Filter Circuit and Plasma Processing Apparatus

Abstract

To provide a filter circuit which can be miniaturized.SOLUTION: A filter circuit comprises a first filter part and a second filter part. The first filter part is provided at a wiring between a conductive member and a power supply part, provided in a plasma processing apparatus. The power supply part supplies a control power as a power of a third frequency that is lower than a second frequency or a control power as a direct-current power. The second filter part is provided at a wiring between the first filter part and the power supply part. Further, the first filter part is connected in series to the wiring between the conductive member and the second filter part, and includes a first coil having a core material. Further, the second filter part is connected in series to the wiring between the first coil and the power supply part, and includes a second coil having the core material. Further, a conductive wire of the second coil is arranged on a surface on the side opposite to a surface of an inner cylinder side in at least one core material arranged in a circle at an inner side cylinder so as to surround an outer side surface of the inner side cylinder of a hollow.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] Various aspects and embodiments of the present disclosure relate to a filter circuit and a plasma processing apparatus.

Background Art

[0002] For example, Patent Document 1 below discloses a filter unit provided between a heater and a heater power supply. The filter unit includes an air-core solenoid coil provided on the heater side and a coil with a core provided between the air-core solenoid coil and the heater power supply.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a filter circuit and a plasma processing apparatus that can be miniaturized.

Means for Solving the Problems

[0005] One aspect of the present disclosure is a filter circuit provided in a plasma processing apparatus in which a substrate is processed using plasma generated using power of a first frequency and power of a second frequency lower than the first frequency, the filter circuit including a first filter section and a second filter section. The first filter section is provided in a wiring between a conductive member provided in the plasma processing apparatus and a power supply section. The power supply section supplies control power, which is power of a third frequency lower than the second frequency or DC power, to the conductive member. The second filter section is provided in a wiring between the first filter section and the power supply section. Further, the first filter section is connected in series in a wiring between the conductive member and the second filter section and has a first coil having no core material. Further, the second filter section is connected in series in a wiring between the first coil and the power supply section and has a second coil having a core material. Further, a conducting wire included in the second coil is disposed on a surface opposite to a surface on the inner cylinder side of at least one core material annularly disposed around the inner cylinder so as to surround an outer surface of the hollow inner cylinder.

Advantages of the Invention

[0006] According to various aspects and embodiments of the present disclosure, the filter circuit and the plasma processing apparatus can be miniaturized.

Brief Description of the Drawings

[0007]

Figure 1

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Figure 13

Embodiments for Carrying Out the Invention

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

[0009] By the way, with the recent improvement in functionality of plasma processing apparatuses, various devices are provided in plasma processing apparatuses. As a result, plasma processing apparatuses tend to become larger. Therefore, it is desired to reduce the size of the entire plasma processing apparatus by reducing the size of the devices provided in the plasma processing apparatus. For example, miniaturization of the filter circuit is one such example.

[0010] Therefore, the present disclosure provides a technique capable of reducing the size of a filter circuit and a plasma processing apparatus.

[0011] [Configuration of Plasma Processing System 100] The configuration example of the plasma processing system 100 will be described below. FIG. 1 is a schematic cross-sectional view showing an example of the plasma processing system 100 in one embodiment of the present disclosure. The plasma processing system 100 includes a capacitively coupled plasma processing apparatus 1 and a control unit 2. The plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The control unit 2 includes a substrate support unit 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a shower head 13. The substrate support unit 11 is disposed in the plasma processing chamber 10. The shower head 13 is disposed above the substrate support unit 11. In one embodiment, the shower head 13 constitutes at least a part of the ceiling of the plasma processing chamber 10.

[0012] The plasma processing chamber 10 has a plasma processing space 10s defined by the shower head 13, the side wall 10a of the plasma processing chamber 10, and the substrate support unit 11. The plasma processing chamber 10 has at least one gas supply port 13a for supplying at least one processing gas to the plasma processing space 10s and at least one gas discharge port 10e for discharging gas from the plasma processing space 10s. The side wall 10a is grounded. The shower head 13 and the substrate support unit 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0013] The substrate support unit 11 includes a main body 111 and a ring assembly 112. The main body 111 has a substrate support surface 111a which is a central region for supporting the substrate W and a ring support surface 111b which is an annular region for supporting the ring assembly 112. The substrate W may also be called a wafer. The ring support surface 111b of the main body 111 surrounds the substrate support surface 111a of the main body 111 in plan view. The substrate W is disposed on the substrate support surface 111a of the main body 111, and the ring assembly 112 is disposed on the ring support surface 111b of the main body 111 so as to surround the substrate W on the substrate support surface 111a of the main body 111.

[0014] 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 functions as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The upper surface of the electrostatic chuck 1111 is a substrate support surface 111a.

[0015] An opening is formed at the bottom of the plasma processing chamber 10, and a hollow cylindrical member 10b is provided in the opening. The cylindrical member 10b is an example of an inner cylinder. In the present embodiment, the cylindrical member 10b has a cylindrical shape, but the cylindrical member 10b may not have a cylindrical shape as long as it is a hollow cylinder. A power supply rod 1110c is disposed in the cylindrical member 10b. The power supply rod 1110c is connected to the conductive member of the base 1110 and the power supply 30. Although not shown, a pipe for supplying a heat transfer gas between the substrate W and the substrate support surface 111a, a drive mechanism for lift pins, etc. are disposed in the cylindrical member 10b. A filter circuit 50 is disposed outside the cylindrical member 10b so as to surround the outer surface of the cylindrical member 10b.

[0016] The filter circuit 50 is provided in a wiring connecting the heater power supply 60 and a heater 1111a provided in the electrostatic chuck 1111. The filter circuit 50 attenuates high-frequency power flowing from the heater 1111a to the heater power supply 60. The heater power supply 60 supplies DC or control power of 100 Hz or less to the heater 1111a. The heater 1111a is an example of a conductive member. The heater power supply 60 is an example of a power supply unit. A frequency of 100 Hz or less is an example of a third frequency.

[0017] The ring assembly 112 includes one or more annular members. At least one of the one or more annular members is an edge ring. Also, although not shown, the substrate support portion 11 may include a temperature control 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 control module may include a flow path 1110a, a heat transfer medium, a heater 1111a, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path 1110a. Further, the substrate support portion 11 may include a heat transfer gas supply portion configured to supply a heat transfer gas between the substrate W and the substrate support surface 111a.

[0018] The shower head 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The shower head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas introduction ports 13c. The process 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 plurality of gas introduction ports 13c. Further, the shower head 13 includes a conductive member. The conductive member of the shower head 13 functions as an upper electrode. Note that the gas introduction portion may include, in addition to the shower head 13, one or more side gas injection portions (SGI) attached to one or more openings formed in the side wall 10a.

[0019] The gas supply unit 20 may include at least one gas source 21 and at least one flow rate controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from the corresponding gas source 21 to the shower head 13 via the corresponding flow rate controller 22. The flow rate controller 22 may include, for example, a mass flow controller or a pressure-controlled flow rate controller. Further, the gas supply unit 20 may include one or more flow rate modulation devices that modulate or pulse the flow rate of at least one process gas.

[0020] The power supply 30 includes an RF (Radio Frequency) 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, such as a source RF signal and a bias RF signal, to the conductive member of the substrate support 11, the conductive member of the shower head 13, or both. For example, the RF power supply 31 supplies at least one RF signal, such as a source RF signal and a bias RF signal, to the conductive member of the substrate support 11 via the power supply rod 1110c. Thereby, plasma is formed from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of a plasma generation unit configured to generate plasma from one or more processing gases in the plasma processing chamber 10. Also, by supplying a bias RF signal to the conductive member of the substrate support 11, a bias potential is generated on the substrate W, and the ion component in the formed plasma can be drawn into the substrate W.

[0021] In one embodiment, the RF power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The first RF generation unit 31a is coupled to the conductive member of the substrate support 11, the conductive member of the shower head 13, or both via at least one impedance matching circuit, and is configured to generate a source RF signal for plasma generation. The source RF signal may be referred to as source RF power. In one embodiment, the source RF signal has a frequency higher than 4 MHz. The source RF signal has a frequency, for example, in the range of 13 MHz to 150 MHz. In this embodiment, the source RF signal is 13 MHz. In one embodiment, the first RF generation unit 31a may be configured to generate a plurality of source RF signals having different frequencies. The generated one or more source RF signals are supplied to the conductive member of the substrate support 11, the conductive member of the shower head 13, or both.

[0022] The second RF generation unit 31b is coupled to the conductive member of the substrate support unit 11 via at least one impedance matching circuit and is configured to generate a bias RF signal. The bias RF signal may be referred to as bias RF power. In one embodiment, the bias RF signal has a frequency lower than that of the source RF signal. In one embodiment, the bias RF signal has a frequency higher than 100 Hz and 4 MHz or less. The bias RF signal has a signal with a frequency in the range of, for example, 400 kHz to 4 MHz. In the present embodiment, the bias RF signal is 400 kHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to the conductive member of the substrate support unit 11 via the power supply rod 1110c. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0023] Also, the power supply 30 may include a DC (Direct Current) power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generation unit 32a and a second DC generation unit 32b. In one embodiment, the first DC generation unit 32a is connected to the conductive member of the substrate support unit 11 and is configured to generate a first DC signal. The generated first DC signal is applied to the conductive member of the substrate support unit 11. In other embodiments, the first DC signal may be applied to other electrodes such as the electrodes in the electrostatic chuck 1111. In one embodiment, the second DC generation unit 32b is connected to the conductive member of the shower head 13 and is configured to generate a second DC signal. The generated second DC signal is applied to the conductive member of the shower head 13. In various embodiments, at least one of the first and second DC signals may be pulsed. Note that the first DC generation unit 32a and the second DC generation unit 32b may be provided in addition to the RF power supply 31, or the first DC generation unit 32a may be provided in place of the second RF generation unit 31b.

[0024] The exhaust system 40 can be connected to, for example, a gas outlet 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 in the plasma processing space 10s is adjusted by the pressure regulating valve. The vacuum pump may include a turbo molecular pump, a dry pump, or a combination thereof.

[0025] The control unit 2 processes computer-executable instructions for causing the plasma processing apparatus 1 to execute various processes described in the present disclosure. The control unit 2 can be configured to control each element of the plasma processing apparatus 1 so as to execute the various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include, for example, a computer 2a. The computer 2a may include, for example, a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 can be configured to perform various control operations based on a program stored in the storage unit 2a2. The processing unit 2a1 may include a CPU (Central Processing Unit). The storage unit 2a2 may include a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 communicates with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

[0026] [Circuit Configuration of Filter Circuit 50] FIG. 2 is a diagram showing an example of the circuit configuration of the filter circuit 50. The heater 1111a and the heater power source 60 are connected via wiring 500a and wiring 500b. The filter circuit 50 is provided in the wiring 500a and the wiring 500b. The filter circuit 50 has a first filter section 51 and a second filter section 52. The first filter section 51 is provided in the wirings 500a and 500b between the heater 1111a and the heater power source 60. The first filter section 51 suppresses the power of the first frequency among the power flowing from the heater 1111a to the heater power source 60. The first frequency is, for example, a frequency higher than 4 MHz. In the present embodiment, the first frequency is, for example, 13 MHz.

[0027] The first filter section 51 has a coil 510a and a series resonance circuit 511a connected to the wiring 500a. The first filter section 51 also has a coil 510b and a series resonance circuit 511b connected to the wiring 500b. The coils 510a and 510b are air-core coils having no core material (i.e., the core material is air or vacuum). Thereby, heat generation of the coil 510 can be suppressed. The coils 510a and 510b are an example of the first coil. Note that the coils 510a and 510b may be provided with a core material having a magnetic permeability of less than 10, such as a resin material such as PTFE (polytetrafluoroethylene).

[0028] The series resonance circuit 511a is connected between a node between the coil 510a and the second filter section 52 and the ground. The series resonance circuit 511a has a coil 512a and a capacitor 513a. The coil 512a and the capacitor 513a are connected in series. In the series resonance circuit 511a, the constants of the coil 512a and the capacitor 513a are selected such that the resonance frequency of the series resonance circuit 511a is near the first frequency. The series resonance circuit 511b is connected between a wiring between the coil 510b and the second filter section 52 and the ground. The series resonance circuit 511b has a coil 512b and a capacitor 513b. The coil 512b and the capacitor 513b are connected in series. Also in the series resonance circuit 511b, the constants of the coil 512b and the capacitor 513b are selected such that the resonance frequency of the series resonance circuit 511b is near the first frequency.

[0029] The coils 512a and 512b are air-core coils having no core material, for example, similar to the coils 510a and 512b. In the present embodiment, the inductance of the coils 512a and 512b is, for example, 6 μH. Also in the present embodiment, the capacitances of the capacitors 513a and 513b are 500 pF or less, for example, 25 pF. Thereby, the resonance frequencies of the series resonance circuits 511a and 511b become about 13 MHz. The capacitors 513a and 513b are preferably, for example, vacuum capacitors in order to suppress fluctuations in constants due to the influence of heat.

[0030] The second filter section 52 includes a coil 520a, a capacitor 521a, a coil 520b, and a capacitor 521b. One end of the coil 520a is connected to a node between the coil 510a and the series resonance circuit 511a, and the other end of the coil 520a is connected to the heater power supply 60. The capacitor 521a is connected between a node between the coil 520a and the heater power supply 60 and the ground. One end of the coil 520b is connected to a node between the coil 510b and the series resonance circuit 511b, and the other end of the coil 520b is connected to the heater power supply 60. The capacitor 521b is connected between a node between the coil 520b and the heater power supply 60 and the ground. The second filter section 52 suppresses the power of the second frequency among the power flowing from the heater 1111a to the heater power supply 60. The second frequency is, for example, a frequency higher than 100 Hz and not more than 4 MHz. In the present embodiment, the second frequency is, for example, 400 kHz.

[0031] Note that the first filter section 51 in the present embodiment includes the series resonance circuits 511a and 511b, but the disclosed technology is not limited thereto. For example, instead of the series resonance circuits 511a and 511b, a capacitor (not shown) adjusted to have a low impedance with respect to the first frequency may be provided. Note that this capacitor not shown is preferably a vacuum capacitor, for example, in order to suppress fluctuations in constants due to the influence of heat.

[0032] Coils 520a and 520b are wound coils having a core material with a magnetic permeability of 10 or more. Coils 520a and 520b are an example of the second coil. In the present embodiment, the inductance of coils 520a and 520b is, for example, 10 mH. Examples of the core material with a magnetic permeability of 10 or more include ferrite, dust material, permalloy, cobalt-based amorphous, and the like. In the present embodiment, since capacitors 521a and 521b are provided at positions away from heater 1111a, they are less affected by the heat from heater 1111a. Therefore, as capacitors 521a and 521b, ceramic capacitors or the like that are less expensive than vacuum capacitors can be used.

[0033] In the present embodiment, the capacitance of capacitors 521a and 521b is, for example, 2000 pF. Also, in the present embodiment, the parasitic capacitance of the wiring between heater 1111a and the first filter section 51, the wiring between the first filter section 51 and the second filter section 52, and the wiring between the second filter section 52 and heater power supply 60 is adjusted to be 500 pF or less. For example, by sandwiching a spacer such as resin between the wiring and the ground and increasing the distance between the wiring and the ground, the parasitic capacitance between the wiring and the ground is adjusted to be 500 pF or less.

[0034] [Structure of Filter Circuit 50] FIG. 3 is a diagram showing an example of the structure of filter circuit 50. Coils 510a and 510b of the first filter section 51 are arranged annularly around cylindrical member 10b so as to surround cylindrical member 10b. In the example of FIG. 3, coil 510a is arranged closer to cylindrical member 10b than coil 510b. Coil 510b is arranged around coil 510a so as to surround coil 510a. In the present embodiment, the conductor 5100 constituting coils 510a and 510b is formed in a plate shape, for example, as shown in FIG. 4. Thereby, the number of turns of the coil can be increased even in a narrow space.

[0035] The coils 520a and 520b of the second filter section 52 are arranged annularly around the cylindrical member 10b so as to surround the cylindrical member 10b. In the example of FIG. 3, the coil 520a is arranged closer to the first filter section 51 than the coil 520b. The coils 520a and 520b have a core material 5200 and a conducting wire 5201. The core material 5200 is formed annularly of a material having a magnetic permeability of 10 or more, such as ferrite. In the present embodiment, the conducting wire 5201 constituting the coils 520a and 520b is arranged inside the core material 5200. Note that in the present embodiment, the core material 5200 is formed in an annular shape, but as long as it is annular, the outer shape may be a shape other than an annular shape, such as a rectangular shape.

[0036] In the present embodiment, the coils 510a and 510b of the first filter section 51 and the coils 520a and 520b of the second filter section 52 are arranged annularly around the cylindrical member 10b so that their central axes coincide. Thereby, the filter circuit 50 can be miniaturized.

[0037] Further, in the present embodiment, as shown in FIG. 5 for example, a plurality of core materials 5200 are arranged annularly around the cylindrical member 10b so as to surround the outer surface of the cylindrical member 10b. In the example of FIG. 5, each core material 5200 is arranged annularly around the cylindrical member 10b in a direction (for example, an orthogonal direction) in which the central axis of the core material 5200 intersects the extending direction of the cylindrical member 10b. And the conducting wire 5201 is arranged inside the plurality of core materials 5200 arranged annularly around the cylindrical member 10b. That is, the conducting wire 5201 is arranged on the surface of the core material 5200 opposite to the surface on the side of the cylindrical member 10b. Also, in the present embodiment, no conducting wire 5201 is arranged between the core material 5200 and the cylindrical member 10b.

[0038] Here, consider a coil structured such that a conducting wire is wound along a toroidal core in a manner that the conducting wire alternately passes through the inside and outside of the opening of the annular toroidal core, for example, like the toroidal coil of Patent Document 1. In a coil wound in such a way, the conducting wire is located on the inside and outside of the toroidal core. Therefore, when arranging the toroidal coil, it is necessary to provide a gap between the conducting wire and the structure outside the toroidal coil. In particular, when there is a conductor connected to the ground around the toroidal coil, it is necessary to widen the gap between that conductor and the conducting wire of the toroidal coil in order to reduce the parasitic capacitance therebetween. Similarly, when there is a conductor connected to the ground, such as the cylindrical member 10b, inside the toroidal coil, it is necessary to widen the gap between that conductor and the conducting wire of the toroidal coil in order to reduce the parasitic capacitance therebetween. Therefore, when using a toroidal coil, it is difficult to miniaturize the filter circuit.

[0039] In contrast, in the present embodiment, the conducting wire 5201 that constitutes the coil of the second filter section 52 is disposed inside the annular core material 5200. Therefore, when arranging the coil of the second filter section 52, the core material 5200 is disposed in the gap between the conducting wire 5201 and the structure around the coil. Therefore, the gap between the conducting wire 5201 and the structure around the coil can be easily formed. Further, since the core material 5200 is disposed in the gap between the conducting wire 5201 and the structure around the coil, the gap between the conducting wire 5201 and the structure around the coil can be efficiently utilized. Thereby, the second filter section 52 can be miniaturized compared to the toroidal core of Patent Document 1, and the filter circuit 50 and the plasma processing apparatus 1 can be miniaturized.

[0040] Also, in the example of FIG. 5, the adjacent core materials 5200 are annularly arranged around the cylindrical member 10b with a space therebetween. Thereby, the heat generated in the coil 520 and the conducting wire 5201 is released from between the adjacent core materials 5200. Thereby, the heat dissipation of the coil 520 and the conducting wire 5201 can be efficiently performed.

[0041] Returning to FIG. 3, the description will be continued. A partition plate 53 formed of a conductive member is disposed between the coils 510a and 510b of the first filter section 51 and the coils 520a and 520b of the second filter section 52. The partition plate 53 is grounded. The partition plate 53 suppresses magnetic coupling between the coils 510a and 510b and the coils 520a and 520b of the second filter section 52.

[0042] Here, the partition plate 53 needs to allow the wiring connecting the coil 510a and the coil 520a and the wiring connecting the coil 510b and the coil 520b to pass through. However, if an opening for allowing these wirings to pass through is provided in the partition plate 53, a part of the magnetic field lines generated from the coils included in the first filter section 51 and the second filter section 52 may pass through the gap between the opening of the partition plate 53 and the wiring. As a result, the magnetic coupling between the coils included in the first filter section 51 and the coils included in the second filter section 52 may be enhanced.

[0043] Therefore, in the present embodiment, as shown in FIG. 6 for example, a first shielding member 530 and a second shielding member 531 are provided in a wiring region 532 of a partition plate 53 through which a wiring 54 passes. The wiring 54 is a wiring that connects a coil included in the first filter section 51 and a coil included in the second filter section 52. A gap in which the wiring 54 is disposed is formed between the first shielding member 530 and the second shielding member 531. Also, the first shielding member 530 and the second shielding member 531 are arranged so as to shield a straight path (in the direction of the dashed arrow in FIG. 6) from the coil included in the first filter section 51 to the coil included in the second filter section 52. Thereby, it is possible to suppress a part of the magnetic flux generated from the coils included in the first filter section 51 and the second filter section 52 from passing through the gap between the opening of the partition plate 53 and the wiring. Thereby, it is possible to suppress the magnetic coupling between the coil included in the first filter section 51 and the coil included in the second filter section 52. When the voltage applied to the wiring 54 is extremely high, there is a risk of abnormal discharge between the wiring 54 and the first shielding member 530 and the second shielding member 531. Therefore, it is desirable that the wiring 54 disposed in the gap between the first shielding member 530 and the second shielding member 531 does not contact either the first shielding member 530 or the second shielding member 531. Particularly when a high voltage of about 1 kV is applied to the wiring 54, it is desirable that the distance between the first shielding member 530 and the wiring 54 and between the second shielding member 531 and the wiring 54 is about 1 mm, and when it is about 10 kV, it is desirable that the distance is about 10 mm. Although air is interposed between the first shielding member 530 and the wiring 54 and between the second shielding member 531 and the wiring 54, an insulator such as an insulator may be interposed.

[0044] Also, when current flows through the coils included in the first filter section 51 and the coils included in the second filter section 52, these coils generate heat. Further, when current flows through the coils included in the second filter section 52, the core material 5200 generates heat. Therefore, heat dissipation of the first filter section 51 and the second filter section 52 is important. Therefore, in the present embodiment, a plurality of through holes 535 are formed in the partition plate 53 to promote the circulation of air in the filter circuit 50.

[0045] Here, when the through holes 535 are formed in the partition plate 53, for example, as shown in FIG. 7(a), eddy currents are generated around the through holes 535 by the magnetic field lines B1 passing through the through holes 535. Then, magnetic field lines B2 in the direction opposite to the magnetic field lines B1 are generated by the generated eddy currents. When the opening of the through hole 535 is sufficiently small, the magnitude of the magnetic field lines B2 generated by the eddy currents becomes equal to that of the magnetic field lines B1. Therefore, the magnetic field lines B3 obtained by synthesizing the magnetic field lines B1 and the magnetic field lines B2 do not pass through the through hole 535.

[0046] On the other hand, when the opening of the through hole 535 is large, the magnitude of the magnetic field lines B2 generated by the eddy currents becomes smaller than that of the magnetic field lines B1. Therefore, for example, as shown in FIG. 7(b), the magnetic field lines B3 obtained by synthesizing the magnetic field lines B1 and the magnetic field lines B2 pass through the through hole 535. Therefore, it is desirable that the size of the opening of the through hole 535 formed in the partition plate 53 is such that magnetic field lines do not pass through. For example, when the opening of the through hole 535 is circular, for magnetic field lines of electromagnetic waves having a frequency of less than 50 MHz, it is preferable that the diameter of the opening is 4 mm or less, for example.

[0047] The above describes one embodiment. As described above, the filter circuit 50 in the present embodiment is a filter circuit 50 provided in a plasma processing apparatus 1 in which a substrate W is processed using plasma generated by power at a first frequency and power at a second frequency lower than the first frequency, and includes a first filter section 51 and a second filter section 52. The first filter section 51 is provided in a wiring between a heater 1111a provided in the plasma processing apparatus 1 and a heater power supply 60. The heater power supply 60 supplies control power, which is power at a third frequency lower than the second frequency or DC power, to the heater 1111a. The second filter section 52 is provided in a wiring between the first filter section 51 and the heater power supply 60. Further, the first filter section 51 is connected in series to a wiring between the substrate support surface 111a and the second filter section 52, and has coils 510a and 510b without a core material. Further, the second filter section 52 is connected in series to a wiring between the coil 510a and the heater power supply 60 and has 520a having a core material 5200, and is connected in series to a wiring between the coil 510b and the heater power supply 60 and has 520b having a core material 5200. Further, the conducting wires included in the coils 520a and 520b are arranged on a surface opposite to the surface on the side of the cylindrical member 10b of at least one core material 5200 annularly arranged around the cylindrical member 10b so as to surround the outer surface of the hollow cylindrical member 10b. Thereby, the filter circuit 50 and the plasma processing apparatus 1 can be miniaturized.

[0048] Further, in the present embodiment, a plurality of core materials 5200 are annularly arranged around the cylindrical member 10b. Each of the second filter sections 52 is annular, and each 5200 is annularly arranged around the cylindrical member 10b in a direction in which the central axis of the core material 5200 intersects the extending direction of the cylindrical member 10b. Further, the conducting wires constituting the coil 520 are arranged in the respective core materials 5200. Thereby, the second filter section 52 can be miniaturized.

[0049] In addition, in the present embodiment, the adjacent core materials 5200 are arranged annularly around the cylindrical member 10b with an interval therebetween. Thereby, heat dissipation of the core material 5200 and the conductive wire 5201 can be efficiently performed.

[0050] In addition, the filter circuit 50 in the present embodiment is formed of a conductive member, and further includes a partition plate 53 provided between the coil included in the first filter portion 51 and the coil included in the second filter portion 52. The partition plate 53 is grounded. Thereby, while suppressing the magnetic coupling between the coil included in the first filter portion 51 and the coil included in the second filter portion 52, the first filter portion 51 and the second filter portion 52 can be arranged close to each other.

[0051] In addition, in the present embodiment, the second filter portion 52 is provided with a wiring region 532 through which a wiring connecting the coil included in the first filter portion 51 and the coil included in the second filter portion 52 passes. In the wiring region 532, a first shielding member 530 and a second shielding member 531 are provided so that a straight path from the coil included in the first filter portion 51 to the coil included in the second filter portion 52 is not formed. Thereby, while suppressing the magnetic coupling between the coil included in the first filter portion 51 and the coil included in the second filter portion 52, the first filter portion 51 and the second filter portion 52 can be arranged close to each other.

[0052] In addition, in the present embodiment, the partition plate 53 is formed with a plurality of through holes 535 having openings with a predetermined size or less. The openings of each partition plate 53 are circular, and the diameter of the openings is, for example, 4 mm or less. Thereby, while suppressing the magnetic field lines passing through the through holes 535, the circulation of air in the filter circuit 50 can be promoted.

[0053] Also, in the present embodiment, the coil included in the first filter unit 51 and the coil included in the second filter unit 52 are arranged such that their central axes coincide. Thereby, the filter circuit 50 and the plasma processing apparatus 1 can be miniaturized.

[0054] Also, in the present embodiment, the first frequency is higher than 4 MHz. Also, the second frequency is higher than 100 Hz and 4 MHz or less. Also, the third frequency is 100 Hz or less. Thereby, the plasma processing apparatus 1 can perform plasma processing using a source RF signal having a frequency higher than 4 MHz and a bias RF signal having a frequency higher than 100 Hz and 4 MHz or less. Also, the heater power supply 60 can control the calorific value of the heater 1111a using DC or control power of 100 Hz or less.

[0055] Also, in the present embodiment, the first filter unit 51 is connected between the wiring between the heater 1111a and the second filter unit 52 and the ground, and further includes series resonance circuits 511a and 511b having a coil and a vacuum capacitor connected in series. Thereby, fluctuations in the constants of the series resonance circuits 511a and 511b due to the influence of heat can be suppressed. Note that instead of the series resonance circuits 511a and 511b, a capacitor adjusted to have a low impedance with respect to the first frequency may be provided.

[0056] Also, in the present embodiment, the core material 5200 is formed of ferrite, dust material, permalloy, or cobalt-based amorphous. Thereby, the second filter unit 52 can be miniaturized.

[0057] In addition, the plasma processing apparatus 1 in the present embodiment includes a plasma processing chamber 10 in which a substrate W is processed using plasma generated by using power of a first frequency and power of a second frequency lower than the first frequency, a heater 1111a provided in the plasma processing chamber 10, and a filter circuit 50. The filter circuit 50 includes a first filter unit 51 and a second filter unit 52. The first filter unit 51 is provided in a wiring between the heater 1111a and a heater power supply 60. The heater power supply 60 supplies control power, which is power of a third frequency lower than the second frequency or DC power, to the heater 1111a. The second filter unit 52 is provided in a wiring between the first filter unit 51 and the heater power supply 60. Further, the first filter unit 51 is serially connected to a wiring between a substrate support surface 111a and the second filter unit 52, and includes coils 510a and 510b having no core material. Further, the second filter unit 52 includes 520a serially connected to a wiring between the coil 510a and the heater power supply 60 and having a core material 5200, and 520b serially connected to a wiring between the coil 510b and the heater power supply 60 and having a core material 5200. Further, conductors included in the coil 520a and the coil 520b are arranged on a surface opposite to a surface on the side of the cylindrical member 10b with respect to at least one core material 5200 annularly arranged around the outer surface of the hollow cylindrical member 10b. Thereby, the plasma processing apparatus 1 can be miniaturized.

[0058] [Others] Note that the technology disclosed in the present application is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist thereof.

[0059] For example, in the above-described embodiment, the plasma processing apparatus 1 in which one heater 1111a is provided in the electrostatic chuck 1111 has been described, but the disclosed technology is not limited thereto. For example, a plurality of heaters 1111a may be provided in the electrostatic chuck 1111. In this case, the first filter unit 51 and the second filter unit 52 are provided one by one for each heater 1111a. The coils 510a and 510b provided one by one for each heater 1111a are arranged, for example, concentrically around the cylindrical member 10b in the region of the first filter unit 51 in FIG. 3. Similarly, the coils 520a and 520b provided one by one for each heater 1111a are also arranged, for example, concentrically around the cylindrical member 10b in the region of the second filter unit 52 in FIG. 3.

[0060] Alternatively, as shown in FIG. 8 for example, a distribution unit 61 may be provided between the plurality of heaters 1111a and the filter circuit 50. The distribution unit 61 individually supplies control power to each of the plurality of heaters 1111a. Thereby, the filter circuit 50 can be miniaturized, and the plasma processing apparatus 1 can be miniaturized.

[0061] Also, in the above-described embodiment, a plurality of annular core materials 5200 are arranged around the cylindrical member 10b, and the conducting wires 5201 constituting the coils included in the second filter unit 52 are arranged in each core material 5200, but the disclosed technology is not limited thereto. As another form, the core material 5200 may be formed in a tubular shape as shown in FIG. 9, for example. The core material 5200 is annularly arranged around the cylindrical member 10b in a direction in which the central axis of the core material 5200 intersects the extending direction of the cylindrical member 10b. The conducting wire 5201 is arranged along the extending direction of the core material 5200 in the tubular core material 5200. Thereby, it is possible to suppress the magnetic flux generated in the core material 5200 by the conducting wire 5201 from saturating in the core material 5200.

[0062] Note that the core material 5200 illustrated in FIG. 9 may be dividable into two portions 5200a and 5200b along a plane along the extending direction (central axis) of the core material 5200, as shown in FIG. 10, for example. Thereby, after arranging the conducting wire 5201 in one portion 5200b, by combining the other portion 5200a and the portion 5200a, the coils 520a and 520b in the state illustrated in FIG. 9 can be easily realized.

[0063] In the above-described embodiment, a plurality of annular core materials 5200 are arranged around the cylindrical member 10b, and the conducting wires 5201 constituting the coils included in the second filter portion 52 are arranged in the respective core materials 5200. However, the disclosed technology is not limited thereto. For example, as shown in FIGS. 11 and 12, a plurality of rod-shaped core materials 5200' may be arranged around the cylindrical member 10b. FIG. 12 shows an example of the positional relationship between the core material 5200' and the coils 520a' and 520b' as viewed from the direction along the extending direction of the cylindrical member 10b. Each core material 5200' is annularly arranged around the cylindrical member 10b such that the longitudinal direction is along the extending direction of the cylindrical member 10b. In this case, the coils 520a' and 520b' of the second filter portion 52 are annularly arranged around the cylindrical member 10b and the plurality of core materials 5200' so as to surround the cylindrical member 10b and the plurality of core materials 5200'. In the examples of FIGS. 11 and 12, the coils 520a' and 520b' of the second filter portion 52 can also be formed of, for example, a plate-shaped wiring as shown in FIG. 4. Thereby, the second filter portion 52 can be miniaturized.

[0064] Further, the core material 5200” provided in the second filter portion 52 may have a shape such as a hollow bobbin, as shown in FIG. 13, for example. With such a shape, while suppressing saturation of the magnetic flux in the core material 5200”, the second filter portion 52 can be miniaturized.

[0065] In the above-described embodiment, control power from the heater power supply 60, which is an example of the power supply unit, is supplied to the heater 1111a, which is an example of the conductive member. However, the conductive member to which the control power is supplied is not limited to this. For example, the power control unit may supply control power to a conductive member other than the heater 1111a provided in the plasma processing apparatus 1. Examples of the conductive member other than the heater 1111a include a conductive member of the substrate support unit 11 to which power of the first frequency and power of the second frequency are supplied, a conductive member of the shower head 13, a ring assembly 112, and the like.

[0066] In the above-described embodiment, the plasma processing apparatus 1 using the capacitively coupled plasma (CCP) as the plasma source has been described as an example. However, the plasma source is not limited to this. Examples of the plasma source other than the capacitively coupled plasma include inductively coupled plasma (ICP) and the like.

[0067] It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. Indeed, the above-described embodiments can be embodied in various forms. Also, the above embodiments may be omitted, replaced, or changed in various forms without departing from the scope and spirit of the appended claims.

Description of Reference Numerals

[0068] B Magnetic field line W Substrate 100 Plasma processing system 1 Plasma processing apparatus 2 Control unit 2a Computer 10 Plasma processing chamber 10b Cylindrical member 11 Substrate support unit 111 Main body portion 111a Substrate support surface 111b Ring support surface 1110 Base 1110a Flow path 1110c Feeding rod 1111 Electrostatic chuck 1111a Heater 112 Ring Assembly 13 Shower Head 20 Gas Supply Unit 30 Power Supply 31 RF Power Supply 32 DC Power Supply 40 Exhaust System 50 Filter Circuit 500 Wiring 51 First Filter Section 510 Coil 5100 Conductive Wire 511 Series Resonance Circuit 512 Coil 513 Capacitor 52 Second Filter Section 520 Coil 5200 Core Material 5200a Portion 5200b Portion 5201 Conductive Wire 521 Capacitor 53 Partition Board 530 First Shielding Member 531 Second Shielding Member 532 Wiring Area 535 Through-Hole 54 Wiring 60 Heater Power Supply 61 Distribution Unit

Claims

1. In a filter circuit provided in a plasma processing apparatus in which a substrate is processed using plasma generated using the power of a first frequency and the power of a second frequency lower than the first frequency, a first filter section provided in a wiring between a conductive member provided in the plasma processing apparatus and a power supply section that supplies control power, which is power of a third frequency lower than the second frequency or DC power, to the conductive member; and a second filter section provided in the wiring between the first filter section and the power supply section are provided, the first filter section is connected in series to the wiring and has a first coil without a core material, the second filter section is connected in series to the wiring between the first coil and the power supply section and has a second coil with a core material, and a filter circuit in which a conducting wire included in the second coil is arranged on a surface opposite to a surface on the inner cylinder side of at least one of the core materials annularly arranged around the inner cylinder so as to surround an outer surface of the hollow inner cylinder.

2. A plurality of the core materials are annularly arranged around the inner cylinder, each of the core materials is annular, each of the core materials is annularly arranged around the inner cylinder in a direction in which a central axis of the core material intersects with an extending direction of the inner cylinder, and a conducting wire constituting the second coil is arranged in each of the core materials, the filter circuit according to claim 1.

3. The adjacent core materials are annularly arranged around the inner cylinder with an interval therebetween, the filter circuit according to claim 2.

4. The core material is tubular, the core material is annularly arranged around the inner cylinder in a direction in which a central axis of the core material intersects with an extending direction of the inner cylinder, The wiring between the first filter section and the power supply section is disposed within the core material. The filter circuit according to claim 1.

5. The core material is separable along a plane along the central axis of the core material. The filter circuit according to claim 4.

6. A plurality of the core materials are annularly arranged around the inner cylinder, Each of the core materials is rod-shaped, Each of the core materials is annularly arranged around the inner cylinder such that the longitudinal direction of the core material is along the extending direction of the inner cylinder. The filter circuit according to claim 1.

7. Further includes a partition plate formed of a conductive member and provided between the first coil and the second coil, The partition plate is grounded. The filter circuit according to any one of claims 1 to 6.

8. The partition plate is provided with a wiring area through which wiring connecting the first coil and the second coil passes, A shielding member is provided in the wiring area so that a straight path from the first coil to the second coil is not formed. The filter circuit according to claim 7.

9. The partition plate is formed with a plurality of through holes having openings with a size equal to or smaller than a predetermined size. The filter circuit according to claim 7 or 8.

10. The opening of the through hole is circular, The diameter of the opening is 4 mm or less. The filter circuit according to claim 9.

11. The first coil and the second coil are arranged such that their central axes coincide. The filter circuit according to any one of claims 1 to 10.

12. The first frequency is higher than 4 MHz, The second frequency is higher than 100 Hz and equal to or less than 4 MHz, The third frequency is equal to or less than 100 Hz. The filter circuit according to any one of claims 1 to 11.

13. The first filter section Is connected between the wiring between the conductive member and the second filter section and the ground, and has a series resonance circuit having a coil and a capacitor connected in series, or further has a capacitor. The filter circuit according to any one of claims 1 to 12.

14. The filter circuit according to any one of claims 1 to 13, wherein the core material is formed of ferrite, dust material, permalloy, or cobalt-based amorphous.

15. The filter circuit according to any one of claims 1 to 14, wherein the conductive member is a heater for controlling the temperature of the substrate.

16. A plurality of conductive members are provided in the plasma processing apparatus, The first coil and the second coil are provided one by one for each of the conductive members. The filter circuit according to any one of claims 1 to 15.

17. In the plasma processing apparatus, a distribution unit is provided for individually supplying the control power to each of the plurality of conductive members provided in the plasma processing apparatus, The control power supplied from the power supply unit through the first coil and the second coil is supplied to each of the conductive members by the distribution unit. The filter circuit according to any one of claims 1 to 15.

18. A chamber in which a substrate is processed using plasma generated using power of a first frequency and power of a second frequency lower than the first frequency, A conductive member provided in the chamber, A filter circuit And comprising The filter circuit is provided with a first filter section provided in a wiring between the conductive member and a power supply section that supplies control power, which is power at a third frequency lower than the second frequency or DC power, to the conductive member via the filter circuit, and a second filter section provided in the wiring between the first filter section and the power supply section, and includes: the first filter section is connected in series to the wiring and has a first coil without a core material, the second filter section is connected in series to the wiring between the first coil and the power supply section and has a second coil with a core material, and in the plasma processing apparatus, the conducting wire included in the second coil is arranged on a surface opposite to the surface on the inner cylinder side of at least one of the core materials arranged in an annular shape around the inner cylinder so as to surround the outer surface of the hollow inner cylinder.

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