Transistor switch control radio frequency matcher structure

Abstract

The utility model relates to a transistor switch control radio frequency matcher structure, which comprises a power detection module, a computer processing module, a motor control module and a matching network, the inductor unit L is composed of at least two branch inductors which are connected in series, the branch inductors are connected with branch transistors in parallel, the computer processing module is connected with the switch control module, and the switch control module is connected with the branch transistors. The inductor unit is composed of at least two branch inductors which are connected in series, the transistors are used as switches to control the access and short-circuit states of the inductors, the process that the inductors need to be assembled and disassembled due to the fact that the inductors need to be fixedly additionally installed in the working process and deviation exists between theoretical values is avoided, controllability of the whole matching network is enhanced, and the matching efficiency is improved. And the working efficiency of practical application is improved.

Description

Technical Field

[0001] This utility model relates to the technical field of radio frequency matching devices, and in particular to a transistor switch-controlled radio frequency matching device structure. Background Technology

[0002] Power radio frequency (RF) sources are widely used in vacuum deposition, semiconductor etching, and induction heating plasma. However, the load impedance is often not equal to the RF source's internal resistance. Directly connecting the RF source and load results in varying degrees of impedance mismatch. This mismatch leads to power reflection on the transmission line, preventing the load from fully receiving the energy and reducing transmission efficiency. Therefore, a matching network is needed between the RF source (or the end of the transmission line) and the load. The load impedance varies within a certain range due to factors such as operating time and the surrounding environment. Only by real-time monitoring of load impedance changes and adjusting the matching network parameters can maximum transmission efficiency be achieved. Therefore, research on automatic impedance matching devices is crucial.

[0003] Automatic impedance matching devices can track the complex impedance changes of the plasma load in a timely manner, ensuring impedance matching between the load and the source, thereby ensuring that all the power output from the RF source can be absorbed by the plasma load.

[0004] Existing automatic impedance matching system structures such as Figure 1 As shown, the system comprises four functional modules: a power detection module, a computer processing module, a motor control module, and a matching network. The RF power supply is connected to the load port, i.e., the plasma equipment, via the matching network. The power detection module collects the power signal induced on the coaxial cable and transmits it to the computer processing module. The computer processes the signal and controls the motor's rotation. The motor is connected to adjustable capacitors C1 and C2. By adjusting these capacitors, the system circuit achieves optimal impedance matching. As the impedance in the plasma equipment gradually changes during the process, the power detection module detects this in real time and transmits the signal to the computer processing module. The motor then controls the capacitors in real time, ensuring the system maintains a matched impedance as the process progresses.

[0005] Existing automatic impedance matching systems use two adjustable vacuum capacitors to adjust the matching state of the matching network. In practical applications, to ensure optimal device performance, the adjustable vacuum capacitors should be adjusted to around 50%. When the capacitor position deviates significantly from 50%, a fixed inductor is added to adjust the matching network. However, during actual operation, the automatic impedance system generates multiple parasitic capacitances and inductances, deviating from the theoretically calculated state. Therefore, the fixed inductor required in actual operation differs from the theoretical value. This necessitates the addition of different components to meet matching requirements in the field, making the process of adding and removing inductors cumbersome. Furthermore, the inductors required for different situations are often pre-fabricated products, which cannot meet the requirement of readily changing the required inductor value in the field. This increases workload, reduces efficiency, and the changes in parasitic parameters caused by replacing different components further affect system stability.

[0006] In view of the above-mentioned shortcomings, the designer actively researched and innovated in order to create a transistor switch-controlled RF matching device structure, making it more valuable for industrial applications. Utility Model Content

[0007] To solve any of the above-mentioned technical problems, the purpose of this utility model is to provide a transistor switch-controlled radio frequency matching circuit structure.

[0008] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0009] A transistor switch-controlled radio frequency matching circuit structure includes a power detection module, a computer processing module, a motor control module, and a matching network;

[0010] The matching network includes variable capacitors C1 and C2, and inductor unit L. Variable capacitor C1 is connected in parallel with the RF power supply, and then variable capacitor C2 is connected in series. Variable capacitor C2 is connected in series with inductor unit L and then connected to the load Z. LO ;

[0011] The power detection module is used to collect the power signal induced on the coaxial cable and transmit the power signal to the computer processing module. After the power signal is processed by the computer processing module, it is then controlled by the motor control module to rotate the first motor and the second motor. The first motor and the second motor are respectively connected to the variable capacitor C1 and the variable capacitor C2.

[0012] It also includes a switch control module. The inductor unit L consists of at least two branch inductors connected in series. The branch inductors are connected in parallel with branch transistors. The computer processing module is connected to the switch control module, and the switch control module is connected to multiple branch transistors respectively.

[0013] As a further improvement of this utility model, it also includes a set of inductor units L, which are connected in series with the variable capacitor C1 and then grounded.

[0014] As a further improvement of this invention, the transistor is a MOSFET type transistor.

[0015] As a further improvement of this utility model, the value of the branch inductance is L. i+1 =m*L i (1≤i≤4,m≥2).

[0016] As a further improvement of this utility model, the inductor unit L is composed of four branch inductors connected in series.

[0017] By means of the above solution, this utility model has at least the following advantages:

[0018] The inductor unit of this invention consists of at least two branch inductors connected in series. A transistor is used as a switch to control the connection and short-circuit states of the inductors. This avoids the need to install and remove inductors due to deviations between the required fixed inductors and theoretical values ​​during operation, thus enhancing the controllability of the overall matching network and improving the efficiency of practical applications.

[0019] This invention uses a MOSFET transistor as the switch control inductor. MOSFET transistors only require one drive voltage signal, making control convenient and power consumption low. Using a MOSFET transistor as the switch control allows it to conduct in the high-level state and be directly controlled by digital signals. In practical applications, this avoids unnecessary circuit design, simplifies the overall circuit structure, and facilitates timely observation of problems during verification and testing. At the same time, using a MOSFET transistor as the switch also ensures the stability of the overall circuit.

[0020] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and to implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram illustrating the working principle of existing technology;

[0023] Figure 2 This is a schematic diagram illustrating the working principle of a transistor switch-controlled radio frequency matching circuit according to this utility model.

[0024] Figure 3 yes Figure 2 A magnified view of a portion of the matching network;

[0025] Figure 4 yes Figure 3 A schematic diagram of another embodiment.

[0026] The meanings of the labels in the figures are as follows.

[0027] 1. RF power supply; 2. Power detection module; 3. Computer processing module; 4. Motor control module; 5. Matching network; 6. Switch control module. Detailed Implementation

[0028] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0029] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0030] Example

[0031] like Figures 1-4 As shown,

[0032] A transistor switch-controlled radio frequency matching circuit structure includes a power detection module 2, a computer processing module 3, a motor control module 4, and a matching network 5.

[0033] Matching network 5 includes variable capacitors C1 and C2, and inductor unit L. Variable capacitor C1 is connected in parallel with RF power supply 1, and then variable capacitor C2 is connected in series. Variable capacitor C2 is connected in series with inductor unit L and then connected to load Z. LO .

[0034] The power detection module 2 is used to collect the power signal induced on the coaxial cable and transmit the power signal to the computer processing module 3. After the power signal is processed by the computer processing module 3, it is then controlled by the motor control module 4 to rotate the first motor and the second motor. The first motor and the second motor are respectively connected to the variable capacitor C1 and the variable capacitor C2.

[0035] It also includes a switch control module 6. The inductor unit L consists of at least two branch inductors connected in series, and branch transistors are connected in parallel to the branch inductors. The transistors are MOSFET type transistors. The computer processing module 3 is connected to the switch control module 6, and the switch control module 6 is connected to multiple branch transistors respectively.

[0036] The inductor unit L consists of four branch inductors connected in series. The value of each branch inductance is L. i+1 =m*L i (1≤i≤4,m≥2).

[0037] In addition, it includes a set of inductor units L, which are connected in series with the variable capacitor C1 and then grounded.

[0038] The first embodiment of this utility model:

[0039] The automatic matching system consists of five functional modules: 1. Power detection module; 2. Computer processing module; 3. Motor control module; 4. Matching network; 5. Switch control module. Combined with... Figure 2 The schematic diagrams of the various functional modules show that the RF power supply 1 is finally connected to the equal load Z after passing through the matching network 5. LO This refers to the plasma equipment. The power detection module collects the power signal induced on the coaxial cable. The collected power signal is divided into incident and reflected components. The detected signal is transmitted to the computer processing module, which processes the signal to control the motor rotation and the conduction of the switching module. The motor is connected to variable capacitors C1 and C2, controlling the adjustment of the capacitors. The switching control module is connected to the inductor unit L to adjust the inductance. Adjusting the capacitors and inductors achieves optimal impedance matching in the system circuit. As the impedance in the plasma equipment gradually changes during the process, the power detection module detects this in real time and transmits the signal to the computer processing module. The motor controls the capacitors and the switching state in real time, allowing the system to achieve a matching state in real time as the process progresses. This achieves the expected automatic matching during operation, reducing the complexity of the work and improving overall efficiency.

[0040] Matching networks in automatic impedance matching systems, such as Figure 3As shown, the matching network consists of a variable capacitor C1 connected in parallel with the RF source, followed by a series variable capacitor C2, and then connected in series with the inductor unit L. The target plasma device structure is then connected after the inductor unit L. The inductor unit L consists of a set of four inductors of the same type but different values. The inductor values ​​are L... i+1 =m*L i (1≤i≤4, m≥2), and each inductor is connected in parallel with a transistor, which is used as a switch for convenient control of the overall inductance. MOSFET transistors are used in the circuit design. Theoretically, the voltage drop of a MOSFET transistor after conduction is zero, resulting in low drive power and avoiding unnecessary power loss due to the matching network. Only a single drive voltage signal is needed, making control convenient. Furthermore, the input impedance of a MOSFET transistor is close to infinite, maximizing voltage division. When used as a switch in static operation, the overall MOSFET transistor structure has low power consumption. This design avoids unnecessary circuit design in practical applications, simplifying the overall circuit structure and facilitating timely observation of problems during verification testing. Using MOSFET transistors as switches also ensures the stability of the overall circuit.

[0041] The four inductors in the switching control section of the matching network are equivalently represented as an inductor element L. Analyzing the matching network, the equivalent impedance Z of the matching network is... L calculate:

[0042]

[0043] To maximize transmission power, the equivalent impedance Z of the matching network is required. L With load impedance Z load Conjugate, meaning the real parts are equal and the imaginary parts are opposite. The load impedance Z... load Defined as consisting of two parts: a real part and an imaginary part, then:

[0044] Z load =R+jX

[0045] Where R is the real part of the load impedance and X is the imaginary part of the load impedance, and given that the equivalent impedance of the matching network is conjugate with the load impedance, we have...

[0046] Right now

[0047]

[0048] In the overall system architecture, the internal resistance R of the RF power supply s This is a fixed state, determined solely by the RF power supply. In practical applications, it is typically set to 50Ω by default, i.e., R... s=50Ω. Adjustments are made to the internal components of the matching network based on the load impedance to achieve a matched state for the entire circuit, maximizing transmission power. Analysis of the equivalent impedance of the matching network and the RF source shows that the real part of the equivalent impedance changes with the capacitance C1, while the imaginary part depends on the entire matching network. When the value of capacitance C1 is fixed with the real part, the imaginary part of the equivalent impedance is adjusted using capacitance C2 and an adjustable inductor unit to ensure optimal performance of the matching network components under matched conditions.

[0049] The obtained load impedance value is compared with the values ​​of existing capacitors C1 and C2, and the switch control inductor L. First, the position of capacitor C1 is determined using the real part value. After determining the position of capacitor C1, the imaginary part is calculated by substituting the value of capacitor C1. The optimal state of capacitor C2 and inductor L is determined using the imaginary part X and capacitor C1. In the default state, inductor L is not connected, that is, all MOSFET transistors are in the conducting state. At this time, the position of capacitor C2 obtained from the imaginary part is recorded. Then, the position of capacitor C2 is adjusted to 50% using inductor L. The corresponding control information is transmitted to the motor control module through the interface module of the computer processing module. The motor control module drives the motor and controls the switch control module. The variable capacitor C1 in the motor control matching network is used to change the position of the capacitor. At the same time, the MOSFET transistor switching structure uses NMOS high-level conduction. The signal processing module can directly use digital signals to control the MOSFET transistors. The switch control module controls the inductor L in the matching network to change the inductor's on state, thereby adjusting the capacitor and inductor, and finally achieving the goal of maximizing the transmission power in the matching state.

[0050] During the design and application process, we can adjust the position of the controllable inductor according to the actual situation to meet different design requirements. For example, the controllable inductor unit can be connected in series with capacitor C1 and then grounded. Figure 4 As shown, the real part of the equivalent impedance matched with the load structure can be adjusted using the controllable inductor unit to meet the optimal state adjustment of capacitor C1.

[0051] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0052] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection" and "connection" should be interpreted broadly. For example, they can be fixed connections, detachable connections, or integral connections; they can be mechanical connections or electrical connections; they can be direct connections or indirect connections through an intermediate medium; and they can be internal connections between two components.

[0053] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A transistor switch-controlled radio frequency matching device structure, comprising a power detection module (2), a computer processing module (3), a motor control module (4), and a matching network (5); The matching network (5) includes a variable capacitor C1, a variable capacitor C2, and an inductor unit L. The variable capacitor C1 is connected in parallel with the RF power supply (1) and then in series with the variable capacitor C2. The variable capacitor C2 is connected in series with the inductor unit L and then connected to the load Z. LO ; The power detection module (2) is used to collect the power signal induced on the coaxial cable and transmit the power signal to the computer processing module (3). After the power signal is processed by the computer processing module (3), the first motor and the second motor are controlled to rotate by the motor control module (4). The first motor and the second motor are respectively connected to the variable capacitor C1 and the variable capacitor C2. Its features are: It also includes a switch control module (6), wherein the inductor unit L is composed of at least two branch inductors connected in series, and the branch inductors are connected in parallel with branch transistors. The computer processing module (3) is connected to the switch control module (6), and the switch control module (6) is connected to multiple branch transistors respectively.

2. The transistor switch-controlled RF matching circuit structure as described in claim 1, characterized in that, It also includes a set of inductor units L, which are connected in series with the variable capacitor C1 and then grounded.

3. The transistor switch-controlled RF matching circuit structure as described in claim 1, characterized in that, The transistor is a MOSFET type transistor.

4. The transistor switch-controlled RF matching circuit structure as described in claim 1, characterized in that, The value of the branch inductance is L i+1 =m*L i (1≤i≤4,m≥2).

5. The transistor switch-controlled RF matching circuit structure as described in claim 1, characterized in that, The inductor unit L consists of four branch inductors connected in series.

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