Plasma processing apparatus and plasma processing method

Abstract

The plasma processing apparatus includes a chamber, a substrate supporting portion, a plasma generating portion, an electromagnet unit, and a power source. The substrate support portion is disposed within the chamber. The substrate support portion includes a first region and a second region surrounding the first region, the substrate can be placed on the first region, and the edge ring can be placed on the second region. The plasma generation unit is configured so as to be capable of generating plasma within the chamber. The electromagnet unit comprises at least one electromagnet. The electromagnet unit is configured so as to be able to form a localized magnetic field in an annular space on the edge ring. The power supply is electrically connected with at least one electromagnet of the electromagnet unit, so that the magnetic field intensity can be adjusted.

Description

Technical Field

[0001] Illustrative embodiments of the present invention relate to a plasma processing apparatus and a plasma processing method. Background Art

[0002] A plasma processing device is used to perform plasma processing on a substrate. The plasma processing device includes a chamber and a substrate support portion. The substrate support portion is disposed in the chamber. The substrate support portion supports the substrate. In addition, the substrate support portion supports an edge ring configured to surround the substrate. Patent document 1 below discloses such a plasma processing device.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2008-16727 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] The present invention provides a technology capable of adjusting the thickness of the plasma sheath above the edge ring.

[0008] Technical means for solving technical problems

[0009] In an exemplary embodiment, a plasma processing device is provided. The plasma processing device includes a chamber, a substrate support, a plasma generating unit, an electromagnet unit, and a power supply. The substrate support is disposed in the chamber. The substrate support includes a first region and a second region surrounding the first region, and a substrate can be placed on the first region, and an edge ring can be placed on the second region. The plasma generating unit is configured to generate plasma in the chamber. The electromagnet unit includes at least one electromagnet. The electromagnet unit is configured to form a magnetic field localized in an annular space on the edge ring (the electromagnet unit is configured to form a magnetic field locally present in an annular space on the edge ring). The power supply is electrically connected to at least one electromagnet of the electromagnet unit, and is configured to adjust the magnetic field strength.

[0010] Effects of the Invention

[0011] According to an exemplary embodiment, the thickness of the plasma sheath above the edge ring can be adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a diagram for explaining a configuration example of a plasma processing system.

[0013] Figure 2 It is a diagram for explaining a configuration example of a capacitive coupling type plasma processing apparatus.

[0014] Figure 3 FIG. 1 is a partially enlarged cross-sectional view of a substrate support portion including an electromagnet unit of a plasma processing apparatus according to an exemplary embodiment.

[0015] Figure 4 FIG. 1 is a partially enlarged cross-sectional view of a substrate support portion including an electromagnet unit of a plasma processing apparatus according to an exemplary embodiment.

[0016] Figure 5 FIG. 1 is a top view of an electromagnet unit of a plasma processing apparatus according to an exemplary embodiment.

[0017] Figure 6 It is a partially enlarged cross-sectional view of a substrate support portion including an electromagnet unit of a plasma processing apparatus according to another exemplary embodiment.

[0018] Figure 7 FIG. 1 is a partially enlarged cross-sectional view of a substrate support portion including an electromagnet unit of a plasma processing apparatus according to still another exemplary embodiment.

[0019] Figure 8 It is a top view of an electromagnet unit of a plasma processing apparatus according to still another exemplary embodiment.

[0020] Fig. 9 FIG. 1 is a partially enlarged cross-sectional view of a substrate support portion including an electromagnet unit of a plasma processing apparatus according to still another exemplary embodiment.

[0021] Fig.10 It is a top view of an electromagnet unit of a plasma processing apparatus according to still another exemplary embodiment.

[0022] Fig.11 is a flow chart of a plasma processing method according to an exemplary embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, various exemplary embodiments will be described in detail with reference to the accompanying drawings, wherein the same reference numerals are given to the same or corresponding parts in each of the drawings.

[0024] Figure 1: is a diagram for illustrating a structural example of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing device 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing device 1 is an example of a substrate processing device. The plasma processing device 1 includes a plasma processing chamber 10, a substrate support portion 11, and a plasma generating portion 12. The plasma processing chamber 10 has a plasma processing space. In addition, the plasma processing chamber 10 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 the gas supply portion 20 described later, and the gas exhaust port is connected to the exhaust system 40 described later. The substrate support portion 11 is arranged in the plasma processing space and has a substrate supporting surface for supporting a substrate.

[0025] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be a capacitively coupled plasma (CCP: Capacitively Coupled Plasma), an inductively coupled plasma (ICP: Inductively Coupled Plasma), an ECR plasma (Electron-Cyclotron-Resonance Plasma, an electron cyclotron resonance plasma), a helicon wave excited plasma (HWP: Helicon Wave Plasma), or a surface wave plasma (SWP: Surface Wave Plasma), etc. In addition, various types of plasma generating units including an AC (Alternating Current: Alternating Current) plasma generating unit and a DC (Direct Current: Direct Current) plasma generating unit may also be used. In one embodiment, the AC signal (AC power) used in the AC plasma generating unit has a frequency in the range of 100kHz to 10GHz. Therefore, the AC signal includes an RF (Radio Frequency: Radio Frequency) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 100kHz to 150MHz.

[0026] The control unit 2 processes computer executable commands that cause the plasma processing device 1 to perform the various steps described in the present invention. The control unit 2 can be configured to control the various elements of the plasma processing device 1 in a manner that enables the various steps described herein to be performed. In one embodiment, a part or all of the control unit 2 may also be included in the plasma processing device 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 can be implemented, for example, by a computer 2a. The processing unit 2a1 can be configured to perform various control actions by reading a program from the storage unit 2a2 and executing the read program. The program can be stored in the storage unit 2a2 in advance, or it can be obtained via a medium when necessary. The acquired program is stored in the storage unit 2a2, and is read and executed from the storage unit 2a2 by the processing unit 2a1. The medium can be various storage media readable by the computer 2a, or it can be a communication line connected to the communication interface 2a3. The processing unit 2a1 can be a CPU (Central Processing Unit). The storage unit 2a2 may include a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may also communicate with the plasma processing device 1 via a communication line such as a LAN (Local Area Network).

[0027] Next, a configuration example of a capacitive coupling type plasma processing apparatus as an example of the plasma processing apparatus 1 will be described. Figure 2 It is a diagram for explaining a configuration example of a capacitive coupling type plasma processing apparatus.

[0028] A capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. In addition, the plasma processing apparatus 1 includes a substrate support unit 11 and a gas inlet unit. The gas inlet unit is configured to be able to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet 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 portion of the ceiling of the plasma processing chamber 10. 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 is grounded. The shower head 13 and the substrate support unit 11 are electrically insulated from the shell of the plasma processing chamber 10.

[0029] The substrate support portion 11 includes a main body 111 and an edge ring 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the edge ring 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 arranged on the central region 111a of the main body 111, and the edge ring 112 is arranged on the annular region 111b of the main body 111 in a manner of surrounding the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also referred to as a substrate support surface for supporting the substrate W, and the annular region 111b is also referred to as a ring support surface for supporting the edge ring 112. The edge ring 112 is formed of a conductive material or an insulating material.

[0030] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive component. The conductive component of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is arranged on the base 1110. The electrostatic chuck 1111 includes a ceramic component 1111a and an electrostatic electrode 1111b arranged in the ceramic component 1111a. The ceramic component 1111a has a central area 111a. In one embodiment, the ceramic component 1111a also has an annular area 111b. Among them, other components surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck and an annular insulating component, may also have an annular area 111b. In this case, the edge ring 112 may be arranged on the annular electrostatic chuck or the annular insulating component, or on both the electrostatic chuck 1111 and the annular insulating component. In addition, at least one RF / DC electrode coupled to the RF power supply 31 and / or DC power supply 32 described later may also be arranged in the ceramic component 1111a. In this case, at least one RF / DC electrode acts (functions) as a lower electrode. In the case where the bias RF signal and / or DC signal described later is supplied to at least one RF / DC electrode, the RF / DC electrode is also referred to as a bias electrode. In addition, the conductive component of the base 1110 and at least one RF / DC electrode may also act as multiple lower electrodes. In addition, the electrostatic electrode 1111b may be used as a lower electrode. Therefore, the substrate support portion 11 includes at least one lower electrode.

[0031] In addition, the substrate support portion 11 may also include a temperature adjustment module, which is configured to adjust at least one of the electrostatic chuck 1111, the edge ring 112 and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid such as brine or gas flows in the flow path 1110a. In one embodiment, the flow path 1110a is formed in the base 1110, and one or more heaters are arranged in the ceramic part 1111a of the electrostatic chuck 1111. In addition, the substrate support portion 11 may also include a heat transfer gas supply portion, which is configured to supply a heat transfer gas to the gap between the back side of the substrate W and the central area 111a.

[0032] The shower head 13 is configured to be able to introduce at least one processing gas from the gas supply part 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 processing gas supplied to the gas supply port 13a is introduced into the plasma processing space 10s from the plurality of gas introduction ports 13c through the gas diffusion chamber 13b. In addition, the shower head 13 includes at least one upper electrode. Among them, in addition to the shower head 13, the gas introduction part may also include one or more side gas injection parts (SGI: Side Gas Injector) installed in one or more openings formed in the side wall 10a.

[0033] The gas supply unit 20 may also 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 processing gas from the respectively corresponding gas source 21 to the shower head 13 via the respectively corresponding flow controller 22. Each flow controller 22 may also include, for example, a mass flow controller or a pressure-controlled flow controller. In addition, the gas supply unit 20 may also include at least one flow modulation device for modulating or pulsing the flow of at least one processing gas.

[0034] 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. Thus, plasma can be 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 the plasma generating unit 12. In addition, by supplying a bias RF signal to at least one lower electrode, a bias potential can be generated on the substrate W, and ion components in the formed plasma can be introduced into the substrate W.

[0035] In one embodiment, the RF power supply 31 includes a first RF generator 31a and a second RF generator 31b. The first RF generator 31a is configured to couple with at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit 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 generator 31a may also be configured to generate a plurality of 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.

[0036] The second RF generating unit 31b is configured to be coupled to at least one lower electrode via at least one impedance matching circuit, and is capable of generating 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 generating source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the generating source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100kHz to 60MHz. In one embodiment, the second RF generating unit 31b may also be configured to generate a plurality of bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In addition, in various embodiments, at least one of the generating source RF signal and the bias RF signal may also be pulsed.

[0037] In addition, 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 generating unit 32a and a second DC generating unit 32b. In one embodiment, the first DC generating unit 32a is connected to at least one lower electrode and is capable of generating a first DC signal. The generated first DC signal is applied to at least one lower electrode. In one embodiment, the second DC generating unit 32b is connected to at least one upper electrode and is capable of generating a second DC signal. The generated second DC signal is applied to at least one upper electrode.

[0038] In various embodiments, the first DC signal and the second DC signal may also 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 pulse may have a pulse waveform of a rectangle, a trapezoid, a triangle, or a combination thereof. In one embodiment, a waveform generator for generating a sequence of voltage pulses from a DC signal is connected between the first DC generator 32a and at least one lower electrode. Therefore, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. In the case where 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 pulse may have a positive polarity or a negative polarity. In addition, the sequence of voltage pulses may also include one or more positive polarity voltage pulses and one or more negative polarity voltage pulses in one cycle. In addition, not only the RF power supply 31 but also the first and second DC generators 32a and 32b may be provided, and the first DC generator 32a may also be provided instead of the second RF generator 31b.

[0039] The exhaust system 40 can be connected to a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10, for example. The exhaust system 40 can also include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s can be adjusted by the pressure regulating valve. The vacuum pump can also include a turbomolecular pump, a dry pump, or a combination thereof.

[0040] The following, with Figure 2 Refer to Figure 3 to Figure 5 . Figure 3 and Figure 4 FIG. 1 is a partially enlarged cross-sectional view of a substrate support portion including an electromagnet unit of a plasma processing apparatus according to an exemplary embodiment. Figure 5 FIG. 1 is a top view of an electromagnet unit of a plasma processing apparatus according to an exemplary embodiment.

[0041] The substrate support portion 11 includes a first region 11R1 and a second region 11R2. The first region 11R1 is a region that supports the substrate W placed thereon. The upper surface of the first region 11R1 is the central region 111a described above. The first region 11R1 is circular in a plan view, and its central axis is the axis AX. The substrate W is placed on the first region 11R1 in such a manner that its center is located on the axis AX.

[0042] The second region 11R2 is a region supporting the edge ring 112 placed thereon. The second region 11R2 surrounds the first region 11R1. The second region 11R2 is annular in a plan view. The central axis of the second region 11R2 is the axis AX. The edge ring 112 is placed on the second region 11R2 in such a way that its central axis is located on the axis AX.

[0043] The plasma processing apparatus 1 further includes an electromagnet unit 50. The electromagnet unit 50 includes at least one electromagnet. The electromagnet unit 50 is configured to form a localized magnetic field in an annular space AS on the edge ring 112. The annular space AS is a space in the chamber 10.

[0044] The plasma processing apparatus 1 further includes a power supply 60. The power supply 60 is a power supply for supplying current to a coil described later of the electromagnet unit 50. The power supply 60 is configured to adjust the intensity of the magnetic field formed by the electromagnet unit 50 by adjusting the current supplied to the coil.

[0045] At least one electromagnet of the electromagnet unit 50 may be disposed in an annular setting area AR. The annular setting area AR is located in the second region 11R2 or in the edge ring 112 and extends around the axis AX. At least one electromagnet of the electromagnet unit 50 may also be disposed in the second region 11R2 and in the ceramic component 1111a of the electrostatic chuck 1111. Alternatively, at least one electromagnet of the electromagnet unit 50 may also be covered by the edge ring 112 on the second region 11R2.

[0046] exist Figure 3 to Figure 5 In the illustrated embodiment, the electromagnet unit 50 includes a single electromagnet 51. The electromagnet 51 is an annular electromagnet, including a coil 50c and a yoke 50y. The coil 50c is arranged in an annular setting area AR and is wound around the axis AX. The yoke 50y exposes the upper end of the coil 50c and surrounds the inner edge, outer edge and bottom of the coil 50c. The yoke 50y is formed of a magnetic material such as an iron material. The yoke 50y includes two cylindrical parts and a bottom. The bottom of the yoke 50y has a ring shape when viewed from above and extends around the axis AX. The two cylindrical parts of the yoke 50y extend coaxially with the axis AX as the center and extend upward from the bottom of the yoke 50y. The coil 50c is arranged on the bottom of the yoke 50y and between the two cylindrical parts of the yoke 50y.

[0047] In the plasma processing apparatus 1, the strength of the magnetic field in the annular space AS above the edge ring 112 can be adjusted. When the strength of the magnetic field in the annular space AS is high, the electron density in the annular space AS becomes high, and the thickness of the sheath (plasma sheath) becomes small. On the other hand, when the strength of the magnetic field in the annular space AS is low, the electron density in the annular space AS becomes low, and the thickness of the sheath becomes large. Therefore, according to the plasma processing apparatus 1, the thickness of the plasma sheath above the edge ring 112 can be adjusted. Therefore, according to the plasma processing apparatus 1, the incident angle of ions from the plasma relative to the edge of the substrate W can be adjusted.

[0048] In one embodiment, the control unit 2 may control the power supply 60 so that the smaller the thickness of the edge ring 112 is, the more the current flowing to the coil 50c is reduced to reduce the strength of the magnetic field. The control unit 2 may determine the thickness of the edge ring 112 based on the time the edge ring 112 is exposed to the plasma or a measured value reflecting the thickness of the edge ring 112. The measured value reflecting the thickness of the edge ring 112 may be obtained electrically or optically by a sensor. The control unit 2 may also use a pre-prepared data table or function to determine the current flowing to the coil 50c corresponding to the thickness of the edge ring 112. In this case, the smaller the thickness of the edge ring 112 is, the greater the thickness of the plasma sheath on the edge ring 112 is. Therefore, the incident angle of ions from the plasma relative to the edge of the substrate W can be corrected to a vertical angle according to the thickness of the edge ring 112.

[0049] Below, refer to Figure 6 . Figure 6 FIG. 1 is a partially enlarged cross-sectional view of a substrate support portion including an electromagnet unit of a plasma processing apparatus according to another exemplary embodiment. Figure 6The electromagnet unit 50A shown can be adopted in the plasma processing apparatus 1 instead of the electromagnet unit 50. The electromagnet unit 50A is also configured to form a magnetic field localized in the annular space AS similarly to the electromagnet unit 50.

[0050] The electromagnet unit 50A includes a single electromagnet 51A similarly to the electromagnet unit 50. The electromagnet 51A includes a yoke 50Ay having a shape different from that of the yoke 50y. The other structures of the electromagnet unit 50A are the same as the corresponding structures of the electromagnet unit 50.

[0051] like Figure 6 As shown, the yoke 50Ay exposes the outer edge of the coil 50c and surrounds the inner edge, upper end and bottom of the coil 50c. The yoke 50Ay includes a bottom, a cylindrical portion and an upper portion. The bottom and upper portion of the yoke 50Ay have a roughly ring shape when viewed from above and extend around the axis AX. The upper portion of the yoke 50Ay extends over the bottom of the yoke 50Ay. The cylindrical portion of the yoke 50Ay extends around the axis AX and extends between the inner edge of the bottom and the inner edge of the upper portion of the yoke 50Ay. The coil 50c is arranged in an area surrounded by the bottom, cylindrical portion and upper portion of the yoke 50Ay.

[0052] Below, refer to Figure 7 and Figure 8 . Figure 7 FIG. 1 is a partially enlarged cross-sectional view of a substrate support portion including an electromagnet unit of a plasma processing apparatus according to still another exemplary embodiment. Figure 8 It is a top view of an electromagnet unit of a plasma processing apparatus according to still another exemplary embodiment. Figure 7 and Figure 8 The electromagnet unit 50B shown can be adopted in the plasma processing apparatus 1 in place of the electromagnet unit 50. The electromagnet unit 50B is also configured to be able to form a magnetic field localized in the annular space AS, similarly to the electromagnet unit 50.

[0053] The electromagnet unit 50B includes a first electromagnet 51B and a second electromagnet 52B. The first electromagnet 51B and the second electromagnet 52B are arranged in an annular arrangement area AR. The first electromagnet 51B and the second electromagnet 52B are respectively annular electromagnets extending around the axis AX. The second electromagnet 52B is arranged outside the first electromagnet 51B (outside in the radial direction relative to the axis AX).

[0054] The first electromagnet 51B includes a coil 51c. The second electromagnet 52B includes a coil 52c. The coil 51c and the coil 52c are wound around the axis AX. The coil 52c is arranged outside the coil 51c so as to surround the coil 51c.

[0055] In one embodiment, the electromagnet unit 50B may further include a yoke 50By. The yoke 50By is formed of a magnetic material such as iron. The yoke 50By is provided so that the upper ends of the coils 51c and 52c are exposed and the inner edges, outer edges, and bottoms of the coils 51c and 52c are surrounded.

[0056] The yoke 50By may also include three cylindrical parts and a bottom. The bottom of the yoke 50By has a roughly ring shape when viewed from above, extending around the axis AX. The three cylindrical parts of the yoke 50By extend coaxially with the axis AX as the center, and extend upward from the bottom of the yoke 50By. The coil 51c is arranged on the bottom of the yoke 50By and between the two inner cylindrical parts of the three cylindrical parts of the yoke 50B. The coil 52c is arranged on the bottom of the yoke 50By and between the two outer cylindrical parts of the three cylindrical parts of the yoke 50B. According to the yoke 50By, the degree of localization of the magnetic field formed by the electromagnet unit 50B in the annular space AS can be further improved.

[0057] In the plasma processing apparatus 1 including the electromagnet unit 50B, the power supply 60 is configured to be able to adjust the strength of the magnetic field formed by the electromagnet unit 50B by adjusting the current supplied to the coil 51c and the coil 52c respectively. The direction of the current flowing through the coil 51c and the direction of the current flowing through the coil 52c may be the same direction or opposite directions. When the direction of the current flowing through the coil 51c and the direction of the current flowing through the coil 52c are opposite directions, the degree of localization of the magnetic field formed by the electromagnet unit 50A in the annular space AS can be further improved.

[0058] In one embodiment, the control unit 2 may also control the power supply 60 so that the smaller the thickness of the edge ring 112 is, the smaller the current flowing to the coil 51c and the coil 52c is, so as to reduce the strength of the magnetic field. The control unit 2 may also use a pre-prepared data table or function to determine the current flowing to the coil 51c and the coil 52c in accordance with the thickness of the edge ring 112. In this case, the incident angle of ions from the plasma with respect to the edge of the substrate W can be corrected to a vertical angle according to the thickness of the edge ring 112.

[0059] Below, refer to Fig. 9 and Fig.10 . Fig. 9 FIG. 1 is a partially enlarged cross-sectional view of a substrate support portion including an electromagnet unit of a plasma processing apparatus according to still another exemplary embodiment. Fig.10 It is a top view of an electromagnet unit of a plasma processing apparatus according to still another exemplary embodiment. Fig. 9 and Fig.10The electromagnet unit 50C shown can be adopted in the plasma processing apparatus 1 in place of the electromagnet unit 50. The electromagnet unit 50C is also configured to be able to form a magnetic field localized in the annular space AS, similarly to the electromagnet unit 50.

[0060] The electromagnet unit 50C includes a plurality of electromagnets 51C and a plurality of electromagnets 52C. The plurality of electromagnets 51C and the plurality of electromagnets 52C each include a coil. The coils of the plurality of electromagnets 51C and the plurality of electromagnets 52C are wound around an axis extending in a direction along the axis AX. The plurality of electromagnets 51C and the plurality of electromagnets 52C are arranged in an annular setting area AR. The plurality of electromagnets 51C and the plurality of electromagnets 52C are alternately arranged in a circumferential direction around the axis AX.

[0061] In the plasma processing apparatus 1 including the electromagnet unit 50C, the power supply 60 is configured to be able to adjust the intensity of the magnetic field formed by the electromagnet unit 50C by adjusting the current supplied to the coils of the plurality of electromagnets 51C and the plurality of electromagnets 52C.

[0062] In addition, the plurality of electromagnets 51C and the plurality of electromagnets 52C are configured so that N poles and S poles appear alternately in the circumferential direction within the annular arrangement area AR. When the coils of the plurality of electromagnets 51C and the coils of the plurality of electromagnets 52C are wound in the same direction, the direction of the current flowing in each of the plurality of electromagnets 51C and the direction of the current flowing in the coils of the plurality of electromagnets 52C may be opposite directions. Alternatively, the coils of the plurality of electromagnets 51C and the coils of the plurality of electromagnets 52C may be wound in opposite directions to each other.

[0063] In one embodiment, the control unit 2 may control the power supply 60 so that the smaller the thickness of the edge ring 112 is, the smaller the current flowing to the coils of the plurality of electromagnets 51C and the plurality of electromagnets 52C is, thereby reducing the strength of the magnetic field. The control unit 2 may also use a pre-prepared data table or function to determine the current flowing to the coils of the plurality of electromagnets 51C and the plurality of electromagnets 52C in accordance with the thickness of the edge ring 112. In this case, the incident angle of ions from the plasma with respect to the edge of the substrate W can be corrected to a vertical angle according to the thickness of the edge ring 112.

[0064] Below, refer to Fig.11 . Fig.11 is a flow chart of a plasma processing method according to an exemplary embodiment. Fig.11 The plasma processing method shown (hereinafter referred to as “method MT”) can be performed using the plasma processing apparatus 1. In each step of the method MT, each unit of the plasma processing apparatus 1 can be controlled by the control unit 2.

[0065] The method MT starts at step STp. In step STp, the substrate W is placed on the substrate support 11 in the chamber 10. In step STa, the thickness of the edge ring 112 is determined. For the determination of the thickness of the edge ring 112, please refer to the above description of the plasma processing apparatus 1.

[0066] Then, in step STb, plasma is generated from the gas in the chamber 10. In step STb, gas is supplied from the gas supply unit 20 into the chamber 10. In addition, the pressure in the chamber 10 is adjusted to a predetermined pressure by the exhaust system 40. In addition, plasma is generated from the gas in the chamber 10 by the plasma generation unit 12.

[0067] Step STc is performed when plasma is generated in step STb. In step STc, a magnetic field having a strength adjusted according to the thickness of the edge ring 112 is generated by the electromagnet unit (electromagnet unit 50, electromagnet unit 50A, electromagnet unit 50B or electromagnet unit 50C) of the plasma processing device 1. As described above, the magnetic field is localized in the annular space AS. As described above, the strength of the magnetic field is adjusted in such a way that the smaller the thickness of the edge ring 112, the lower the strength of the magnetic field.

[0068] Various exemplary embodiments have been described above, but the present invention is not limited to the exemplary embodiments described above, and various additions, omissions, substitutions, and changes may be made. In addition, elements of different exemplary embodiments may be appropriately combined to form other exemplary embodiments.

[0069] Hereinafter, first to fifteenth simulations performed to evaluate the plasma processing apparatus 1 will be described.

[0070] In the first simulation, the magnetic field formed by the electromagnet unit 50 was calculated. In the second simulation, the magnetic field was calculated when the yoke 50y was removed from the electromagnet 51 of the electromagnet unit 50. In the third simulation, the magnetic field formed by the electromagnet unit 50A was calculated. In the first to third simulations, the current flowing to the coil 50c was 1 (A).

[0071] In the 4th to 15th simulations, the magnetic field formed by the electromagnet unit 50B was calculated. In the 4th to 15th simulations, the total of the current flowing to the coil 51c and the current flowing to the coil 52c was set to 2 (A). In addition, in the 4th to 9th simulations, the direction of the current flowing to the coil 51c and the direction of the current flowing to the coil 52c were the same direction. In the 10th to 15th simulations, the direction of the current flowing to the coil 51c and the direction of the current flowing to the coil 52c were opposite directions. In the 4th to 6th simulations and the 10th to 12th simulations, the yoke 50By was removed from the electromagnet unit 50B. In the 7th to 9th simulations and the 13th to 15th simulations, the electromagnet unit 50B had the yoke 50By. In the 4th to 6th simulations, the ratio of the current flowing to the coil 51c and the current flowing to the coil 52c was set to 25:75, 50:50, and 75:25. In the 7th to 9th simulations, the ratio of the current flowing to the coil 51c to the current flowing to the coil 52c was set to 25:75, 50:50, and 75:25. In the 10th to 12th simulations, the ratio of the current flowing to the coil 51c to the current flowing to the coil 52c was set to 25:75, 50:50, and 75:25. In the 13th to 15th simulations, the ratio of the current flowing to the coil 51c to the current flowing to the coil 52c was set to 25:75, 50:50, and 75:25.

[0072] In the 1st to 14th simulations, B was calculated as an indicator of the localization of the magnetic field. ER / B W . B W B is the intensity (magnetic flux density) of the magnetic field on the substrate W at a distance of 150 mm from the axis AX. ER is the maximum value of the intensity (magnetic flux density) of the magnetic field on the edge ring 112 .

[0073] B in the first simulation ER / B W The value of B in the second simulation is 3.1. ER / B W The value of is 2.0. Therefore, it is confirmed that the electromagnet unit 50 can improve the degree of localization of the magnetic field by the yoke 50y. ER / B W The value of is 2.9. Therefore, it is confirmed that the electromagnet unit 50A can also improve the degree of localization of the magnetic field by the yoke 50Ay.

[0074] B in the 4th to 6th simulations ER / B W The values ​​of are 2.0, 2.4, and 2.2 respectively. ER / B WThe values ​​of are 3.3, 3.0, and 3.0, respectively. Therefore, it was confirmed that when the electromagnet unit 50B is used, even if the direction of the current flowing to the coil 51c is the same as the direction of the current flowing to the coil 52c, and even if the yoke 50By is removed, the magnetic field can be localized. In addition, it was confirmed that the degree of localization of the magnetic field can be further improved by using the yoke 50By.

[0075] B in the 10th to 12th simulations ER / B W The values ​​of are 3.1, 5.8, and 2.1 respectively. ER / B W The values ​​of are 4.9, 9.2, and 3.2, respectively. The results of the fourth to fifteenth simulations confirm that the degree of localization of the magnetic field can be further improved when the direction of the current flowing to the coil 51c and the direction of the current flowing to the coil 52c are opposite.

[0076] According to the above description, it should be understood that the various embodiments of the present invention are described in this specification for the purpose of illustration, and various changes can be made without departing from the scope and spirit of the present invention. Therefore, the various embodiments recorded in this specification are not intended to limit the present invention, and the true scope and spirit are represented by the claims.

[0077] Description of Reference Numerals

[0078] 1 ... plasma processing device; 2 ... control unit; 10 ... chamber; 12 ... plasma generating unit; 11 ... substrate supporting unit; 112 ... edge ring; 50 ... electromagnet unit; 60 ... power supply.

Claims

1. A plasma processing device, characterized in that: include: Chamber; a substrate support portion disposed in the chamber, the substrate support portion comprising a first area and a second area surrounding the first area, the substrate can be placed on the first area, and the edge ring can be placed on the second area; a plasma generating unit configured to generate plasma in the chamber; an electromagnet unit, comprising at least one electromagnet configured to form a localized magnetic field in an annular space on the edge ring; and A power supply is electrically connected to at least one electromagnet of the electromagnet unit and is configured to be able to adjust the intensity of the magnetic field.

2. The plasma processing device according to claim 1, wherein: The at least one electromagnet of the electromagnet unit is disposed in the second region or in the edge ring within an annular arrangement region extending around the central axis of the second region.

3. The plasma processing device according to claim 2, wherein: The electromagnet unit includes a single electromagnet as the at least one electromagnet, The single electromagnet comprises: A coil wound around the central axis in the annular arrangement area; and A yoke is provided to expose the upper end of the coil and surround the inner edge, the outer edge and the bottom of the coil.

4. The plasma processing apparatus according to claim 2, wherein: The electromagnet unit includes a single electromagnet as the at least one electromagnet, The single electromagnet comprises: A coil wound around the central axis in the annular arrangement area; and A yoke is provided to expose the outer edge of the coil and surround the inner edge, the upper end and the bottom of the coil.

5. The plasma processing apparatus according to claim 2, wherein: The electromagnet unit includes a first electromagnet and a second electromagnet as the at least one electromagnet, The first electromagnet and the second electromagnet each include a coil wound around the central axis in the annular arrangement area, The coil of the second electromagnet is arranged so as to surround the coil of the first electromagnet.

6. The plasma processing apparatus according to claim 5, wherein: The electromagnet unit further includes a yoke that exposes an upper end of each of the coils of the first electromagnet and the second electromagnet and surrounds an inner edge, an outer edge, and a bottom of each of the coils of the first electromagnet and the second electromagnet.

7. The plasma processing apparatus according to claim 2, wherein: The electromagnet unit includes a plurality of electromagnets as the at least one electromagnet, Each of the plurality of electromagnets comprises a coil wound around an axis thereof, the axis being along an extension direction of the central axis, The plurality of electromagnets are arranged in the annular arrangement region in a circumferential direction relative to the central axis, and are configured such that N poles and S poles appear alternately.

8. The plasma processing apparatus according to any one of claims 1 to 7, characterized in that: It also includes a control unit configured to control the power supply. The control unit is configured to be capable of controlling the power supply so that the intensity of the magnetic field is reduced as the thickness of the edge ring is reduced.

9. A plasma treatment method, characterized in that: include: The step of generating plasma in a chamber of a plasma processing device, the plasma processing device comprising: the chamber; a substrate support portion disposed in the chamber, the substrate support portion comprising a first area and a second area surrounding the first area, the substrate can be placed on the first area, and the edge ring can be placed on the second area; a plasma generating unit configured to generate plasma in the chamber; an electromagnet unit, comprising at least one electromagnet configured to form a localized magnetic field in an annular space on the edge ring; and a power source electrically connected to at least one electromagnet of the electromagnet unit and configured to be able to adjust the strength of the magnetic field; and the step of generating the magnetic field having a strength adjusted according to the thickness of the edge ring when generating the plasma, The intensity of the magnetic field is adjusted so that the intensity of the magnetic field decreases as the thickness of the edge ring decreases.

Images