Impedance matching circuit, power supply device provided with the same, and plasma processing apparatus

Abstract

Embodiments of the present invention provide an impedance matching circuit for rapid impedance matching, a power supply device having the same, and a plasma processing apparatus. The impedance matching circuit according to the present invention includes: a parallel capacitor array connected in parallel with an RF power supply that generates an RF (radio frequency) signal; and a series capacitor array connected in series with the RF power supply, wherein the parallel capacitor array or the series capacitor array includes a mechanical vacuum variable capacitor and an electronic switched capacitor module connected in parallel with the mechanical vacuum variable capacitor.

Description

Technical Field

[0001] This invention relates to impedance matching circuits, power supply devices having the same, and plasma processing equipment. Background Technology

[0002] Semiconductor (or display) manufacturing processes are processes used to manufacture semiconductor devices on a substrate (e.g., a wafer), including processes such as exposure, evaporation, etching, ion implantation, and cleaning. To perform these processes, semiconductor manufacturing equipment is installed in the cleanroom of a semiconductor manufacturing plant to process the substrates placed into the equipment.

[0003] In semiconductor manufacturing, plasma-based processes are widely used, such as etching and vapor deposition. Plasma processing equipment can simultaneously perform various process conditions, including process gases, temperature, pressure, the frequency of the RF (Radio Frequency) signal used to generate the plasma, and power.

[0004] On the other hand, with the increasing demands for high-level stacked structures in semiconductors such as 3D NAND flash memory, the number of steps in plasma processing is increasing, and plasma state changes occur when these steps are changed. These plasma state changes induce impedance changes, which can lead to impedance mismatches. Plasma processing equipment performs impedance matching to address these mismatches, but requires a power supply for rapid matching. Summary of the Invention

[0005] Therefore, embodiments of the present invention provide an impedance matching circuit for rapid impedance matching, a power supply device having the same, and a plasma processing apparatus.

[0006] The problems solved by the present invention are not limited to those mentioned above, and those skilled in the art will clearly understand from the following description other problems not mentioned.

[0007] The impedance matching circuit according to the present invention includes: a parallel capacitor array connected in parallel with an RF power supply that generates an RF (radio frequency) signal; and a series capacitor array connected in series with the RF power supply, wherein the parallel capacitor array or the series capacitor array includes a mechanical vacuum variable capacitor and an electronic switched capacitor module connected in parallel with the mechanical vacuum variable capacitor.

[0008] According to an embodiment of the present invention, the parallel capacitor array includes: a parallel mechanical vacuum variable capacitor; and a plurality of parallel electronic switched capacitor modules connected in parallel with the parallel mechanical vacuum variable capacitor. Alternatively, the parallel electronic switched capacitor module may include: a parallel fixed capacitor having a fixed capacitance; and a parallel switch connected in series with the parallel fixed capacitor.

[0009] According to an embodiment of the present invention, the parallel mechanical vacuum variable capacitor may have a larger capacitance than the parallel fixed capacitor.

[0010] According to an embodiment of the present invention, the series capacitor array may include: a series mechanical vacuum variable capacitor; and a plurality of series electronic switched capacitor modules connected in parallel with the series mechanical vacuum variable capacitor. Alternatively, the series electronic switched capacitor module may include: a series fixed capacitor having a fixed capacitance; and a series switch connected in series with the series fixed capacitor.

[0011] According to an embodiment of the present invention, the series mechanical vacuum variable capacitor may have a larger capacitance than the series fixed capacitor.

[0012] The power supply device of the plasma processing apparatus according to an embodiment of the present invention includes: a first power supply unit, comprising a first RF power supply for generating a first RF (radio frequency) signal, a first matching circuit connected to the first RF power supply, and a first power transmission circuit for transmitting the first RF signal to a plasma load; a second power supply unit, comprising a second RF power supply for generating a second RF signal, a second matching circuit connected to the second RF power supply, and a second power transmission circuit for transmitting the second RF signal to the plasma load; and a decoupling unit for eliminating interference between the first power supply unit and the second power supply unit.

[0013] The first matching circuit and the second matching circuit each include a mechanical vacuum variable capacitor and a plurality of electronic switched capacitor modules connected in parallel with the mechanical vacuum variable capacitor.

[0014] According to an embodiment of the present invention, the decoupling unit may include: a first decoupling inductor connected between the first matching circuit and the first power transmission circuit; a second decoupling inductor connected between the second matching circuit and the second power transmission circuit and magnetically coupled to the first decoupling inductor; and a decoupling capacitor connected to the first matching circuit and the second matching circuit.

[0015] According to an embodiment of the present invention, the first matching circuit may include: a first parallel capacitor array, including a plurality of capacitors connected in parallel to and grounded to the first RF power supply; and a first series capacitor array, including a plurality of capacitors connected in series to and grounded to the first RF power supply and the decoupling unit. Alternatively, the second matching circuit may include: a second parallel capacitor array, including a plurality of capacitors connected in parallel to and grounded to the second RF power supply; and a second series capacitor array, including a plurality of capacitors connected in series to and grounded to the second RF power supply and the decoupling unit.

[0016] According to an embodiment of the present invention, the first parallel capacitor array may include: a parallel mechanical vacuum variable capacitor; and a plurality of parallel electronic switched capacitor modules connected in parallel with the parallel mechanical vacuum variable capacitor. Alternatively, the first series capacitor array may include: a series mechanical vacuum variable capacitor; and a plurality of series electronic switched capacitor modules connected in parallel with the series mechanical vacuum variable capacitor.

[0017] According to an embodiment of the present invention, the parallel electronic switched capacitor module may include: a parallel fixed capacitor having a fixed capacitance; and a parallel switch connected in series with the parallel fixed capacitor. Alternatively, the series electronic switched capacitor module may include: a series fixed capacitor having a fixed capacitance; and a series switch connected in series with the series fixed capacitor.

[0018] According to an embodiment of the present invention, the parallel mechanical vacuum variable capacitor may have a larger capacitance than the parallel fixed capacitor. Alternatively, the series mechanical vacuum variable capacitor may have a larger capacitance than the series fixed capacitor.

[0019] According to an embodiment of the present invention, the first matching circuit may include: a fixed parallel capacitor connected to the first RF power supply and ground; a first series capacitor array including a plurality of capacitors connected to the first RF power supply and the fixed parallel capacitor and connected in parallel with each other; and a second series capacitor array including a plurality of capacitors connected to the fixed parallel capacitor and the decoupling unit and connected in parallel with each other.

[0020] According to an embodiment of the present invention, the first series capacitor may include a plurality of first parallel electronic switched capacitor modules connected in parallel with a first mechanical vacuum variable capacitor and the first mechanical vacuum variable capacitor, and the second series capacitor may include a plurality of second parallel electronic switched capacitor modules connected in parallel with a second mechanical vacuum variable capacitor and the second mechanical vacuum variable capacitor. Alternatively, the first parallel electronic switched capacitor module may include a first switch connected in series with a first fixed capacitor and the first fixed capacitor, and the second parallel electronic switched capacitor module may include a second switch connected in series with a second fixed capacitor and the second fixed capacitor.

[0021] The plasma processing apparatus according to the present invention includes: a process chamber for performing process processing on a substrate; and a power supply device for supplying power to the process chamber for forming plasma.

[0022] The power supply device includes: a first power supply unit, comprising a first RF power supply for generating a first RF (radio frequency) signal, a first matching circuit connected to the first RF power supply, and a first power transmission circuit for transmitting the first RF signal to the plasma load; a second power supply unit, comprising a second RF power supply for generating a second RF signal, a second matching circuit connected to the second RF power supply, and a second power transmission circuit for transmitting the second RF signal to the plasma load; and a decoupling unit to eliminate interference between the first power supply unit and the second power supply unit. The first matching circuit and the second matching circuit each include a mechanical vacuum variable capacitor and a plurality of electronic variable capacitor modules connected in parallel with the mechanical vacuum variable capacitor. When the process conditions of the process chamber are changed, with the capacitance of the mechanical vacuum variable capacitor fixed, the impedance of the first matching circuit and the second matching circuit is adjusted by controlling the electronic variable capacitor modules.

[0023] According to an embodiment of the present invention, the first matching circuit may include: a first parallel capacitor array comprising a plurality of capacitors connected in parallel with each other; and a first series capacitor array comprising a plurality of capacitors connected in series with the parallel capacitor array. Alternatively, the second matching circuit may include: a second parallel capacitor array comprising a plurality of capacitors connected in parallel with each other; and a second series capacitor array comprising a plurality of capacitors connected in series with the second parallel capacitor array.

[0024] According to an embodiment of the present invention, the first parallel capacitor array may include: a parallel mechanical vacuum variable capacitor; and a plurality of parallel electronic switched capacitor modules connected in parallel with the parallel mechanical vacuum variable capacitor. Alternatively, the first series capacitor array may include: a series mechanical vacuum variable capacitor; and a plurality of series electronic switched capacitor modules connected in parallel with the series mechanical vacuum variable capacitor.

[0025] According to an embodiment of the present invention, the parallel electronic switched capacitor module may include: a parallel fixed capacitor having a fixed capacitance; and a parallel switch connected in series with the parallel fixed capacitor. Alternatively, the series electronic switched capacitor module may include: a series fixed capacitor having a fixed capacitance; and a series switch connected in series with the series fixed capacitor.

[0026] According to an embodiment of the present invention, the parallel mechanical vacuum variable capacitor may have a larger capacitance than the parallel fixed capacitor. Alternatively, the series mechanical vacuum variable capacitor may have a larger capacitance than the series fixed capacitor.

[0027] According to an embodiment of the present invention, the capacitance of the parallel mechanical vacuum variable capacitor and the series mechanical vacuum variable capacitor may be adjusted to a preset value, which is determined by the type, flow rate, pressure or power supply of the process gas of the plasma processing equipment.

[0028] According to an embodiment of the present invention, the impedance can be matched by switching control of the parallel electronic switching capacitor module and the series electronic switching capacitor module when the process conditions of the process chamber are changed, while the capacitances of the parallel mechanical vacuum variable capacitor and the series mechanical vacuum variable capacitor are fixed at the preset values.

[0029] A substrate processing method performed by a plasma processing apparatus according to the present invention includes: a step of adjusting the impedance of a first matching circuit and a second matching circuit; and a step of performing a process processing on the substrate if the impedance adjustment is completed. The step of adjusting the impedance includes: a step of adjusting the capacitance of the mechanical vacuum variable capacitor to a preset value; a step of measuring the input impedance of the first matching circuit and the second matching circuit; a step of determining whether the reflection coefficient from the plasma load is greater than a reference reflection coefficient; a step of measuring the impedance of the plasma load when the reflection coefficient is greater than the reference reflection coefficient; and a step of adjusting the capacitance of the electronic variable capacitor module by controlling the opening and closing of the switches of the plurality of electronic variable capacitor modules based on the input impedance and the impedance of the plasma load.

[0030] According to an embodiment of the present invention, the step of adjusting the capacitance of the electronic variable capacitor module may include: calculating an impedance adjustment value based on the input impedance and the impedance of the plasma load; and closing the switch of the electronic variable capacitor module having a capacitance corresponding to the impedance adjustment value.

[0031] According to the present invention, a faster matching can be performed by using an impedance matching circuit that applies a parallel connection structure of a vacuum mechanical variable capacitor and an electronic switched capacitor module.

[0032] Furthermore, according to the present invention, by constructing a decoupling section that eliminates interference between multiple power supply units, the operating area required for a single matching circuit is maintained at a low level, thus enabling rapid impedance matching.

[0033] The effects of the present invention are not limited to those mentioned above, and those skilled in the art can clearly understand other effects not mentioned from the following description. Attached Figure Description

[0034] Figure 1 The outline structure of the plasma processing equipment is shown.

[0035] Figures 2 to 5 The structure of a power supply device for high-speed matching of multiple independent power sources in a plasma processing apparatus according to the present invention is illustrated in summary.

[0036] Figure 6 The equivalent circuit for modeling a parallel power supply device is shown.

[0037] Figure 7 An equivalent circuit is shown that is modeled for a parallel power supply device to which the decoupling part according to the present invention is applied.

[0038] Figure 8a as well as Figure 8b The equivalent circuit of the dual-power supply system and the transmission coefficient of the dual-power supply system are shown.

[0039] Figure 9a as well as Figure 9b The equivalent circuit of a dual power supply system including a decoupling unit and the transmission coefficient of the dual power supply system including the decoupling unit are shown.

[0040] Figure 10a The distribution of plasma load impedance at each process step in a single-power supply system is shown. Figure 10b as well as Figure 10c The distribution of plasma load impedance at each process step in the parallel power supply system is shown.

[0041] Figure 11 The structure of the matching circuit in a power supply device for high-speed matching according to the present invention is shown.

[0042] Figure 12 The structure of the matching system in the power supply device is shown.

[0043] Figure 13a This is a flowchart illustrating a substrate processing method performed by a plasma processing apparatus according to the present invention. Figure 13b This is a flowchart illustrating the process of adjusting impedance according to the present invention.

[0044] Figure 14 A power supply device for a suitable matching circuit according to another embodiment of the present invention is shown.

[0045] (Explanation of reference numerals in the attached diagram)

[0046] 1: Plasma processing equipment

[0047] 2: Power supply device

[0048] 3: Processing Chamber

[0049] 10: First Power Supply Department

[0050] 20: Second Power Supply Department

[0051] 30: Decoupling section

[0052] 40: Plasma Load Detailed Implementation

[0053] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art to which this invention pertains can readily implement it. The present invention can be implemented in various different ways and is not limited to the embodiments described herein.

[0054] To clearly illustrate the invention, irrelevant parts have been omitted, and the same or similar components are marked with the same reference numerals throughout the specification.

[0055] Furthermore, in multiple embodiments, the same reference numerals are used to describe only representative embodiments of the constituent elements having the same structure, while in other embodiments only structures different from the representative embodiments are described.

[0056] In the specification as a whole, when a part is described as being "connected (or combined)" with other parts, it not only refers to "direct connection (or combination)" but also includes cases where other components are placed in between for "indirect connection (or combination)". Furthermore, when a part is described as "including" a constituent element, unless otherwise stated otherwise, it means that other constituent elements may be included, rather than excluding them.

[0057] Unless otherwise defined, all terms used herein, including technical or scientific terms, shall have the same meaning as commonly understood by one of ordinary knowledge in the art to which this invention pertains. Terms such as those defined in commonly used dictionaries shall be interpreted as having the same meaning as in the relevant technical context, and shall not be ideally or excessively interpreted as having a formal meaning unless explicitly defined in this application.

[0058] Figure 1 The schematic structure of plasma processing apparatus 1 is shown. Plasma processing apparatus 1 includes a power supply device 2 that supplies power for forming plasma and a process processing chamber 3 that performs process processing on a substrate using the plasma formed by the power supply device 2. The process processing chamber 3 forms plasma while the substrate (e.g., a wafer) undergoes process processing; the power supply device 2 provides power to the process processing chamber 3 to form plasma.

[0059] In process chamber 3, the process is executed while the process gas, temperature, pressure, etc., are changed according to process conditions. However, with the recent demand for high-level stack structures, plasma state changes occur at each process step. These plasma state changes cause impedance changes in the plasma load, which may lead to impedance mismatch. Therefore, power supply unit 2 performs impedance matching to minimize such impedance mismatch, especially since rapid impedance matching is required to increase process efficiency.

[0060] Therefore, embodiments of the present invention provide a high-speed matching method with a high-level operating area.

[0061] Figures 2 to 5 The structure of the power supply device 2 for high-speed matching in the plasma processing apparatus 1 according to the present invention is shown in summary.

[0062] Reference Figure 2 as well as Figure 3 In the plasma processing apparatus 1 according to an embodiment of the present invention, the power supply device 2 for high-speed matching includes a first power supply unit 10 for transmitting a first RF signal to a plasma load 40, a second power supply unit 20 for transmitting a second RF signal to the plasma load 40, and a decoupling unit 30 for eliminating interference between the first power supply unit 10 and the second power supply unit 20. According to the present invention, the first power supply unit 10 and the second power supply unit 20, which operate independently of one plasma load 40, are connected in parallel. This allows the operating range required for the matching circuit to be maintained at a low level within a single power supply unit.

[0063] On the other hand, a power supply unit for a plasma load 40 operating independently can be as follows: Figure 4 As shown, N units are configured (N is a natural number). However, for ease of explanation, this document will focus on an example where power is supplied to the plasma load 40 via two power supply units. However, the scope of the invention is not limited to embodiments using two power supply units; substantially the same concept can be applied to embodiments using three or more power supply units.

[0064] Reference Figure 3 as well as Figure 5 The first power supply unit 10 includes a first RF power supply 110-1 that generates a first RF signal, a first matching circuit 120-1 connected between the first RF power supply 110-1 and the decoupling unit 30, and a first power transmission circuit 130-1 connected to the decoupling unit 30 and transmitting the first RF signal to the plasma load 40. Similarly, the second power supply unit 20 includes a second RF power supply 110-2 that generates a second RF signal, a second matching circuit 120-2 connected between the second RF power supply 110-2 and the decoupling unit 30, and a second power transmission circuit 130-2 connected to the decoupling unit 30 and transmitting the second RF signal to the plasma load 40. On the other hand, the decoupling unit 30 includes a first decoupling inductor L1 connected in series with the first power supply unit 10, a second decoupling inductor L2 connected in series with the second power supply unit 20 and magnetically coupled to the first decoupling inductor L1, and a decoupling capacitor C3 connected to the first power supply unit 10 and the second power supply unit 20.

[0065] The decoupling unit 30 may be composed of a portion of the first matching circuit 120-1 or the second matching circuit 120-2, or may be composed of separately divided modules.

[0066] According to the present invention, the first RF signal and the second RF signal may have the same frequency or within a reference range (e.g., 5%).

[0067] According to the present invention, the decoupling unit 30 is designed to cancel the coupling coefficient between the first power supply unit 10 (first power transmission circuit 130-1) and the second power supply unit 20 (second power transmission circuit 130-2) as well as the crosstalk generated by the reactance of the first power supply unit 10 and the reactance of the second power supply unit 20. The decoupling unit 30 connects an N-port network that minimizes interference between the first power supply unit 10 and the second power supply unit 20 to the first power supply unit 10 and the second power supply unit 20.

[0068] You can refer to Figure 6 as well as Figure 7 This will explain the decoupling principle of the N-port network through the decoupling unit 30.

[0069] Figure 6 The equivalent circuit for modeling a parallel power supply device is shown. Figure 6 The circuit on the left is the equivalent circuit of the first power supply unit 10. Figure 7 The circuit on the right is the equivalent circuit of the second power supply unit 20.

[0070] pass Figure 6 The electrical coupling between the reactive components of a single independent power source applies power (P1) to the load of the equivalent circuit of the first power supply unit 10 as shown in the following mathematical formula 1.

[0071]

Mathematical Formula 1

[0072]

[0073] At this time, if Figure 7 In this way, the reactive power generated by the decoupling unit 30 is added to each circuit, and the load (P1) of the equivalent circuit of the conventional first power supply unit 10 and the total power of the decoupling reactive power is as shown in the following mathematical formula 2.

[0074]

Mathematical Formula 2

[0075]

[0076] Here, the decoupling reactive power element of the additional decoupling section is designed to satisfy the conditions of the following mathematical formula 3.

[0077]

Mathematical Expression 3

[0078]

[0079] In mathematical formulas 1 to 3, R1 and X1 represent the impedance components (resistance and reactance) in the equivalent circuit of the first power supply unit 10, R2 and X2 represent the impedance components (resistance and reactance) in the equivalent circuit of the second power supply unit 20, k represents the coupling coefficient between the equivalent circuit of the first power supply unit 10 and the equivalent circuit of the second power supply unit 20 generated by the coupling between the power transmission circuits (antennas), k' represents the coupling coefficient between the reactance added by the decoupling unit 30 in the equivalent circuit of the first power supply unit 10 and the equivalent circuit of the second power supply unit 20 through the decoupling unit 30 generated by the coupling between the inductive reactive elements (first decoupling inductor L1 and second decoupling inductor L2), and X... 1D This indicates the reactance added by the decoupling unit 30 in the equivalent circuit of the first power supply unit 10. 2D This refers to the reactance added by the decoupling unit 30 in the equivalent circuit of the second power supply unit 20.

[0080] Figure 8a as well as Figure 8b The equivalent circuit of the dual-power supply system and its transmission coefficient are shown. For example... Figure 8a As shown, the first power transmission circuit 130-1 can be modeled using the first power transmission inductor L3 and the first power transmission capacitor C4, and the second power transmission circuit 130-2 can be modeled using the second power transmission inductor L4 and the first power transmission capacitor C5. The plasma load 40 can be modeled using the load inductor L... P and load resistance R P Modeling.

[0081] Figure 8b The diagram shows the situation as follows: Figure 8a The variation of the transmission coefficient S21 observed in such a dual-power supply system. Without a decoupling unit, a high transmission coefficient is achieved at the operating frequency (13.56MHz) due to the coupling between the power transmission circuits and the influence of the plasma load 40. However, this high transmission coefficient affects the matching circuit on the opposite side, causing abnormal operation and resulting in a high level of reflection in the power supply system on the opposite side.

[0082] Figure 9a as well as Figure 9b The equivalent circuit of a dual power supply system including the decoupling unit 30 and the transmission coefficient of the dual power supply system including the decoupling unit are shown. Figure 9a As shown, the first power transmission circuit 130-1 can be modeled using the first power transmission inductor L3 and the first power transmission capacitor C4, and the second power transmission circuit 130-2 can be modeled using the second power transmission inductor L4 and the first power transmission capacitor C5. The plasma load 40 can be modeled using the load inductor L... P and load resistance R PModeling. The decoupling unit 30 is modeled using the first decoupling inductor L1 connected to the first power transmission circuit 130-1, the second decoupling inductor L2 connected to the second power transmission circuit 130-2, and the decoupling capacitor C3 connected to both the first power transmission circuit 130-1 and the second power transmission circuit 130-2.

[0083] If so Figure 9a Adding a decoupling section 30 composed of reactive components would then, as in Figure 9b As can be confirmed from the curve, a low coupling coefficient is observed in the region where the operating frequency f0 is used. A certain level of coupling coefficient is also observed in adjacent frequencies at the same or within ±5% of the operating frequency f0.

[0084] By constructing a parallel single-circuit power supply system as described in this invention, the voltage and current operating ranges of each matching circuit 120-1 and 120-2 can be reduced by distributing the power supply to the plasma load 40, thereby minimizing the impedance variations of the matching circuits 120-1 and 120-2. By reducing the operating range and impedance variations, higher-speed impedance matching can be achieved.

[0085] Figure 10a The distribution of plasma load impedance at each process step in a single-power supply system is shown. Figure 10b as well as Figure 10c The distribution of plasma load impedance at each process step in the parallel power supply system is shown. Figure 10a This is a Smith chart showing the change in load impedance caused by variations in plasma conditions in a system powered by an RF power supply, a matching circuit, and a splitter circuit. Figure 10b as well as Figure 10c These are Smith charts showing the load impedance changes of the first matching circuit 120-1 of the first power supply unit 10 in the power supply system according to the present invention, and Smith charts showing the load impedance changes of the second matching circuit 120-2 of the second power supply unit 20.

[0086] When Figure 10a In such a single-circuit power supply system, it was found that due to variations in plasma process conditions, such as differences in the type, flow rate, pressure, and charge of process gases at each process step, the distribution range of plasma load in the matching circuit for each process step is relatively wide. This leads to drastic changes in the variable reactive power components within the matching circuit as the semiconductor stack structure, such as 3D NAND flash memory, undergoes continuous etching and the resulting process steps. These drastic changes in the variable reactive power components shorten the lifespan of the mechanical vacuum variable capacitors. Furthermore, the increased time for reflected power generation due to the long rematching time further shortens the power supply's lifespan.

[0087] Conversely, in a parallel dual-power supply system as described in this invention, such as Figure 10b as well as Figure 10c As shown, the impedance distribution of the plasma load 40 at each process step is narrow. By constructing a parallel dual-power supply system, the reactance variation of the plasma load 40 that should be borne by a single matching circuit can be dispersed, and each matching circuit can quickly perform impedance matching.

[0088] On the other hand, as an embodiment of the present invention, the power supply device 2 having a high-level operating area can be as follows: Figure 11 The impedance matching circuit shown includes a mechanical vacuum variable capacitor (VVC) and an electronic variable capacitor (EVC) connected in parallel. Hereinafter, a detailed structure of the impedance matching circuit according to the present invention will be described, with a representative example of the structure of the first matching circuit 120-1 configured in the first power supply unit 10. However, the same or similar configuration can be applied to the second matching circuit 120-2.

[0089] The impedance matching circuit according to the present invention includes a first parallel capacitor array 122-1 connected in parallel with the RF power supply 110-1 that generates the RF signal, and a first series capacitor array 124-1 connected in series with the RF power supply 110-1. The first parallel capacitor array 122-1 includes a parallel mechanical vacuum variable capacitor C1 and electronic switched capacitor modules 1220-1, 1220-2, ..., 1220-N connected in parallel with the parallel mechanical vacuum variable capacitor C1. The first series capacitor array 124-1 includes a series mechanical vacuum variable capacitor C2 and electronic switched capacitor modules 1240-1, 1240-2, ..., 1240-N connected in parallel with the series mechanical vacuum variable capacitor C2.

[0090] Reference Figure 11 The impedance matching circuit includes: a first parallel capacitor array 122-1, comprising a parallel mechanical vacuum variable capacitor C1 connected between the RF power supply 110-1 that generates the RF signal and ground, and a plurality of parallel electronic switched capacitor modules 1220-1, 1220-2, ..., 1220-N connected in parallel with the parallel mechanical vacuum variable capacitor C1; and a first series capacitor array 124-1, comprising a series mechanical vacuum variable capacitor C2 connected between the power supply 110-1 and the plasma load 40 side, and a plurality of series electronic switched capacitor modules 1240-1, 1240-2, ..., 1240-N connected in parallel with the series mechanical vacuum variable capacitor C2. Figure 11The diagram shows that both the first parallel capacitor array 122-1 and the first series capacitor array 124-1 are constructed by connecting mechanical vacuum variable capacitors and electronic switched capacitor modules in parallel. However, it is possible that one of the first parallel capacitor array 122-1 and the first series capacitor array 124-1 is constructed by connecting mechanical vacuum variable capacitors and electronic switched capacitor modules in parallel, while the other is constructed by connecting mechanical vacuum variable capacitors.

[0091] According to the present invention, the parallel electronic switched capacitor modules 1220-1, 1220-2, ..., 1220-N may include parallel fixed capacitors C with fixed capacitance. P1 C P2 C Pn and parallel fixed capacitor C P1 C P2 C Pn Parallel switches SP1, SP2, ..., SPn are connected in series.

[0092] According to the present invention, the parallel mechanical vacuum variable capacitor C1 can have a higher capacitance than the parallel fixed capacitor C. P1 C P2 C Pn Large capacitance. Relatively speaking, mechanical vacuum variable capacitors require a longer time to adjust their capacitance compared to electronic variable capacitors. Therefore, the capacitance can be adjusted more quickly by controlling the switching of an electronic variable capacitor, which has a relatively small capacitance, while keeping the mechanical vacuum variable capacitor at a fixed value.

[0093] According to the present invention, the series electronic switched capacitor modules 1240-1, 1240-2, ..., 1240-N may include a series fixed capacitor C having a fixed capacitance. S1 C S2 C Sn and series fixed capacitor C S1 C S2 C Sn Series-connected series switches S S1 S S2 S Sn .

[0094] According to the present invention, the series-connected mechanical vacuum variable capacitor C2 can have a higher capacitance than the series-connected fixed capacitor C. S1 C S2 C Sn Large capacitor.

[0095] On the other hand, the impedance matching circuit described above can be applied to the first matching circuit 120-1 and the second matching circuit 120-2 of the power supply device 2 of the plasma processing equipment 1.

[0096] According to the present invention, the first matching circuit 120-1 includes: a first parallel capacitor array 122-1, comprising a plurality of capacitors C1, C2, C3, C4, C5, C6, C7, C8, C9, C1, C9, C1, C2, C9, C1, C2, C1, C2, C1, C2, C2, C2, C3 ... P1 C P2 C Pn ; and a first series capacitor array 124-1, including a plurality of capacitors C2, C3, C4, C5, C6, C7, C8, C9 ... S1 C S2 C Sn Similarly, the second matching circuit 120-2 may include a second parallel capacitor array 122-2, including multiple capacitors connected in parallel to each other and grounded to the second RF power supply 110-2; and a second series capacitor array 124-2, including multiple capacitors connected in series to the second RF power supply 110-2 and the decoupling section 30 and connected in series with the second parallel capacitor array 122-2.

[0097] The first parallel capacitor array 122-1 includes a parallel mechanical vacuum variable capacitor C1 and multiple parallel electronic switched capacitor modules 1220-1, 1220-2, ..., 1220-N connected in parallel with the parallel mechanical vacuum variable capacitor C1. The first series capacitor array 124-1 includes a series mechanical vacuum variable capacitor C2 and multiple series electronic switched capacitor modules 1240-1, 1240-2, ..., 1240-N connected in parallel with the series mechanical vacuum variable capacitor C2.

[0098] Parallel electronic switched capacitor modules 1220-1, 1220-2, ..., 1220-N include parallel fixed capacitors C with fixed capacitance. P1 C P2 C Pn and parallel fixed capacitor C P1 C P2 C Pn Parallel switch S connected in series P1 S P2 S Pn The series-connected electronic switched capacitor modules 1240-1, 1240-2, ..., 1240-N include a series fixed capacitor C with a fixed capacitance.S1 C S2 C Sn and series fixed capacitor C S1 C S2 C Sn Series-connected series switches S S1 S S2 S Sn .

[0099] The parallel mechanical vacuum variable capacitor C1 has a higher capacitance than the parallel fixed capacitor C. P1 C P2 C Pn Large capacitance. The series-connected mechanical vacuum variable capacitor C2 has a larger capacitance than the series-connected fixed capacitor C. S1 C S2 C Sn Large capacitor.

[0100] The total capacitance (C) of the first parallel capacitor array 122-1 connected to the first RF power supply 110-1 tot As shown in mathematical formula 4 below.

[0101]

Mathematical Expression 4

[0102] C tot =C1+C P1 +C P2 +…+C Pn

[0103] The voltages generated across each element of the first parallel capacitor array 122-1 are the same, therefore the current flowing through all elements is as shown in Equation 5 below, when combined with an electronically controllable parallel switch S. P1 S P2 S Pn Connected parallel fixed capacitor C P1 C P2 C Pn When the parallel mechanical vacuum variable capacitor C1 is connected, most of the RF current flows through the parallel mechanical vacuum variable capacitor C1.

[0104]

Mathematical Expression 5

[0105]

[0106] The first series capacitor array 124-1 also uses the same principle to determine the total capacitance and current.

[0107] like Figure 11Thus, by constructing the first matching circuit 120-1, the RF current flowing through a single switch can be reduced; conversely, the overall allowable current of the first matching circuit 120-1 can be increased. The reduction in the RF current flowing to a single switch can mitigate the heat loss caused by the internal resistance of the electronic switch and improve the resulting heat generation problem, thereby ensuring the overall operational stability of the first matching circuit 120-1. The second matching circuit 120-2 operates on the same principle.

[0108] On the other hand, the impedance matching circuit according to the present invention can be configured in various ways. For example, it can be... Figure 14 The capacitor array configuration according to the invention is applicable to the T-shaped impedance matching circuit shown. (Refer to...) Figure 14 The first matching circuit 120-1 may include: a fixed parallel capacitor C connected to the first RF power supply 110-1 and grounded. S This includes the first RF power supply 110-1 and the fixed parallel capacitor C. S A first series capacitor array 122-1 consisting of multiple capacitors connected in parallel to each other; and including a fixed parallel capacitor C S And a second series capacitor array 124-1 consisting of a decoupling section 30 and multiple capacitors connected in parallel to each other.

[0109] The first series capacitor array 122-1 includes a first mechanical vacuum variable capacitor C1 and multiple first parallel electronic switched capacitor modules connected in parallel with the first mechanical vacuum variable capacitor C1. The second series capacitor array 124-1 includes a second mechanical vacuum variable capacitor C2 and multiple second parallel electronic switched capacitor modules connected in parallel with the second mechanical vacuum variable capacitor C2. The first parallel electronic switched capacitor module includes a first fixed capacitor C. 11 C 12 C 1N and the first fixed capacitor C 11 C 12 C 1N The first switch S connected in series 11 S 12 S 1N The second parallel electronic switched capacitor module includes a second fixed capacitor C. 21 C 22 C 2N and the second fixed capacitor C 21 C 22 C 2N The second switch S connected in series 21 S 22S 2N .

[0110] In addition, embodiments of the present invention provide a control method for a matching circuit for high-speed matching in a high-level operating region.

[0111] Figure 12 The structure of the matching system in power supply unit 2 is shown. (Refer to...) Figure 12 If the first RF power supply 110-1 is working, the input sensor set in the first matching circuit 120-1 measures the input impedance Z. IN The corresponding reflection coefficient (Γ). When the reflection coefficient (Γ) is higher than the reference value, the impedance of the plasma load 40 is calculated using the controller, and the impedance (capacitance) in the first matching circuit 120-1 is adjusted. When the reflection coefficient (Γ) is lower than the reference value after impedance adjustment, the process is executed without further impedance adjustment. The input impedance Z is also monitored during process execution. IN Whether it matches the output of the first RF power supply 110-1, and repeat the process of readjusting the impedance when the reflection coefficient (Γ) is higher than the reference value.

[0112] When adjusting the capacitance of a mechanical vacuum variable capacitor, the reliance on mechanical operation can lead to a high probability of matching time delay. Therefore, embodiments of the present invention provide a method for achieving rapid matching by electronic switching control while the capacitance of the mechanical variable capacitor remains fixed at a preset value, when the process conditions of the process chamber 3 are changed.

[0113] That is, the plasma processing apparatus 1 according to the present invention includes a process processing chamber 3 for performing process processing on a substrate and a power supply device 2 for supplying power to the process processing chamber 3 for forming plasma. The power supply device 2 includes: a first power supply unit 10, including a first RF power supply 110-1 for generating a first RF signal, a first matching circuit 120-1 connected to the first RF power supply 110-1, and a first power transmission circuit 130-1 for transmitting the first RF signal to the plasma load 40; a second power supply unit 20, including a second RF power supply 110-2 for generating a second RF signal, a second matching circuit 120-2 connected to the second RF power supply 110-2, and a second power transmission circuit 130-2 for transmitting the second RF signal to the plasma load 40; and a decoupling unit 30 for eliminating interference between the first power supply unit 10 and the second power supply unit 20. The first matching circuit 120-1 includes a mechanical vacuum variable capacitor C1 and multiple electronic switched capacitor modules 1220-1, 1220-2, ..., 1220-N connected in parallel with the mechanical vacuum variable capacitor C1. The second matching circuit 120-2 includes a mechanical vacuum variable capacitor C2 and multiple electronic switched capacitor modules 1240-1, 1240-2, ..., 1240-N connected in parallel with the mechanical vacuum variable capacitor C2. When the process conditions of the process chamber 3 are changed, the impedance of the first matching circuit 120-1 is adjusted by controlling the electronic switched capacitor modules 1220-1, 1220-2, ..., 1220-N when the capacitance of the mechanical vacuum variable capacitor C1 is fixed. The impedance of the second matching circuit 120-2 is adjusted by controlling the electronic switched capacitor modules 1240-1, 1240-2, ..., 1240-N when the capacitance of the mechanical vacuum variable capacitor C2 is fixed.

[0114] According to the present invention, the first matching circuit 120-1 includes: a parallel capacitor array 122-1, comprising a plurality of capacitors C1, C2, C3, C4, C5, C6, C7, C8, C9, C1 ...1, C9, C1, C1, C9, C1, C1, C1, C1, C1, C1, C1, C1, C1, C1, C1, C1, C1, C1, C1, C1, C1, C1, C1, C1, C P1 C P2 C Pn ; and a first series capacitor array 124-1, including a plurality of capacitors C2, C3, C4, C5, C6, C7, C8, C9 ... S1 C S2 C SnSimilarly, the second matching circuit 120-2 may include: a second parallel capacitor array 122-2, including multiple capacitors connected in parallel to each other and grounded to the second RF power supply 110-2; and a second series capacitor array 124-2, including multiple capacitors connected in series to the second RF power supply 110-2 and the decoupling section 30 and connected in series with the second parallel capacitor array 122-2.

[0115] The first parallel capacitor array 122-1 includes a parallel mechanical vacuum variable capacitor C1 and multiple parallel electronic switched capacitor modules 1220-1, 1220-2, ..., 1220-N connected in parallel with the parallel mechanical vacuum variable capacitor C1. The first series capacitor array 124-1 includes a series mechanical vacuum variable capacitor C2 and multiple series electronic switched capacitor modules 1240-1, 1240-2, ..., 1240-N connected in parallel with the series mechanical vacuum variable capacitor C2.

[0116] Parallel electronic switched capacitor modules 1220-1, 1220-2, ..., 1220-N include parallel fixed capacitors C with fixed capacitance. P1 C P2 C Pn and parallel fixed capacitor C P1 C P2 C Pn Parallel switch S connected in series P1 S P2 S Pn The series-connected electronic switched capacitor modules 1240-1, 1240-2, ..., 1240-N include a series fixed capacitor C with a fixed capacitance. S1 C S2 C Sn and series fixed capacitor C S1 C S2 C Sn Series-connected series switches S S1 S S2 S Sn .

[0117] The parallel mechanical vacuum variable capacitor C1 has a higher capacitance than the parallel fixed capacitor C. P1 C P2 C Pn Large capacitance. The series-connected mechanical vacuum variable capacitor C2 has a larger capacitance than the series-connected fixed capacitor C. S1 C S2C Sn Large capacitor.

[0118] According to the present invention, the capacitance of the parallel mechanical vacuum variable capacitor C1 and the series mechanical vacuum variable capacitor C2 is adjusted to a preset value. The preset value of the capacitance of the parallel mechanical vacuum variable capacitor C1 and the series mechanical vacuum variable capacitor C2 is determined according to the type, flow rate, pressure, or power supply of the process gas of the plasma processing equipment 1.

[0119] Figure 13a This is a flowchart illustrating a substrate processing method performed by a plasma processing apparatus according to the present invention. Figure 13b This is a flowchart illustrating the process of adjusting impedance according to the present invention.

[0120] Reference Figure 13a The process includes a step of adjusting the impedance of the impedance matching circuit (first matching circuit 120-1 and second matching circuit 120-2) (S1301) and a step of performing a process on the substrate if the impedance adjustment is completed (S1302).

[0121] Reference Figure 13b The step of adjusting the impedance of the impedance matching circuit (S1301) includes: adjusting the capacitance of the mechanical vacuum variable capacitors C1 and C2 to a preset value (S1310); and measuring the input impedance Z of the first matching circuit 120-1 and the second matching circuit 120-2. IN Step (S1320); Step (S1330) to determine whether the reflection coefficient (Γ) from the plasma load 40 is greater than the reference reflection coefficient; When the reflection coefficient (Γ) is greater than the reference reflection coefficient, measuring the impedance Z of the plasma load 40. P Step (S1340); Step (S1350) to adjust the capacitance of the electronic variable capacitor modules 1220-1, 1220-2, ..., 1220-N, 1240-1, 1240-2, ..., 1240-N by controlling the opening and closing of the switches of the multiple electronic variable capacitor modules 1220-1, 1220-2, ..., 1220-N, 1240-1, 1240-2, ..., 1240-N based on the impedance of the plasma load 40.

[0122] In step (S1310) of adjusting the capacitance of the mechanical vacuum variable capacitor to a preset value, the capacitances of the parallel mechanical vacuum variable capacitor C1 and the series mechanical vacuum variable capacitor C2 are adjusted to preset values. The preset values ​​of the capacitances of the parallel mechanical vacuum variable capacitor C1 and the series mechanical vacuum variable capacitor C2 are determined by the type, flow rate, pressure, or power supply of the process gas in the plasma processing equipment 1.

[0123] Next, the input impedance Z was measured. IN Step (S1320). Here, the input sensor set in the first matching circuit 120-1 measures the input impedance Z. IN The corresponding reflection coefficient (Γ).

[0124] In measuring the input impedance Z IN After determining the corresponding reflection coefficient (Γ), the step of confirming whether the reflection coefficient (Γ) is less than the reference value is executed (S1330). When the reflection coefficient (Γ) is less than the reference value, the input impedance Z can be measured while repeating the process. IN Step (S1320).

[0125] When the reflection coefficient (Γ) is greater than or equal to the reference value, the load impedance Z is measured. P Step (S1340) and based on input impedance Z IN and the impedance Z of plasma load 40 P The step (S1350) involves adjusting the capacitance of the electronic variable capacitor modules 1220-1, 1220-2, ..., 1220-N, 1240-1, 1240-2, ..., 1240-N by controlling the opening and closing of the switches of multiple electronic variable capacitor modules 1220-1, 1220-2, ..., 1220-N, 1240-1, 1240-2, ..., 1240-N.

[0126] The step (S1350) of adjusting the capacitance of the electronic variable capacitor modules 1220-1, 1220-2, ..., 1220-N, 1240-1, 1240-2, ..., 1240-N may include adjusting the impedance Z based on the plasma load 40. P The steps for calculating the impedance adjustment value and closing the switch S of the electronic variable capacitor modules 1220-1, 1220-2, ..., 1220-N, 1240-1, 1240-2, ..., 1240-N with capacitance corresponding to the impedance adjustment value. P1 S P2 S Pn CS1 C S2 C Sn The steps.

[0127] As a method for adjusting the capacitance of electronic variable capacitor modules 1220-1, 1220-2, ..., 1220-N, 1240-1, 1240-2, ..., 1240-N, one or more switches can be closed (On) while the remaining switches are open (Off). The capacitances of the capacitors with the switches closed (On) are added to the impedance of the impedance matching circuit, thereby adjusting the impedance of the overall matching circuit.

[0128] That is, with the capacitances of the parallel mechanical vacuum variable capacitor C1 and the series mechanical vacuum variable capacitor C2 fixed at preset values, impedance matching is achieved through switching control of the parallel electronic switching capacitor modules 1220-1, 1220-2, ..., 1220-N and the series electronic switching capacitor modules 1240-1, 1240-2, ..., 1240-N. If impedance matching is achieved, the process is repeated while simultaneously measuring the input impedance Z. IN Step (S1320).

[0129] This embodiment and the accompanying drawings are merely illustrative of a portion of the technical concept included in this invention. It is obvious that variations and specific embodiments that can be readily derived by those skilled in the art within the scope of the technical concept included in the specification and drawings of this invention are all included within the scope of the claims of this invention.

[0130] Therefore, the concept of the present invention should not be limited to the illustrated embodiments, not only to the appended claims, but also to all concepts that are equivalent or modified from the claims.

Claims

1. A power supply device for a plasma processing apparatus, comprising: The first power supply unit includes a first RF power supply that generates a first RF signal, a first matching circuit connected to the first RF power supply, and a first power transmission circuit that transmits the first RF signal to the plasma load. The second power supply unit includes a second RF power supply that generates a second RF signal, a second matching circuit connected to the second RF power supply, and a second power transmission circuit that transmits the second RF signal to the plasma load. as well as The decoupling unit eliminates interference between the first power supply unit and the second power supply unit. The first matching circuit and the second matching circuit each include a mechanical vacuum variable capacitor and a plurality of electronic switched capacitor modules connected in parallel with the mechanical vacuum variable capacitor. The decoupling unit includes: A first decoupling inductor is connected between the first matching circuit and the first power transmission circuit; A second decoupling inductor is connected between the second matching circuit and the second power transmission circuit and is magnetically coupled to the first decoupling inductor; and A decoupling capacitor is connected to the first matching circuit and the second matching circuit.

2. The power supply device according to claim 1, wherein, The first matching circuit includes: A first parallel capacitor array includes a plurality of capacitors connected in parallel to each other and grounded, combined with the first RF power supply; and The first series capacitor array includes multiple capacitors connected in series with the first RF power supply and the decoupling unit and the first parallel capacitor array. The second matching circuit includes: The second parallel capacitor array includes a plurality of capacitors connected to the second RF power supply and grounded and connected in parallel with each other; and The second series capacitor array includes a plurality of capacitors connected to the second RF power supply and the decoupling section and connected in series with the second parallel capacitor array.

3. The power supply device according to claim 2, wherein, The first parallel capacitor array includes: Parallel mechanical vacuum variable capacitors; and Multiple parallel electronic switched capacitor modules are connected in parallel with the parallel mechanical vacuum variable capacitor. The first series capacitor array includes: Series mechanical vacuum variable capacitor; and Multiple series-connected electronic switched capacitor modules are connected in parallel with the series-connected mechanical vacuum variable capacitor.

4. The power supply device according to claim 3, wherein, The parallel electronic switched capacitor module includes: Parallel fixed capacitors have a fixed capacitance; and A parallel switch is connected in series with the parallel fixed capacitor. The series-connected electronic switched capacitor module includes: A series-connected fixed capacitor has a fixed capacitance; and A series switch is connected in series with the series fixed capacitor.

5. The power supply device according to claim 4, wherein, The parallel mechanical vacuum variable capacitor has a larger capacitance than the parallel fixed capacitor. The series mechanical vacuum variable capacitor has a larger capacitance than the series fixed capacitor.

6. The power supply device according to claim 1, wherein, The first matching circuit includes: A fixed parallel capacitor is connected to the first RF power supply and ground; A first series capacitor array includes a plurality of capacitors connected in parallel to each other, in conjunction with the first RF power supply and the fixed parallel capacitor; and The second series capacitor array includes multiple capacitors that are combined with the fixed parallel capacitor and the decoupling section and connected in parallel with each other.

7. The power supply device according to claim 6, wherein, The first series capacitor includes a plurality of first parallel electronic switched capacitor modules connected in parallel with the first mechanical vacuum variable capacitor and the first mechanical vacuum variable capacitor. The second series capacitor includes a plurality of second parallel electronic switched capacitor modules connected in parallel with the second mechanical vacuum variable capacitor and the second mechanical vacuum variable capacitor. The first parallel electronic switched capacitor module includes a first switch connected in series with a first fixed capacitor and the first fixed capacitor. The second parallel electronic switched capacitor module includes a second switch connected in series with the second fixed capacitor and the second fixed capacitor.

8. A plasma processing apparatus, comprising: The process chamber is used to perform process treatments on the substrate. as well as The power supply unit supplies electricity to the process chamber for plasma formation. The power supply device includes: The first power supply unit includes a first RF power supply that generates a first RF signal, a first matching circuit connected to the first RF power supply, and a first power transmission circuit that transmits the first RF signal to the plasma load. The second power supply unit includes a second RF power source for generating a second RF signal, a second matching circuit connected to the second RF power source, and a second power transmission circuit for transmitting the second RF signal to the plasma load; and The decoupling unit eliminates interference between the first power supply unit and the second power supply unit. The first matching circuit and the second matching circuit each include a mechanical vacuum variable capacitor and a plurality of electronic variable capacitor modules connected in parallel with the mechanical vacuum variable capacitor. When the process conditions of the processing chamber are changed, with the capacitance of the mechanical vacuum variable capacitor fixed, the impedance of the first matching circuit and the second matching circuit is adjusted by controlling the electronic variable capacitor module. The decoupling unit includes: A first decoupling inductor is connected between the first matching circuit and the first power transmission circuit; A second decoupling inductor is connected between the second matching circuit and the second power transmission circuit and is magnetically coupled to the first decoupling inductor; and A decoupling capacitor is connected to the first matching circuit and the second matching circuit.

9. The plasma processing apparatus according to claim 8, wherein, The first matching circuit includes: A first parallel capacitor array includes multiple capacitors connected in parallel with each other; and The first series capacitor array includes multiple capacitors connected in series with the parallel capacitor array. The second matching circuit includes: The second parallel capacitor array includes multiple capacitors connected in parallel with each other; and The second series capacitor array comprises multiple capacitors connected in series with the second parallel capacitor array.

10. The plasma processing apparatus according to claim 9, wherein, The first parallel capacitor array includes: Parallel mechanical vacuum variable capacitors; and Multiple parallel electronic switched capacitor modules are connected in parallel with the parallel mechanical vacuum variable capacitor. The first series capacitor array includes: Series mechanical vacuum variable capacitor; and Multiple series-connected electronic switched capacitor modules are connected in parallel with the series-connected mechanical vacuum variable capacitor.

11. The plasma processing apparatus according to claim 10, wherein, The parallel electronic switched capacitor module includes: Parallel fixed capacitors have a fixed capacitance; and A parallel switch is connected in series with the parallel fixed capacitor. The series-connected electronic switched capacitor module includes: A series-connected fixed capacitor has a fixed capacitance; and A series switch is connected in series with the series fixed capacitor. The parallel mechanical vacuum variable capacitor has a larger capacitance than the parallel fixed capacitor. The series mechanical vacuum variable capacitor has a larger capacitance than the series fixed capacitor.

12. The plasma processing apparatus according to claim 11, wherein, The capacitance of both the parallel mechanical vacuum variable capacitor and the series mechanical vacuum variable capacitor is adjusted to a preset value. The preset value is determined by the type, flow rate, pressure, or power supply of the process gas in the plasma processing equipment. The configuration is such that when the process conditions of the process chamber are changed, with the capacitances of the parallel mechanical vacuum variable capacitor and the series mechanical vacuum variable capacitor fixed at the preset values, impedance matching is achieved through the switching control of the parallel electronic switched capacitor module and the series electronic switched capacitor module.

13. A substrate processing method, performed by the plasma processing apparatus of claim 8, wherein, The substrate processing method includes: The steps of adjusting the impedance of the first matching circuit and the second matching circuit; and If the impedance adjustment is completed, then the substrate is subjected to a process treatment step. The steps for adjusting the impedance include: The step of adjusting the capacitance of the mechanical vacuum variable capacitor to a preset value; The step of measuring the input impedance of the first matching circuit and the second matching circuit; The step of determining whether the reflection coefficient from the plasma load is greater than the reference reflection coefficient; The step of determining the impedance of the plasma load when the reflection coefficient is greater than the reference reflection coefficient; and The step of adjusting the capacitance of the electronic variable capacitor module based on the impedance of the plasma load by controlling the opening and closing of the switches of the plurality of electronic variable capacitor modules.

14. The substrate processing method according to claim 13, wherein, The steps for adjusting the capacitance of the electronic variable capacitor module include: The steps of calculating the impedance adjustment value based on the impedance of the plasma load; and The step of closing the switch of the electronic variable capacitor module having a capacitance corresponding to the impedance adjustment value.

Images