Frequency division control radio frequency power supply solid-state impedance matcher and method thereof

Abstract

The invention discloses a frequency division control radio frequency power supply solid-state impedance matcher and a method thereof, and aims to solve the problems that a traditional mechanical impedance matcher is slow in response, low in adjustment precision and difficult to adapt to a dynamic load. According to the system, an all-solid-state impedance matcher is adopted, impedance dynamic adjustment is achieved through a matching network composed of an adjustable inductance module and a switched capacitor module, closed-loop control is constructed in combination with a radio frequency signal detection module and a digital signal processor, and a frequency division control strategy is adopted, and the high-frequency band realizes high-precision matching through a control strategy of coarse adjustment of the adjustable inductance module and fine adjustment of the switched capacitor module. The device has the advantages of high response speed, wide frequency band coverage and the like, and is particularly suitable for industrial plasma application scenes with remarkable dynamic impedance characteristics.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radio frequency power supply control and impedance matching, in particular to a frequency division controlled radio frequency power supply solid-state impedance matching device and method thereof. It is suitable for radio frequency systems with high requirements for impedance stability and matching response speed, especially in high-frequency dynamic load scenarios such as plasma discharge and radio frequency heating, and can realize fast and stable impedance adaptive adjustment. BACKGROUND

[0002] With the wide application of radio frequency power supply technology in the fields of plasma processing, semiconductor manufacturing, radio frequency heating, etc., the impedance matching device is the core component for efficient transmission between the radio frequency power supply and the load, and its performance directly affects the stability of the system. The existing impedance matching relies on mechanical adjustable structure, which has the problems of slow response speed, large size and low reliability, and is difficult to meet the dynamic matching demand when the load of the radio frequency power supply changes rapidly.

[0003] Therefore, how to provide a solution to the above problems is a problem that those skilled in the art need to solve at present. SUMMARY

[0004] The present application provides a frequency division controlled radio frequency power supply solid-state impedance matching device and method thereof, aiming to solve the problems of complex structure, slow matching response, weak frequency band adaptation ability and insufficient matching precision of traditional impedance matching devices under high frequency conditions.

[0005] A frequency division controlled radio frequency power supply solid-state impedance matching device, comprising: a radio frequency power supply, a power control unit, a communication interface module, a digital signal processor, a matching control module, a matching network, a switched capacitor controller and an adjustable inductor controller, a plasma load, and a radio frequency signal detection module. The radio frequency power supply generates a high-frequency alternating current signal to provide a radio frequency power source with a fixed output impedance for the matching system. The power control unit dynamically adjusts the output power of the radio frequency power supply, and adjusts the output power in real time according to the load state and the adjustment result of the matching network. The communication interface module realizes the transmission of instructions and states between the radio frequency power supply and the digital signal processor. The digital signal processor receives the feedback data of the radio frequency signal detection module, executes the impedance matching algorithm and outputs the control instructions. The matching control module controls the adjustable inductor controller and the switched capacitor controller according to the control instructions of the digital signal processor, to realize the dynamic adjustment of the impedance in the matching network. The matching network is located between the radio frequency power supply and the plasma load, and includes an adjustable inductor module and a switched capacitor module, to realize the impedance transformation of the system. The adjustable inductance controller is used to drive the adjustable inductance, and the switch capacitor controller is used to drive the switch capacitor array, so as to realize dynamic adjustment of inductance and capacitance parameters respectively. The plasma load ensures stable output of radio frequency power through real-time impedance matching. The radio frequency signal detection module collects forward power, reflected power, voltage, current and phase information in real time, and feeds back the detection results to the digital signal processor.

[0006] The adjustable inductance module includes a magnetic core structure, the magnetic core adopts high-frequency NiZn ferrite, and the magnetic permeability is controlled by a bias current source, so that the inductance is adjustable.

[0007] The switch capacitor module is composed of multiple groups of capacitor units and GaN device switches, and the capacitance is adjustable by controlling the conduction state of the GaN device.

[0008] The matching control module divides the working frequency into low and high frequency bands according to the frequency data collected by the radio frequency signal detection module, and switches the matching network according to the frequency band identification result, including: In the low frequency band, the matching control module uses an active magnetic control inductance, and adjusts the bias current source by combining a fuzzy PID control algorithm to control the magnetic permeability, so as to realize rough matching of the impedance network. In the high frequency band, the matching control module adopts a control strategy of inductance coarse adjustment and capacitance fine adjustment: coarse adjustment realizes preliminary positioning of the impedance by active magnetic control inductance, and fine adjustment is realized by the switch capacitor module, combining lookup table algorithm and fast switching mechanism to realize accurate matching of the impedance network.

[0009] A control method of a frequency division controlled radio frequency power supply solid-state impedance matching device, comprising the following steps: Step 1: The radio frequency signal detection module collects voltage, current, reflected power and phase information at the load end in real time, and the sampled data is transmitted to the digital signal processor after amplitude and phase detection; Step 2: The digital signal processor determines the current working frequency by a frequency band identification algorithm; Step 3: If the low frequency band is detected, the matching control module drives the adjustable inductance controller to adjust the bias current source to change the magnetic permeability of the magnetic core, so as to realize inductance adjustment and complete rough matching; Step 4: If the high frequency band is detected, first perform coarse adjustment by the adjustable inductance module, and then drive the switch capacitor controller to control the conduction state of the GaN device, so as to realize capacitance adjustment and accurate matching; Step 5: The adjusted data is sampled by the radio frequency signal detection module and fed back to the digital signal processor to form a closed loop control.

[0010] The radio frequency power supply solid-state impedance matcher and the control method thereof have the advantages of fast dynamic response speed and high matching precision. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Other drawings can be obtained by those of ordinary skill in the art without any creative effort on the basis of these drawings.

[0012] Figure 1 A structure principle block diagram of the radio frequency power supply solid-state impedance matcher of the present application is shown in the figure. Figure 2 A control flow chart of the radio frequency power supply solid-state impedance matcher of the present application is shown in the figure. DETAILED DESCRIPTION In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Other drawings can be obtained by those of ordinary skill in the art without any creative effort on the basis of these drawings.

[0013] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0014] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediate element. In addition, in the following embodiments, "connected" between the connected objects should be understood as "electrically connected", "communicatively connected" and the like if there is transmission of electrical signals or data between the connected objects.

[0015] As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", or the like, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

[0016] To make the technical solutions of the present application more clear and explicit, the following will combine the Figure 1 and Figure 2 Embodiments of the present application are described in detail.

[0017] As Figure 1 shown, the present application provides a frequency division controlled RF power supply solid-state impedance matching device, the system structure mainly includes: RF power supply, power control unit, communication interface module, digital signal processor, matching control module, matching network, switched capacitor controller and adjustable inductance controller, plasma load, RF signal detection module and other components.

[0018] First, the RF power supply provides high-frequency AC signal for the system, which is connected to the plasma load through the matching network. To ensure maximum power transmission, the system needs to achieve dynamic matching of the RF power supply output impedance and the load impedance. After being processed by the power control unit and the RF signal detection module, the RF signal detection module collects real-time forward power, reflected power, voltage, current and phase information, and feeds back the detection results to the digital signal processor.

[0019] As Figure 2 shown, the signal sampling unit includes voltage sampling and current sampling modules, which collect the voltage u (t) and current i (t) across the load, respectively. After pre-signal conditioning, they are sent to amplitude and phase detection for real-time analysis of input impedance Z L . Finally, the data is sent to the feedback controller for subsequent frequency band identification and matching control strategy. The present application adopts a frequency division impedance matching control strategy: The matching control module divides the working frequency into low and high frequency bands according to the frequency data collected by the RF signal detection module, and switches the matching network according to the frequency band identification results, including: In the low frequency band, the matching control module uses active magnetic control inductance, combined with fuzzy PID control algorithm to adjust the bias current source, control the magnetic permeability, and realize impedance rough matching; In the high frequency band, the matching control module adopts the control strategy of inductance coarse adjustment and capacitance fine adjustment: coarse adjustment realizes preliminary positioning of impedance through active magnetic control inductance, and fine adjustment is realized by a switch capacitor module, combined with a lookup table algorithm and a fast switching mechanism, to realize accurate matching in the high frequency band.

[0020] The above has carried out the detailed explanation to one embodiment of the application, but the content described is only the preferred embodiment of the application, cannot be considered for limiting the implementation range of the application. Any equivalent change and improvement made according to the application scope of the application should still belong to the patent coverage range of the application.

Claims

1. A frequency-division controlled solid-state impedance matching circuit for radio frequency power supplies, characterized in that, include: RF power supply, power control unit, communication interface module, digital signal processor, matching control module, matching network, switched capacitor controller and adjustable inductor controller, plasma load, RF signal detection module; The radio frequency power supply generates a high-frequency AC signal to provide a radio frequency power source with a fixed output impedance for the matching system; The power control unit dynamically adjusts the output power of the RF power supply, and adjusts the output power in real time according to the load status and the adjustment results of the matching network; The communication interface module enables the transmission of instructions and status between the radio frequency power supply and the digital signal processor. The digital signal processor receives feedback data from the radio frequency signal detection module, executes an impedance matching algorithm, and outputs control commands. The matching control module controls the adjustable inductor controller and the switched capacitor controller respectively according to the control instructions of the digital signal processor, so as to realize the dynamic adjustment of the impedance in the matching network. The matching network is located between the RF power supply and the plasma load, and includes an adjustable inductor module and a switched capacitor module to realize the impedance transformation of the system. The adjustable inductor controller is used to drive the adjustable inductor, and the switched capacitor controller is used to drive the switched capacitor array, so as to realize the dynamic adjustment of the inductor and capacitor parameters respectively. The plasma load ensures stable RF power output through real-time impedance matching. The radio frequency signal detection module collects forward power, reflected power, voltage, current and phase information in real time, and feeds back the detection results to the digital signal processor.

2. The RF power supply solid-state impedance matching device according to claim 1, characterized in that, The adjustable inductor module includes a magnetic core structure. The magnetic core is made of high-frequency NiZn ferrite, and its permeability is controlled by a bias current source, making the inductance adjustable.

3. The RF power supply solid-state impedance matching device according to claim 1, characterized in that, The switched capacitor module consists of multiple sets of capacitor units and GaN device switches. By controlling the conduction state of the GaN device, the capacitance can be adjusted.

4. The RF power supply solid-state impedance matching device according to claim 1, characterized in that, The matching control module divides the operating frequency into low-frequency and high-frequency bands based on the frequency data collected by the radio frequency signal detection module, and switches the matching network according to the frequency band identification results, including: In the low-frequency band, the matching control module uses an active magnetically controlled inductor, combined with a fuzzy PID control algorithm to adjust the bias current source, control the permeability, and achieve coarse matching of the impedance network. In the high-frequency band, the matching control module adopts a control strategy of coarse inductor adjustment and fine capacitor adjustment: coarse adjustment is achieved by active magnetically controlled inductor to achieve initial impedance positioning, and fine adjustment is achieved by switched capacitor module. Combined with table lookup algorithm and fast switching mechanism, the impedance network is accurately matched.

5. A control method for a frequency-division controlled solid-state impedance matching circuit for a radio frequency power supply, characterized in that, Includes the following steps: Step 1: The RF signal detection module collects the voltage, current, reflected power and phase information of the load in real time. The sampled data is transmitted to the digital signal processor after amplitude and phase detection. Step 2: The digital signal processor determines the current operating frequency using a frequency band identification algorithm; Step 3: If a low frequency band is detected, the matching control module drives the adjustable inductor controller to adjust the bias current source to change the magnetic core permeability, thereby achieving adjustable inductance and completing coarse matching. Step 4: If a high-frequency band is detected, first perform coarse adjustment through the adjustable inductor module, and then drive the switched capacitor controller to control the conduction state of the GaN device, so that the capacitor is adjustable and precise matching is achieved. Step 5: The adjusted data is sampled by the radio frequency signal detection module and fed back to the digital signal processor to form a closed-loop control.

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