Filter circuit and plasma processing apparatus

Abstract

To provide a filter circuit and a plasma processing apparatus capable of reducing cost and suppressing processing waste.SOLUTION: The filter circuit includes an input port, an output port, a ground base, an antenna base, a ground fin, and an antenna fin. The input port has a first inner conductor and a first outer conductor. The output port has a second inner conductor and a second outer conductor. In the ground base portion, a first outer conductor on the input port side and a second outer conductor on the output port side are connected to each other. In the antenna base, a first inner conductor on an input port side and a second inner conductor on an output port side are connected to each other. The ground fin is configured to extend from the ground base portion toward the antenna base portion. The antenna fin is configured to extend from the antenna base toward the ground base with a gap between the antenna fin and the ground fin. The antenna fin is formed of a plurality of first rod-like bodies connected to the antenna base.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a filter circuit and a plasma processing apparatus. [Background technology]

[0002] It is disclosed that a plasma processing apparatus is provided with a heater power supply line, a filter unit having a coil and a capacitor for attenuating or blocking high-frequency noise entering the heater power supply line via a heating element, and a casing for accommodating the coil and capacitor (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-99585 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a filter circuit and a plasma processing apparatus that can reduce costs and reduce processing waste. [Means for solving the problem]

[0005] A filter circuit according to one embodiment of the present disclosure includes an input port, an output port, a ground base, an antenna base, a ground fin, and an antenna fin. The input port is configured to have a first inner conductor and a first outer conductor. The output port is configured to have a second inner conductor and a second outer conductor. The ground base is configured so that the first outer conductor on the input port side is connected to the second outer conductor on the output port side. The antenna base is configured so that the first inner conductor on the input port side is connected to the second inner conductor on the output port side. The ground fin is configured to extend from the ground base toward the antenna base. The antenna fin is configured to extend from the antenna base toward the ground base with a gap between the ground fin and the antenna fin. The antenna fin is formed of a plurality of first rod-shaped bodies connected to the antenna base. [Effects of the Invention]

[0006] According to the present disclosure, cost reduction and reduction of processing waste can be achieved. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a plasma processing apparatus according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view illustrating an example of a filter circuit according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing an example of the internal configuration of a filter circuit corresponding to the cross-section AA in FIG. [Figure 4] FIG. 4 is a diagram showing an example of machining an inner conductor having a three-dimensional structure. [Figure 5] FIG. 5 is a diagram showing an example of an inner conductor according to the first embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of an inner conductor according to the first embodiment. [Figure 7] FIG. 7 is a diagram illustrating an example of a dielectric material according to the first embodiment. [Figure 8]FIG. 8 is a diagram showing an example of an outer conductor according to the first embodiment. [Figure 9] FIG. 9 is a graph showing an example of frequency characteristics of the filter circuit according to the first embodiment. [Figure 10] FIG. 10 is a diagram showing an example of the aperture ratio of the outer conductor. [Figure 11] FIG. 11 is a graph showing an example of the amount of variation in resonant frequency depending on the aperture ratio of the outer conductor. [Figure 12] FIG. 12 is a graph showing an example of the amount of change in resonant frequency depending on the aperture ratio of the inner conductor. [Figure 13] FIG. 13 is a perspective view illustrating an example of a filter circuit according to the second embodiment. [Figure 14] FIG. 14 is a cross-sectional view showing an example of the cross section BB of FIG. [Figure 15] FIG. 15 is a cross-sectional view showing an example of the CC cross section of FIG. [Figure 16] FIG. 16 is a cross-sectional view showing an example of the DD cross section of FIG. [Figure 17] FIG. 17 is a cross-sectional view showing another example of the DD cross section of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the disclosed filter circuit and plasma processing apparatus will be described in detail with reference to the accompanying drawings. Note that the disclosed technology is not limited to the following embodiments.

[0009] In a plasma processing apparatus, a power supply located outside the processing chamber is connected to an electrostatic chuck and a heater provided on a substrate support section that supports a substrate to be processed. Because the substrate support section constitutes a lower electrode for generating plasma, the high-frequency waves used to generate plasma can affect the power supply lines to the electrostatic chuck and the heater. For this reason, a high-frequency filter composed of a coil and a capacitor is inserted in these power supply lines. However, a high-frequency filter composed of a coil and a capacitor has a complex structure and large dimensions. To address this issue, a high-frequency filter can be constructed using a three-dimensional structure, for example, including an aluminum member and a dielectric. However, a three-dimensional high-frequency filter can be difficult to machine, for example, when machining an aluminum member into a comb-tooth structure with a high aspect ratio, which can increase processing costs and waste material. Furthermore, a three-dimensional high-frequency filter can require a large number of machined parts due to the combination of multiple machined parts. Therefore, it is expected to achieve cost reduction and reduction in processing waste material.

[0010] (First embodiment) [Configuration of plasma processing system] An exemplary configuration of a plasma processing system will be described below. FIG. 1 is a schematic cross-sectional view showing an exemplary configuration of a plasma processing apparatus according to a first embodiment of the present disclosure. As shown in FIG. 1, the plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a controller 2. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, an exhaust system 40, a DC power supply 45, and a filter circuit 50. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 has at least one gas inlet for supplying at least one processing gas into the plasma processing space 10s and at least one gas outlet for exhausting gas from the plasma processing space 10s. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0011] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0012] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that the annular region 111b may also be provided by another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. The electrostatic electrode 1111b is connected to a DC power supply 45 via a filter circuit 50. When a voltage is applied to the electrostatic electrode 1111b from the DC power supply 45, an electrostatic attractive force is generated between the electrostatic chuck 1111 and the substrate W. The generated electrostatic attractive force attracts the substrate W to the electrostatic chuck 1111, and the substrate W is held by the electrostatic chuck 1111.

[0013] Furthermore, at least one RF / DC electrode coupled to an RF (Radio Frequency) power supply 31 and / or a DC (Direct Current) power supply 32 (described later) may be disposed within the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal (described later) is supplied to the at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple lower electrodes. Alternatively, the electrostatic electrode 1111b may function as the lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0014] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate W to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow path 1110a. In one embodiment, the flow path 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0015] The showerhead 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas introduction unit may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0016] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include one or more flow modulation devices to modulate or pulse the flow rate of the at least one process gas.

[0017] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. This generates a plasma from at least one process gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of a plasma generating unit configured to generate a plasma from one or more process gases in the plasma processing chamber 10. In addition, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0018] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 300 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0019] The second RF generating unit 31b is coupled to at least one lower electrode via at least one impedance matching circuit and configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generating unit 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0020] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to at least one lower electrode and configured to generate a first DC signal. The generated first DC signal (bias DC signal) is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0021] In various embodiments, at least one of the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof. In one embodiment, a waveform generator for generating a sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0022] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the pressure in the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0023] When plasma is generated in the plasma processing space 10s, the filter circuit 50 removes the influence of high frequency power for plasma generation or bias to the DC power supply 45. The filter circuit 50 passes DC applied from the DC power supply 45 to the electrostatic electrode 1111b and blocks high frequency power flowing in the reverse direction from the electrostatic electrode 1111b.

[0024] The controller 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform the various processes described in this disclosure. The controller 2 may be configured to control each element of the plasma processing apparatus 1 to perform the various processes described herein. In one embodiment, part or all of the controller 2 may be included in the plasma processing apparatus 1. The controller 2 may include a processor 2a1, a storage unit 2a2, and a communication interface 2a3. The controller 2 may be implemented, for example, by a computer 2a. The processor 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. The program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processor 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processor 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0025] [Structure of filter circuit 50] Next, the filter circuit 50 will be described in detail with reference to FIGS. 2 to 8. The filter circuit 50 will be described with reference to FIGS. 3 and 4, which illustrate a filter circuit 70 using an antenna and ground fins machined from an aluminum member. Then, differences between the filter circuit 50 according to this embodiment and the filter circuit 70 will be described. FIG. 2 is a perspective view showing an example of the filter circuit according to the first embodiment. As shown in FIG. 2, the filter circuit 50 has a housing 51. The housing 51 is made of a conductor such as aluminum or copper. The housing 51 also has an input port 52 and an output port 55. Since the present embodiment blocks high-frequency power, the side connected to the electrostatic electrode 1111b will be referred to as the input port 52, and the side connected to the DC power supply 45 will be referred to as the output port 55, based on the flow direction of the high-frequency power. The input port 52 and the output port 55 may be interchanged.

[0026] The input port 52 and the output port 55 are formed by outer conductors 53 and 56 and inner conductors 54 and 57, respectively. That is, the input port 52 and the output port 55 have a coaxial structure. The housing 51 is electrically connected to the outer conductors 53 and 56 and is at ground potential together with the grounded plasma processing chamber 10 via the coaxial cable connected to the input port 52 and the frame on which the filter circuit 50 is installed. The housing 51 is cylindrical, and the input port 52 is formed on a side surface 59 of the cylinder. The housing 51 may also have a cylindrical shape with a square cross section. The output port 55 is formed at the end of the cylinder on the side where the input port 52 is formed, and the ground base 58 at the other end is formed in a disk shape to close the cylinder. 2, the height of the end faces of outer conductors 53 and 56 and dielectric 66 is approximately the same as the height of the end face of housing 51, and inner conductors 54 and 57 are shaped to be connected as terminals, but the shapes of input port 52 and output port 55 may be changed as appropriate depending on the connection destination. For example, input port 52 and output port 55 may be coaxial connectors or the like.

[0027] That is, the input port 52 is configured to have a first inner conductor (inner conductor 54) and a first outer conductor (outer conductor 53). The output port 55 is configured to have a second inner conductor (inner conductor 57) and a second outer conductor (outer conductor 56). The ground base 58 is configured to connect the first outer conductor (outer conductor 53) on the input port 52 side with the second outer conductor (outer conductor 56) on the output port 55 side.

[0028] Fig. 3 is a cross-sectional view showing an example of the internal configuration of a filter circuit corresponding to the cross section AA in Fig. 2. Fig. 3 illustrates a cross section of a filter circuit 70 that uses an antenna 80 machined from an aluminum member as an antenna provided inside a housing 51. The filter circuit 70 is a filter circuit to be compared with the filter circuit 50 of this embodiment, and is configured by replacing the antenna 60 (to be described later) with the antenna 80 and replacing the ground fins 91 and 92 (to be described later) with ground fins 71 and 72.

[0029] Ground fins 71 and 72, which are made of a conductor such as aluminum or copper and are provided to protrude into the housing 51, are connected to the ground base 58. The ground fin 71 is an example of a second rod-shaped body and has, for example, a cylindrical shape. The ground fin 72 is provided so as to protrude in a cylindrical shape into the housing 51 around the ground fin 71. In other words, the ground fins 71 and 72 have, for example, a concentric cylindrical shape and a cylindrical column shape.

[0030] An antenna 80 is provided inside the housing 51. The antenna 80 has an antenna base 81, an antenna fin 82 formed to surround the ground fin 71, and an antenna fin 83 formed to surround the ground fin 72. The antenna fins 82 and 83 are connected to the antenna base 81. The ground fins 71 and 72 and the antenna fins 82 and 83 are arranged coaxially. The antenna 80 is formed of a conductor such as aluminum or copper and has a cylindrical shape with one end closed by the antenna base 81. That is, the antenna 80 is a double-tube multipole antenna in which the antenna fin 82 and the antenna fin 83 are connected by the antenna base 81. In other words, the antenna 80 is an antenna (coaxial insertion multipole antenna) that does not radiate electromagnetic waves at a frequency to be blocked. Note that the antenna 80 may also be a cylindrical monopole antenna in which the antenna fin 82 is connected to the antenna base 81.

[0031] The antenna base 81 is disk-shaped, and its center is convex so as to be offset toward the output port 55. The inner conductor 54 is connected to the side of the antenna base 81. The inner conductor 57 is connected to the top surface of the antenna base 81. That is, the inner conductor (input side conductor) 54 of the input port 52, the inner conductor (output side conductor) 57 of the output port 55, and the antenna 80 form a feed line 84 that is insulated from the housing 51. The feed line 84 is a path for feeding DC from the DC power supply 45 to the electrostatic electrode 1111b.

[0032] A dielectric 66 is provided between the housing 51 and the feed line 84. That is, the dielectric 66 is filled between the ground fin 71 and the antenna fin 82, between the antenna fin 82 and the ground fin 72, between the ground fin 72 and the antenna fin 83, between the antenna fin 83 and the side surface 59 of the cylinder, and between the tips of the antenna fins 82, 83 and the ground base 58. Similarly, the dielectric 66 is filled between the outer conductor 53 and the inner conductor 54 of the input port 52, and between the outer conductor 56 and the inner conductor 57 of the output port 55. The dielectric 66 may be, for example, PTFE (Poly Tetra Fluoro Ethylene) or the like.

[0033] Furthermore, in the antenna 80, the space between the side surface 59 of the cylinder and the ground fins 71, 72 and the antenna fins 82, 83 forms a choke structure based on the length of a quarter wavelength of the electromagnetic wave to be blocked, a so-called λ / 4 choke. In other words, since the electromagnetic wave to be blocked travels back and forth along the transmission path length W1, the antenna 80 becomes a half-wavelength antenna with a length twice the transmission path length W1. In this case, the length L from the antenna base 81 to the ground base 58 is expressed by the following equations (1) and (2), and the transmission path length W1 is expressed by the following equation (3). Note that λ g is the wavelength of the electromagnetic wave, and δ1 is a fine-tuning parameter.

[0034] L=(λ g / 16)+δ1···(1) -(3 / 100)λ g ≦δ1≦(3 / 100)λ g ···(2) W1=L×4 (3)

[0035] FIG. 4 is a diagram showing an example of machining an inner conductor having a three-dimensional structure. As shown in FIG. 4, in the manufacturing process of the antenna 80, a cylindrical aluminum member 85 is machined. Note that FIG. 4 shows a longitudinal cross section of the cylindrical aluminum member 85. At this time, the antenna fins 82, 83 are difficult to machine because they are formed by cutting a high-aspect-ratio comb-shaped cylinder from the cylindrical aluminum member 85. In addition, there are many cut portions 86 around the periphery of the antenna base 81. If there are many cut portions 86, the processing cost and processing waste will increase. In contrast, in the first embodiment, an antenna 60 is used instead of the antenna 80.

[0036] 5 and 6 are diagrams illustrating an example of an inner conductor according to the first embodiment. As illustrated in FIGS. 5 and 6, the antenna 60 of the filter circuit 50 according to the first embodiment includes an antenna base 61 and antenna fins 62 and 63. The antenna base 61 corresponds to the antenna base 81 of the antenna 80. The inner conductor 57 of the output port 55 is connected to the disk-shaped center (top side in FIG. 5) of the antenna base 61. The inner conductor 54 of the input port 52 is connected to the side of the antenna base 61. That is, the antenna fins 62 and 63 correspond to the antenna fins 82 and 83 of the antenna 80. The inner conductor (input side conductor) 54 of the input port 52, the inner conductor (output side conductor) 57 of the output port 55, and the antenna 60 form a feed line 64 insulated from the housing 51. The antenna fin 62 is an example of a plurality of first rod-shaped bodies, and the antenna fin 63 is an example of a plurality of fourth rod-shaped bodies. Furthermore, the shapes of the inner conductors 54 and 57 and the antenna base 61 (the shape of the feed line 64) may be changed as appropriate depending on the connection destination and processing method.

[0037] The antenna fins 62, 63 are formed by, for example, a plurality of rod-shaped members connected concentrically to the bottom surface 61a of the antenna base 61. The rod-shaped members of the antenna fins 62, 63 may be, for example, general-purpose metal spacers. The rod-shaped members have threads formed on one end. Note that the rod-shaped members of the antenna fins 62 and 63 may each be formed by, for example, metal spacers of the same size. The diameters of the rod-shaped members of the antenna fins 62, 63 may be approximately the same as the thicknesses of the antenna fins 82, 83. Note that the antenna 60 may be, like the antenna 80, a cylindrical monopole antenna formed by a plurality of rod-shaped members, with the antenna fin 62 connected to the antenna base 61.

[0038] The bottom surface 61a of the antenna base 61 is provided with multiple holes for connecting the antenna fins 62, 63. The multiple holes are tapped so that the antenna fins 62, 63 can be screwed into them. Adjusting the position of the holes can change the frequency characteristics of the filter circuit 50. For example, by locating some of the rod-shaped antenna fins 62, 63 on the inner or outer side of the concentric circles, it is possible to adjust the center frequency of the high-frequency filter or the filter width. Furthermore, by locating multiple holes for connecting the antenna fins 62, 63 not only on the concentric circles but also on the inner or outer side of the concentric circles, it is possible to configure a filter circuit with desired characteristics. The rod-shaped antenna fins 62, 63 may have a cross-sectional shape such as a circle, a hexagon, or a sector. The rod-shaped antenna fin 62 and the rod-shaped antenna fin 63 may have different cross-sectional diameters or shapes.

[0039] FIG. 7 is a diagram illustrating an example of a dielectric according to the first embodiment. As shown in FIG. 7, a dielectric 66 fills the interior of the housing 51 and has a plurality of holes 62a, 63a corresponding to the rod-shaped antenna fins 62, 63 and a plurality of holes 91a, 92a corresponding to the rod-shaped ground fins 91, 92, which will be described later. The dielectric 66 is made up of, for example, a plurality of members. When the upper member in FIG. 7 is removed, the plurality of holes 62a, 63a become visible, and the rod-shaped antenna fins 62, 63 can be inserted into the holes 62a, 63a. Furthermore, the rod-shaped ground fins 91, 92 can be inserted into the holes 91a, 92a from the lower side in FIG. 7.

[0040] FIG. 8 is a diagram illustrating an example of an outer conductor according to the first embodiment. The ground fins 91 and 92 of the filter circuit 50 shown in FIG. 8 correspond to the ground fins 71 and 72 of the filter circuit 70. The lower ends of the ground fins 91 and 92 in FIG. 8 are connected to the inner surface 58a of the housing 51 of the ground base 58. The ground fin 91 is an example of a second rod-shaped body, e.g., a cylindrical body. The ground fin 92 is provided so that multiple rod-shaped bodies protrude from the housing 51 around the ground fin 91. The ground fin 92 is an example of multiple third rod-shaped bodies. As with the multiple rod-shaped bodies of the antenna fins 62 and 63, the ground fin 92 can be formed using a general-purpose metal spacer. In other words, the ground fins 91 and 92 are, for example, a concentric cylindrical body and multiple rod-shaped bodies arranged in a cylindrical shape. Note that the antenna 60 and the ground fins 71 and 72 may be combined to form a filter circuit.

[0041] That is, the antenna base 61 is configured such that a first inner conductor (inner conductor 54) on the input port 52 side and a second inner conductor (inner conductor 57) on the output port 55 side are connected to each other. The ground fins (ground fins 91, 92) are configured to extend from the ground base 58 toward the antenna base 61. The antenna fins (antenna fins 62, 63) are configured to extend from the antenna base 61 toward the ground base 58 with gaps provided between them. The antenna fins are formed of a plurality of first rod-shaped bodies (antenna fins 62) connected to the antenna base 61. The ground fins also include a second rod-shaped body (ground fin 91) connected to the ground base 58, and the antenna fins are configured such that the plurality of first rod-shaped bodies (antenna fins 62) are arranged to surround the second rod-shaped body. The ground fins also include a plurality of third rod-shaped bodies (ground fins 92) connected to the ground base 58 so as to surround the plurality of first rod-shaped bodies (antenna fins 62).

[0042] The antenna fins include a plurality of fourth rod-shaped bodies (antenna fins 63) connected to the antenna base 61 so as to surround a plurality of third rod-shaped bodies (ground fins 92). The antenna fins include a plurality of first rod-shaped bodies (antenna fins 62) and a plurality of fourth rod-shaped bodies (antenna fins 63), which function as a multipole antenna. The ground base 58 forms a part of the housing 51 of the filter circuit 50, and the housing 51 is filled with a dielectric 66. The dielectric 66 has holes (holes 91a, 92a, 62a, 63a) formed therein corresponding to the ground fins (ground fins 91, 92) and the antenna fins (antenna fins 62, 63).

[0043] Next, the frequency characteristics of the filter circuit 50 will be described with reference to Fig. 9. Fig. 9 is a graph showing an example of the frequency characteristics of the filter circuit according to the first embodiment. A graph 200 shown in Fig. 9 represents the frequency characteristics of the filter circuit 50 using the S parameter S 21 In Figure 9, the vertical axis of the graph is S 21The graph 200 represents the insertion loss (insertion loss), and the attenuation increases toward the negative side. In addition, FIG. 9 shows the fundamental frequency (220 MHz) of the electromagnetic wave to be blocked as fundamental frequency 201. As shown in graph 200, the attenuation of filter circuit 50 is maximized at the fundamental frequency of 220 MHz, resulting in an insertion loss of -62 dB. Furthermore, the insertion loss in the range of 200 MHz to 240 MHz is -30 dB or less. In other words, filter circuit 50 forms a band-stop filter with a center frequency of 220 MHz. In this way, the high-frequency wave to be blocked is resonated in a three-dimensional circuit using a multipole antenna. This allows for a simple and compact filter circuit for high-output high-frequency power, such as 1000 W in the VHF (Very High Frequency) band. Furthermore, because power supply line 64 is insulated from housing 51, the output of DC power supply 45 can be applied to electrostatic electrode 1111b without causing a ground fault. Furthermore, in this embodiment, in the frequency range where the insertion loss is −30 dB or less, it is possible to block electromagnetic waves (single peak waveform) whose frequency is varied using FM modulation or the like, and electromagnetic waves (broadband waveform) of multiple frequencies generated as multi-tones. Also, the filter circuit 50 may be configured to simultaneously attenuate and block the harmonic of the electromagnetic wave to be blocked, for example, the third harmonic (660 MHz), together with the fundamental frequency (220 MHz).

[0044] Next, the aperture ratios of the ground fin 92 and the antenna fin 62 in the circumferential direction will be described with reference to FIGS. 10 to 12. FIG. 10 is a diagram illustrating an example of the aperture ratio of the outer conductor. In FIG. 10, the aperture ratios of the ground fin 92 in the circumferential direction in a cross section of the cylindrical housing 51, from 0% to 100%, will be described using several examples, designated as states 202a to 202e, in order from the 0% aperture ratio side. Note that in this cross section, the dielectric 66 is omitted, and the positions (areas) of the ground fin 91, the antenna fin 62, the ground fins 72 and 92, the antenna fin 63, and the side surface 59 are shown in order from the center of the cylindrical housing 51 with dotted or solid lines around them. That is, the antenna fins 62 and 63 are shown as a cross section in which the rod-shaped members are omitted and the area where the rod-shaped members are present is surrounded by a dotted line. Furthermore, the ground fin 92 is not shaded to indicate the distance (spacing) between the rod-shaped members.

[0045] In state 202a, the opening ratio is 0%, and there are no gaps in the circumferential direction of the ground fins 92, which is equivalent to the ground fins 72 that are cylindrical and continuous in the circumferential direction. In state 202b, the multiple rod-shaped bodies of the ground fins 92 are spaced apart in the circumferential direction by d b In the state 202c, the rods of the ground fin 92 are arranged in the circumferential direction at intervals d b Wider spacing than d c In state 202c, the areas 92b where the rods of the ground fin 92 are absent are more numerous in the circumferential direction, and the aperture ratio exceeds 50%. The areas 92b are filled with the omitted dielectric 66. In state 202d, the rods of the ground fin 92 are spaced apart in the circumferential direction by the interval d in state 202c. c Wider spacing than d d In state 202e, the opening ratio is 100%, and the ground fins 92 are not provided with a plurality of rod-shaped bodies.

[0046] Here, the plurality of rod-shaped bodies (third rod-shaped bodies) of the ground fin 92 are spaced apart by a distance d (the above-mentioned distance d b ~d d) can be defined by the following formula (4). Similarly, the plurality of rod-shaped bodies (first rod-shaped bodies) of the antenna fin 62 can be defined by the following formula (4).

[0047]

number

[0048] In equation (4), d represents the spacing between the multiple rod-shaped members (third rod-shaped members) of the ground fin 92 or the multiple rod-shaped members (first rod-shaped members) of the antenna fin 62, and λ represents the wavelength of the resonant frequency f0 of the filter circuit 50. r indicates the relative permittivity of the dielectric 66 (medium) between the ground fins 91, 92 and the antenna fins 62, 63, δ2 indicates the amount of variation in the resonance frequency f0, and A indicates a coefficient based on δ2. A can be, for example, the amount of variation δ2 / aperture ratio. For example, if the amount of variation δ2=5% and the aperture ratio=60%, the coefficient A=0.08. The resonance frequency f0 corresponds to the frequency that is desired to be cut off in the filter circuit 50, and may also be simply referred to as the filter frequency.

[0049] Fig. 11 is a graph showing an example of the amount of variation in resonant frequency depending on the aperture ratio of the outer conductor. As shown in graph 203 of Fig. 11, the amount of variation δ2 in resonant frequency f0 tends to increase according to the aperture ratio of ground fin 92. If the amount of variation δ2 in resonant frequency f0 is set to 5% or less compared to that of cylindrical ground fin 72 (tolerance of 5% or less), the aperture ratio of ground fin 92 can be increased to approximately 56%.

[0050] 12 is a graph showing an example of the amount of variation in resonant frequency depending on the aperture ratio of the inner conductor. As shown in graph 204 of FIG. 12, the amount of variation δ2 in resonant frequency f0 tends to increase according to the aperture ratio of the antenna fin 62. If the amount of variation δ2 in resonant frequency f0 is set to 5% or less compared to the cylindrical antenna fin 82 (allowance rate of 5% or less), the aperture ratio of the antenna fin 62 can be increased to approximately 60%. In this way, the filter circuit 50 of the first embodiment can reduce costs and reduce processing waste. In other words, the filter circuit 50 can reduce material costs and processing difficulty (processing man-hours).

[0051] (Second embodiment) In the first embodiment described above, a cylindrical filter circuit 50 was used as the filter circuit, but when the filter circuit is installed along the length of the power feed line, a filter circuit 350 with a shorter width dimension may be used, and this embodiment will be described as the second embodiment. Note that the plasma processing apparatus in the second embodiment is similar to the first embodiment described above except for the filter circuit, and therefore a description of the overlapping configuration and operation will be omitted.

[0052] FIG. 13 is a perspective view showing an example of a filter circuit according to the second embodiment. FIG. 14 is a cross-sectional view showing an example of the BB cross section of FIG. 13. In the following description, the longitudinal direction of the filter circuit 350 is the X direction along the X axis, and the lateral direction is the Y direction along the Y axis. The direction along the Z axis perpendicular to the X and Y axes is the Z direction. The X direction is an example of a first direction, the Y direction is an example of a second direction, and the Z direction is an example of a third direction. The cross sections shown in FIGS. 14 to 17 illustrate a case where air is used as a dielectric 368 (described later). As shown in FIGS. 13 and 14, the filter circuit 350 includes a housing 351. The housing 351 is made of a conductor such as aluminum or copper. The housing 351 includes an input port 352 and an output port 355. In this embodiment, since the high frequency power is cut off, the description will be given with the flow direction of the high frequency power as the reference, with the side connected to the electrostatic electrode 1111b as the input port 352 and the side connected to the DC power supply 45 as the output port 355. Note that the connections of the input port 352 and the output port 355 may be interchanged.

[0053] The input port 352 and the output port 355 are formed by outer conductors 353 and 356 and inner conductors 354 and 357, respectively. That is, the input port 352 and the output port 355 have a coaxial structure. The housing 351 is electrically connected to the outer conductors 353 and 356, and is at ground potential together with the grounded plasma processing chamber 10 via the coaxial cable connected to the input port 352 and the frame on which the filter circuit 350 is installed. That is, the housing 351 is formed of a conductor, and includes the input port 352 and the output port 355, which are formed by the outer conductors 353 and 356 and the inner conductors 354 and 357, and is at ground potential together with the outer conductors 353 and 356 of the input port 352 and the output port 355. The housing 351 has, for example, a rectangular parallelepiped shape and includes a bottom surface 358 and a top surface 359 that intersect with the Z direction of the rectangular parallelepiped, side surfaces 360a and 360b that intersect with the X direction, and side surfaces 360c and 360d that intersect with the Y direction. That is, the housing 351 is configured so that the internal space extends in the X and Y directions in a plan view (seen from the Z direction). Note that corners of the internal space in the X and Y directions may be rounded. The housing 351 has an input port 352 formed on side surface 360a and an output port 355 formed on side surface 360b opposite side surface 360a. Inner conductors 354 and 357 of the input port 352 and the output port 355 are connected to side surfaces 363 and 364, respectively, of an upper portion 362a of an antenna base 362 located approximately at the center of the X and Y plane in the internal space of the housing 351. That is, the input port 352 and the output port 355 extend in the X direction passing through the antenna base 362. Furthermore, the inner conductor (input side conductor) 354 of the input port 352, the inner conductor (output side conductor) 357 of the output port 355, the antenna unit 365, and the antenna base 362 form a feed line 361 that is insulated from the housing 351. The feed line 361 is an example of a second feed line, and constitutes a part of a first feed line that is a path for feeding direct current from the DC power supply 45 to the electrostatic electrode 1111b.

[0054] The antenna base 362 connects the inner conductors 354, 357, which are input and output conductors, to the antenna unit 365. The antenna base 362 has, for example, a cylindrical shape and extends in the Z direction. The antenna unit 365 is provided on the Z-direction lower surface 358 side of the inner conductors 354, 357 and has a first fin 366 and a second fin 367. The second fin 367 includes, for example, multiple second fins 367a to 367c. The first fin 366 and the second fin 367 are formed of a plate-shaped conductor such as aluminum or copper, and are connected to the antenna base 362 approximately at the center of the plane in the X and Y directions. The first fin 366 is formed, for example, thicker than each of the second fins 367a to 367c. Note that the first fin 366 may have the same thickness as each of the second fins 367a to 367c. That is, antenna section 365 is provided so as to extend in the X and Y directions from antenna base section 362. Furthermore, antenna section 365 is not in contact with the four side surfaces 360a to 360d of housing 351. That is, antenna section 365 has a rectangular shape that is slightly smaller than top surface 359 in a plan view (when viewed from the Z direction).

[0055] The internal space of the housing 351 is provided with a partition 370, which is made of a conductor such as aluminum or copper and is connected to the housing 351 while separating the internal space of the housing 351. The partition 370 includes, for example, a plurality of partitions 370a to 370c. Each of the partitions 370a to 370c is made of, for example, a plurality of rod-shaped bodies. As with the ground fin 92 of the first embodiment, the rod-shaped bodies may be, for example, general-purpose metal spacers. That is, the partition 370 is made of a plurality of rod-shaped conductors such as aluminum or copper and is connected to the side surfaces 360a and 360b. The partitions 370 are arranged in an annular shape with a fixed gap (gap 371 in FIG. 15 , which will be described later) between them and the cylindrical antenna base 362.

[0056] In other words, the partition 370 is an example of a ground fin, and the side surfaces 360a and 360b are examples of a ground base. The side surface 360a is an example of a first surface to which the first outer conductor (outer conductor 353) on the input port 352 side is connected. The side surface 360b faces the first surface and is an example of a second surface to which the second outer conductor (outer conductor 356) on the output port 355 side is connected. In other words, the partition 370 is an example of a ground fin that is connected to at least one of the first surface and the second surface of the ground base and extends from one of the first surface and the second surface to the other. The ground fin is formed by a plurality of first rod-shaped bodies (partitions 370a to 370c) in the second embodiment that are connected to at least one of the first surface and the second surface. The multiple first rod-shaped bodies (dividers 370a to 370c) in the second embodiment correspond to the second rod-shaped bodies (ground fins 91) and multiple third rod-shaped bodies (ground fins 92) in the first embodiment. Therefore, the spacing between the multiple first rod-shaped bodies (dividers 370a to 370c) in the second embodiment corresponds to the spacing between the multiple first rod-shaped bodies forming the divider 370a, for example. This spacing can be determined by equation (4) in the first embodiment. The ground base is a housing 351 configured so that the internal space thereof expands in a first direction and a second direction perpendicular to the first direction in a plan view.

[0057] Antenna unit 365 and partition unit 370 are formed so that first fin 366, second fins 367a-367c, and partition units 370a-370c are alternately intertwined in cross section B-B. That is, antenna unit 365 is connected to inner conductors 354, 357, which are input and output conductors, and extends into the internal space so as to be stacked with partition unit 370. That is, filter circuit 350 is formed so that transmission path length W2 in the space between first fin 366 and second fins 367a-367c and partition units 370a-370c and bottom surface 358 forms a choke structure based on the length of a quarter wavelength of the frequency to be blocked. That is, in the filter circuit 350, the space between the housing 351 and the partition 370 and the antenna unit 365, from the X-direction end of the first fin 366 of the antenna unit 365 that is closest to the input port 352 and the output port 355 to the center of the end 362b of the antenna base 362 to which the second fin 367c that is farthest from the input port 352 and the output port 355 is connected, forms a choke structure based on the length of a quarter wavelength of the electromagnetic waves to be blocked.

[0058] FIG. 15 is a cross-sectional view showing an example of the CC cross section of FIG. 14. FIG. 16 is a cross-sectional view showing an example of the DD cross section of FIG. 14. As shown in FIG. 15, partitions 370a-370c connected to housing 351 are disposed at a fixed distance 371 from antenna base 362. On the other hand, as shown in FIG. 16, second fins 367a-367c connected to antenna base 362 are disposed at a fixed distance 372 from side surfaces 360a-360d of housing 351. Note that, as shown in FIGS. 13 and 14, first fin 366, like second fins 367a-367c, is also disposed at a fixed distance from side surfaces 360a-360d of housing 351. Here, it is preferable that second fins 367a-367c have dimensions such that the total propagation length (path length) in the X direction is λ / 4+α, where λ is the wavelength of the electromagnetic wave. Note that α is a parameter for fine adjustment. In contrast, the second fins 367a to 367c can be sized so that the total propagation length (path length) in the Y direction is sufficiently smaller than λ / 4, where λ is the wavelength of the electromagnetic wave. For example, if the filter frequency is 220 MHz, the dimension X can be 55 mm and the dimension Y can be 25 mm in FIG. 16. That is, the external dimensions of the housing 351 are 110 mm in the X direction and 50 mm in the Y direction.

[0059] Furthermore, the second fins 367a to 367c may be formed of a plurality of rod-shaped bodies connected radially to the antenna base 362. FIG. 17 is a cross-sectional view showing another example of the DD cross section of FIG. 14. As shown in FIG. 17, the second fins 467a to 467c are formed of a plurality of rod-shaped bodies and connected radially to the antenna base 362. Like the second fins 367a to 367c, the tips of the second fins 467a to 467c are disposed at a fixed interval from the side surfaces 360a to 360d of the housing 351. Note that the second fins 467a to 467c may have rod-shaped bodies bent at their middle portions in the X direction.

[0060] That is, the antenna base 362 is disposed at the center of the housing 351 in a plan view. The antenna fins are formed of a plurality of second rod-shaped bodies (second fins 467a to 467c) in the second embodiment that are radially connected to the antenna base 362. The plurality of second rod-shaped bodies (second fins 467a to 467c) in the second embodiment correspond to the plurality of first rod-shaped bodies (antenna fins 62) in the first embodiment.

[0061] 14, the filter circuit 350 has a dielectric 368 between the housing 351 and the feed line 361. That is, the dielectric 368 is filled between the inner conductors 354, 357 and the upper surface 359 and the side surfaces 360a-360d, between the inner conductors 354, 357 and the first fin 366, and between the first fin 366 and the partition 370a. The dielectric 368 is also filled between the second fins 367a-367c and the partitions 370a-370c, between the second fin 367c and the lower surface 358, and between the first fin 366 and the second fins 367a-367c and the side surfaces 360a-360d. When a solid material is used as the dielectric 368 between the first fin 366 and the second fins 367a-367c and the partitions 370a-370c, a sheet-like dielectric 368 can be sandwiched between the spaces between the first fin 366 and the second fins 367a-367c and the partitions 370a-370c, thereby easily filling the spaces with the dielectric 368. Similarly, the dielectric 368 is filled between the outer conductor 353 and the inner conductor 354 of the input port 352, and between the outer conductor 356 and the inner conductor 357 of the output port 355. For example, the dielectric 368 may be air, PTFE, or the like. That is, the dielectric 368 having a higher dielectric constant than air may be provided between the partitions 370 and the antenna unit 365.

[0062] In this way, in filter circuit 350 of the second embodiment, partition 370 and one or more of second fins 467a to 467c can be formed from rod-shaped bodies, thereby realizing cost reduction and suppression of processing waste. In other words, in filter circuit 350, material costs and processing difficulty (processing man-hours) can be reduced.

[0063] As described above, according to the first embodiment, the filter circuit 50 includes an input port 52, an output port 55, a ground base 58, an antenna base 61, ground fins (ground fins 91 and 92), and antenna fins (antenna fins 62 and 63). The input port 52 is configured to include a first inner conductor (inner conductor 54) and a first outer conductor (outer conductor 53). The output port 55 is configured to include a second inner conductor (inner conductor 57) and a second outer conductor (outer conductor 56). The ground base 58 is configured to connect the first outer conductor on the input port 52 side with the second outer conductor on the output port 55 side. The antenna base 61 is configured to connect the first inner conductor on the input port 52 side with the second inner conductor on the output port 55 side. The ground fins (ground fins 91 and 92) are configured to extend from the ground base 58 toward the antenna base 61. The antenna fins (antenna fins 62, 63) are configured to extend from the antenna base 61 toward the ground base 58 with a gap provided between them. The antenna fins are formed of a plurality of first rod-shaped bodies (antenna fins 62) connected to the antenna base 61. As a result, costs can be reduced and processing waste can be suppressed.

[0064] Furthermore, according to the first embodiment, the ground fin includes a second rod-shaped body (ground fin 91) connected to the ground base 58, and the antenna fin includes a plurality of first rod-shaped bodies (antenna fins 62) arranged to surround the second rod-shaped body, thereby achieving a compact high-frequency filter.

[0065] Furthermore, according to the first embodiment, the spacing between the multiple first rod-shaped bodies is defined by the above formula (4), which makes it possible to control the amount of fluctuation in the filter frequency.

[0066] Furthermore, according to the first embodiment, the antenna fins are made up of a plurality of first rod-shaped bodies (antenna fins 62) that function as a monopole antenna, which results in reduced costs and reduced waste material.

[0067] Furthermore, according to the first embodiment, the ground fins include a plurality of third rod-shaped bodies (ground fins 92) connected to the ground base 58 so as to surround the plurality of first rod-shaped bodies (antenna fins 62). As a result, a compact high-frequency filter can be realized.

[0068] Furthermore, according to the first embodiment, the spacing between the multiple third rod-shaped bodies (ground fins 92) is defined by the above formula (4), which makes it possible to control the amount of fluctuation in the filter frequency.

[0069] Furthermore, according to the first embodiment, the antenna fin includes a plurality of fourth rod-shaped bodies (antenna fins 63) connected to the antenna base 61 so as to surround a plurality of third rod-shaped bodies (ground fins 92). As a result, a compact high-frequency filter can be realized.

[0070] Furthermore, according to the first embodiment, the antenna fins, which are the multiple first rod-shaped bodies (antenna fins 62) and the multiple fourth rod-shaped bodies (antenna fins 63), operate as a multipole antenna, thereby achieving a compact high-frequency filter.

[0071] Furthermore, according to the first embodiment, the ground base 58 forms a part of the housing 51 of the filter circuit 50, and the inside of the housing 51 is filled with the dielectric 66. As a result, a compact high-frequency filter can be realized.

[0072] Furthermore, according to the first embodiment, holes (holes 91a, 92a, 62a, 63a) corresponding to the ground fins (ground fins 91, 92) and antenna fins (antenna fins 62, 63) are formed in the dielectric 66. As a result, the filter circuit 50 can be easily assembled.

[0073] According to the second embodiment, the filter circuit 350 includes an input port 352, an output port 355, a ground base (housing 351), an antenna base 362, ground fins (partition 370), and antenna fins (first fin 366, second fin 367). The input port 352 includes a first inner conductor (inner conductor 354) and a first outer conductor (outer conductor 353). The output port 355 includes a second inner conductor (inner conductor 357) and a second outer conductor (outer conductor 356). The ground base is configured such that the first outer conductor on the input port 352 side is connected to the second outer conductor on the output port 355 side. The antenna base 362 is configured such that the first inner conductor on the input port 352 side is connected to the second inner conductor on the output port 355 side. The ground fin is connected to at least one of the ground base's first surface (side surface 360a), to which the first outer conductor on the input port 352 side is connected, and the second surface (side surface 360b), which faces the first surface and is to which the second outer conductor on the output port 355 side is connected, and is configured to extend from one of the first and second surfaces to the other. The antenna fin is configured to extend from the antenna base 362 so as to be stacked on the ground fin, with a gap provided between it and the ground fin. The ground fin is formed of multiple first rod-shaped bodies (partition portions 370a to 370c) connected to at least one of the first and second surfaces. This reduces costs and waste material. A simple and compact high-frequency filter can also be realized.

[0074] Furthermore, according to the second embodiment, the ground base is a housing 351 configured so that the internal space thereof expands in a first direction and a second direction perpendicular to the first direction in a plan view. The antenna base 362 is disposed at the center of the housing 351 in a plan view. The antenna fins are formed of a plurality of second rod-shaped bodies (second fins 467a to 467c) radially connected to the antenna base 362. As a result, costs can be reduced and processing waste can be suppressed.

[0075] Furthermore, according to the second embodiment, the spacing between the multiple first rod-shaped bodies (partitions 370a to 370c) is defined by the above formula (4), making it possible to control the amount of fluctuation in the filter frequency.

[0076] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and various omissions, substitutions, and modifications may be made to the above-described embodiments without departing from the spirit and scope of the appended claims.

[0077] In the first embodiment, the antenna 60 has been described as an example of a multipole antenna, but the present invention is not limited to this. For example, the antenna 60 may further include antenna fins that concentrically surround the antenna fins 62 and 63. In this case, the longitudinal length of the cylinder of the filter circuit 50 can be further shortened, resulting in a more compact high-frequency filter. For example, by increasing the number of antenna fins from two to four, the longitudinal length of the cylinder of the filter circuit 50 can be halved while maintaining the filter performance.

[0078] In the above-described embodiments, the transmission path length is set to a quarter wavelength of the electromagnetic wave to be blocked, but this is not limiting. For example, the number and dimensions of the antenna fins and ground fins that form concentric circles may be set so that the transmission path length is such that the forward wave and the reflected wave cancel each other out.

[0079] In addition, in each of the above-described embodiments, the filter circuits 50 and 350 are connected to the electrostatic electrode 1111b inside the electrostatic chuck 1111. However, the present invention is not limited to this. For example, the filter circuits 50 and 350 may be connected to a heater (not shown) provided inside the substrate support 11.

[0080] Furthermore, in each of the above-described embodiments, the plasma processing apparatus 1 is described as an example in which a process such as etching is performed on a substrate W using capacitively coupled plasma as a plasma source, but the disclosed technology is not limited to this. As long as the apparatus performs a process on a substrate W using plasma, the plasma source is not limited to capacitively coupled plasma, and any plasma source such as inductively coupled plasma, microwave plasma, or magnetron plasma can be used.

[0081] The present disclosure can also be configured as follows. (1) an input port configured with a first inner conductor and a first outer conductor; an output port configured with a second inner conductor and a second outer conductor; a ground base configured to connect a first outer conductor on the input port side and a second outer conductor on the output port side; an antenna base configured to connect a first inner conductor on the input port side and a second inner conductor on the output port side; a ground fin configured to extend from the ground base toward the antenna base; an antenna fin configured to extend from the antenna base toward the ground base with a gap provided between the antenna fin and the ground fin; The antenna fins are formed of a plurality of first rods connected to the antenna base. Filter circuit. (2) the ground fin comprises a second rod-shaped body connected to the ground base; The antenna fin includes a plurality of first rod-shaped bodies arranged to surround the second rod-shaped body. The filter circuit according to (1) above. (3) The plurality of first rod-shaped bodies have intervals between the first rod-shaped bodies defined by the following formula (A1): The filter circuit according to (2) above.

number

number

number

[0082] 1. Plasma processing equipment 10 Plasma Processing Chamber 11 Substrate support 45 DC power supply 50,350 filter circuit 51,351 cabinets 52,352 input ports 53, 56, 353, 356 Outer conductor 54,57,354,357 Inner conductor 55,355 output ports 58 Ground base 61,362 Antenna base 62,63 Antenna fin 62a, 63a, 91a, 92a holes 66 Dielectric 91,92 Grand Fin 360a,360b side 366 First Fin 367, 467a~467c Second Fin 370, 370a~370c Partition

Claims

1. an input port configured with a first inner conductor and a first outer conductor; an output port configured with a second inner conductor and a second outer conductor; a ground base configured to connect a first outer conductor on the input port side and a second outer conductor on the output port side; an antenna base configured so that a first inner conductor on the input port side and a second inner conductor on the output port side are connected; a ground fin configured to extend from the ground base toward the antenna base; an antenna fin configured to extend from the antenna base toward the ground base with a gap provided between the antenna fin and the ground fin; the antenna fins are formed of a plurality of first rods connected to the antenna base; Filter circuit.

2. the ground fin includes a second rod-shaped body connected to the ground base; The antenna fin includes a plurality of first rod-shaped bodies arranged to surround the second rod-shaped body.

2. The filter circuit according to claim 1.

3. The plurality of first rod-shaped bodies are arranged such that the intervals between the first rod-shaped bodies are defined by the following formula (1):

3. The filter circuit according to claim 2. [Equation 1] However, in the above formula (1), d １ represents the spacing between the first rods, and λ represents the resonant frequency f ０ denotes the wavelength of ε ｒ denotes the relative permittivity of the medium between the ground fin and the antenna fin, and δ ２ is the resonant frequency f ０ A indicates the amount of fluctuation of δ ２ The coefficients based on

4. The antenna fin is configured such that the plurality of first rod-shaped bodies operate as a monopole antenna.

3. The filter circuit according to claim 2.

5. The ground fin includes a plurality of third rods connected to the ground base so as to surround the plurality of first rods.

3. The filter circuit according to claim 2.

6. The spacing between the third rod-shaped bodies is defined by the following formula (2):

6. The filter circuit according to claim 5. [Equation 2] However, in the above formula (2), d ２ represents the spacing between the third rods, and λ represents the resonant frequency f ０ denotes the wavelength of ε ｒ denotes the relative permittivity of the medium between the ground fin and the antenna fin, and δ ２ is the resonant frequency f ０ A indicates the amount of fluctuation of δ ２ The coefficients based on

7. the antenna fin includes a plurality of fourth rods connected to the antenna base so as to surround the plurality of third rods; 6. The filter circuit according to claim 5.

8. The antenna fin includes a plurality of first rod-shaped bodies and a plurality of fourth rod-shaped bodies, and the first rod-shaped bodies and the fourth rod-shaped bodies function as a multipole antenna.

8. The filter circuit according to claim 7.

9. the ground base forms a part of a housing of the filter circuit, and the housing is filled with a dielectric. The filter circuit according to any one of claims 1 to 8.

10. the dielectric body has holes formed therein corresponding to the ground fin and the antenna fin; 10. The filter circuit according to claim 9.

11. an input port configured with a first inner conductor and a first outer conductor; an output port configured with a second inner conductor and a second outer conductor; a ground base configured to connect a first outer conductor on the input port side and a second outer conductor on the output port side; an antenna base configured so that a first inner conductor on the input port side and a second inner conductor on the output port side are connected; a ground fin connected to at least one of a first surface of the ground base to which the first outer conductor on the input port side is connected and a second surface facing the first surface and to which the second outer conductor on the output port side is connected, the ground fin extending from one of the first surface and the second surface to the other surface; an antenna fin configured to extend from the antenna base to be stacked on the ground fin with a gap provided between the antenna fin and the ground fin, the ground fin is formed of a plurality of first rod-shaped bodies connected to at least one of the first surface and the second surface; Filter circuit.

12. the ground base is a housing configured such that an internal space thereof extends in a first direction and a second direction perpendicular to the first direction in a plan view, the antenna base is disposed at the center of the housing in a plan view, The antenna fin is formed of a plurality of second rod-shaped bodies radially connected to the antenna base.

12. The filter circuit according to claim 11.

13. The plurality of first rod-shaped bodies have intervals between the first rod-shaped bodies defined by the following formula (3):

13. A filter circuit according to claim 11 or 12. [Equation 3] However, in the above formula (3), d ３ represents the spacing between the first rods, and λ represents the resonant frequency f ０ denotes the wavelength of ε ｒ denotes the relative permittivity of the medium between the ground fin and the antenna fin, and δ ２ is the resonant frequency f ０ A indicates the amount of fluctuation of δ ２ The coefficients based on

14. A processing vessel; a filter circuit provided in a power supply line that supplies power to an electrode that is exposed to electromagnetic waves for generating plasma in the processing chamber, The filter circuit comprises: an input port configured with a first inner conductor and a first outer conductor; an output port configured with a second inner conductor and a second outer conductor; a ground base configured to connect a first outer conductor on the input port side and a second outer conductor on the output port side; an antenna base configured so that a first inner conductor on the input port side and a second inner conductor on the output port side are connected; a ground fin configured to extend from the ground base toward the antenna base; an antenna fin configured to extend from the antenna base toward the ground base with a gap provided between the antenna fin and the ground fin; the antenna fins are formed of a plurality of first rods connected to the antenna base; Plasma processing equipment.

Images