Plasma processing apparatus and method of processing a substrate

Abstract

A plasma processing apparatus disclosed in the present invention has a chamber, a substrate support, a plasma generating section, and first and second electromagnet assemblies. The substrate support is disposed in the chamber. A center of a substrate on the substrate support is located on a central axis of the chamber. The plasma generating section is configured to generate plasma in the chamber. The first electromagnet assembly is configured to include one or more first annular coils, and is disposed on or above the chamber and configured to generate a first magnetic field in the chamber. The second electromagnet assembly is configured to include one or more second annular coils, and is configured to generate a second magnetic field in the chamber. The second magnetic field reduces a strength of the first magnetic field at the center of the substrate on the substrate support.

Description

Technical Field

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

[0002] In the manufacture of electronic devices, a substrate is subjected to plasma treatment. Plasma treatment requires radial uniformity of the substrate. To improve the uniformity of plasma treatment of the substrate in the radial direction, Japanese Patent Application Publication No. 2017-73518 (Patent Document 1) uses a plasma treatment device equipped with an electromagnet. Japanese Patent Application Publication No. 2017-73518 discloses a plasma treatment device equipped with an electromagnet. The electromagnet is disposed above a chamber. The electromagnet has a coil wound around the central axis of the chamber. The central axis of the electromagnet extends in a vertical direction. The substrate is placed on a substrate support with its center located on the central axis.

[0003] Plasma etching of a silicon film on a substrate is a known type of plasma treatment. The silicon film is etched using chemical species from a plasma generated from hydrogen bromide gas and / or chlorine gas. This type of plasma treatment is described in Japanese Patent Application Laid-Open No. 2003-218093. Summary of the Invention

[0004] The present invention provides a technique for suppressing a local increase in the processing speed of a plasma process performed in a plasma processing apparatus including an electromagnet having a coil wound around the central axis of a chamber at the center of a substrate.

[0005] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, a plasma generating unit, a first electromagnet assembly, and a second electromagnet assembly. The chamber has a central axis. The substrate support is disposed in the chamber. The center of the substrate on the substrate support is located on the central axis. The plasma generating unit is configured to generate plasma from a processing gas supplied into the chamber. The first electromagnet assembly is configured to include one or more first annular coils and is disposed on or above the chamber, and generates a first magnetic field in the chamber. The second electromagnet assembly is configured to include one or more second annular coils and generates a second magnetic field in the chamber. The second magnetic field reduces the intensity of the first magnetic field at the center of the substrate on the substrate support.

[0006] According to one exemplary embodiment, it is possible to suppress a processing speed of a plasma process performed in a plasma processing apparatus including an electromagnet having a coil wound around a central axis of a chamber from being locally increased in a central portion of a substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1FIG. 1 is a diagram schematically showing a plasma processing apparatus according to an exemplary embodiment.

[0008] Figure 2 It is a plan view showing an example of a plurality of first electromagnets.

[0009] Figure 3 It is a top view showing an example of the second electromagnet.

[0010] Figure 4 is a flow chart of a method of processing a substrate according to an exemplary embodiment.

[0011] Figure 5 This is a partially enlarged cross-sectional view of an example of a substrate. DETAILED DESCRIPTION

[0012] Various exemplary embodiments are described below.

[0013] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, a plasma generating unit, a first electromagnet assembly, and a second electromagnet assembly. The chamber has a central axis. The substrate support is disposed in the chamber. The center of the substrate on the substrate support is located on the central axis. The plasma generating unit is configured to generate plasma from a processing gas supplied into the chamber. The first electromagnet assembly is configured to include one or more first annular coils and is disposed on or above the chamber, and generates a first magnetic field in the chamber. The second electromagnet assembly is configured to include one or more second annular coils and generates a second magnetic field in the chamber. The second magnetic field reduces the intensity of the first magnetic field at the center of the substrate on the substrate support.

[0014] The density of negative ions in the plasma generated within the chamber tends to increase near or along the chamber's central axis. When this plasma is generated and a magnetic field is formed within the chamber by the first electromagnet assembly, the substrate processing speed increases locally at the center of the substrate. In a plasma processing apparatus according to one exemplary embodiment, the intensity of the magnetic field formed by the first electromagnet assembly is reduced by the magnetic field formed by the second electromagnet assembly at the location where a substrate placed on a substrate support intersects the chamber's central axis. This results in a reduction in the substrate processing speed from increasing locally at the center of the chamber.

[0015] In one exemplary embodiment, the second electromagnet assembly may be disposed below the substrate supporter.

[0016] In an exemplary embodiment, the second electromagnet assembly may be disposed on or above the chamber.

[0017] In an exemplary embodiment, the first electromagnet assembly may include a plurality of first annular coils as the at least one first annular coil.

[0018] In an exemplary embodiment, the second electromagnet assembly may include more than one second annular coil and may include a plurality of second annular coils.

[0019] In one exemplary embodiment, the second magnetic field may offset the strength of the first magnetic field at the center of the substrate on the substrate supporter.

[0020] In another exemplary embodiment, a method for processing a substrate within a chamber of a plasma processing apparatus is provided. The method includes a) placing a substrate on a substrate support within the chamber. The center of the substrate on the substrate support is located on the central axis of the chamber. The method also includes b) generating plasma from a processing gas supplied to the chamber. The method also includes c) during b) above, generating a first magnetic field within the chamber using a first electromagnet assembly disposed on or above the chamber. The first electromagnet assembly includes one or more first annular coils. The method also includes d) during c) above, generating a second magnetic field within the chamber using a second electromagnet assembly. The second electromagnet assembly includes one or more second annular coils, and the second magnetic field reduces the intensity of the first magnetic field at the center of the substrate on the substrate support.

[0021] In one exemplary embodiment, the process gas may include hydrogen bromide gas and / or chlorine gas.

[0022] In one exemplary embodiment, the above b) may include a process of etching the silicon film on the substrate.

[0023] Hereinafter, various exemplary embodiments will be described in detail with reference to the accompanying drawings. In addition, in each of the drawings, the same or corresponding parts are marked with the same symbols.

[0024] Figure 1 FIG. 1 is a diagram schematically showing a plasma processing apparatus according to an exemplary embodiment. Figure 1 The plasma processing apparatus 1 shown is a capacitively coupled plasma processing apparatus. The plasma processing apparatus 1 includes a chamber 10. The chamber 10 provides an internal space 10s therein. The internal space 10s can be decompressed by an exhaust device.

[0025] The chamber 10 includes a chamber body 12. The chamber 10 has a central axis Z (described later). The chamber body 12 is a generally cylindrical container. An internal space 10s is provided inside the chamber body 12. The chamber body 12 is formed from a conductive material, such as aluminum. The inner wall surface of the chamber body 12 is covered with a plasma-resistant film, such as an aluminum oxide film or an yttrium oxide film. The chamber body 12 is electrically grounded.

[0026] The plasma processing apparatus 1 further includes a substrate support 14. The substrate support 14 is disposed within the chamber 10. The substrate support frame 14 is configured to support a substrate W placed thereon. The substrate W may have a diameter of, for example, 300 mm. The substrate W is placed on the substrate support 14 such that its center is located on the central axis Z. The central axis Z is the central axis of the chamber 10 and the internal space 10s and extends in the vertical direction. Furthermore, the central axis of the substrate support 14 is substantially consistent with the central axis Z. That is, the center of the substrate W on the substrate support 14 is located on the central axis Z.

[0027] An edge ring 26 is mounted on the substrate support 14. The edge ring 26 is a generally annular plate. The edge ring 26 is formed of a material selected based on the plasma processing to be performed using the plasma processing apparatus 1. The edge ring 26 is formed, for example, of silicon, silicon carbide, or silicon oxide. The substrate W is positioned on the substrate support 14 within an area surrounded by the edge ring 26.

[0028] In one embodiment, the substrate support 14 includes a susceptor 14a and an electrostatic chuck 14b. The susceptor 14a is formed of a conductive material such as aluminum and has a substantially disk shape.

[0029] The electrostatic chuck 14b is mounted on the base 14a. The electrostatic chuck 14b includes a main body and electrodes. The main body of the electrostatic chuck 14b is substantially disc-shaped and formed of a dielectric. The electrodes of the electrostatic chuck 14b are film-shaped electrodes and are disposed within the main body of the electrostatic chuck 14b. A DC power supply is connected to the electrodes of the electrostatic chuck 14b via a switch. When a DC voltage from the DC power supply is applied to the electrodes of the electrostatic chuck 14b, an electrostatic attraction is generated between the electrostatic chuck 14b and the substrate W. This generated electrostatic attraction attracts the substrate W to the electrostatic chuck 14b and holds it.

[0030] The susceptor 14a constitutes the lower electrode. A first high-frequency power source 18 is electrically connected to the susceptor 14a via a first matching device 22. The first high-frequency power source 18 generates a first high-frequency power for generating plasma. The frequency of the first high-frequency power is, for example, 100 MHz, but is not limited thereto. The first matching device 22 includes a matching circuit for matching the output impedance of the first high-frequency power source 18 with the impedance of the load side (lower electrode side) of the first high-frequency power source 18. Alternatively, the first high-frequency power source 18 may be connected to the upper electrode 16 instead of the susceptor 14a via the first matching device 22.

[0031] A second high-frequency power source 20 is electrically connected to the susceptor 14a via a second matching unit 24. The second high-frequency power source 20 generates a second high-frequency power. The second high-frequency power has a frequency suitable for attracting ions to the substrate W. The frequency of the second high-frequency power is lower than that of the first high-frequency power. The frequency of the second high-frequency power is, for example, 3.2 MHz, but is not limited thereto. The second matching unit 24 includes a matching circuit for matching the output impedance of the second high-frequency power source 20 with the impedance of the load side (lower electrode side).

[0032] The plasma processing apparatus 1 further includes an upper electrode 16. The upper electrode 16 is disposed above the substrate support 14. The upper electrode 16 closes the upper opening of the chamber body 12. The upper electrode 16 also functions as a showerhead. In one embodiment, the upper electrode 16 includes a buffer chamber 16a, a gas line 16b, and a plurality of gas holes 16c. The buffer chamber 16a is connected to the plurality of gas holes 16c. These gas holes 16c extend downward and open into the internal space 10s.

[0033] One end of a gas pipeline 16b is connected to the buffer chamber 16a. A gas source group 40 is connected to the gas pipeline 16b via a flow controller group 42 and a valve group 44. The gas source group 40, the flow controller group 42, and the valve group 44 constitute a gas supply unit. The gas source group 40 includes a plurality of gas sources. The flow controller group 42 includes a plurality of flow controllers. The plurality of flow controllers are mass flow controllers or pressure-controlled flow controllers. The valve group 44 includes a plurality of valves (e.g., on-off valves). The plurality of gas sources of the gas source group 40 are connected to the gas pipeline 16b via corresponding flow controllers of the flow controller group 42 and corresponding valves of the valve group 44.

[0034] When the plasma processing apparatus 1 is in operation, the processing gas is supplied from the gas supply unit to the chamber 10. Furthermore, the pressure of the space within the chamber 10 is reduced by the exhaust device. Furthermore, since plasma is generated by the processing gas in the internal space 10s, the first high-frequency power and / or the second high-frequency power are supplied. In one embodiment, the first high-frequency power is supplied from the first high-frequency power source via the first matching device to the upper electrode or the lower electrode, and the second high-frequency power is supplied from the second high-frequency power source via the second matching device to the lower electrode. Therefore, the first and / or second high-frequency power sources can function as at least a part of a plasma generating unit configured to generate plasma from the processing gas supplied into the chamber. Furthermore, the film of the substrate W is processed by chemical species from the plasma. The processing of the film of the substrate, i.e., plasma processing, is, for example, plasma etching.

[0035] The plasma processing apparatus 1 includes a first electromagnet assembly 3 including one or more first electromagnets 30. The first electromagnet assembly 3 is configured to generate a first magnetic field in the chamber 10. In one embodiment, the plasma processing apparatus 1 includes a first electromagnet assembly 3 including a plurality of first electromagnets 30. Figure 1 In the illustrated embodiment, the plurality of first electromagnets 30 include electromagnets 31 to 34 . Figure 2 1 is a top view showing an example of a plurality of first electromagnets. Figure 2 , the plurality of first electromagnets 30 are shown as viewed from the inner space 10s side. The plurality of first electromagnets 30 are provided on or above the chamber 10. That is, the first electromagnet assembly 3 is arranged on or above the chamber 10. Figure 1 In the illustrated example, a plurality of first electromagnets 30 are provided on the upper electrode 16 .

[0036] The one or more first electromagnets 30 each include a first coil. Figure 1 and Figure 2 In the example shown, the electromagnets 31 to 34 include coils 61 to 64 as first coils, respectively. Coils 61 to 64 are wound around the central axis Z. That is, the first electromagnet assembly 3 includes first annular coils 61 to 64. Coils 61 to 64 are coaxially arranged at the same height.

[0037] The first electromagnet assembly 3 also includes a coil bobbin 50 (or yoke). The coils 61 to 64 are wound around the coil bobbin 50 (or yoke). The coil bobbin 50 is formed of, for example, a magnetic material. The coil bobbin 50 has a columnar portion 51, a plurality of cylindrical portions 52 to 55 and a base 56. The base 56 has a roughly disc shape, and its central axis is consistent with the central axis Z. The columnar portion 51 and the plurality of cylindrical portions 52 to 55 extend downward from the lower surface of the base 56. The columnar portion 51 has a roughly cylindrical shape, and its central axis is roughly consistent with the central axis Z. The radius L1 of the columnar portion 51 is, for example, 30 mm. The cylindrical portions 52 to 55 extend radially outside the columnar portion 51 relative to the central axis Z.

[0038] Each of the cylindrical portions 52-55 has a cylindrical shape extending in the vertical direction. The central axes of the cylindrical portions 52-55 are substantially aligned with the central axis Z. In other words, the cylindrical portions 52-55 are arranged coaxially. The radius L2 of the cylindrical portion 52, the radius L3 of the cylindrical portion 53, the radius L4 of the cylindrical portion 54, and the radius L5 of the cylindrical portion 55 are greater than the radius L1, and have the relationship L2 < L3 < L4 < L5. For example, the radius L2, radius L3, radius L4, and radius L5 are 76 mm, 127 mm, 178 mm, and 229 mm, respectively. Furthermore, the radius L2 is the distance between the radial midpoint between the inner and outer circumferences of the cylindrical portion 52 and the central axis Z. The radius L3 is the distance between the radial midpoint between the inner and outer circumferences of the cylindrical portion 53 and the central axis Z. The radius L4 is the distance between the radial midpoint between the inner and outer circumferences of the cylindrical portion 54 and the central axis Z. The radius L5 is the distance between the center axis Z and a radially intermediate position between the inner and outer peripheral surfaces of the cylindrical portion 55 .

[0039] Coil 61 is wound around the outer circumference of columnar portion 51 and is housed in the slot between columnar portion 51 and cylindrical portion 52. Coil 62 is wound around the outer circumference of cylindrical portion 52 and is housed in the slot between cylindrical portion 52 and cylindrical portion 53. Coil 63 is wound around the outer circumference of cylindrical portion 53 and is housed in the slot between cylindrical portion 53 and cylindrical portion 54. Coil 64 is wound around the outer circumference of cylindrical portion 54 and is housed in the slot between cylindrical portion 54 and cylindrical portion 55.

[0040] A current source 70 is connected to the first coil of one or more first electromagnets 30. The control unit Cnt controls the supply and stop of current from the current source 70 to each of the first coils of the one or more first electromagnets 30, as well as the direction and value of the current. Furthermore, when the plasma processing apparatus 1 includes a plurality of first electromagnets 30, each of the first coils of the plurality of first electromagnets 30 may be connected to a single current source or to independent, different current sources.

[0041] The one or more first electromagnets 30 form a magnetic field within the chamber 10 that is axially symmetric about the central axis Z. By controlling the current supplied to each of the one or more first electromagnets 30, the intensity distribution (or magnetic flux density) of the magnetic field can be adjusted in the radial direction relative to the central axis Z. Thus, the plasma processing apparatus 1 can adjust the radial distribution of the density of the plasma generated within the chamber 10, thereby adjusting the distribution of the processing speed (e.g., etching rate) of the film on the substrate W in the radial direction.

[0042] The plasma processing apparatus 1 further includes a second electromagnet assembly 8 including one or more second electromagnets 80. The second electromagnet assembly 8 is configured to generate a second magnetic field in the chamber 10. The second magnetic field reduces the intensity of the first magnetic field at the center of the substrate W on the substrate support 14. Figure 1 In the illustrated example, the number of the second electromagnet 80 is 1. Hereinafter, an embodiment in which the plasma processing apparatus 1 includes one second electromagnet 80 will be described, but the number of the second electromagnet 80 included in the plasma processing apparatus 1 may be plural.

[0043] Figure 3 : is a top view showing an example of the second electromagnet. Figure 3 , the second electromagnet 80 is shown as viewed from the inner space 10s side. In one embodiment, the second electromagnet 80 is provided below the substrate support 14. That is, the second electromagnet assembly 8 is disposed below the chamber 10.

[0044] The second electromagnet 80 includes a coil 81 as a second coil. The coil 81 is wound around the central axis Z. That is, the second electromagnet assembly 8 includes the second annular coil 81. When the plasma processing apparatus 1 includes a plurality of second electromagnets 80, the second coils of the plurality of second electromagnets 80 can be coaxially arranged around the central axis Z at the same height.

[0045] The second electromagnet assembly 8 also includes a coil bobbin 90 (or yoke). The coil 81 is wound around the coil bobbin 90 (or yoke). The coil bobbin 90 is formed of, for example, a magnetic material. The coil bobbin 90 has a plurality of cylindrical portions 91 to 92 and a base 93. The base 93 has a roughly disc shape, and its central axis is consistent with the central axis Z. A plurality of cylindrical portions 91 to 92 extend upward from the upper surface of the base 93. The cylindrical portions 91 to 92 are coaxially arranged around the central axis Z. The coil 81 is wound along the outer circumferential surface of the cylindrical portion 91 and is accommodated in the groove between the cylindrical portion 91 and the cylindrical portion 92.

[0046] The second coil is connected to a current source 100. The control unit Cnt controls the supply and stop of current from the current source 100 to the second coil, as well as the direction and value of the current. Furthermore, when the plasma processing apparatus 1 includes a plurality of second electromagnets 80, each second coil of the plurality of second electromagnets 80 may be connected to a single current source or to independent, different current sources.

[0047] The second electromagnet 80 generates a magnetic field that reduces the intensity of the magnetic field formed by the one or more first electromagnets 30 at the location where the substrate W placed on the substrate support 14 intersects the central axis Z, that is, at the center of the substrate W. The current supplied to the second electromagnet 80 is controlled to generate this magnetic field. In one embodiment, the second electromagnet 80 generates a magnetic field that sets the intensity of the magnetic field formed by the one or more first electromagnets 30 to zero at this location.

[0048] In one embodiment, the plasma processing apparatus 1 may further include the above-mentioned control unit Cnt. The control unit Cnt is a computer device including a processor, a storage unit such as a memory, an input device, a display device, a signal input / output interface, and the like. The control unit Cnt controls the various components of the plasma processing apparatus 1. In the control unit Cnt, an operator can use an input device to input commands and perform other operations in order to manage the plasma processing apparatus 1. Furthermore, in the control unit Cnt, the operating status of the plasma processing apparatus 1 can be visually displayed through a display device. In addition, a control program and recipe data are stored in the storage unit. In order for the plasma processing apparatus 1 to perform various processes, the control program is executed by the processor. The processor executes the control program and controls the various components of the plasma processing apparatus 1 according to the recipe data.

[0049] The density of negative ions in the plasma generated within the chamber 10 tends to increase on or near the chamber's central axis Z. When a magnetic field is formed within the chamber 10 by one or more first electromagnets 30 while this plasma is generated, the processing speed (e.g., etching rate) of the substrate W increases locally at the center of the substrate W. In the plasma processing apparatus 1, the intensity of the magnetic field generated by the one or more first electromagnets 30 is reduced by the magnetic field generated by the second electromagnet 80 at the location where the substrate W placed on the substrate support 14 intersects the central axis Z. As a result, the processing speed of the substrate W is prevented from increasing locally at the center of the substrate W.

[0050] In one embodiment, the plasma processing apparatus 1 may include a first electromagnet assembly 3 comprising a plurality of first electromagnets 30. In this embodiment, the radial distribution of plasma density is adjusted by the resultant magnetic field formed within the chamber 10 by the plurality of first electromagnets 30. Therefore, when the plasma processing apparatus 1 includes the first electromagnet assembly 3 comprising a plurality of first electromagnets 30, the radial distribution of plasma density can be more easily controlled.

[0051] In one embodiment, the plasma processing apparatus 1 may include a second electromagnet assembly 8 including a plurality of second electromagnets 80. In this embodiment, a composite magnetic field is formed in the chamber 10 by the plurality of second electromagnets 80. Therefore, the intensity distribution of the magnetic field in the chamber 10 can be more easily controlled.

[0052] Below, reference Figure 4 , a method for processing a substrate according to an exemplary embodiment is described. Figure 4 FIG. 1 is a flow chart of a method for processing a substrate according to an exemplary embodiment. Figure 4 The method shown (hereinafter referred to as "Method MT") is described. The plasma processing apparatus used in executing Method MT includes: a first electromagnet assembly 3 including one or more first electromagnets described above; and a second electromagnet assembly 8 including one or more second electromagnets. Method MT will be described below using an example using the plasma processing apparatus 1.

[0053] Method MT is performed with the substrate W placed on the substrate support 14 . The substrate W is placed on the substrate support 14 so that its center is located on the central axis Z. Figure 5 This is a partially enlarged cross-sectional view of an example of a substrate. Figure 5 The illustrated substrate W includes a film EF. Film EF is the film that is subjected to plasma treatment in method MT. In one example, film EF is a silicon film. Film EF may also be formed of other materials. Substrate W may further include a base region UR and a mask MSK. Film EF is disposed on base region UR. Mask MSK is disposed on film EF. Mask MSK is patterned. In one embodiment, by applying method MT to substrate W, the pattern of mask MSK is transferred to film EF.

[0054] In method MT, step ST1 is performed with the substrate W placed on the substrate support 14. In step ST1, plasma is generated from the processing gas in the chamber 10. In step ST1, the processing gas is supplied to the chamber 10. The processing gas used in step ST1 includes one or more gases selected for plasma processing of the substrate W. In one example, in order to perform plasma etching of the film EF which is a silicon film, the processing gas can include hydrogen bromide gas and / or chlorine gas. In step ST1, the pressure in the chamber 10 is set to a specified pressure. Furthermore, in step ST1, the first high-frequency power and / or the second high-frequency power are supplied to excite the processing gas and generate plasma from the processing gas.

[0055] To execute step ST1, the control unit Cnt controls the gas supply unit to supply a processing gas into the chamber 10. To execute step ST1, the control unit Cnt controls the exhaust device to set the pressure in the chamber 10 to a specified pressure. Furthermore, to execute step ST1, the control unit Cnt controls the first high-frequency power source 18 and / or the second high-frequency power source 20 to supply the first high-frequency power and / or the second high-frequency power.

[0056] In addition to step ST1 , method MT includes steps ST2 and ST3 . Steps ST2 and ST3 are performed during step ST1 . That is, steps ST2 and ST3 are performed when plasma is generated from the processing gas in chamber 10 .

[0057] In step ST2, a magnetic field is formed in the chamber 10 using the first electromagnet assembly 3 including one or more first electromagnets 30. The current supplied from the current source 70 to each of the one or more first electromagnets 30 is controlled by the control unit Cnt.

[0058] In step ST3, a magnetic field is formed within the chamber 10 using the second electromagnet assembly 8, which includes one or more second electromagnets 80. The current supplied from the current source 100 to each of the one or more second electromagnets 80 is controlled by the controller Cnt. In step ST3, the one or more second electromagnets 80 form a magnetic field that reduces the intensity of the magnetic field formed by the one or more first electromagnets 30 at the location where the substrate W placed on the substrate support 14 intersects the central axis Z, i.e., at the center of the substrate W. In one embodiment, the one or more second electromagnets 80 form a magnetic field that sets the intensity of the magnetic field formed by the one or more first electromagnets 30 to zero at the location where the substrate W placed on the substrate support 14 intersects the central axis Z.

[0059] In method MT, while a magnetic field is formed in chamber 10 by one or more first electromagnets and one or more second electromagnets, substrate W is processed by chemical species from plasma in chamber 10. In one example of method MT, film EF, which is a silicon film on substrate W, is etched by ions from plasma formed from a processing gas including hydrogen bromide gas and / or chlorine gas.

[0060] In method MT, the intensity of the magnetic field formed by the one or more first electromagnets 30 at the location where the substrate W intersects the central axis Z is reduced by the magnetic field formed by the second electromagnet 80. Therefore, according to method MT, it is possible to suppress the processing speed of the substrate W from being locally increased at the center of the substrate W. In the example of etching a film EF, which is a silicon film, using ions from a plasma formed by a process gas containing hydrogen bromide gas and / or chlorine gas, it is possible to suppress the etching rate of the film EF from being locally increased at the center of the substrate W.

[0061] 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 can be made. Furthermore, elements of different embodiments can be combined to form other embodiments.

[0062] For example, a second electromagnet assembly 8 comprising one or more second electromagnets can be disposed on or above the chamber 10. In one embodiment, one or more of the electromagnets 31-34 can function as the first electromagnet, and one or more other electromagnets of the electromagnets 31-34 can function as the second electromagnet. Specifically, a first group comprising one or more of the annular coils 61-64 can be included in the first electromagnet assembly 3, and a second group comprising one or more other of the annular coils 61-64 can be included in the second electromagnet assembly 8. In this case, the second electromagnet assembly 8 is positioned at the same height as the first electromagnet assembly 3. Even in this case, the current supplied to the first coil of each first electromagnet and the second coil of each second electromagnet is controlled so that the magnetic field formed by the one or more second electromagnets at the aforementioned locations reduces the intensity of the magnetic field formed by the one or more first electromagnets. For example, a current is supplied to the coil of each second electromagnet in a direction opposite to the direction of the current supplied to each first electromagnet. In one embodiment, the second electromagnet assembly 8 can be arranged on or above the chamber 10 at a different height from the first electromagnet assembly 3. For example, the second electromagnet assembly 8 can be arranged on or above the first electromagnet assembly 3, or between the chamber 10 and the first electromagnet assembly 3.

[0063] As can be seen from the above description, the various embodiments of the present invention are described in this specification for illustrative purposes and various modifications may be made without departing from the scope and spirit of the present invention. Therefore, the various embodiments disclosed in this specification are not intended to be limiting, and the true scope and spirit are shown by the scope of the attached technical solutions.

Claims

1. A plasma processing apparatus comprising: a chamber having a central axis; a substrate supporter disposed in the chamber, wherein the center of the substrate on the substrate supporter is located on the central axis; a plasma generating unit configured to generate plasma from a processing gas supplied into the chamber; a first electromagnet assembly disposed on or above the chamber, comprising a first annular coil, a second annular coil surrounding the first annular coil, a third annular coil surrounding the second annular coil, and a fourth annular coil surrounding the third annular coil; at least one first power supply configured to supply a first current, a second current, a third current, and a fourth current to the first, second, third, and fourth annular coils, respectively, to generate a first magnetic field in the chamber; a second electromagnet assembly disposed below the substrate support, comprising a fifth annular coil that overlaps with the first annular coil in the longitudinal direction and is not accompanied by any annular coil that overlaps with the third annular coil and the fourth annular coil in the longitudinal direction; and The second power supply is configured to supply a fifth current to the fifth annular coil to generate a second magnetic field at the center of the substrate on the substrate supporter that reduces the intensity of the first magnetic field.

2. The plasma processing apparatus according to claim 1, wherein The second power supply is configured to supply the fifth current to the fifth annular coil in a direction opposite to the directions of the first current, the second current, the third current, and the fourth current supplied to the first annular coil, the second annular coil, the third annular coil, and the fourth annular coil, respectively.

3. The plasma processing apparatus according to claim 1 or 2, wherein: The second power supply is configured to supply the fifth current to the fifth annular coil so as to suppress a processing speed of the substrate on the substrate support from being locally increased at a central portion of the substrate.

4. A method for processing a substrate in a chamber of a plasma processing apparatus, wherein: The plasma processing device comprises: a chamber having a central axis; a substrate supporter disposed in the chamber, wherein the center of the substrate on the substrate supporter is located on the central axis; a first electromagnet assembly disposed on or above the chamber, comprising a first annular coil, a second annular coil surrounding the first annular coil, a third annular coil surrounding the second annular coil, and a fourth annular coil surrounding the third annular coil; and a second electromagnet assembly disposed below the substrate support, comprising a fifth annular coil that overlaps with the first annular coil in the longitudinal direction and is not accompanied by any annular coil that overlaps with the third annular coil and the fourth annular coil in the longitudinal direction; The method comprises: a) placing a substrate on the substrate support; b) generating plasma from a processing gas supplied into the chamber; c) during step b), supplying a first current, a second current, a third current, and a fourth current to the first, second, third, and fourth annular coils, respectively, to generate a first magnetic field in the chamber; d) During step c), a fifth current is supplied to the fifth annular coil to form a second magnetic field in the chamber, wherein the second magnetic field reduces the intensity of the first magnetic field at the center of the substrate on the substrate support.

5. The method according to claim 4, wherein In d), the fifth current is supplied in a direction opposite to the directions of the first current, the second current, the third current, and the fourth current supplied to the first, second, third, and fourth annular coils, respectively.

6. The method according to claim 4 or 5, wherein: In the above d), the fifth current is supplied to suppress a local increase in the processing speed of the substrate on the substrate supporter at the center portion of the substrate.

7. The method according to claim 4 or 5, wherein: The process gas includes hydrogen bromide and / or chlorine.

8. The method according to claim 7, wherein: The step b) includes etching the silicon film on the substrate.

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