferrite, silicon steel, amorphous alloy, nanocrystalline alloy, powder core, Permalloy, iron-nickel alloy, or soft magnetic composite material; for example, 3F4 material may be used.

[0056] It should be noted that, in addition to the LC tuning circuit provided herein, the first tuning sub-circuit 131 and the second tuning sub-circuit 133 may also adopt an RC tuning circuit, a crystal tuning circuit, or a digital tuning circuit, etc., and the present disclosure does not impose any limitation on this.

[0057] For the first input signal S1 and the second input signal S2, the phase difference between the two signals is φ S For the first drive signal D1 and the second drive signal D2, the phase difference between the two signals is φ D It should be noted that the phase difference φ between the first drive signal D1 and the second drive signal D2 generated by the drive circuit 1 provided in the present disclosure is D , and the phase difference φ between the first input signal S1 and the second input signal S2 SThe same. According to the "wave superposition principle", the amplitude of the signal formed by the superposition of two signals depends on the phase difference between the two signals. The wave superposition principle can be described as follows:

[0058] Assume that the first signal Y1 and the second signal Y2 are both sinusoidal signals with the same frequency, ω0, where the phase of the first signal Y1 is α1 and the amplitude is A1, and the phase of the second signal Y2 is α2 and the amplitude is A2. In this case, the first signal Y1 and the second signal Y2 can be expressed by the wave equation (1) and the wave equation (2), respectively:

[0059] Y1=A1×sin(ω0t+α1) (1)

[0060] Y2=A2×sin(ω0t+α2) (2)

[0061] The superimposed signal Y of the first signal Y1 and the second signal Y2 T It can be expressed by the wave equation (3):

[0062]

[0063] From the above wave equation (3), it can be seen that when the first signal Y1 and the second signal Y2 are equal in phase, the superimposed signal Y T The amplitude is the largest; when the phase difference between the first signal Y1 and the second signal Y2 is 180 degrees, the combined superposition signal Y T The amplitude of is minimum and equals to 0. That is, the amplitude of the composite wave depends on the phase difference (α1-α2) between the first signal Y1 and the second signal Y2.

[0064] It can be seen that the power of the RF output signal of the RF power supply depends on the phase difference φ between the first drive signal D1 and the second drive signal D2. D The driving circuit of the present disclosure makes the phase difference φ between the first driving signal D1 and the second driving signal D2 D The phase difference φ between the first input signal S1 and the second input signal S2 S Keeping it consistent, the RF power supply can adjust the phase difference φ between the first input signal S1 and the second input signal S2 S , adjust the phase difference φ between the first drive signal D1 and the second drive signal D2 D, thereby adjusting the power of the RF output signal (the above adjustment process and principles are described in detail below). Those skilled in the art will appreciate that, in the wave generation process, square waves are relatively simpler to generate than sine waves. For example, sine waves typically require analog circuits (such as LC oscillators or RC oscillators), and analog circuits require high component precision and stability. However, square waves can be generated by quickly switching high and low levels using switching circuits (transistors or MOSFETs, etc.). Furthermore, square waves are also relatively easier to control the phase of the wave than sine waves. For example, sine waves generated by analog circuits typically require the use of analog phase shifters (such as RC phase shift networks or LC phase shifters), but the accuracy of analog phase shifters is significantly affected by component parameters, making high-precision control difficult. However, square waves generated by digital circuits can achieve precise phase control using digital delay lines, counters, or FPGAs. Therefore, square wave generation is simpler, phase control is easier and more precise, and compared to related technologies, the output signal power can be precisely controlled.

[0065] Figure 4 Schematic diagram of the waveforms of the first input signal S1 and the second input signal S2. Figure 4 As shown, the first input signal S1 and the second input signal S2 are both square waves, wherein the period of the first input signal S1 is T1, the frequency is ω1, and the amplitude is A; the period of the second input signal S2 is T2, the frequency is ω2, and the amplitude is B. Preferably, the frequencies of the first input signal S1 and the second input signal S2 are the same, that is, ω1=ω2, T1=T2; in this case, the phase difference between the first input signal S1 and the second input signal S2 is Here, δt represents the difference between the starting time of the rising edge of the first input signal S1 and the second input signal S2 in the same cycle, or δt represents the difference between the ending time of the falling edge of the first input signal S1 and the second input signal S2 in the same cycle.

[0066] Figure 5 Schematic diagram of the waveforms of the first input signal S1 and its inverted signal S1'. Figure 5 As shown, the inverted signal S1 ′ of the first input signal S1 has the same frequency and amplitude as the first input signal S1 , but the difference is that the phase difference between the two signals is 180°.

[0067] Figure 6 Schematic diagram of the waveforms of the first input signal S1 and the first drive signal D1, and the second input signal S2 and the second drive signal D2. Figure 5As shown, the first input signal S1 and the second input signal S2 are both square waves, the first drive signal D1 and the second drive signal D2 are both sine waves, with amplitudes A' and B' respectively; and the frequencies of the first drive signal D1, the first input signal S1, the second drive signal D2 and the second input signal S2 are the same. It will be understood by those skilled in the art that Figure 5 The phase difference between the first input signal S1 and the second input signal S2 is For example, at this time, the phase difference φ between the first drive signal D1 and the second drive signal D2 is D Also π.

[0068] Next, the structure and beneficial effects of the radio frequency power supply based on this driving circuit 1 are described in detail.

[0069] In a second aspect, based on the same inventive concept, the present disclosure also provides a radio frequency power supply. Figure 7 This is a schematic diagram of the first module structure of the radio frequency power supply provided by the present disclosure; Figure 8 This is a schematic diagram of the second module structure of the radio frequency power supply provided by the present disclosure.

[0070] The first type of RF power supply is Figure 7 As shown, it includes at least one driving circuit 1 as described in any embodiment of the first aspect, a control module 2, and a driving signal processing module 3 corresponding to the driving circuit 1. The control module 2 is configured to provide a first input signal S1 and a second input signal S2 to the driving circuit 1; the driving signal processing module 3 is configured to process the first driving signal D1 and the second driving signal D2 to generate a radio frequency output signal.

[0071] Figure 7 Taking the radio frequency power supply including multiple driving circuits 1 as an example, for example, the radio frequency power supply includes N driving circuits 1 .

[0072] At this time, the control module 2 is configured to provide a first input signal S1 and a second input signal S2 to each drive circuit 1. The first input signal S1 corresponding to each drive circuit 1 may have a different phase, and the second input signal S2 corresponding to each drive circuit 2 may also have a different phase. To distinguish, for the first drive circuit 1, the first input signal 1_S1 and the second input signal 1_S2 provided by the control module 2 are output by the first drive circuit 1 as 1_D1 and the second drive signal 1_D2; for the second drive circuit 1, the first input signal 2_S1 and the second input signal 2_S2 provided by the control module 2 are output by the second drive circuit 1 as 2_D1 and the second drive signal 2_D2; ...; for the Nth drive circuit 1, the first input signal N_S1 and the second input signal N_S2 provided by the control module 2 are output by the Nth drive circuit 1 as N_D1 and the second drive signal N_D2. Since the superposition of two waves of the same frequency will produce a stable interference pattern, resulting in constructive interference (enhancement) and destructive interference (weakening), it is preferred that the frequencies of the first input signals S1 and the second input signals S2 be set to be the same, and the frequencies of the first input signal S1 and the second input signal S2 be the same. Such a setting can make the superposition effect more stable.

[0073] Accordingly, the RF power supply includes N drive signal processing modules 3 that are arranged in a one-to-one correspondence with the drive circuits 1. In general, the drive signal processing module 3 is configured to process the first drive signal D1 and the second drive signal D2 to generate a RF output signal. Specifically, the drive signal processing module 3 corresponding to the first drive circuit 1 is used to process the first drive signal 1_D1 and the second drive signal 1_D2 generated by the first drive circuit 1 to generate a first RF output signal 1_OUT; the drive signal processing module 3 corresponding to the second drive circuit 1 is used to process the first drive signal 2_D1 and the second drive signal 2_D2 generated by the second drive circuit 1 to generate a second RF output signal 2_OUT; ...; the drive signal processing module 3 corresponding to the Nth drive circuit 1 is used to process the first drive signal N_D1 and the second drive signal N_D2 generated by the Nth drive circuit 1 to generate an Nth RF output signal N_OUT. In this embodiment, the power of the RF output signal corresponding to each driving circuit 1 can be different. Therefore, the RF power supply provided by this embodiment has the following beneficial effects: 1. It can provide high-frequency voltage to multiple loads at the same time to meet the voltage requirements of different devices; 2. When a driving circuit 1 fails, other normally working driving circuits 1 can be used to achieve high-frequency voltage output, thereby having higher reliability.

[0074] Further, continue to refer to Figure 7 The RF power supply also includes a sampling module 4 corresponding to each drive signal processing module 3, and an operation module 5 corresponding to each drive signal processing module 3. For each sampling module 4 and operation module 5 corresponding to each drive circuit 1, the sampling module 4 and operation module 5 are connected accordingly. The input end of the sampling module 4 is connected to the output end of the corresponding drive signal processing module 3. The sampling module 4 is configured to collect the RF output signal of the corresponding drive signal processing module 3, generate a sampling signal, and transmit it to the corresponding operation module 5. The output end of the operation module 5 is connected to the control module 2. The operation module 5 is configured to generate a compensation signal based on the sampling signal and transmit it to the control module 2. The control module 2 is further configured to adjust the first input signal S1 and / or the second input signal S2 corresponding to each drive circuit 1 based on the compensation signal corresponding to each drive circuit 1, so as to change the phase difference between the first input signal S1 and the second input signal S2, thereby adjusting the phase difference between the first drive signal D1 and the second drive signal D2 corresponding to each drive circuit 1, thereby adjusting the amplitude or power of the RF output signal.

[0075] In the first type of RF power supply, a corresponding sampling module 4 and a calculation module 5 are provided for each driving circuit 1. The sampling module 4 monitors the corresponding RF output signal in real time and generates a corresponding sampling signal. The calculation module 5 generates a compensation signal based on the sampling signal and transmits it to the control module 2. The control module 2 then adjusts the first input signal S1 and the second input signal S2 provided by it according to the compensation signal, changing the phase difference between the two, thereby adjusting the amplitude of the RF output signal. This arrangement can, on the one hand, reduce the output deviation of the RF power supply and improve the output accuracy of the RF power supply; on the other hand, it helps the RF power supply maintain stability in the face of external interference or internal changes (such as rising device temperature), preventing large output fluctuations. Finally, the automatic monitoring, feedback, and adjustment process reduces reliance on human intervention, thereby enabling rapid response to changes in output demand and improving the operating efficiency of the RF power supply.

[0076] The second circuit structure of RF power supply is as follows Figure 8 As shown, it includes: a multi-channel driving circuit 1, a control module 2, a driving signal processing module 3 connected one-to-one with the driving circuit 1, and a first synthesizer 6. In summary, the control module 2 is configured to provide the driving circuit 1 with a first input signal S1 and a second input signal S2; the driving signal processing module 3 is configured to process the first driving signal D1 and the second driving signal D2 to generate a radio frequency output signal; and the first synthesizer 6 is configured to synthesize the various radio frequency output signals to generate a composite radio frequency signal RF_OUT.

[0077] Specifically, the control module 2 is configured to provide a first input signal S1 and a second input signal S2 to each drive circuit 1. The first input signal S1 corresponding to each drive circuit 1 may have a different phase, and the second input signal S2 corresponding to each drive circuit 2 may also have a different phase. Preferably, the frequencies of the first input signals S1 and the second input signals S2 may be set to be the same, and the frequencies of the first input signal S1 and the second input signal S2 may be the same. Such a setting can make the superposition effect more stable. Accordingly, the second type of RF power supply also includes N drive signal processing modules 3 that are set one-to-one corresponding to the drive circuits 1. In general, the drive signal processing module 3 is configured to process the first drive signal D1 and the second drive signal D2 to generate an RF output signal.

[0078] Generally, the power of the RF output signal output by a single driving circuit 1 is limited, and it is impossible to output a high-power signal, which makes it difficult to meet the device's requirements for high-power high-frequency voltage. Figure 7 As shown), the second RF power supply (as Figure 8 The second type of RF power supply utilizes a power combiner to generate a high-power, high-frequency voltage. This power combiner can meet the high-power, high-frequency voltage requirements of semiconductor process equipment and is suitable for a wide range of applications.

[0079] Further, continue to refer to Figure 8 The second RF power supply further includes a sampling module 4 and a calculation module 5 connected to the sampling module 4. The input end of the sampling module 4 is connected to the output end of the first synthesizer 6. The sampling module 4 is configured to collect the composite RF signal RF_OUT, generate a sampling signal, and transmit it to the calculation module 5. The calculation module 5 is configured to generate a compensation signal based on the sampling signal and transmit it to the control module 2. The control module 2 is further configured to adjust the first input signal S1 and / or the second input signal S2 corresponding to at least some of the driving circuits 1 in the multi-channel driving circuit 1 based on the compensation signal, so as to change the phase difference φ between the first input signal S1 and the second input signal S2. S , to change the phase difference φ between the first drive signal D1 and the second drive signal D2 D , thereby changing the power of the RF output signal and then changing the power of the composite RF signal.

[0080] In the second RF power supply, a sampling module 4 and an operation module 5 are provided. The sampling module 4 monitors the composite RF signal RF_OUT in real time. The operation module 5 generates a compensation signal based on the sampled signal and transmits it to the control module 2. The control module 2 then adjusts the first input signal S1 and the second input signal S2 provided by it according to the compensation signal, changes the phase difference between the two, changes the phase difference between the first drive signal D1 and the second drive signal D2, thereby adjusting the amplitude of the RF output signal, and then adjusting the power of the composite RF signal. This arrangement can, on the one hand, reduce the output deviation of the RF power supply and improve the output accuracy of the RF power supply; on the other hand, it helps the RF power supply maintain stability in the face of external interference or internal changes (such as rising device temperature), preventing large output fluctuations; and on the other hand, the automatic monitoring, feedback, and adjustment process reduces reliance on manual intervention, thereby quickly responding to changes in output demand and improving the working efficiency of the RF power supply.

[0081] Figure 9 It is a structural diagram of the driving signal processing module. Figure 9 As shown, the driving signal processing module 3 includes: a first power amplifier circuit 31, a second power amplifier circuit 32, and a second synthesizer 7. The input end of the first power amplifier circuit 31 is connected to the output end of the corresponding driving circuit 1, and is configured to amplify the first driving signal D1 output by the driving circuit 1; the input end of the second power amplifier circuit 32 is connected to the output end of the corresponding driving circuit 1, and is configured to amplify the second driving signal D2 output by the driving circuit 1; the two input ends of the second synthesizer 7 are respectively connected to the output ends of the first power amplifier circuit 31 and the second power amplifier circuit 32, and is configured to synthesize the amplified first driving signal D1 and the amplified second driving signal D2 to generate a radio frequency output signal.

[0082] Exemplarily, the first power amplifier circuit 31 and the second power amplifier circuit 32 may adopt other types of driver chips such as Skyworks, Qorvo, Broadcom, Texas Instruments or STMicroelectronics.

[0083] Next, the circuit structure and working process of the sampling module 4 and the operation module 5 are introduced. Prior to this, the theoretical principle based on the operation module 5 is described first.

[0084] First, the sampling signal obtained by the sampling module 4 should include a sampling voltage signal and a sampling current signal. The sampling current signal can be converted into a voltage signal. In this paper, the sampling voltage signal is referred to as the first sampling voltage signal U1, and the voltage signal converted from the sampling current signal is referred to as the second sampling voltage signal U2. Theoretically, after obtaining the first sampling voltage signal U1 and the second sampling voltage signal U2, the forward power P can be obtained using the following formulas (4) and (5) respectively. F and reflected power P R :

[0085]

[0086] Wherein, ω is the frequency of the RF output signal or the composite RF signal RF_OUT.

[0087] In order to verify the use of formula (4) and formula (5) to obtain the forward power P F and reflected power P R The feasibility of , is then briefly deduced and proved.

[0088] Assume that the first sampling voltage signal U1 and the second sampling voltage signal U2 can be described as:

[0089] U1=A1×sinωt (6)

[0090] U2=A2×sin(ωt+θ) (7)

[0091] Wherein, A1 and A2 are the amplitudes of the first sampled voltage signal U1 and the second sampled voltage signal U2 respectively, ω is the frequency of the first sampled voltage signal U1 and the second sampled voltage signal U2, which is equal to the frequency of the RF output signal or the composite RF signal RF_OUT; θ is the phase of the second sampled voltage signal.

[0092] The reflection coefficient Γ represents the proportion of the signal reflected at the output port during transmission and is defined as the reflection voltage V R and the incident voltage V F The ratio of:

[0093]

[0094] The absolute value of the reflection coefficient is between 0 and 1. In an ideal state, the reflection coefficient is 0, indicating that the input and output impedances are completely matched and there is no reflected voltage; while the value of 1 indicates that the input and output impedances are not matched and the voltage is completely reflected. Therefore, the relationship between the reflection coefficient Γ and the impedance satisfies:

[0095]

[0096] Among them, Z LIndicates the impedance of the load, that is, the electrical impedance of the device connected to the output of the RF power supply (such as semiconductor process equipment); the characteristic impedance of the RF power supply is represented by Z0, which is determined by the physical structure and electrical characteristics of the RF power supply and is usually 50Ω or 75Ω; under ideal conditions, the actual impedance of the load is Z L It should be the same as the characteristic impedance Z0 of the RF power supply (i.e., matched). At this time, the signal transmission efficiency is the highest, that is, the reflection coefficient is 0.

[0097] Return loss RL is an indicator used to measure the reflection loss of the signal during transmission, and is generally defined as the forward power P F and reflected power P R The ratio of , and its relationship with the reflection coefficient Γ can be described as follows:

[0098]

[0099] Those skilled in the art will appreciate that the amplitude and phase of the first sampling voltage signal U1 and the second sampling voltage signal U2 are related to sampling circuit parameters, where the sampling circuit parameters include parameters of each component therein, which will be described in detail below.

[0100] When the reflection coefficient is 0, the sampling circuit parameters can be adjusted so that the amplitude A1 of the first sampling voltage signal U1 is equal to the amplitude A2 of the second sampling voltage signal U2 and the phase of the second sampling voltage signal U2 is 0.

[0101] When the reflection coefficient is not 0, that is, the load impedance Z L The characteristic impedance is not equal. Assume that the first sampling signal and the second sampling voltage signal are:

[0102] U1=A1' ×sinωt (11)

[0103] U2=A2' ×sin(ωt+θ) (12)

[0104] Wherein, A1′ and A2′ are the amplitudes of the first sampling voltage signal and the second sampling voltage signal respectively when the impedance is mismatched.

[0105] The voltage signal transmission theorem (Equation (13)) and the current signal transmission theorem (Equation (14)) are:

[0106] V(z)=V F e -jβz +V R e jβz (13)

[0107]

[0108] Where V is voltage, I is current, z represents the position variable, and β is the propagation constant, which characterizes the amplitude attenuation and phase change of the signal during propagation.

[0109] According to the above voltage signal transmission theorem, current signal transmission theorem and the definition of reflection coefficient, it can be inferred that A1' and A1 satisfy: A1 ′ =(1+Γ)A1; A2' and A2 satisfy: A2 ′ =(1-Γ)A2=(1-Γ)A1; At this time, according to equations (4) and (5), the forward power P can be calculated F and reflected power P R They are:

[0110]

[0111] Obviously, the ratio of the above reflected power to the forward power is Γ 2 , which is consistent with the definition of return loss RL in formula (10). It can be seen that it is feasible to calculate the forward power and reflected power according to formulas (4) and (5).

[0112] Next, the circuit structure and working process of the sampling module 4 will be described in detail. Figure 7 The sampling module 4 in Figure 8 The circuit structure of the sampling module 7 is the same as that of Figure 7 The input end of the sampling module 4 receives the RF output signal, and Figure 8 The input end of the sampling module 4 receives the composite RF signal RF_OUT. Figure 8 Taking the sampling module 4 as an example, the circuit structure and working process of the sampling module 4 are introduced.

[0113] Figure 10 This is the circuit structure diagram of the sampling module. Figure 10As shown, the sampling module 4 includes a first sampling circuit 41 and a second sampling circuit 42. In general, the first sampling circuit 41 is configured to sample the composite RF signal RF_OUT and generate a first sampled voltage signal U1 based on the composite RF signal RF_OUT; the second sampling circuit 42 is configured to sample the composite RF signal RF_OUT and, based on the composite RF signal RF_OUT, obtain a first sampled current signal and convert the first sampled current signal into a second sampled voltage signal U2. Specifically, the first sampling circuit 41 includes a third capacitor C3 and a fourth capacitor C4 connected in series, wherein a first end of the third capacitor C3 is connected to the output end of the first synthesizer 6 to divide the composite RF signal RF_OUT, a second end of the third capacitor C3 is connected to the first end of the fourth capacitor C4, and a second end of the fourth capacitor C4 is connected to the analog ground AGND. The second sampling circuit 42 includes a current transformer TC and a second resistor R2, wherein a first end of the current transformer TC is connected to the output end of the first synthesizer 6, a second end is connected to the input end of the load, a third end 423 is connected to the input end of the measuring instrument, and a fourth end 424 is connected to the ground end of the measuring instrument and to the analog ground AGND; wherein the measuring instrument can be an ammeter, and its input end and ground end refer to its positive terminal and negative terminal, respectively; the current transformer TC is used to sample and obtain a first sampled current signal, a first end of the second resistor R2 is connected to the third end 423 of the current transformer TC, and a second end of the second resistor R2 is connected to the fourth end 424 of the current transformer TC. The second resistor R2 is used to convert the first sampled current signal into a second sampled voltage signal U2.

[0114] The "sampling circuit parameters" mentioned above may include the capacitance value of the third capacitor C3, the capacitance value of the fourth capacitor C4, and the number of coils of the current transformer TC. Due to different composite RF signal power values, the corresponding amplitudes and phases of the first sampling voltage signal U1 and the second sampling voltage signal U2 are different. Therefore, it is necessary to obtain in advance the mapping relationship between the power value and U1 and U2, which is referred to as the first mapping relationship in this article. The first mapping relationship can be pre-stored in the operation module 5. In a specific implementation, the sampling circuit parameters can be fixed first; then, under this fixed parameter, the corresponding relationship between the power of different composite RF signals RF_OUT and the first sampling voltage signal U1 and the second sampling voltage signal U2 is obtained; wherein, when obtaining the corresponding relationship between the power of different composite RF signals RF_OUT and the first sampling voltage signal U1 and the second sampling voltage signal U2, a standard power meter can be connected to the output end of the RF power supply to measure the power value of the composite RF signal RF_OUT.

[0115] Next, we will introduce the specific circuit structure and working process of the operation module 5. Before that, it should be noted that Figure 7 The operation module 5 and Figure 8The circuit structure and working process of the operation module 5 in the RF power supply shown can be the same, and the only difference is that the compensation signals output by the two are different. The compensation signal output by the former is used to represent the phase compensation value of the first input signal and the second input signal corresponding to the operation module 5, while the compensation signal output by the latter is used to represent the phase compensation value between the first input signal and the second input signal corresponding to each of the multiple driving circuits. Figure 8 Taking the operation module 5 in the radio frequency power supply shown as an example, its circuit structure and working process are introduced.

[0116] Figure 11 Schematic diagram of the circuit structure of the operation module 5. Figure 11 As shown, the operation module 5 includes: an adder 51, a subtractor 52, a multiplier 54, an operational amplifier 56, and a data processing unit 57. The adder 51 is configured to calculate a sum signal (U1+U2) based on the first sampled voltage signal U1 and the second sampled voltage signal U2; the subtractor 52 is configured to calculate a difference signal (U1-U2) based on the first sampled voltage signal U1 and the second sampled voltage signal U2; the multiplier 54 is configured to calculate the square of the sum signal (U1+U2) and the square of the difference signal (U1-U2); the operational amplifier 56 is configured to calculate the square of the sum signal (U1+U2) based on the sum signal (U1+U2). 2 Get the forward power signal and the square of the difference signal (U1-U2) 2 Acquire a reflected power signal; the data processing unit 57 is configured to acquire a compensation signal based on the forward power signal and the reflected power signal.

[0117] Furthermore, the operation module 5 also includes a first filter 53 and a second filter 55, wherein the input end of the first filter 53 is connected to the output end of the adder 51 and the output end of the subtractor 52. The first filter 53 is configured to filter the sum signal (U1+U2) and the difference signal (U1-U2) respectively, filter out the harmonic signals, and then transmit them to the multiplier 54. The input end of the second filter 55 is connected to the output end of the multiplier 54, and is configured to filter out the noise of the squared signal of the sum signal and the squared signal of the difference signal and then transmit them to the operational amplifier.

[0118] Specifically, the "first mapping relationship" mentioned above can be pre-stored in the data processing unit 57. After obtaining the forward power signal and the reflected power signal, the forward power value and the reflected power value corresponding to the forward power signal and the reflected power signal, respectively, can be inferred based on the first mapping relationship. After obtaining the forward power value and the reflected power value, the data processing unit 57 obtains a compensation signal based on the forward power value, the set power value, and the reflected power value. The compensation signal is used to represent the phase compensation value. It can be understood that the phase compensation value depends on the power compensation value. Therefore, the correspondence between the power compensation value and the phase compensation value can be obtained in advance based on the "wave superposition principle". This is called the second mapping relationship and is pre-stored in the data processing unit 57. After obtaining the forward power value and the reflected power value, the data processing unit 57 obtains the power compensation value based on the forward power value, the set power value, and the reflected power value, and then obtains the phase compensation value corresponding to the power compensation value based on the second mapping relationship.

[0119] In addition, the specific method of calculating the power compensation value disclosed in the present invention is as follows. The threshold value of the reflected power can be set in advance, and after the data processing unit 57 obtains the reflected power data, it compares it with the threshold value. When the reflected power is 0, it indicates that the reflection coefficient is 0. At this time, the power compensation value can be the difference between the forward power data and the target power value. The phase compensation value corresponding to the power compensation value should make the forward power data approach the set power value. When the reflected power is greater than 0 and less than the threshold, the compensation power value can be: the difference between the forward power data and the target power value, plus the reflected power data; the phase compensation value corresponding to the power compensation value should make the difference between the forward power data and the reflected power data approach the target power value. When the reflected power is greater than the threshold, the compensation power value is the difference between the reflected power and the threshold, but it should be noted that the phase compensation value corresponding to the compensation power value should make the forward power data no longer increase, so as to play a role in protecting the circuit.

[0120] The above calculation method has the following beneficial effects: On the one hand, in actual circuits, the load impedance often does not match the characteristic impedance, that is, the reflected power is not zero. Therefore, the compensation signal calculated based on the target power value, the forward power, and the reflected power is more accurate. On the other hand, when the reflection coefficient is too large, if the forward power is still adjusted to increase it, it can easily cause the device to burn out. In this case, adjusting the forward power according to the reflection coefficient to below the output threshold can protect the RF power supply and improve its reliability and safety. In summary, the calculation module 5 of the present disclosure can improve the output accuracy, reliability, and safety of the RF power supply.

[0121] In summary, the RF power supply provided by the present disclosure has at least the following beneficial effects: 1. The input signal of the RF power supply of the present disclosure is two digital square wave signals, and the output is an analog sine wave signal. Due to its discreteness, the digital signal has better resistance to the influence of the analog signal to a certain extent. Therefore, the interference between the digital signal and the analog signal is weaker than the interference between the analog signal and the analog signal, and the generation and phase control of the digital signal are relatively simple and precise. Therefore, the RF power supply provided by the present disclosure has better anti-interference ability and output accuracy; 2. By setting up a sampling module and an operation module, the output signal power is monitored, and the phase difference of the input signal is timely adjusted based on this. Such a setting can, on the one hand, reduce the output deviation and improve the output accuracy of the RF power supply; on the other hand, it helps the RF power supply to remain stable when facing external interference or internal changes (such as rising device temperature) and prevent large output fluctuations; on the other hand, the process of automatic monitoring, feedback, and adjustment reduces the dependence on manual intervention, so that it can quickly respond to changes in output demand and improve the working efficiency of the RF power supply.

[0122] Thirdly, based on the same inventive concept, the present disclosure also provides a semiconductor process equipment. Figure 12 It is a structural diagram of semiconductor process equipment, such as Figure 12 As shown, it includes the RF power supply provided by any of the above examples, and in addition, also includes a RF matcher 801 and a process chamber 802.

[0123] It can be understood that the process chamber 802 can generally include multiple sub-chambers, for example, an etching chamber, a thin film deposition chamber, an epitaxial growth chamber, and a pre-cleaning chamber, etc., wherein the load impedance of each sub-chamber and the RF voltage required for the reaction environment of each sub-chamber are different. Therefore, the RF power supply in the semiconductor process equipment needs to be flexibly selected according to the needs of each sub-chamber.

[0124] Next, two exemplary structures of semiconductor process equipment are provided.

[0125] The first example is Figure 13 As shown, in this example, when the radio frequency signal power required by each sub-chamber is small, you can choose Figure 7 The RF power supply shown is used as the RF power supply for semiconductor process equipment to provide RF signals to each sub-chamber. Figure 13 As shown, the process chamber 802 of the semiconductor process equipment in this example includes N sub-chambers (N is an integer greater than 2), namely the first sub-chamber, the second sub-chamber, ..., the Nth sub-chamber. The radio frequency signal power required by each sub-chamber is relatively small. For this type of semiconductor process equipment, it is possible to use Figure 7 The RF power supply shown. Figure 7As shown, the RF power supply includes N RF output signals, namely, 1_OUT, 2_OUT, ..., N_OUT. Accordingly, the RF matcher 801 of the semiconductor process equipment may include N sub-matchers, namely, a first sub-matcher connected to the first RF output signal 1_OUT, a second sub-matcher connected to the second RF output signal 2_OUT, ..., and an Nth sub-matcher connected to the Nth RF output signal N_OUT. Specifically, one RF output signal is connected to one sub-chamber through one sub-matcher to provide an RF signal to the sub-chamber.

[0126] The second example is Figure 14 As shown, in this example, at least some of the sub-chambers require a larger RF signal power. Figure 7 The power of any RF output signal in the RF power supply shown cannot meet the electric field required by the reaction environment in this sub-chamber, so it is necessary to select Figure 8 The RF power supply shown provides RF signals to the sub-chambers. Figure 14 As shown, the process chamber 802 of the semiconductor process equipment in this example also includes N sub-chambers (N is an integer greater than 2), namely the first sub-chamber, the second sub-chamber, ..., the Nth sub-chamber; accordingly, the RF matcher 801 of the semiconductor process equipment may include N sub-matchers, each connected to the N sub-chambers. Among them, at least some of the sub-chambers, such as the first sub-chamber, require a larger RF signal power. In this case, the RF power supply may include a first power supply and a second power supply, wherein the first power supply is Figure 8 The RF power supply shown in FIG. 1 outputs a composite RF signal RF_OUT; the second power supply is Figure 7 The RF power supply shown includes multiple RF output signals. The output of the first power supply is connected to the first sub-matching device to provide RF signals to the first sub-chamber. The multiple RF output signals of the second power supply are connected to the other sub-matching devices to provide RF signals to the other sub-chambers.

[0127] It should be noted that, in some examples, when the radio frequency signal power required by each sub-chamber is relatively large, the radio frequency power supply of the semiconductor process equipment may include multiple first power supplies ( Figure 8 The type of RF power supply can be flexibly selected and combined according to the RF electric field actually required by each sub-chamber. This article only provides a few examples and does not constitute a limitation on the structure of semiconductor process equipment.

[0128] Next, taking the etching chamber as an example, the structure of semiconductor process equipment is introduced. Figure 15 FIG. 1 is another structural diagram of semiconductor process equipment. Figure 15 As shown, it is a plasma etching device used to complete micro-nanoscale etching of the wafer surface through plasma bombardment. Figure 15 The semiconductor process equipment mainly includes a radio frequency power system and an etching chamber 94.

[0129] Among them, the RF power system includes an upper RF power supply 91, an upper matcher 92, a current distribution unit 93, a lower RF power supply 95, a lower matcher 96 and a phase-locked cable 97; specifically, the upper RF power supply 91 is mainly used to excite the reaction gas to ionize and form plasma, the upper matcher 92 and the current distribution unit 93 are connected between the upper RF power supply 91 and the etching chamber 94, the upper matcher 92 is used to adjust the RF transmission impedance to ensure that the RF energy is efficiently transmitted to the etching chamber, and the current distribution unit 93 is configured to monitor the current distribution in the etching chamber in real time to ensure etching uniformity; the lower RF power supply 95 is used to provide a substrate bias voltage, fix the wafer by electrostatic adsorption, and control the ion bombardment energy; the lower matcher 96 is connected between the lower RF power supply 95 and the etching chamber 94, and is used to adjust the transmission impedance of the lower RF power supply 95 to ensure that the RF energy is efficiently transmitted to the etching chamber 94. In addition, the RF power system further includes a phase-locked cable 97 connected between the upper RF power source 91 and the lower RF power source 95 . The phase-locked cable 97 is configured to coordinate the RF phase difference between the upper RF power source 91 and the lower RF power source 95 to improve the stability of the plasma.

[0130] The internal structure of the etching cavity 94 is as follows Figure 15 As shown, the system comprises: a multi-stage RF coil, a dielectric window 945, a nozzle 944, a plasma 943, a wafer 942, and a base 941. Each primary RF coil includes an outer coil 946 and an inner coil 947. The multi-stage RF coil is configured to enhance plasma density through electromagnetic induction. The dielectric window 945 is disposed between the multi-stage RF coil and the plasma 943 and is configured to isolate the coil from the plasma reaction chamber, thereby allowing the alternating magnetic field to penetrate while sealing the plasma reaction chamber. The dielectric window 945 can be made of quartz or ceramic. The base 941 is an electrostatic chuck used to secure the wafer 942 and adjust the process temperature.

[0131] It will be understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present invention, and the present invention is not limited thereto. Those skilled in the art will appreciate that various modifications and improvements can be made without departing from the spirit and substance of the present invention, and such modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A driving circuit, characterized in that: The driving circuit includes: an inversion module configured to receive a first input signal and a second input signal, and generate a first signal group based on the first input signal and a second signal group based on the second input signal; the first signal group includes the first input signal and its inverted signal, and the second signal group includes the second input signal and its inverted signal; a signal amplification module, configured to amplify the first signal group and the second signal group; A signal processing module is configured to generate a first driving signal based on the amplified first signal group, and a second driving signal based on the amplified second signal group. generating a second driving signal; The first input signal and the second input signal are digital signals, and the first drive signal and the second drive signal are analog signals.

2. The driving circuit according to claim 1, wherein: The inverting module includes: a first inverter circuit comprising a first inverter and a second inverter; the first inverter being configured to receive the first input signal and generate an inverted signal of the first input signal; an input terminal of the second inverter being connected to an output terminal of the first inverter, the second inverter being configured to receive the inverted signal of the first input signal and generate the first input signal; The second inverter circuit includes a third inverter and a fourth inverter; the third inverter is configured to receive the second input signal and generate an inverted signal of the second input signal; the input end of the fourth inverter is connected to the output end of the third inverter, and the fourth inverter is configured to receive the inverted signal of the second input signal and generate the second input signal.

3. The driving circuit according to claim 1, wherein: The signal processing module includes: a first tuning subcircuit, configured to tune the amplified first input signal to generate a first tuning signal; a first transformer configured to receive the first tuning signal and an inverted signal of the amplified first input signal to generate the first driving signal; a second tuning subcircuit, configured to tune the amplified second input signal to generate a second tuning signal; The second transformer is configured to receive the second tuning signal and an inverted signal of the amplified second input signal to generate the second driving signal.

4. A radio frequency power supply, characterized in that: comprising at least one driving circuit according to any one of claims 1 to 3, a control module, and a driving signal processing module corresponding one-to-one to the driving circuit; The control module is configured to provide the first input signal and the second input signal to the driving circuit; The driving signal processing module is configured to process the first driving signal and the second driving signal to generate a radio frequency output signal.

5. The radio frequency power supply according to claim 4, characterized in that: It also includes a sampling module and a calculation module corresponding one-to-one to the driving signal processing module; The sampling module is configured to collect the RF output signal of the corresponding driving signal processing module to generate a sampling signal; The operation module is configured to generate a compensation signal based on the sampling signal and transmit it to the control module; The control module is further configured to adjust the first input signal and / or the second input signal corresponding to each driving circuit based on the compensation signal corresponding to each driving circuit to change the phase difference between the first input signal and the second input signal.

6. The radio frequency power supply according to claim 4, characterized in that: When the radio frequency power supply includes multiple driving circuits, the radio frequency power supply further includes a first synthesizer; The first synthesizer is configured to synthesize the RF output signals to generate a composite RF signal.

7. The radio frequency power supply according to claim 6, characterized in that: It also includes a sampling module and an operation module; The sampling module is configured to collect the composite radio frequency signal and generate a sampling signal; The operation module is configured to generate a compensation signal based on the sampling signal and transmit it to the control module; The control module is further configured to adjust the first input signal and / or the second input signal corresponding to at least some of the driving circuits in the multiple driving circuits based on the compensation signal to change the phase difference between the first input signal and the second input signal.

8. The radio frequency power supply according to claim 4, characterized in that: The driving signal processing module includes: a first power amplifier circuit, configured to amplify the first driving signal; a second power amplifier circuit, configured to amplify the second driving signal; The second synthesizer is configured to synthesize the amplified first drive signal and the amplified second drive signal to generate the RF output signal.

9. The radio frequency power supply according to claim 5, characterized in that: The sampling module includes: a first sampling circuit configured to collect the radio frequency output signal and generate a first sampling voltage signal based on the radio frequency output signal; The second sampling circuit is configured to collect the RF output signal, obtain a first sampling current signal based on the RF output signal, and convert the first sampling current signal into a second sampling voltage signal.

10. The radio frequency power supply according to claim 7, characterized in that: The sampling module includes: a first sampling circuit configured to collect the composite RF signal and generate a first sampling voltage signal based on the composite RF signal; The second sampling circuit is configured to collect the composite RF signal, obtain a first sampling current signal based on the composite RF signal, and convert the first sampling current signal into a second sampling voltage signal.

11. The radio frequency power supply according to claim 9 or 10, characterized in that: The operation module includes: an adder configured to calculate a sum signal based on the first sampled voltage signal and the second sampled voltage signal; a subtractor configured to calculate a difference signal based on the first sampled voltage signal and the second sampled voltage signal; a multiplier configured to calculate the square of the sum signal and to calculate the square of the difference signal; an operational amplifier configured to obtain a forward power signal based on the square of the sum signal and to obtain a reflected power signal based on the square of the difference signal; The data processing unit is configured to obtain the compensation signal based on the forward power signal and the reflected power signal.

12. A semiconductor process equipment, characterized in that: include: A radio frequency power supply, a radio frequency matcher, and a process chamber; wherein the radio frequency power supply is the radio frequency power supply according to any one of claims 4 to 11, and the radio frequency matcher is connected between the radio frequency power supply and the process chamber.

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