Rapid automatic impedance matching system and matching method

Abstract

The invention relates to a fast automatic impedance matching system and a matching method, and belongs to the technical field of semiconductor equipment manufacturing, the fast automatic impedance matching system comprises a frequency-adjustable radio frequency power supply module, a radio frequency cable module, a matcher module and a cavity load module, the frequency-adjustable radio frequency power supply is integrated with a VI sensor, the measuring module is used for measuring output voltage V, current I and phase difference phi in real time; the matcher only comprises a single adjustable capacitor element C, and the capacitance value is adjusted through motor driving. The matching method comprises the following steps: calculating the impedance Zs of the output end of the radio-frequency power supply based on VI sensor data, deducing the input admittance of the matcher in combination with cable characteristic parameters, and solving a target frequency value f and a target capacitance value C by analyzing load resistance R and inductance L to realize single-step matching control. The method improves the matching speed, simplifies the hardware, reduces the cost, and improves the stability.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor device manufacturing, and particularly relates to a rapid automatic impedance matching system and a matching method. BACKGROUND

[0002] An inductively coupled plasma (ICP) device is a key equipment in the integrated circuit manufacturing process, and is widely used in etching, thin film deposition and other core processes. The ICP device transmits energy to the load through a radio frequency system to excite and maintain plasma, which directly affects the precision and yield of chip manufacturing. The radio frequency system of the ICP device mainly consists of a radio frequency generator (RFG), a radio frequency cable, an impedance matcher (Match) and a radio frequency coil. Each component has a clear division of labor: the radio frequency generator generates a radio frequency power signal at a specific frequency of 13.56 MHz, the output impedance is fixed at 50Ω, and a voltage current sensor (VI Sensor) is provided to detect the forward power and reflected power; the radio frequency cable is responsible for power transmission; the impedance matcher needs to convert the non-50Ω impedance at the load end to 50Ω impedance at the input end to achieve impedance matching with the radio frequency power supply, minimize the reflected power and ensure efficient energy delivery to the radio frequency coil. In actual processes, the impedance at the load end is affected by parameters such as chamber pressure, gas flow and plasma density, and is always in a state of dynamic change, so the impedance matcher needs to track and adjust the impedance in real time.

[0003] With the continuous upgrading of semiconductor processes, advanced processes have higher requirements for the matching speed and accuracy of radio frequency systems, and the defects of traditional impedance matching schemes are increasingly prominent. The current mainstream impedance matching scheme is an L-type circuit automatic matcher, which includes a parallel branch adjustable capacitor, a series branch adjustable capacitor, and an input sensor on the input side of the matcher. The two adjustable capacitors are respectively controlled and adjusted by a motor, and the control unit collects voltage, current and phase information through the input sensor, calculates the amplitude error and phase error of the input impedance with 50Ω, and adjusts the capacitance value to reduce the error. However, this scheme has two key problems: first, the matching speed is slow, which cannot meet the requirements of advanced processes. Because of the strong coupling effect between the parallel branch adjustable capacitor and the series branch adjustable capacitor, adjusting any capacitor will simultaneously affect the amplitude error and the phase error, and it is impossible to adjust to the right place in one step, so multiple iterations are required to achieve matching, resulting in a long matching process and making it impossible to adapt to process scenarios with strict matching speed requirements. Second, the input sensor precision is highly dependent, increasing the design and use cost. The matching effect completely depends on the measurement accuracy of the input sensor, and the strong radio frequency interference environment of the matcher easily affects the performance of the sensor. In order to ensure accuracy, a large amount of cost needs to be invested in sensor design, electromagnetic shielding and regular calibration, which also increases the difficulty of matcher manufacturing and maintenance, and is not conducive to the improvement of equipment economy.

[0004] In summary, the existing L-type circuit automatic matcher cannot meet the needs of advanced ICP devices for matching speed, accuracy and cost control, and the development of a fast automatic impedance matching system and matching method that can solve the above problems has become an urgent need in the field of integrated circuit manufacturing equipment. SUMMARY

[0005] Based on the problems in the prior art, the present application provides a fast automatic impedance matching system and a matching method.

[0006] According to the first aspect of the technical scheme of the present application, the present application specifically provides a fast automatic impedance matching system, comprising an adjustable frequency radio frequency power supply module, a radio frequency cable module, a matcher module and a chamber load module: The adjustable frequency radio frequency power supply module comprises a power supply unit, a power amplifier unit, a VI sensor and a power supply control unit; the power supply unit is used to generate an adjustable frequency radio frequency signal, the power amplifier unit is used to amplify the signal power, the VI sensor is arranged at the output end of the power amplifier, and is used to measure the voltage amplitude V, the current amplitude I and the phase difference φ in real time, and calculate the output end impedance ; the power supply control unit is used to receive the frequency adjustment signal of the matcher module and dynamically adjust the radio frequency output frequency; the output end of the adjustable frequency radio frequency power supply module is connected to the input end of the matcher module through the radio frequency cable module; The radio frequency cable module is used for transmitting radio frequency power and signals, and is connected to an output end of the adjustable frequency radio frequency power supply module and an input end of the matching module; The matching module comprises an adjustable capacitance element C1 and a control unit, the adjustable capacitance element C1 is used for adjusting the capacitance value through a motor to change the impedance value of the output end of the matching module, and the control unit is used for reading the radio frequency information of the adjustable frequency radio frequency power supply, calculating the load impedance parameters, and connecting the control module of the adjustable frequency radio frequency power supply through a communication bus. The chamber load module comprises a radio frequency coil and a plasma load, and is used for receiving the matched radio frequency power output by the matching module to excite and maintain an inductively coupled plasma; the chamber load module is connected to the output end of the matching module to form a load loop.

[0007] Further, the calculation of the load impedance parameters comprises a load resistance R and a load inductance L, and a motor control signal is output to adjust the capacitance value of C1, and a power frequency adjustment signal is output to the adjustable frequency radio frequency power supply to realize closed-loop control of impedance matching.

[0008] Further, the adjustment element of the adjustable capacitance element C1 comprises a stepper motor, a motor-capacitance matching assembly, a motor drive board and an encoder.

[0009] Further, the control unit is used for calculating the impedance of the output end of the radio frequency power supply based on the measurement data of the VI sensor, deriving the input admittance of the matching module according to the cable parameters, analyzing the load resistance R and the inductance L, solving the target frequency and the target capacitance, synchronously outputting the frequency adjustment signal to the power supply control unit and the capacitance adjustment signal to the adjustable capacitance element C1, and realizing single-step impedance matching.

[0010] Further, the formula used for solving the target frequency and the target capacitance comprises: ; ; Wherein R is the load resistance, L is the load inductance, ω1 is the target angular frequency, and ω1=2πf1. .

[0011] Further, the formula used by the control unit to calculate the load resistance R and the load inductance L comprises: ; ; Wherein G0 is the real part of the admittance, ω0 is the initial angular frequency, ω0=2πf0, f0 is the initial frequency, and M0 is an intermediate variable.

[0012] The application further discloses a fast automatic impedance matching method applied to the fast automatic impedance matching system, and comprises the following steps: (a) outputting radio frequency power at initial frequency f0, measuring |V|, |I|, φ by VI sensor; (b) calculating radio frequency power output end impedance Z s ; (c) deriving matching input impedance Z in ; (d) converting Z in into admittance Y in , Y in =G0+jB0; (e) analyzing load resistance R and inductance L; (f) solving target frequency value f1 and target capacitance value C1; (g) adjusting radio frequency power output frequency value to f1 and capacitance value to C1.

[0013] Further, the target parameter calculation of step (f) satisfies: ; , wherein ω1 is the target angular frequency, .

[0014] Further, in the pulse mode: Step (a) increases the pulse frequency and the duty cycle synchronous sampling; Step (g) combines the pulse rising edge to predict the adjustment opportunity.

[0015] Further, the analysis of load parameters R and L in step (e) uses a lookup table method or a Newton iteration method instead of real-time calculation; the analysis formula of step (e) is: ； ; , wherein G0 is the real part of admittance, ω0 is the initial angular frequency, ω0=2πf0, f0 is the initial frequency, and M0 is an intermediate variable.

[0016] Compared with the prior art, the present application has the following beneficial effects: 1. The present application significantly improves the efficiency of semiconductor equipment detection through innovative design.

[0017] 2. The technical solution of the present application realizes a single-step matching mechanism, greatly speeding up the matching speed; the hardware structure is highly simplified, only a single adjustable capacitance element is needed, effectively reducing the system complexity and manufacturing and maintenance costs; at the same time, the special input sensor inside the matching device is saved, and the built-in sensor of the radio frequency power supply is reused, saving the design difficulty and calibration cost.

[0018] 3. The system of this invention possesses strong adaptive capabilities, flexibly adapting to different equipment sizes and process modes, including continuous wave and pulse operation. In pulse scenarios, the stability and reliability of the process are ensured through optimized transient response mechanisms. These advantages collectively enhance overall performance, making this invention widely applicable in advanced semiconductor manufacturing. Attached Figure Description

[0019] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of an automatic impedance matching system for ICP equipment according to the present invention; Figure 2 This is a schematic diagram of an automatic impedance matching method for ICP equipment according to the present invention; Figure 3 This is a schematic diagram of the L-type circuit automatic matching device in Comparative Example 1. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] Example One like Figure 1 As shown, this embodiment provides a fast automatic impedance matching system, including a frequency-tunable RF power supply module 10, an RF cable module 20, a matching module 30, and a chamber load module 40.

[0024] The adjustable frequency radio frequency power supply module 10 comprises a power supply unit 101, a power amplifier unit 102, a VI sensor 103 and a power supply control unit 104. The power supply unit 101 is used for generating an adjustable frequency radio frequency signal, the power amplifier unit 102 is used for amplifying the signal power, the VI sensor 103 is arranged at the output end of the power amplifier and is used for measuring the voltage amplitude |V|, the current amplitude |I| and the phase difference φ in real time and calculating the output end impedance , ; the power supply control unit 104 is used for receiving the frequency adjustment signal of the matching module 30 and dynamically adjusting the radio frequency output frequency. The output end of the adjustable frequency radio frequency power supply module 10 is connected to the input end of the matching module 30 through the radio frequency cable module 20.

[0025] The radio frequency cable module 20 is used for transmitting a radio frequency power signal, has a length l and a characteristic impedance Z0 of 50Ω, and is connected in a mode that one end is connected to the output end of the adjustable frequency radio frequency power supply module 10 and the other end is connected to the input end of the matching module 30, so as to form a signal transmission channel. The radio frequency cable is used for transmitting impedance information, and the input impedance of the radio frequency cable is calculated by the formula (wherein β = 2π / λ, λ is the signal wavelength), which is used for deducing the load admittance Yin; wherein is the characteristic impedance of the radio frequency cable, which means the characteristic impedance of the cable and has a unit of ohm; β is the phase constant, which means the phase change rate of the signal in the cable and has a unit of radian per meter; is the length of the radio frequency cable, which means the physical length of the cable and has a unit of meter; λ is the signal wavelength, which means the wavelength of the radio frequency signal in vacuum or medium and has a unit of meter; is the output end impedance of the radio frequency power supply, which has a unit of ohm; is a virtual number and has no unit; is the input impedance of the matching module, which means the complex impedance value of the input end of the matching module and has a unit of ohm.

[0026] The matching module 30 comprises an adjustable capacitance element C1 and a control unit 301. The adjustable capacitance element C1 is used for adjusting the capacitance value through a motor to change the admittance value of the output end of the matching module. The control unit 301 is used for reading the radio frequency frequency information of the adjustable frequency radio frequency power supply 10, calculating the load impedance parameter R and the load inductance parameter L, outputting a motor control signal to adjust the capacitance value of the adjustable capacitance element C1, and outputting a power frequency adjustment signal to the adjustable frequency radio frequency power supply 10 to realize closed-loop control of impedance matching. The control unit and the control module of the adjustable frequency radio frequency power supply 10 are connected through a communication bus to realize data interaction, such as the transmission of the frequency f0 and the impedance data Zs.

[0027] The chamber load module 40 includes a radio frequency coil and a plasma load for receiving the matched radio frequency power output from the matching module 30 to excite and sustain an inductively coupled plasma. The impedance characteristic of the chamber load is where R is the real part resistance, L is the inductance value, and ω0 = 2πf0 is the angular frequency. The chamber load module 40 is connected in a way that it is directly connected to the output of the matching module 30 to form a load loop, and the impedance variation is compensated in real time by the matching algorithm.

[0028] Specifically, the adjustable capacitance element C1 can be a stepper motor, a relay, or a voltage-controlled diode, with a capacitance range of 0-500 pF (determined according to the specific configuration calculated by the load network); the radio frequency cable length l can be dynamically compensated based on the wavelength β = 2π / λ (λ is the signal wavelength); in the ICP scenario (400 k~100 MHz), the load inductance L can be a fixed metal piece (such as a spiral type); in the CCP scenario (400 k~100 MHz), the matching module needs to be connected in series with an inductance in the radio frequency network, and the load is a capacitive electrode (such as a metal electrode plate).

[0029] The technical effects of the above scheme are: Improved single-step matching speed: by combining frequency adjustment and single-capacitance adjustment, the strong coupling effect of traditional double-capacitance is eliminated, one-step matching is achieved, the matching speed is improved, and the fast response requirement of high-demand processes such as semiconductor manufacturing is met. The technical principle is based on the algorithm of the control unit, which directly calculates the target frequency f1 and the capacitance C1 from the measured impedance, avoiding iterative adjustment.

[0030] Simplified network structure: compared with traditional matching modules (≥2 adjustable elements), only one adjustable capacitance element C1 is used, which simplifies the hardware complexity of the matching module, reduces the manufacturing cost and maintenance difficulty. This technical scheme is based on the design of the matching module 30, which reduces the number of elements and mechanical structures.

[0031] Cost reduction by eliminating input sensors: the VI sensor built-in the adjustable frequency radio frequency power supply module 10 replaces the internal sensor of the matching module, reducing the design, calibration, and anti-radio frequency interference requirements of additional sensors, and reducing the cost of the matching module. The technical principle is based on the multiplexing of the VI sensor, and the data is shared through communication, avoiding the precision dependence problem of the input sensor.

[0032] Example Two The embodiment provides a fast automatic impedance matching system, which is applied to 200mm or 300mm ICP semiconductor equipment on the basis of the embodiment one. The system composition is the same as that of the embodiment one, but the chamber load module 40 is optimized for wafer size as follows: in the 200mm equipment, the load impedance R ranges from 10 to 100Ω, and the L ranges from 0.1 to 1μH; in the 300mm equipment, the R ranges from 5 to 50Ω, and the L ranges from 0.05 to 0.5μH. The matching control unit pre-stores the equipment parameter database, automatically calibrates the calculation algorithm according to the equipment type (200mm or 300mm), and ensures fast matching in a wide load range.

[0033] Specifically, the driving motor of the adjustable capacitance element C1 can be a high-precision stepping motor or a voltage-controlled diode to adapt to high dynamic loads of large-size equipment; the length l of the radio frequency cable is fixed as 1-3m, and the matching control unit compensates the cable effect through formula 2.

[0034] The technical effect of the above technical scheme is that the equipment size can be self-adapted, the matching speed is effectively improved in the 300mm equipment, and the one-step matching precision error is small.

[0035] Example Three The embodiment provides a fast automatic impedance matching system, which is applied to 200mm or 300mm ICP semiconductor equipment on the basis of the embodiment one. The system composition is the same as that of the embodiment one, but the chamber load module 40 is optimized for wafer size as follows: in the 200mm equipment, the load impedance R ranges from 10 to 100Ω, and the L ranges from 0.1 to 1μH; in the 300mm equipment, the R ranges from 5 to 50Ω, and the L ranges from 0.05 to 0.5μH. The matching control unit pre-stores the equipment parameter database, automatically calibrates the calculation algorithm according to the equipment type (200mm or 300mm), and ensures fast matching in a wide load range.

[0036] The technical effect of the above scheme is that the matching speed in the pulse mode is improved, and the effect is derived from the high-frequency sampling and pre-adjustment mechanism to avoid overshoot.

[0037] Example Four As shown in the embodiment, a fast automatic impedance matching method is provided, which is applied to a fast automatic impedance matching system, and the automatic detection method specifically comprises the following steps: Figure 2 (a) the radio frequency power supply outputs power at an initial frequency f0, and the VI sensor measures voltage |V|, current |I| and phase difference φ; (b) the impedance of the power supply output end is calculated as , (formula 1); wherein ​V is the voltage amplitude, meaning the amplitude of the RF power output voltage, in volts; I is the current amplitude, meaning the amplitude of the RF power output current, in amperes; φ is the phase difference, meaning the phase angle difference between the voltage and the current, in radians; Z0 is the RF cable characteristic impedance, meaning the characteristic impedance of the RF cable, in ohms; (c) calculate the input impedance of the matching device Zin based on the RF cable length l and the characteristic impedance Z0 , (2), where , λ is the signal wavelength, meaning the wavelength of the RF signal in vacuum or a medium, in meters; Z0 is the transmission line characteristic impedance, typically 50 Ω; where Z0 is the RF cable characteristic impedance, meaning the characteristic impedance of the cable, in ohms; β is the phase constant, meaning the rate of change of phase of a signal in the cable, in radians per meter; l is the RF cable length, meaning the physical length of the cable, in meters; λ is the signal wavelength, meaning the wavelength of the RF signal in vacuum or a medium, in meters; Z0 is the RF cable characteristic impedance, in ohms; Zin is the input impedance of the matching device, meaning the complex impedance value of the input of the matching device, in ohms; (d) convert Zin to admittance Y: (3); where Yin is the input admittance of the matching device, meaning the inverse of the impedance, in siemens; Yin is the input admittance of the matching device, meaning the inverse of the impedance, in siemens; Yin is the input admittance of the matching device, meaning the inverse of the impedance, in siemens; (e) based on the current operating point and the measured admittance, calculate the equivalent resistance R and the equivalent inductance L of the load by calculating the intermediate variable M0, using the formulas: (8) and (9); where ω0 is the initial angular frequency, meaning the angular frequency corresponding to the initial RF frequency, in radians per second; C0 is the initial capacitance value, meaning the initial capacitance value of the adjustable capacitor in the matching device (before matching adjustment), in farads; R L R is the load resistance, meaning the equivalent resistance value of the chamber load; ​​​is an intermediate variable, consistent with R, emphasizing the load side, unit ohm; is the imaginary part of the admittance, meaning the imaginary part of the input admittance of the matching device, unit siemens; is the load resistance, meaning the equivalent resistance value of the chamber load, unit ohm; is the load inductance, meaning the equivalent inductance value of the chamber load, unit henry.

[0038] (f) Calculate the target angular frequency value ω 11 and the target capacitance value C1: substitute the calculated R and L into the analytical solution formula derived from the matching target equation (formula 10) to directly solve the target angular frequency ω1 and the target capacitance value C1 required to achieve matching (Z=50Ω); the formula used is: (formula 10); wherein is the target angular frequency, meaning the angular frequency under the matching target, unit rad / s; is the target capacitance value, meaning the target capacitance value of the adjustable capacitor of the matching device, unit farad; is the admittance under the matching condition, meaning the admittance value of the output end of the matching device, unit siemens; (formula 11); (formula 12); wherein, is the output frequency value of the radio frequency power supply; the load impedance of the chamber is , wherein is the real part impedance, is the imaginary part impedance, is the frequency , the capacitance value of the adjustable capacitor at this time is , and the adjustment signal is directly output to complete the matching in one step.

[0039] The technical effect of the above scheme is that the method of the embodiment is beneficial to the improvement of the matching speed; the effect is derived from the accurate calculation of the load parameters, and the iteration step is saved.

[0040] Specifically, the specific adjustment method and formula derivation process are as follows: The radio frequency power supply first outputs power at a frequency At this time, the VI sensor inside the radio frequency power supply collects the voltage and current amplitudes and the phase difference . Then the impedance at the output end of the radio frequency power supply is (formula 1); If the length of the radio frequency cable is l , the input impedance at the front end of the impedance matching device is ( Formula 2 ) ; wherein, , is the wavelength of the signal propagating on the transmission line, is the characteristic impedance of the transmission line, usually 50 Ω.

[0041] Converts to admittance: ( Formula 3 ) ; At this time, the load impedance of the chamber is wherein, is the real part impedance, is the imaginary part impedance, is the frequency corresponding to the angular frequency, at this time, the capacitance of the adjustable capacitor element is .

[0042] Then the admittance in front of the matching device calculated from the load impedance and is ( Formula 4 ) ; Bring (4) into (3), we can get ( Formula 5 ) ; ( Formula 6 ) ; Formula transformation is carried out, and the following is obtained: ( Formula 7 ) ; Bring (6) into (4), we can get ( Formula 8 ) ; ( Formula 9 ) ; The control strategy is as follows: Assuming that the output frequency of the radio frequency power supply is under the condition of impedance matching, the capacitance of the adjustable capacitor element is . The goal of the control strategy is to calculate the resistance and inductance of the load by (8) and (9) through the measured , and the known and , and to obtain and that make the system match based on this.

[0043] Under the conditions of frequency and capacitance , ​Matched with the RF power output impedance 50Ω, so the admittance at this time S, can be obtained (Formula 10); Solving (10) can obtain (Formula 11); (Formula 12); Wherein, is the RF power output frequency value.

[0044] Example Five The embodiment provides a fast automatic impedance matching method, and on the basis of embodiment four, the calculation process is optimized: in step (e), R and L are solved by using a table lookup method or an approximate algorithm, so that real-time calculation of the load is reduced. The matching control unit pre-stores typical load curves, and combines f0 and C0 to quickly index.

[0045] The technical effect of the above scheme is that the matching accuracy is improved through calculation optimization; the effect is derived from hardware acceleration and pre-stored data, and the practicability is enhanced.

[0046] Example Six The embodiment provides a fast automatic impedance matching method, and on the basis of embodiment four, the method is specially used for a pulse mode: in step (a), pulse synchronous sampling (measuring |V|, |I| and φ during the duty cycle) is added; in step (f), f1 and C1 adjustment are combined with pulse rising edge prediction to realize zero-delay matching.

[0047] Specifically, when the pulse repetition frequency is 1-100 kHz, adaptive filtering is used to reduce noise interference; the method can be combined with the system in embodiment three, and a voltage-controlled diode is used for fast response.

[0048] The technical effect of the above scheme is that through the pulse synchronization mechanism, the matching speed is improved by 60% under the 100 kHz pulse; the effect is derived from timing optimization, and reflection power accumulation is avoided.

[0049] Comparative Example One As Figure 3As shown, the comparative example 1 is an L-type circuit automatic matcher, a control unit reads measurement data (voltage, current, phase) of an input sensor, calculates amplitude error and phase error of an input impedance with 50Ω, and adjusts capacitance values of adjustable capacitor elements C1 and C2 through an iterative algorithm; due to strong coupling effect of the adjustable capacitor elements C1 and C2, adjustment of any capacitor will simultaneously affect amplitude and phase errors, multiple iterations are required for matching, and high-precision input sensors are required, which is easily affected by radio frequency interference, and additional design, calibration and shielding measures are required, which is used for traditional ICP equipment, but cannot meet the requirements of speed and accuracy of advanced semiconductor processes.

[0050] In summary, the application provides a detection scheme capable of automatically simulating dynamic impedance characteristics of a process chamber, supporting multi-port testing and having a self-calibration function, to solve the problems of incomplete performance evaluation of a radio frequency matcher and low testing efficiency.

[0051] The principles and implementation manners of the application are described by applying specific examples in the present application, and the above example descriptions are only used to help understand the method of the application and its core idea. The above descriptions are only preferred embodiments of the application, and it should be pointed out that due to the limited nature of the language expression, there are infinite specific structures, and for ordinary skilled persons in the technical field, on the premise of not departing from the principles of the application, a number of improvements, refinements or changes can be made, and the above technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, shall be regarded as the protection scope of the application.

Claims

1. A fast automatic impedance matching system, characterized in that, It includes a frequency-tunable RF power supply module (10), an RF cable module (20), a matching module (30), and a chamber load module (40): The tunable RF power supply module (10) includes a power supply unit (101), a power amplifier unit (102), a VI sensor (103), and a power control unit (104). The power supply unit (101) is used to generate tunable RF signals, the power amplifier unit (102) is used to amplify the signal power, and the VI sensor (103) is located at the output of the power amplifier to measure the voltage amplitude |V|, current amplitude |I|, and phase difference φ in real time, and to calculate the output impedance. The power control unit (104) is used to receive the frequency adjustment signal from the matching module (30) and dynamically adjust the RF output frequency; the output of the adjustable RF power module (10) is connected to the input of the matching module (30) through the RF cable module (20); The radio frequency cable module (20) is used to transmit radio frequency power and signals. The radio frequency cable module (20) is connected to the output end of the adjustable frequency radio frequency power supply module (10) and connected to the input end of the matching module (30). The matching module (30) includes an adjustable capacitor element C1 and a control unit (301). The adjustable capacitor element C1 is used to adjust the capacitance value through a motor to change the impedance value at the output of the matching unit. The control unit (301) is used to read the radio frequency information of the adjustable frequency power supply (10) and calculate the load impedance parameters. The control unit is connected to the control module of the adjustable frequency power supply (10) through a communication bus. The chamber load module (40) includes a radio frequency coil and a plasma load, which are used to receive the matching radio frequency power output by the matching module (30), excite and generate inductively coupled plasma and maintain the plasma; the chamber load module (40) is connected to the output terminal of the matching module (30) to form a load circuit.

2. The fast automatic impedance matching system according to claim 1, characterized in that, The load impedance parameters are calculated, including resistance R and inductance L. The motor control signal is output to adjust the capacitance value of the adjustable capacitor C1. At the same time, the power supply frequency adjustment signal is output to the adjustable frequency RF power supply (10) to realize closed-loop control of impedance matching.

3. The fast automatic impedance matching system according to claim 1, characterized in that, The adjustable capacitor element C1 includes a stepper motor, a motor capacitor matching assembly, a motor drive board, and an encoder.

4. The fast automatic impedance matching system according to claim 1, characterized in that, The control unit (301) is used to calculate the impedance of the RF power supply output terminal based on the measurement data of the VI sensor (103), derive the matching unit input admittance according to the cable parameters, analyze the load resistance R and inductance L, solve the target frequency and target capacitance, and synchronously output the frequency adjustment signal to the power control unit (104) and the capacitance adjustment signal to the adjustable capacitor element C1 to achieve single-step impedance matching.

5. The fast automatic impedance matching system according to claim 4, characterized in that, The formulas used to solve for the target angular frequency and the target capacitance include: ； ； Where R is the load resistance, L is the load inductance, ω1 is the target angular frequency, f1 is the target frequency, and ω1 = 2πf1. .

6. The fast automatic impedance matching system according to claim 4, characterized in that, The formulas used by the control unit (301) to calculate the load resistance R and load inductance L include: ； Where G0 is the real part of the admittance, ω0 is the initial angular frequency, ω0=2πf0, f0 is the initial frequency, and M0 is an intermediate variable.

7. A fast automatic impedance matching method, applied to the fast automatic impedance matching system according to any one of claims 1-6, characterized in that, Includes the following steps: (a) Output RF power at an initial frequency f0 and measure |V|, |I|, φ using VI sensor (103); (b) Calculate the output impedance Z of the RF power supply s ; (c) Deriving the matching circuit input impedance Z based on cable parameters in ; (d) Transformation Z in To guide Y in Y in =G0+jB0; (e) Analyze the load resistance R and inductance L; (f) Solve for the target frequency value f1 and the target capacitance value C1; (g) Adjust the RF power supply output frequency to f1 and the capacitor value to C1.

8. The rapid automatic impedance matching method according to claim 7, characterized in that, The objective parameter calculation in step (f) satisfies: ； Where R is the load resistance, L is the load inductance, ω1 is the target angular frequency, f1 is the target frequency, and ω1 = 2πf1. .

9. The rapid automatic impedance matching method according to claim 7, characterized in that, In pulse mode: Step (a) Increase pulse frequency and duty cycle for synchronous sampling; Step (g) combines pulse rising edge prediction to determine the timing of adjustments.

10. The rapid automatic impedance matching method according to claim 8, characterized in that, In step (e), the load parameters R and L are analyzed using a lookup table method or Newton's iteration method instead of real-time calculation; the analytical formula for step (e) is: ； ； Where G0 is the real part of the admittance, ω0 is the initial angular frequency, ω0 = 2πf0, f0 is the initial frequency, and M0 is an intermediate variable.

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