Plasma processing device and cleaning method

Abstract

A plasma processing device according to the present invention comprises: a chamber that has a side wall; a substrate support part for supporting a substrate inside the chamber; a gas supply part that is configured to supply a processing gas into the chamber; a plasma generation part that is configured to generate plasma from the processing gas inside the chamber; and an electromagnet unit that is provided outside the chamber and is configured to form a magnetic field inside the chamber. The substrate support part has a center axis that extends along the side wall, and the electromagnet unit comprises a first electromagnet that is in an outermost position in a radial direction that is orthogonal to the center axis. An inner edge of the first electromagnet is positioned further to the outside in the radial direction than an outer edge of the substrate support part.

Description

Plasma processing apparatus and cleaning method

[0001] SUMMARY OF THE INVENTION Exemplary embodiments of the present disclosure relate to plasma processing apparatuses and cleaning methods.

[0002] Patent Document 1 discloses a substrate processing apparatus that generates an electric field in a processing space between a lower electrode to which high-frequency power is supplied and an upper electrode disposed opposite the lower electrode, and performs plasma processing on a substrate placed on the lower electrode using plasma generated by the electric field. The distribution of plasma density in the processing space is adjusted by a magnetic field generated by controlling multiple electromagnets provided on the upper surface of the upper electrode opposite the processing space.

[0003] JP 2013-168449 A

[0004] The present disclosure provides a technique capable of efficiently removing deposits that have accumulated on the inner wall surface of the sidewall of a chamber.

[0005] In one exemplary embodiment, a plasma processing apparatus includes a chamber having a sidewall, a substrate support for supporting a substrate in the chamber, a gas supply configured to supply a processing gas into the chamber, a plasma generation unit configured to generate plasma from the processing gas in the chamber, and an electromagnet unit disposed outside the chamber and configured to form a magnetic field within the chamber, wherein the substrate support has a central axis extending along the sidewall, and the electromagnet unit includes a first electromagnet located outermost in a radial direction perpendicular to the central axis, and an inner edge of the first electromagnet is located outer than an outer edge of the substrate support in the radial direction.

[0006] According to one exemplary embodiment, deposits accumulated on the inner wall surface of the sidewall of the chamber can be efficiently removed.

[0007] FIG. 1 is a diagram for explaining an example of the configuration of a plasma processing system. FIG. 2 is a diagram for explaining an example of the configuration of a capacitively coupled plasma processing apparatus. FIG. 3 is a cross-sectional view showing a plasma processing apparatus according to an exemplary embodiment. FIG. 4 is a cross-sectional view showing a plasma processing apparatus according to another exemplary embodiment. FIG. 5 is a flowchart of a cleaning method according to an exemplary embodiment. FIG. 6 is a graph showing an example of the relationship between the position from the central axis in the radial direction and the strength of the magnetic field.

[0008] Various exemplary embodiments will be described in detail below with reference to the drawings, in which the same or equivalent parts are designated by the same reference numerals.

[0009] FIG. 1 is a diagram illustrating an exemplary configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0010] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma generated in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), surface wave plasma (SWP), or the like. Various types of plasma generators may be used, including alternating current (AC) plasma generators and direct current (DC) plasma generators. In one embodiment, the AC signal (AC power) used in the AC plasma generator has a frequency in the range of 100 kHz to 10 GHz. Thus, AC signals include radio frequency (RF) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0011] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform 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 a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. This 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 processing unit 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 processing unit 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).

[0012] The following describes a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0013] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply 20, a power supply 30, and an exhaust system 40. 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 process 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 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0014] 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.

[0015] 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. Furthermore, at least one RF / DC electrode coupled to an RF power supply 31 and / or a DC power supply 32, which will be 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, which will be 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. Furthermore, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0016] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0017] 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 to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow passage 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow passage 1110a. In one embodiment, the flow passage 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.

[0018] The showerhead 13 is configured to introduce at least one process 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 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 multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0019] 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 at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0020] 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 processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generation unit 12. Furthermore, 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.

[0021] 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 150 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.

[0022] The second RF generator 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is 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 generator 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.

[0023] 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 the at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to the 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.

[0024] In various embodiments, 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 pulse waveform. In one embodiment, a waveform generator for generating the 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.

[0025] 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 in the plasma processing space 10s is regulated by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0026] Fig. 3 is a cross-sectional view showing a plasma processing apparatus according to an exemplary embodiment. The plasma processing apparatus 1 of Figs. 1 and 2 may include an electromagnet unit MU as shown in Fig. 3. The plasma processing apparatus 1 of Fig. 3 includes a plasma processing chamber 10, a substrate support 11, a gas supply unit 20 (see Fig. 2), a plasma generation unit 12 (see Fig. 1), and the electromagnet unit MU. The plasma processing apparatus 1 may further include a control unit 2 (see Fig. 2).

[0027] The plasma processing chamber 10 has a sidewall 10a. The sidewall 10a may have an inner wall surface 10ae2 facing the plasma processing space 10s. The sidewall 10a may include an insulating member having the inner wall surface 10ae2. An example of the insulating member is a quartz member. The inner wall surface 10ae2 is located on a cylindrical surface P1 surrounding the central axis Ax of the substrate support 11.

[0028] The substrate support 11 can support a substrate W in the plasma processing chamber 10. The substrate support 11 has a central axis Ax extending along the sidewall 10a. The central axis Ax may pass through the center of the substrate support surface of the substrate support 11. When the substrate W is supported on the substrate support surface, the central axis Ax may pass through the center of the substrate W. The substrate support 11 has an outer edge 11e1. The outer edge 11e1 is located on a cylindrical surface P5 that surrounds the central axis Ax. The substrate support 11 may include an edge ring (or focus ring) ER arranged to surround the central axis Ax. The edge ring ER has an outer edge ERe1. The outer edge ERe1 is located on a cylindrical surface P6 that surrounds the central axis Ax. The substrate support 11 may include a lower electrode.

[0029] The gas supply 20 is configured to supply a process gas into the plasma processing chamber 10 .

[0030] The plasma generating unit 12 is configured to generate a plasma PL from the process gas in the plasma processing chamber 10. The plasma generating unit 12 may include an upper electrode UE disposed above the substrate support 11. The upper electrode UE may be included in the showerhead 13. The plasma PL may be generated by applying power between the upper electrode UE and a lower electrode in the substrate support 11.

[0031] The electromagnet unit MU is disposed outside the plasma processing chamber 10. The electromagnet unit MU may be disposed on the showerhead 13 of the plasma processing chamber 10. The electromagnet unit MU may be provided to surround the central axis Ax. The electromagnet unit MU is configured to form a magnetic field within the plasma processing chamber 10. The magnetic field has a radial component RD that is perpendicular to the central axis Ax. The density of the plasma PL can be controlled by controlling the strength of the magnetic field.

[0032] The electromagnet unit MU may include first to fourth electromagnets M1 to M4. Each of the first to fourth electromagnets M1 to M4 may be annular electromagnets surrounding the central axis A. Each of the first to fourth electromagnets M1 to M4 may have a yoke and a coil. The yoke includes a magnetic material. The coil is wound around the central axis Ax. The electromagnet unit MU may not include at least one of the second to fourth electromagnets M2 to M4. The electromagnet unit MU may include additional electromagnets in addition to the first to fourth electromagnets M1 to M4. The first electromagnet M1 is located outermost in the radial direction RD. The second electromagnet M2 is located inside the first electromagnet M1 in the radial direction RD. The third electromagnet M3 is located inside the second electromagnet M2 in the radial direction RD. The fourth electromagnet M4 is located inside the third electromagnet M3 in the radial direction RD. The fourth electromagnet M4 is located at the innermost position in the radial direction RD.

[0033] The first electromagnet M1 has an outer edge M1e1 and an inner edge M1e2. The outer edge M1e1 is located on a cylindrical surface P2 surrounding the central axis Ax. The inner edge M1e2 is located on a cylindrical surface P3 surrounding the central axis Ax. The second electromagnet M2 has an inner edge M2e2. The inner edge M2e2 is located on a cylindrical surface P4 surrounding the central axis Ax.

[0034] In the radial direction RD, the inner edge M1e2 (cylindrical surface P3) of the first electromagnet M1 is located outside the outer edge 11e1 (cylindrical surface P5) of the substrate support 11. The outer edge M1e1 (cylindrical surface P2) of the first electromagnet M1 may be located inside the inner wall surface 10ae2 (cylindrical surface P1) of the sidewall 10a of the plasma processing chamber 10. In the radial direction RD, the distance between the outer edge M1e1 (cylindrical surface P2) and the inner wall surface 10ae2 (cylindrical surface P1) may be 10 mm or less.

[0035] In the radial direction RD, the inner edge M2e2 (cylindrical surface P4) of the second electromagnet M2 may be located outside the outer edge ERe1 (cylindrical surface P6) of the edge ring ER, or may be located outside the outer edge 11e1 (cylindrical surface P5) of the substrate support portion 11.

[0036] The control unit 2 may be configured to control the electromagnet unit MU to form a magnetic field in the plasma processing chamber 10 by supplying a current to the electromagnet unit MU. The control unit 2 may be configured to control the electromagnet unit MU, the gas supply unit 20, and the plasma generation unit 12 to generate plasma PL from a processing gas supplied into the plasma processing chamber 10 while the magnetic field is formed. In the process of generating plasma PL, the amount of electricity (amount of current) supplied to the first electromagnet M1 may be greater than the amount of electricity supplied to the third electromagnet M3. The amount of electricity may be the product of the current value and the current-flow time. The amount of electricity supplied to the second electromagnet M2 may be the same as the amount of electricity supplied to the first electromagnet M1 or may be smaller than the amount of electricity supplied to the first electromagnet M1. The amount of electricity supplied to the fourth electromagnet M4 may be the same as the amount of electricity supplied to the first electromagnet M1 or may be smaller than the amount of electricity supplied to the first electromagnet M1. It is not necessary to supply current to at least one of the second electromagnet M2 to the fourth electromagnet M4.

[0037] FIG. 4 is a cross-sectional view showing a plasma processing apparatus according to another exemplary embodiment. The plasma processing apparatus 1 of FIG. 4 has the same configuration as the plasma processing apparatus 1 of FIG. 3, except that the cylindrical surface P1 is located inside the cylindrical surface P2 in the radial direction RD. In the radial direction RD, the outer edge M1e1 (cylindrical surface P2) of the first electromagnet M1 is located outside the inner wall surface 10ae2 (cylindrical surface P1) of the sidewall 10a of the plasma processing chamber 10. In the radial direction RD, the outer edge M1e1 (cylindrical surface P2) of the first electromagnet M1 may be located inside the outer wall surface of the sidewall 10a of the plasma processing chamber 10. When viewed from the direction of the central axis Ax, at least a portion of the first electromagnet M1 may overlap the sidewall 10a of the plasma processing chamber 10.

[0038] According to the plasma processing apparatus 1 shown in FIGS. 3 and 4 , the strength of the magnetic field can be increased by the first electromagnet M1 near the inner wall surface 10ae2 of the sidewall 10a of the plasma processing chamber 10. The plasma PL generated under a strong magnetic field has a high plasma density (electron density). Therefore, the plasma PL can efficiently remove deposits (e.g., films) accumulated on the inner wall surface 10ae2 of the sidewall 10a of the plasma processing chamber 10. That is, the rate of deposit removal can be increased. Furthermore, deposits accumulated on components (e.g., baffle plates) within the plasma processing chamber 10 can also be efficiently removed. Examples of deposits include substances generated by processes (e.g., etching) performed within the plasma processing chamber 10. Furthermore, when etching a substrate W using the plasma processing apparatus 1, a high plasma density can be maintained even near the periphery of the substrate W, improving the in-plane etching distribution.

[0039] 5 is a flowchart of a cleaning method according to one exemplary embodiment. The cleaning method MT1 shown in FIG. 5 (hereinafter referred to as "method MT1") can be performed by the plasma processing apparatus 1 according to the above-described embodiment. When the plasma processing apparatus 1 is used, the method MT1 can be performed in the plasma processing apparatus 1 by controlling each part of the plasma processing apparatus 1 by the control unit 2. The method MT1 is a method for cleaning the inner wall surface 10ae2 of the sidewall 10a of the plasma processing chamber 10. The method MT1 may be performed in a state where a substrate W, such as a dummy substrate, is supported by the substrate support 11, or in a state where the substrate W is not supported by the substrate support 11.

[0040] 5, the method MT1 may include steps ST1 and ST2. Steps ST1 and ST2 may be performed in order or at least partially simultaneously.

[0041] (Step ST1) In step ST1, a magnetic field is formed in the plasma processing chamber 10 by supplying a current to the electromagnet unit MU (see FIGS. 3 and 4).

[0042] (Process ST2) In process ST2, while a magnetic field is being formed, the inner wall surface 10ae2 of the sidewall 10a of the plasma processing chamber 10 is cleaned by plasma PL generated from a processing gas supplied into the plasma processing chamber 10. In process ST2, the amount of electricity supplied to the first electromagnet M1 may be greater than the amount of electricity supplied to the third electromagnet M3. This allows the strength of the magnetic field to be increased near the inner wall surface 10ae2.

[0043] FIG. 6 is a graph showing an example of the relationship between the position from the central axis in the radial direction and the magnetic field strength. The horizontal axis represents the position (mm) from the central axis Ax in the radial direction RD. The vertical axis represents the strength (G) of the magnetic field (radial RD component). FIG. 6 shows the results of calculating the magnetic field strength through simulation. In this example, the inner wall surface 10ae2 of the sidewall 10a of the plasma processing chamber 10 is located approximately 300 mm from the central axis Ax. Therefore, it can be seen that the magnetic field strength can be increased near the inner wall surface 10ae2 of the sidewall 10a of the plasma processing chamber 10.

[0044] According to the method MT1, the inner wall surface 10ae2 of the sidewall 10a of the plasma processing chamber 10 can be efficiently cleaned.

[0045] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various omissions, substitutions, and modifications may be made. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0046] Various exemplary embodiments included in the present disclosure are now described in [E1] to [E8] below.

[0047] [E1] A plasma processing apparatus comprising: a chamber having a sidewall; a substrate support for supporting a substrate in the chamber; a gas supply unit configured to supply a processing gas into the chamber; a plasma generation unit configured to generate plasma from the processing gas in the chamber; and an electromagnet unit disposed outside the chamber and configured to form a magnetic field within the chamber, wherein the substrate support has a central axis extending along the sidewall, and the electromagnet unit comprises a first electromagnet located outermost in a radial direction perpendicular to the central axis, and an inner edge of the first electromagnet is located outer than an outer edge of the substrate support in the radial direction.

[0048] [E2] The plasma processing apparatus according to [E2], wherein the electromagnet unit includes a second electromagnet located inside the first electromagnet in the radial direction, the substrate support portion includes an edge ring arranged to surround the central axis, and the inner edge of the second electromagnet is located outside the outer edge of the edge ring in the radial direction.

[0049] [E3] The plasma processing apparatus according to [E2], wherein the electromagnet unit includes a third electromagnet located radially inside the second electromagnet, and the plasma processing apparatus further includes a control unit configured to control the electromagnet unit, the gas supply unit, and the plasma generation unit so as to form the magnetic field in the chamber by supplying current to the electromagnet unit, and generate the plasma from the processing gas supplied into the chamber while the magnetic field is formed, and wherein the amount of electricity supplied to the first electromagnet is greater than the amount of electricity supplied to the third electromagnet in the plasma generating step.

[0050] [E4] The plasma processing apparatus according to any one of [E1] to [E3], wherein the plasma generating unit includes an upper electrode provided above the substrate supporting unit.

[0051] [E5] The plasma processing apparatus according to any one of [E1] to [E4], wherein an outer edge of the first electromagnet is located outside the inner wall surface of the side wall of the chamber in the radial direction.

[0052] [E6] A method for cleaning an inner wall surface of a sidewall of a chamber of a plasma processing apparatus, wherein the plasma processing apparatus comprises: a substrate support part for supporting a substrate in the chamber; and an electromagnet unit arranged outside the chamber and configured to form a magnetic field within the chamber, wherein the substrate support part has a central axis extending along the sidewall, and the electromagnet unit comprises a first electromagnet located outermost in a radial direction perpendicular to the central axis, and an inner edge of the first electromagnet is located outer than an outer edge of the substrate support part in the radial direction, and the cleaning method includes: forming a magnetic field within the chamber by supplying current to the electromagnet unit; and cleaning the inner wall surface of the sidewall of the chamber with plasma generated from a processing gas supplied into the chamber while the magnetic field is formed.

[0053] [E7] The cleaning method described in [E6], wherein the electromagnet unit includes a second electromagnet located inside the first electromagnet in the radial direction, the substrate support part includes an edge ring arranged to surround the central axis, and the inner edge of the second electromagnet is located outside the outer edge of the edge ring in the radial direction.

[0054] [E8] The cleaning method according to [E7], wherein the electromagnet unit includes a third electromagnet located inside the second electromagnet in the radial direction, and in the cleaning step, the amount of electricity supplied to the first electromagnet is greater than the amount of electricity supplied to the third electromagnet.

[0055] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims.

[0056] 1...plasma processing apparatus, 10...plasma processing chamber, 10a...side wall, 10ae2...inner wall surface, 11...substrate support portion, 11e1...outer edge, 12...plasma generation portion, 20...gas supply portion, Ax...central axis, M1...first electromagnet, M1e2...inner edge, MU...electromagnet unit, PL...plasma, RD...radial direction, W...substrate.

Claims

1. A plasma processing apparatus comprising: a chamber having a sidewall; a substrate support for supporting a substrate within the chamber; a gas supply unit configured to supply a processing gas into the chamber; a plasma generation unit configured to generate plasma from the processing gas within the chamber; and an electromagnet unit disposed outside the chamber and configured to form a magnetic field within the chamber, wherein the substrate support unit has a central axis extending along the sidewall, and the electromagnet unit comprises a first electromagnet located outermost in a radial direction perpendicular to the central axis, and an inner edge of the first electromagnet is located outer than an outer edge of the substrate support unit in the radial direction.

2. The plasma processing apparatus of claim 1, wherein the electromagnet unit includes a second electromagnet located inside the first electromagnet in the radial direction, the substrate support portion includes an edge ring arranged to surround the central axis, and the inner edge of the second electromagnet is located outside the outer edge of the edge ring in the radial direction.

3. The plasma processing apparatus of claim 2, wherein the electromagnet unit comprises a third electromagnet located inside the second electromagnet in the radial direction, and the plasma processing apparatus further comprises a control unit, the control unit being configured to control the electromagnet unit, the gas supply unit and the plasma generation unit to form the magnetic field in the chamber by supplying current to the electromagnet unit, and to generate the plasma from the processing gas supplied into the chamber while the magnetic field is formed, and wherein in the process of generating the plasma, the amount of electricity supplied to the first electromagnet is greater than the amount of electricity supplied to the third electromagnet.

4. A plasma processing apparatus according to any one of claims 1 to 3, wherein the plasma generating section comprises an upper electrode provided above the substrate supporting section.

5. A plasma processing apparatus according to claim 1, wherein an outer edge of the first electromagnet is positioned outside the inner wall surface of the side wall of the chamber in the radial direction.

6. A method for cleaning an inner wall surface of a sidewall of a chamber of a plasma processing apparatus, the plasma processing apparatus comprising: a substrate support part for supporting a substrate in the chamber; and an electromagnet unit arranged outside the chamber and configured to form a magnetic field within the chamber, the substrate support part having a central axis extending along the sidewall, the electromagnet unit comprising a first electromagnet located outermost in a radial direction perpendicular to the central axis, and an inner edge of the first electromagnet located outer than an outer edge of the substrate support part in the radial direction, the cleaning method comprising: forming a magnetic field within the chamber by supplying a current to the electromagnet unit; and cleaning the inner wall surface of the sidewall of the chamber with plasma generated from a processing gas supplied into the chamber while the magnetic field is formed.

7. A cleaning method as described in claim 6, wherein the electromagnet unit includes a second electromagnet located inside the first electromagnet in the radial direction, the substrate support portion includes an edge ring arranged to surround the central axis, and the inner edge of the second electromagnet is located outside the outer edge of the edge ring in the radial direction.

8. The cleaning method according to claim 7, wherein the electromagnet unit includes a third electromagnet located inside the second electromagnet in the radial direction, and in the cleaning step, the amount of electricity supplied to the first electromagnet is greater than the amount of electricity supplied to the third electromagnet.

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