Plasma radio frequency power source and radio frequency system

Abstract

The invention relates to a plasma radio frequency power source and a radio frequency system. The plasma radio frequency power source comprises a radio frequency power amplifier module; the impedance compression unit comprises at least one impedance compression network, and the impedance compression network is provided with a series branch circuit or a parallel branch circuit, or both of the series branch circuit and the parallel branch circuit. The radio frequency power amplifier module, the matcher and the impedance compression unit are sequentially connected in series, the output end of the impedance compression unit is used as a load cavity connecting port, and the impedance compression unit is used for compressing impedance of a load cavity to be within a matchable impedance range of the matcher. According to the invention, the impedance compression unit is arranged between the matcher and the cavity, so that different and large-range changing load impedances of a plurality of cavities can be compressed to a narrow range, the design requirement on the matcher is reduced, and the requirements on larger-range impedance matching capability and higher matching speed of a radio frequency system in different processes can be met; and the product cost is reduced and the product structure is miniaturized.

Description

Technical Field

[0001] This application belongs to the field of radio frequency plasma system technology, specifically relating to a plasma radio frequency power source and radio frequency system. Background Technology

[0002] A typical RF plasma power supply system architecture includes an RF power amplifier module, a matching circuit, and a load (cavity). See the system structure section below. Figure 1 The RF power amplifier module outputs power signals to generate and control plasma within the load cavity for required process operations. Due to the significant impedance differences within the load cavity, it cannot be directly matched to the RF power amplifier module. Therefore, a matching converter is added to perform impedance matching on the cavity load, ensuring efficient power delivery to the cavity load. Furthermore, during operation, the cavity load will change due to process variations. The matching converter promptly adjusts its impedance according to these load changes, ensuring that the impedance of the matching converter combined with the cavity load approaches a standard value and stabilizes.

[0003] A common matching scheme uses an adjustable vacuum capacitor combined with a motor. During operation, the size of the vacuum capacitor can be controlled by adjusting the motor rotation based on externally received information, thereby adjusting the impedance of the matching device. This ensures that the impedance of the cavity load, after being adjusted by the matching device, is presented to the RF power amplifier module in a state that is closer to the ideal value and tends to be stable. This makes the impedance of the cavity load basically match the output impedance of the RF power amplifier module, thus forming an RF system that minimizes reflected power and maximizes forward power transmitted to the plasma. This is a prerequisite for achieving the process requirements of repeatable, high-precision, and high-efficiency semiconductor manufacturing.

[0004] Radio frequency (RF) systems typically employ two cavity load characteristics: CCP and ICP. ICP cavities, in particular, exhibit high impedance with a wide range of variations. This necessitates matching devices with sufficiently fast response times and a broad dynamic impedance coverage, significantly increasing the design complexity. For processes requiring precise and rapid device response, such as semiconductor fabrication and high-precision coating, methods that use motors to adjust vacuum capacitors have long matching times, often on the order of seconds (s), which are insufficient to meet the rapid impedance matching requirements of these processes. Impedance test data for an ICP cavity serves as an example. Figure 2 The left-middle image is a Smith chart. The load impedance is shown in the black area on the right side of the Smith chart, which is also a high-impedance area, indicating a relatively large impedance. For ease of data display, a complex plane coordinate system is used, such as... Figure 2The right-hand diagram shows that the imaginary and real parts of the load vary greatly, with the imaginary part ranging from -400J to 1500J and the real part from 200 to 3000Ω. Taking a commonly used RF power supply as an example, its output impedance is typically designed to be 50+0JΩ. Therefore, it is almost impossible to match such a wide range of high load impedances to 50+0JΩ using existing matching devices.

[0005] In addition, vacuum capacitors are expensive, bulky, and take up a lot of space. If a larger vacuum capacitor adjustment range is selected, the adjustment device (such as a stepper motor) will also need to be changed, which will undoubtedly further increase the overall size of the RF system and restrict the further miniaturization of plasma RF systems. Summary of the Invention

[0006] In view of the problems existing in the prior art, this application proposes a plasma radio frequency power source and radio frequency system. An impedance compression unit is set between the matching unit and the cavity, which can compress the different and wide-range load impedances of many cavities into a narrower range, thereby reducing the design requirements of the matching unit.

[0007] In some embodiments, this application provides a plasma radio frequency power source, comprising: RF power amplifier module; The matching device is an adjustable matching device that has the ability to tune impedance variations within a certain impedance range to be compatible with the output impedance of the RF power amplifier module. An impedance compression unit includes at least one impedance compression network, wherein the impedance compression network comprises at least one series branch and / or at least one parallel branch connected together, wherein the series branch is composed of several fixed-value inductors and / or several fixed-value capacitors connected in series or in parallel, and the parallel branch is composed of several fixed-value inductors and / or several fixed-value capacitors connected in series or in parallel. The RF power amplifier module, the matching unit, and the impedance compression unit are connected in series. The output terminal of the impedance compression unit is used as a load cavity connection port. The impedance compression unit is used to compress the impedance of the load cavity to within the impedance range that the matching unit can match.

[0008] In some alternatives, the plasma radio frequency power source includes: The system comprises a first connecting line, a second connecting line, and a third connecting line; the output terminal of the RF power amplifier module is connected to the matching unit via the first connecting line, the input terminal of the impedance compression unit is directly connected to the output terminal of the matching unit or connected via the second connecting line, and the output terminal of the impedance compression unit is directly connected to the load cavity or connected via the third connecting line.

[0009] In some alternative embodiments, the impedance compression unit includes: Fourth connecting line; The impedance compression unit contains multiple impedance compression networks, which are connected in series by the fourth connecting line. The circuit structures of each impedance compression network may be the same or different.

[0010] In some alternatives, the RF power amplifier module is a power supply with a 50Ω output impedance, the first connection line is a 50Ω standard RF coaxial cable, and the matching unit is used to match the impedance compressed by the impedance compression unit to a 50Ω standard characteristic impedance.

[0011] In some alternatives, the load chamber is an ICP chamber.

[0012] In some alternatives, the load cavity has an imaginary part of impedance that varies at least from -400J to 1500J, and a real part of impedance that varies at least from 200Ω to 3000Ω.

[0013] In some alternatives, the impedance compression network consists of a series branch and a parallel branch connected together, forming a τ-type circuit structure and an L-type circuit structure.

[0014] In some alternatives, the impedance compression network consists of two series branches and one parallel branch, forming a T-shaped circuit structure.

[0015] In some alternatives, the impedance compression network consists of a series branch and two parallel branches connected together to form a π-type circuit structure.

[0016] In another embodiment, this application provides a plasma radio frequency system, comprising: RF power amplifier module; A matching circuit can tune impedance variations within a certain range to the standard impedance of an RF system. An impedance compression unit includes one or more impedance compression networks, each impedance compression network comprising at least one series branch and / or at least one parallel branch connected together. The series branch is composed of several fixed-value inductors and / or several fixed-value capacitors connected in series or in parallel. Each parallel branch is composed of several fixed-value inductors and / or several fixed-value capacitors connected in series or in parallel. The load cavity has an imaginary part of its load impedance that varies at least from -400J to 1500J, and a real part of its load impedance that varies at least from 200Ω to 3000Ω. First connecting line, second connecting line and third connecting line; The RF power amplifier module is connected to the matching unit via the first connection line, the input terminal of the impedance compression unit is connected to the output terminal of the matching unit via the second connection line, and the output terminal of the impedance compression unit is connected to the load cavity via the third connection line. The impedance compression unit is used to compress the impedance of the load cavity to within the matchable impedance range of the matching device.

[0017] In another embodiment, this application provides a plasma radio frequency system, including the aforementioned radio frequency power source; wherein the radio frequency power amplifier module and the matching unit are integrated into a single unit, and the output terminal of the radio frequency power amplifier module is directly connected to the input terminal of the matching unit.

[0018] The beneficial effects of this application are: This application sets an impedance compression unit between the matching unit and the cavity, which can compress the different and wide-range load impedances of many cavities into a narrower range, reducing the design requirements of the matching unit. It can meet the needs of different processes for a wider range of impedance matching capabilities and faster matching speeds for RF systems, and is also conducive to reducing product costs and miniaturizing product structure. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an existing radio frequency matching system. Figure 2 These are schematic diagrams of impedance test data for ICP cavities in some examples; Figure 3 This is a connection diagram of the radio frequency power source in some embodiments of this application; Figure 4 This is a schematic diagram of the impedance range after compression in some embodiments of this application; Figure 5 This is a schematic diagram showing the effective value of the output current of the matching unit of the RF power source or the effective value of the input current of the impedance compression unit in this application. Figure 6 This is a schematic diagram showing that the load compression unit in some embodiments of this application includes multiple impedance compression networks; Figure 7 This is a schematic diagram of the impedance compression unit connection in some embodiments of this application; Figure 8 This is a schematic diagram of the impedance compression unit connection in some embodiments of this application; Figure 9 This is a schematic diagram of the impedance compression unit connection in some embodiments of this application; Figure 10 This is a schematic diagram of multiple impedance compression network connections in some embodiments of this application; Figure 11This is a schematic diagram of the τ-type circuit structure of the impedance compression network in some embodiments of this application; Figure 12 This is a schematic diagram of the L-shaped circuit structure of the impedance compression network in some embodiments of this application; Figure 13 This is a schematic diagram of the T-type circuit structure of the impedance compression network in some embodiments of this application; Figure 14 This is a schematic diagram of the π-type circuit structure of the impedance compression network in some embodiments of this application; The reference numerals in the diagram are as follows: 101, RF power amplifier module; 102, matching circuit; 103, load cavity; 104, impedance compression unit; 1041 indicates the first network in a configuration containing multiple impedance compression networks; 104 n Indicates the nth network when multiple impedance compression networks are included; 106, first connection line; 107, second connection line; 108, third connection line; 109, fourth connection line; 1091 indicates the first of multiple fourth connection lines; 109 （n-1） This indicates the (n-1)th fourth connector that contains multiple fourth connectors. Detailed Implementation

[0020] The specific embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but are not intended to limit the scope of this application. Similarly, the following examples are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0022] In this application, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly, meaning electrical connection or intercommunication, or connection through other equivalent means; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal connection of two elements or the interaction between two elements, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0024] In some implementations, please refer to Figure 3 This application provides a plasma radio frequency power source, comprising: RF power amplifier module 101, matching unit 102 and impedance compression unit 104.

[0025] Matching unit 102 is an adjustable matching unit that has the ability to tune impedance variations within an impedance range to be nominal to the output impedance of RF power amplifier module 101.

[0026] The impedance compression unit 104 includes at least one impedance compression network, which is composed of at least one series branch or at least one parallel branch, or at least one series branch and at least one parallel branch. Depending on the actual needs, the series branch is composed of several fixed-value inductors or several fixed-value capacitors connected in series or in parallel. A series branch can also simultaneously include both fixed-value inductors and several fixed-value capacitors connected in series or in parallel. Similarly, the parallel branch can be composed of several fixed-value inductors, fixed-value capacitors, or both, with the devices connected in series or in parallel.

[0027] In this configuration, the RF power amplifier module 101, the matching unit 102, and the impedance compression unit 104 are connected in series. The output of the impedance compression unit 104 serves as the connection port for the load cavity 103. The impedance compression unit 104 is used to compress the impedance variation of the load cavity 103 to an impedance range within which the matching unit 102 can easily perform impedance matching. Alternatively, for cavities with lower impedance, the impedance compression unit 104 can directly compress the cavity load impedance to a more favorable impedance range, such as... Figure 4Within the impedance range shown. Matching unit 102 only needs to match the impedance within a small range after the impedance compression unit 104 is compressed to approach the standard value. This allows the overall impedance of matching unit 102, combined with the fixed impedance unit and the cavity load, to approach and stabilize towards the standard value until it matches the output impedance of RF power amplifier module 101. This significantly improves the speed and efficiency of system impedance matching, meeting the needs of RF systems in different processes. Furthermore, there are no excessive requirements on the matchable impedance range and response speed of matching unit 102, reducing the design requirements for matching unit 102. Thus, matching unit 102 can be designed with a simpler structure and smaller size, which is beneficial for reducing product costs and miniaturizing the product structure.

[0028] This application, by setting an impedance compression unit 104 in conjunction with a matching unit 102, enables rapid and efficient adaptation to a wide range of impedance changes in the load cavity 103, thereby improving the impedance coverage, matching accuracy, and efficiency of the RF system. Based on this, in some examples, the RF power amplifier module 101 can be selected with a fixed-frequency RF power supply, eliminating the need to adjust the RF power supply frequency for impedance matching, reducing system variables, and resulting in better process stability and repeatability. Fixed-frequency power supplies typically include two adjustable paths in conjunction with a fixed-frequency matching unit, each with an adjustable vacuum capacitor. However, vacuum capacitors are relatively expensive and have a slow adjustment speed (on the order of seconds). Therefore, to save costs, the RF power amplifier module 101 can also be configured with a frequency-adjustable RF power supply. Typically, one of the adjustable branches of the matching unit is modified to consist of a fixed inductor and a fixed capacitor, such as an LC resonant path composed of a fixed inductor in series with a fixed capacitor. This path has a relatively high Q value, and by adjusting the frequency of the RF power amplifier module, the impedance of this path can be varied within a certain range. Of course, as the frequency of the RF power amplifier module changes, the impedance of the branch with the adjustable vacuum capacitor will also change even if the capacitance value remains constant. However, this adjustable vacuum capacitor branch is usually not sensitive to frequency changes; the impedance is mainly determined by the change in the vacuum capacitor. Therefore, it should be noted that this scheme of setting the RF power amplifier module to be frequency-adjustable has a limited impedance variation range. It is still difficult to replace the scheme of this application, which combines an adjustable impedance compression unit with a matching circuit for fixed impedance compression adjustment and dynamic matching. However, this scheme can eliminate the need for a vacuum capacitor in one branch, resulting in relatively lower cost and improved frequency modulation speed.

[0029] As an example, please refer to Figure 2 and Figure 3The plasma RF power source of this application includes an RF power amplifier module 101, a matching unit 102, and an impedance compression unit 104, which are connected in series. The impedance compression unit 104 includes at least one impedance compression network, which consists of two impedance branches: a series branch and a parallel branch. These two impedance branches can be formed by any combination of inductors and capacitors, and both the inductor and capacitor are fixed values. For ease of description, in this embodiment, the impedance compression network consists of two impedance branches: a series inductor and a parallel capacitor. The load cavity 103 is connected to the output terminal of the impedance compression unit 104.

[0030] For example, regarding the ICP chamber, please refer to [link / reference]. Figure 2 Typically, the load impedance characteristic in ICP mode lies to the right of the Smith chart, and the imaginary and real parts of the impedance characteristic vary considerably. Commonly used matching circuits, such as the 102, are typically equipped with adjustable vacuum capacitors. Figure 1 As shown. Its typical matchable impedance range is approximately: real part from 0Ω to +50Ω, and imaginary part from -100Ω to +100Ω. Matching circuits struggle to match impedances with such a wide range of variations to the standard output impedance of RF power amplifier modules.

[0031] At this point, impedance compression is performed through the impedance compression unit: first, pre-compression is achieved through the series or parallel branches of the impedance compression unit. For example, the load cavity 103 first moves downward along the equal conductance circle through the parallel capacitor of the impedance compression network into the capacitive region of the Smith circle. The size of the parallel capacitor in the parallel branch can be adjusted to change the distance moved along the equal conductance circle. At this point, the impedance is in the high impedance region, and the real part of the impedance is still relatively large. Then, the real impedance is reduced by moving upward along the equal resistance circle through the inductor of the series branch, thereby completing the compression and relocation of the load impedance.

[0032] However, the load impedance may still not be within the expected optimal impedance range at this point, requiring further impedance adjustment. This can be achieved by appropriately optimizing the inductance and capacitance parameters in the series and parallel branches, ultimately bringing the impedance to a more optimal range after the integrated system is connected. For example, as an example, the impedance characteristics of the cavity load can be compressed to a point such as... Figure 4 The impedance range shown indicates that the matching unit 102 can easily match it with the output impedance of the RF power amplifier module 101, so that the cavity load impedance is matched by the matching unit 102 to be basically commensurate with the output impedance of the RF power amplifier module 101, thereby enabling the entire RF system to achieve a better working state.

[0033] It should be noted that a certain small reflection coefficient is allowed in the radio frequency system. That is, it is not required that the impedance of the radio frequency power amplifier and the compressed and matched amplifier be exactly the same. A small range of impedance deviation between the two is allowed, which is also within the scope of obtaining the better working state mentioned above.

[0034] On the other hand, please see Figure 5 This refers to the effective value of the output current of the matching circuit after impedance compression is performed by the impedance compression unit in the RF power source of this application, which is also the effective value of the input current at the front end of the impedance compression unit. Traditional impedance matching methods can achieve effective current values ​​of tens of amperes, resulting in low overall efficiency of the matching circuit (below 70%) and making the circuit design difficult. In contrast, this application, based on... Figure 5 The effective current values ​​shown are relatively low at each power point of the RF power amplifier module, corresponding to low effective output current values ​​of the matching circuit (maximum value less than 7 amps). By rationally designing and matching the sample compression unit and its impedance compression network, the device stress (e.g., voltage and current stress) in the matching network can be effectively reduced, facilitating the design of the matching circuit and achieving a significant improvement in overall impedance matching efficiency (overall efficiency > 85%).

[0035] This embodiment employs an impedance compression unit 104 to compress the cavity load impedance, which works in conjunction with the existing impedance matching capability of the adjustable matching unit 102 at the front end to form an RF power source that includes impedance compression and impedance matching, thereby meeting the matching requirements of an ultra-wide load range. It also reduces the design requirements for the matching unit 102, allowing for a simpler configuration. Compared to a matching unit 102 combining a vacuum capacitor and a motor, the device size and cost are significantly reduced, which is beneficial for miniaturizing the entire RF system, reducing manufacturing costs, and improving the matching efficiency of the RF system.

[0036] In some implementations, please refer to Figure 3 The plasma radio frequency power source of this application also includes: The system comprises a first connecting line, a second connecting line, and a third connecting line; the output terminal of the RF power amplifier module is connected to the matching unit via the first connecting line, the input terminal of the impedance compression unit is directly connected to the output terminal of the matching unit or connected via the second connecting line, and the output terminal of the impedance compression unit is directly connected to the load cavity or connected via the third connecting line.

[0037] As an example, the RF power amplifier module 101 can be a power supply with a 50Ω output impedance, the first connection line 106 is a 50Ω standard RF coaxial line, and the matching unit 102 can match the impedance compressed by the impedance compression unit 104 to a 50Ω standard characteristic impedance. After the RF power amplifier module 101 is connected to the matching unit 102 through the first connection line 106, it forms a 50Ω standard impedance RF power supply unit.

[0038] In some implementations, the connection method of the first connecting line 106, the second connecting line 107, and the third connecting line 108 can be selected according to the specific application scenario. For example, the first connecting line 106 and the third connecting line 108 can be set, while the second connecting line 107 is not set, such as... Figure 7As shown. The third connection line 108 can be omitted, as... Figure 8 As shown. Alternatively, the first connecting line 106 can be omitted, and the RF power amplifier module 101 and the matching unit 102 can be directly connected or integrated into a single unit, as shown. Figure 9 As shown. This facilitates the assembly and combination of the system, and gives the system the advantages of simple structure and small size.

[0039] In some implementations, please refer to Figure 6 and Figure 10 The plasma radio frequency power source of this application also includes: a fourth connecting line 109; the impedance compression unit 104 contains multiple impedance compression networks, and the impedance compression networks are connected by the fourth connecting line (109). n ...109 （n-1） ) are connected in series, and each impedance compression network (1041-104) n The circuit structures of ( ) can be the same or different. For example Figure 10 As shown, the impedance compression unit 104 includes multiple impedance compression networks connected in series (1041...104). n (where n represents a natural number), and the impedance compression networks are connected by a fourth connection line (1091...109). （n-1） The RF power source formed by connecting these components has a wide impedance matching range.

[0040] In this embodiment, the impedance compression network consists of two branches: a series branch and a parallel branch. The series branch is a fixed-value inductor, and the parallel branch is a fixed-value capacitor. Specifically, the output of the matching unit 102 is connected to the first impedance compression network 1041 of the impedance compression unit 104 via the second connection line 107. The first impedance compression network 1041 is connected to the next first impedance compression network 104 via the next fourth connection line 1091. （n-1） One end of the series branch is connected to the impedance compression network 104. （n-1） The other end of the series branch is connected to the fourth connecting line 109. （n-1） With the last impedance compression network 104 n One end of the series branch is connected, and the last impedance compression network 104 n The other end of the series branch is connected to the load cavity 103 via the third connecting line 108. One end of the parallel branch is connected to the series branch, and the other end is grounded. Where n is greater than or equal to 2, the number is set according to actual needs.

[0041] The specific matching method is as follows: Taking an ICP cavity as an example, the load impedance characteristic in ICP mode is usually located on the right side of the Smith chart. First, pre-matching is performed. Through the capacitor in the parallel branch of the impedance compression network 1041, the impedance characteristic of the load cavity 103 is moved downwards along the equal-conductivity circle into the capacitive region of the Smith chart. The capacitor's parameters can be adjusted by adjusting the distance moved along the equal-conductivity circle. At this point, the real part of the impedance is still relatively large. Then, through the series inductor of the first impedance compression network 1041, the real part of the impedance is reduced by moving upwards along the equal-resistance circle. At this point, the impedance range is still relatively large. Further matching is then performed through the impedance compression network 104... （n-1） The capacitors in the parallel branches move downwards along the equal-conductance circle and then through the impedance compression network 104. （n-1） As the series inductor moves upward along the circle of equal resistance, this process gradually shifts the impedance towards... Figure 4 If the target impedance range is close to the target impedance range, matching can be terminated if it meets the requirements; otherwise, 104 can continue to be used. n Further matching is performed until a better impedance point is reached. Finally, the RF power amplifier module 101 is connected to the matching unit 102 through the first connecting line 106. This completes the compression and relocation of the overall load cavity 103 impedance, bringing the impedance characteristics of the load cavity 103 into the matchable impedance range of the matching unit 102, allowing the matching unit 102 to easily perform impedance matching.

[0042] While a good matching range can be obtained at this point, impedance adjustment can still be further performed. In some methods, the parameters of the inductors and capacitors in multiple impedance compression networks can be appropriately optimized and adjusted to gradually bring the impedance characteristics of the load cavity 103 closer to the required impedance range. Ultimately, the impedance can reach a better impedance range after the integrated system is connected, allowing the entire RF system to achieve better operating conditions.

[0043] In this embodiment, the impedance compression unit 104 is configured to include multiple impedance compression networks. The inductors and capacitors of the impedance compression networks can be flexibly configured as needed, and the inductors and capacitors are fixed-value components, which has the advantages of small size and low cost.

[0044] When using a single impedance matching module under certain load cavity 103 conditions, it is necessary to select a larger inductor and capacitor, which poses certain difficulties in manufacturing and production. In this embodiment, multiple impedance compression networks are connected in series to form an impedance compression unit 104. Compared with the single impedance compression network scheme, smaller inductors can be selected in each series branch, and smaller capacitors can be selected in the parallel branches, which is beneficial to the miniaturization of the matching module.

[0045] In some implementations, such as Figure 2As shown, the load cavity 103 has an imaginary part of impedance that varies at least from -400J to 1500J, and a real part of impedance that varies at least from 200Ω to 3000Ω.

[0046] The commonly used matching circuit 102 is generally a matching circuit with an adjustable vacuum capacitor. The typical matchable impedance range is roughly: real part from 0Ω to +50Ω, imaginary part from -100Ω to +100Ω. The imaginary part range can be wider, but it is very difficult to achieve. It can be seen that existing matching circuits are unable to match the cavity load impedance with such a wide range of variation to the system's standard impedance requirements.

[0047] This application utilizes the impedance compression network of the impedance compression unit 104 to compress the aforementioned wide-ranging cavity load impedance to a smaller impedance range that is easily matched by the matching unit 102, thus reducing the requirements for the matching unit 102. In other words, the entire RF system only requires the addition of the impedance compression unit 104 between the matching unit 102 and the cavity to achieve matching between the matching unit 102 and the different impedances of numerous load cavities 103, without requiring any design modifications to the matching unit 102. The impedance compression unit 104 is composed of fixed-value inductors and capacitors, lacking actively adjustable components such as vacuum capacitors and regulating motors, resulting in a small size and low cost.

[0048] In some implementations, the impedance compression network consists of a series branch and a parallel branch connected together, forming a τ-type circuit structure and an L-type circuit structure, wherein the τ-type circuit structure is as follows: Figure 11 As shown, the L-shaped circuit structure is as follows: Figure 12 As shown.

[0049] In some implementations, the impedance compression network consists of two series branches and one parallel branch connected together, forming a T-type circuit structure, such as... Figure 13 As shown.

[0050] In some implementations, the impedance compression network consists of one series branch and two parallel branches connected together, forming a π-type circuit structure, such as... Figure 14 As shown.

[0051] In some embodiments, this application provides a plasma radio frequency system, comprising: RF power amplifier module 101; Matching unit 102 can tune impedance variations within a certain impedance range to the standard impedance of the RF system; Impedance compression unit 104 includes one or more impedance compression networks. Each impedance compression network comprises at least one series branch and / or at least one parallel branch. The series branch is formed by connecting several fixed-value inductors and / or several fixed-value capacitors in series or parallel. Each parallel branch is formed by connecting several fixed-value inductors and / or several fixed-value capacitors in series or parallel. The load cavity 103 has an imaginary part of its load impedance that varies at least from -400J to 1500J, and a real part of its load impedance that varies at least from 200Ω to 3000Ω. First connecting line 106, second connecting line 107 and third connecting line 108; The RF power amplifier module 101 is connected to the matching unit 102 via a first connecting line 106. The input terminal of the impedance compression unit 104 is connected to the output terminal of the matching unit 102 via a second connecting line 107. The output terminal of the impedance compression unit 104 is connected to the load cavity 103 via a third connecting line 108. The impedance compression unit 104 is used to compress the impedance of the load cavity 103 to within the matchable impedance range of the matching unit 102.

[0052] The RF power amplifier module 101 and the matching unit 102 are connected via a first connection line 106. The input terminal of the impedance compression unit is connected to the output terminal of the matching unit via a second connection line 107, and the output terminal of the impedance compression unit is connected to the load cavity via a third connection line 108, thus forming an RF system. The impedance compression unit 104 is used to compress the impedance of the load cavity 103 to a more favorable impedance range for the RF system. For example, compressing it to... Figure 4 Within a relatively small impedance range, the matching unit 102 only needs to match the impedance within a small range after compression by the impedance compression unit 104 to the 50Ω standard impedance. This allows the overall impedance of the matching unit 102, combined with the fixed impedance unit and the cavity load, to approach and stabilize towards the standard value, such as approaching the 50Ω impedance standard. This significantly improves the matching speed and efficiency of the system, meeting the needs of RF systems in different processes. Furthermore, there are no excessively high requirements for the matchable impedance range and response speed of the matching unit 102, reducing the design requirements for the matching unit 102. Thus, the matching unit 102 can be designed with a simpler structure and smaller size, which is beneficial for reducing product costs and miniaturizing the product structure.

[0053] In some embodiments, this application provides a plasma radio frequency system, including the plasma radio frequency power source in the above embodiments; wherein, the radio frequency power amplifier module 101 and the matching unit 102 are integrated into a single unit, and the output terminal of the radio frequency power amplifier module 101 is directly connected to the input terminal of the matching unit 102, such as... Figure 9As shown, thanks to the fixed impedance unit and connecting lines, the design requirements for the matching unit are low, and simpler and smaller devices can be selected. Thus, the matching unit 102 can be integrated with the RF power amplifier module 101, which is beneficial to the overall miniaturization of the system.

[0054] The above are merely some embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, and substitutions to the above embodiments within the scope of this application.

Claims

1. A plasma radio frequency power source, characterized in that, include: RF power amplifier module; The matching device is an adjustable matching device that has the ability to tune impedance variations within a certain impedance range to be compatible with the output impedance of the RF power amplifier module. An impedance compression unit includes at least one impedance compression network, wherein the impedance compression network comprises at least one series branch and / or at least one parallel branch connected together, wherein the series branch is composed of several fixed-value inductors and / or several fixed-value capacitors connected in series or in parallel, and the parallel branch is composed of several fixed-value inductors and / or several fixed-value capacitors connected in series or in parallel. The RF power amplifier module, the matching unit, and the impedance compression unit are connected in series. The output terminal of the impedance compression unit is used as a load cavity connection port. The impedance compression unit is used to compress the impedance of the load cavity to within the impedance range that the matching unit can match.

2. The plasma radio frequency power source according to claim 1, characterized in that, m includes: The system comprises a first connecting line, a second connecting line, and a third connecting line; the output terminal of the RF power amplifier module is connected to the matching unit via the first connecting line, the input terminal of the impedance compression unit is directly connected to the output terminal of the matching unit or connected via the second connecting line, and the output terminal of the impedance compression unit is directly connected to the load cavity or connected via the third connecting line.

3. The plasma radio frequency power source according to claim 1, characterized in that, Also includes: Fourth connecting line; The impedance compression unit contains multiple impedance compression networks, which are connected in series by the fourth connecting line. The circuit structures of each impedance compression network may be the same or different.

4. The plasma radio frequency power source according to claim 3, characterized in that, The RF power amplifier module is a power supply with a 50Ω output impedance, the first connection line is a 50Ω standard RF coaxial line, and the matching unit is used to match the impedance compressed by the impedance compression unit to the 50Ω standard characteristic impedance.

5. The plasma radio frequency power source according to claim 1, characterized in that: The load chamber is an ICP chamber.

6. The plasma radio frequency power source according to claim 1, characterized in that: The load cavity has an imaginary part of impedance that varies at least from -400J to 1500J, and a real part of impedance that varies at least from 200Ω to 3000Ω.

7. The plasma radio frequency power source according to claim 1, characterized in that: The impedance compression network consists of a series branch and a parallel branch connected together, forming a τ-type circuit structure and an L-type circuit structure.

8. The plasma radio frequency power source according to claim 1, characterized in that: The impedance compression network consists of two series branches and one parallel branch, forming a T-shaped circuit structure.

9. The plasma radio frequency power source according to claim 1, characterized in that: The impedance compression network consists of one series branch and two parallel branches, forming a π-type circuit structure.

10. A plasma radio frequency system, characterized in that, include: RF power amplifier module; A matching circuit can tune impedance variations within a certain range to the standard impedance of an RF system. An impedance compression unit includes one or more impedance compression networks, each impedance compression network comprising at least one series branch and / or at least one parallel branch connected together. The series branch is composed of several fixed-value inductors and / or several fixed-value capacitors connected in series or in parallel. Each parallel branch is composed of several fixed-value inductors and / or several fixed-value capacitors connected in series or in parallel. The load cavity has an imaginary part of its load impedance that varies at least from -400J to 1500J, and a real part of its load impedance that varies at least from 200Ω to 3000Ω. First connecting line, second connecting line, and third connecting line; The RF power amplifier module is connected to the matching unit via the first connection line, the input terminal of the impedance compression unit is connected to the output terminal of the matching unit via the second connection line, and the output terminal of the impedance compression unit is connected to the load cavity via the third connection line. The impedance compression unit is used to compress the impedance of the load cavity to within the matchable impedance range of the matching device.

11. A plasma radio frequency system, characterized in that, The radio frequency power source includes any one of claims 1 to 9; wherein the radio frequency power amplifier module and the matching unit are integrated into a single unit, and the output terminal of the radio frequency power amplifier module is directly connected to the input terminal of the matching unit.

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