Plasma processing device and substrate supporter

Abstract

To provide a technology of supplying bias power efficiently to an object mounted on a substrate supporter.SOLUTION: A plasma processing device disclosed includes a chamber, a substrate supporter disposed in the chamber and including a first part having a substrate supporting surface and a second part disposed so as to surround the first part and having a ring supporting surface, in which a gap exists between the first part and the second part, the first part including a substrate bias electrode, and the second part including a ring bias electrode, an edge ring disposed on the ring supporting surface so as to surround the substrate on the substrate supporting surface, a first voltage pulse generator that is electrically connected to the substrate bias electrode and configured to generate a first pulsed voltage, and a second voltage pulse generator that is electrically connected to the ring bias electrode and configured to generate a second pulsed voltage.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate to a substrate support and a plasma processing apparatus.

Background Art

[0002] A plasma processing apparatus is used in the processing of a substrate. The plasma processing apparatus includes a chamber and a substrate support. The substrate support has a base and an electrostatic chuck, and is provided in the chamber. The electrostatic chuck is provided on the base. The electrostatic chuck holds the substrate placed thereon. Bias power is supplied from a high-frequency power source to the base in order to draw ions from the plasma generated in the chamber to the substrate.

[0003] An edge ring is mounted on the substrate support. The substrate is disposed on the electrostatic chuck and within a region surrounded by the edge ring. The substrate support may be configured to hold the edge ring by electrostatic attraction. Substrate supports configured to hold an edge ring by electrostatic attraction are described in Patent Documents 1 to 3 below.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure provides a technique for efficiently supplying bias power to an object mounted on a substrate support.

Means for Solving the Problems

[0006] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber and a substrate support disposed within the chamber. The substrate support includes a first portion having a substrate support surface and a second portion disposed so as to surround the first portion and having a ring support surface. A gap exists between the first portion and the second portion. The first portion includes a substrate bias electrode, and the second portion includes a ring bias electrode. The plasma processing apparatus further includes an edge ring disposed on the ring support surface so as to surround a substrate on the substrate support surface, a first voltage pulse generator electrically connected to the substrate bias electrode and configured to generate a first pulsed voltage, and a second voltage pulse generator electrically connected to the ring bias electrode and configured to generate a second pulsed voltage.

Advantages of the Invention

[0007] According to one exemplary embodiment, it is possible to efficiently supply bias power to an object mounted on a substrate support.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, various exemplary embodiments will be described.

[0010] In one exemplary embodiment, a substrate support is provided. The substrate support includes a dielectric part and at least one electrode. The at least one electrode is provided in the dielectric part to supply bias power to an object placed on the dielectric part. In the substrate support according to this embodiment, the electrode to which the bias power is supplied is provided in the dielectric part on which the object is placed. Therefore, the bias power can be efficiently supplied to the object placed on the substrate support.

[0011] In one exemplary embodiment, the substrate support may include a first electrostatic chuck region and a second electrostatic chuck region. The first electrostatic chuck region is configured to hold a substrate placed thereon. The second electrostatic chuck region is provided to surround the first electrostatic chuck region and is configured to hold an edge ring placed thereon. The second electrostatic chuck region has one or more electrodes provided therein to generate an electrostatic attraction force between the second electrostatic chuck region and the edge ring and to supply bias power to the edge ring through the second electrostatic chuck region. In this embodiment, the one or more electrodes include at least one of the above electrodes.

[0012] In the above embodiment, the one or more electrodes may include a common electrode to which a voltage is applied to generate an electrostatic attraction force between the second electrostatic chuck region and the edge ring and to which bias power is supplied. Alternatively, in the above embodiment, the one or more electrodes may include an electrode to which a voltage is applied to generate an electrostatic attraction force between the second electrostatic chuck region and the edge ring and an electrode to which bias power is supplied. Since such one or more electrodes are provided within the second electrostatic chuck region, it is possible to supply bias power to the edge ring through the second electrostatic chuck region while holding the edge ring in the second electrostatic chuck region. Therefore, the substrate support provides a structure capable of independently and stably supplying bias power to the edge ring.

[0013] In one exemplary embodiment, the at least one electrode may be a common electrode to which a voltage is applied to generate an electrostatic attraction force and to which bias power is supplied. In this embodiment, bias power is supplied to the electrode to which a voltage is applied to generate an electrostatic attraction force. Therefore, a dedicated electrode to which bias power is supplied can be omitted from the second electrostatic chuck region. Thus, the structure of the second electrostatic chuck region can be a simple structure. As a result, the substrate support can be created at low cost and easily.

[0014] In one exemplary embodiment, one or more electrodes may include a first electrode to which a voltage is applied to generate an electrostatic attraction, and a second electrode to which a bias power is supplied. In this embodiment, the second electrode is the at least one electrode described above.

[0015] In one exemplary embodiment, the second electrostatic chuck region may be a bipolar electrostatic chuck. That is, one or more electrodes may include a pair of electrodes constituting a bipolar electrode. In another exemplary embodiment, the second electrostatic chuck region may be a unipolar electrostatic chuck.

[0016] In one exemplary embodiment, the second electrostatic chuck region may further have at least a part of the dielectric portion. One or more electrodes are provided in at least a part of the dielectric portion.

[0017] In one exemplary embodiment, the first electrostatic chuck region and the second electrostatic chuck region may share the dielectric portion. The first electrostatic chuck region may have a chuck electrode. The chuck electrode is an electrode to which a voltage for attracting a substrate to the first electrostatic chuck region is applied, and is provided in the dielectric portion.

[0018] In one exemplary embodiment, the first electrostatic chuck region may have a first dielectric portion and a chuck electrode. The chuck electrode is an electrode to which a voltage for attracting a substrate to the first electrostatic chuck region is applied, and is provided in the first dielectric portion. The second dielectric portion, which is the dielectric portion of the second electrostatic chuck region, may be separated from the first dielectric portion.

[0019] In one exemplary embodiment, the substrate support may further include a heater provided in the dielectric portion of the second electrostatic chuck region.

[0020] In one exemplary embodiment, the substrate support may further include a gas line for supplying a heat transfer gas between the second electrostatic chuck region and the edge ring.

[0021] In one exemplary embodiment, the first electrostatic chuck region may further include another electrode. The other electrode is an electrode to which a bias power is supplied and is provided within the first electrostatic chuck region. According to this embodiment, it becomes possible to independently control the bias power supplied to the substrate via the first electrostatic chuck region and the bias power supplied to the edge ring via the second electrostatic chuck region.

[0022] In one exemplary embodiment, the substrate support may further include a base. The base has conductivity. Bias power may be supplied to the base. The first electrostatic chuck region and the second electrostatic chuck region may be provided on the base.

[0023] In various other exemplary embodiments, a plasma processing apparatus is provided.

[0024] A plasma processing apparatus according to one exemplary embodiment includes a chamber and a substrate support. The substrate support is any of the substrate supports of the various exemplary embodiments described above. The substrate support is provided within the chamber.

[0025] In one exemplary embodiment, the plasma processing apparatus is any of the substrate supports having the first electrostatic chuck region and the second electrostatic chuck region among the substrate supports of the various exemplary embodiments described above. The plasma processing apparatus further includes a DC power source and a bias power source. The DC power source is configured to generate a voltage for generating an electrostatic attraction between the second electrostatic chuck region and the edge ring. The bias power source is configured to generate a bias power supplied to the edge ring via the second electrostatic chuck region.

[0026] In a plasma processing apparatus according to one exemplary embodiment, the substrate support is a substrate support having the other electrode provided in the first electrostatic chuck region. In this embodiment, the plasma processing apparatus may further include another bias power supply configured to generate bias power supplied to the other electrode.

[0027] In a plasma processing apparatus according to one exemplary embodiment, the substrate support is a substrate support having the base. In this embodiment, the plasma processing apparatus may further include another bias power supply configured to generate bias power supplied to the base.

[0028] In one exemplary embodiment, a plasma processing apparatus includes a chamber, a substrate support, a DC power supply, a common electrical path, a first electrical path, a second electrical path, and an impedance circuit. The substrate support is a substrate support having the other electrode provided in the first electrostatic chuck region. The substrate support is provided in the chamber. The DC power supply is configured to generate a voltage for generating an electrostatic attraction between the second electrostatic chuck region and the edge ring. The bias power supply is configured to generate bias power. The common electrical path is connected to the bias power supply. The first electrical path and the second electrical path branch from the common electrical path. The first electrical path is an electrical path for bias power supplied to the other electrode. The second electrical path is an electrical path for bias power supplied to the edge ring through the second electrostatic chuck region. The impedance circuit is provided on at least one of the first electrical path and the second electrical path. In this embodiment, the bias power supplied to the edge ring through the second electrostatic chuck region and the bias power supplied to the other electrode are generated by distributing the bias power generated by the bias power supply to the first electrical path and the second electrical path.

[0029] In one exemplary embodiment, the plasma processing apparatus includes a chamber, a substrate support, a DC power supply, a common electrical path, a first electrical path, a second electrical path, and an impedance circuit. The substrate support is a substrate support having the base. The substrate support is provided in the chamber. The DC power supply is configured to generate a voltage for generating an electrostatic attraction between the second electrostatic chuck region and the edge ring. The bias power supply is configured to generate bias power. The common electrical path is connected to the bias power supply. The first electrical path and the second electrical path branch from the common electrical path. The first electrical path is an electrical path for bias power supplied to the base. The second electrical path is an electrical path for bias power supplied to the edge ring via the second electrostatic chuck region. The impedance circuit is provided on at least one of the first electrical path and the second electrical path. In this embodiment, the bias power supplied to the edge ring via the second electrostatic chuck region and the bias power supplied to the base are generated by distributing the bias power generated by the bias power supply to the first electrical path and the second electrical path.

[0030] Hereinafter, various exemplary embodiments will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts will be denoted by the same reference numerals.

[0031] FIG. 1 is a diagram schematically showing a plasma processing apparatus according to one exemplary embodiment. The plasma processing apparatus 1 shown in FIG. 1 includes a chamber 10. FIG. 2 is a diagram showing in detail the configuration inside the chamber of the plasma processing apparatus according to one exemplary embodiment. As shown in FIG. 2, the plasma processing apparatus 1 can be a capacitively coupled plasma processing apparatus.

[0032] Chamber 10 provides an internal space 10s therein. The central axis of the internal space 10s is an axis AX extending in the vertical direction. In one embodiment, chamber 10 includes a chamber body 12. The chamber body 12 has a substantially cylindrical shape. The internal space 10s is provided within the chamber body 12. The chamber body 12 is made of, for example, aluminum. The chamber body 12 is electrically grounded. A plasma-resistant film is formed on the inner wall surface of the chamber body 12, that is, the wall surface defining the internal space 10s. This film can be a ceramic film such as a film formed by anodization or a film formed from yttrium oxide.

[0033] A passage 12p is formed in the side wall of the chamber body 12. Substrate W passes through the passage 12p when being transported between the internal space 10s and the outside of chamber 10. A gate valve 12g is provided along the side wall of the chamber body 12 for opening and closing this passage 12p.

[0034] The plasma processing apparatus 1 further includes a substrate support 16 according to one exemplary embodiment. The substrate support 16 is configured to support the substrate W placed thereon within the chamber 10. The substrate W has a substantially disc shape. The substrate support 16 is supported by a support portion 17. The support portion 17 extends upward from the bottom of the chamber body 12. The support portion 17 has a substantially cylindrical shape. The support portion 17 is formed of an insulating material such as quartz.

[0035] The substrate support 16 has a base 18 and an electrostatic chuck 20. The base 18 and the electrostatic chuck 20 are provided within the chamber 10. The base 18 is formed of a conductive material such as aluminum and has a substantially disc shape.

[0036] A flow path 18f is formed inside the base 18. The flow path 18f is a flow path for a heat exchange medium. As the heat exchange medium, for example, a liquid refrigerant is used. A supply device (for example, a chiller unit) for the heat exchange medium is connected to the flow path 18f. This supply device is provided outside the chamber 10. The heat exchange medium is supplied to the flow path 18f via a pipe 23a from the supply device. The heat exchange medium supplied to the flow path 18f is returned to the supply device via a pipe 23b.

[0037] The electrostatic chuck 20 is provided on the base 18. When the substrate W is processed in the internal space 10s, it is placed on the electrostatic chuck 20 and held by the electrostatic chuck 20. Also, an edge ring ER is mounted on the substrate support 16. The edge ring ER is a plate having a substantially annular shape. The edge ring ER has conductivity. The edge ring ER is formed of, for example, silicon or silicon carbide. The edge ring ER is mounted on the substrate support 16 such that its central axis coincides with the axis AX. The substrate W accommodated in the chamber 10 is disposed on the electrostatic chuck 20 and within a region surrounded by the edge ring ER.

[0038] The plasma processing apparatus 1 may further include a gas supply line 25. The gas supply line 25 supplies a heat transfer gas, such as He gas, from a gas supply mechanism, to the gap between the upper surface of the electrostatic chuck 20 (a first electrostatic chuck region described later) and the back surface (lower surface) of the substrate W.

[0039] The plasma processing apparatus 1 may further include an outer peripheral portion 28 and an outer peripheral portion 29. The outer peripheral portion 28 extends upward from the bottom of the chamber body 12. The outer peripheral portion 28 has a substantially cylindrical shape and extends along the outer periphery of the support portion 17. The outer peripheral portion 28 is formed of a conductive material and has a substantially cylindrical shape. The outer peripheral portion 28 is electrically grounded. A plasma-resistant film is formed on the surface of the outer peripheral portion 28. This film may be a ceramic film such as a film formed by anodization or a film formed of yttrium oxide.

[0040] The outer peripheral portion 29 is provided on the outer peripheral portion 28. The outer peripheral portion 29 is formed of a material having insulation. The outer peripheral portion 29 is formed of a ceramic such as quartz, for example. The outer peripheral portion 29 has a substantially cylindrical shape. The outer peripheral portion 29 extends along the outer peripheries of the base 18 and the electrostatic chuck 20.

[0041] The plasma processing apparatus 1 further includes an upper electrode 30. The upper electrode 30 is provided above the substrate support 16. The upper electrode 30 closes the upper opening of the chamber body 12 together with the member 32. The member 32 has insulation. The upper electrode 30 is supported above the chamber body 12 via this member 32.

[0042] The upper electrode 30 includes a top plate 34 and a support 36. The lower surface of the top plate 34 defines the internal space 10s. A plurality of gas discharge holes 34a are formed in the top plate 34. Each of the plurality of gas discharge holes 34a penetrates the top plate 34 in the plate thickness direction (vertical direction). This top plate 34 is formed of, for example, silicon, although not limited thereto. Alternatively, the top plate 34 may have a structure in which a plasma-resistant film is provided on the surface of an aluminum member. This film may be a ceramic film such as a film formed by anodization or a film formed of yttrium oxide.

[0043] The support 36 detachably supports the top plate 34. The support 36 is formed of a conductive material such as aluminum, for example. A gas diffusion chamber 36a is provided inside the support 36. A plurality of gas holes 36b extend downward from the gas diffusion chamber 36a. The plurality of gas holes 36b communicate with the plurality of gas discharge holes 34a respectively. A gas introduction port 36c is formed in the support 36. The gas introduction port 36c is connected to the gas diffusion chamber 36a. A gas supply pipe 38 is connected to the gas introduction port 36c.

[0044] A gas source group 40 is connected to a gas supply pipe 38 via a valve group 41, a flow controller group 42, and a valve group 43. The gas source group 40, the valve group 41, the flow controller group 42, and the valve group 43 constitute a gas supply unit. The gas source group 40 includes a plurality of gas sources. Each of the valve group 41 and the valve group 43 includes a plurality of valves (e.g., on-off valves). The flow controller group 42 includes a plurality of flow controllers. Each of the plurality of flow controllers in the flow controller group 42 is a mass flow controller or a pressure-controlled flow controller. Each of the plurality of gas sources in the gas source group 40 is connected to the gas supply pipe 38 via a corresponding valve in the valve group 41, a corresponding flow controller in the flow controller group 42, and a corresponding valve in the valve group 43. The plasma processing apparatus 1 can supply gas from one or more selected gas sources in the gas source group 40 to the internal space 10s at individually adjusted flow rates.

[0045] A baffle plate 48 is provided between the outer peripheral portion 28 and the side wall of the chamber body 12. The baffle plate 48 can be formed, for example, by coating a member made of aluminum with a ceramic such as yttrium oxide. A large number of through holes are formed in the baffle plate 48. Below the baffle plate 48, an exhaust pipe 52 is connected to the bottom of the chamber body 12. An exhaust device 50 is connected to this exhaust pipe 52. The exhaust device 50 has a pressure controller such as an automatic pressure control valve and a vacuum pump such as a turbo molecular pump, and can reduce the pressure in the internal space 10s.

[0046] Hereinafter, the substrate supporter 16 will be described in detail. As described above, the substrate supporter 16 has a base 18 and an electrostatic chuck 20. As shown in FIG. 1, a high-frequency power supply 61 is connected to the base 18 via a matcher 62. The high-frequency power supply 61 is a power supply that generates high-frequency power for plasma generation. The high-frequency power generated by the high-frequency power supply 61 has a frequency in the range of 27 to 100 MHz, for example, a frequency of 40 MHz or 60 MHz. The matcher 62 has a matching circuit for matching the output impedance of the high-frequency power supply 61 and the impedance on the load side (the base 18 side). Note that the high-frequency power supply 61 may not be electrically connected to the base 18 and may be connected to the upper electrode 30 via the matcher 62.

[0047] In the plasma processing apparatus 1, when high-frequency power from the high-frequency power supply 61 is supplied, the gas in the chamber 10 is excited, and plasma is generated from the gas. The substrate W is processed by chemical species such as ions and / or radicals from the generated plasma.

[0048] The electrostatic chuck 20 has a first electrostatic chuck region 21 and a second electrostatic chuck region 22. The first electrostatic chuck region 21 and the second electrostatic chuck region 22 are provided on the base 18. In the substrate supporter 16 of the plasma processing apparatus 1, the first electrostatic chuck region 21 and the second electrostatic chuck region 22 are continuous with each other and integrated. In FIG. 1, the boundary between the first electrostatic chuck region 21 and the second electrostatic chuck region 22 is indicated by a dashed line.

[0049] The first electrostatic chuck region 21 is configured to hold the substrate W placed thereon (i.e., above its upper surface). The first electrostatic chuck region 21 is a region having a disk shape. The central axis of the first electrostatic chuck region 21 substantially coincides with the axis AX. The first electrostatic chuck region 21 shares the dielectric part 20d with the second electrostatic chuck region 22. The dielectric part 20d is formed of a dielectric such as aluminum nitride or aluminum oxide. The dielectric part 20d has a substantially disk shape. In one embodiment, the thickness of the dielectric part 20d in the second electrostatic chuck region 22 is smaller than the thickness of the dielectric part 20d in the first electrostatic chuck region 21. The position of the upper surface of the dielectric part 20d in the second electrostatic chuck region 22 in the vertical direction may be lower than the position of the upper surface of the dielectric part 20d in the first electrostatic chuck region 21 in the vertical direction.

[0050] The first electrostatic chuck region 21 has an electrode 21a (chuck electrode). The electrode 21a is a film-like electrode and is provided in the dielectric part 20d in the first electrostatic chuck region 21. A DC power supply 55 is connected to the electrode 21a via a switch 56. When a DC voltage from the DC power supply 55 is applied to the electrode 21a, an electrostatic attraction force is generated between the first electrostatic chuck region 21 and the substrate W. Due to the generated electrostatic attraction force, the substrate W is attracted to the first electrostatic chuck region 21 and held by the first electrostatic chuck region 21.

[0051] The first electrostatic chuck region 21 may further have an electrode 21c. The electrode 21c is a film-like electrode and is provided in the dielectric part 20d in the first electrostatic chuck region 21. Note that the electrode 21a may extend closer to the upper surface of the first electrostatic chuck region 21 than the electrode 21c in the vertical direction. A bias power supply 63 is connected to the electrode 21c via a matcher 64 and a filter 65. Note that the bias power supply 63 may be electrically connected to the base 18 via the matcher 64 and the filter 65. In this case, the first electrostatic chuck region 21 may not have the electrode 21c.

[0052] The bias power supply 63 generates a bias power for attracting ions from the plasma generated in the chamber 10 to the substrate W. The bias power generated by the bias power supply 63 may have periodicity. In one embodiment, the bias power generated by the bias power supply 63 is high-frequency power. In this case, the bias power generated by the bias power supply 63 has a frequency lower than the frequency of the high-frequency power generated by the high-frequency power supply 61. The frequency of the bias power generated by the bias power supply 63 is a frequency within the range of 400 kHz to 13.56 MHz, for example, 400 kHz.

[0053] The matcher 64 is connected between the bias power supply 63 and the electrode 21c. The matcher 64 is configured to match the output impedance of the bias power supply 63 and the impedance on the load side (electrode 21c side). The filter 65 is connected between the matcher 64 and the electrode 21c. The filter 65 is an electrical filter that blocks or reduces the high-frequency power generated by the high-frequency power supply 61. The filter 65 prevents the high-frequency power generated by the high-frequency power supply 61 from flowing into the bias power supply 63 or reduces the high-frequency power flowing into the bias power supply 63.

[0054] In another embodiment, the bias power generated by the bias power supply 63 may be pulsed high-frequency power that is periodically generated. That is, the supply and supply stop of the high-frequency power from the bias power supply 63 to the electrode 21c may be alternately switched. In still another embodiment, the bias power supply 63 may be configured to periodically apply a pulsed negative-polarity DC voltage to the electrode 21c as the bias power. In this case, the bias power supply 63 may periodically generate a pulsed negative-polarity DC voltage at a period defined by a frequency such as 400 kHz. The level of the pulsed negative-polarity DC voltage may change within the period during which the pulsed negative-polarity DC voltage is applied to the electrode 21c.

[0055] The first electrostatic chuck region 21 may further include a heater 21h. The heater 21h is provided in the dielectric part 20d in the first electrostatic chuck region 21. Note that the electrodes 21a and 21c may extend closer to the upper surface of the first electrostatic chuck region 21 than the heater 21h in the vertical direction. The heater 21h may be a resistance heating element. A heater controller 68 is connected to the heater 21h. The heater controller 68 supplies power to the heater 21h. The heater controller 68 is configured to control the level of power supplied to the heater 21h. Note that the first electrostatic chuck region 21 may have a plurality of heaters.

[0056] The first electrostatic chuck region 21 may further include a part of the gas supply line 25. As described above, the gas supply line 25 is a gas line provided to supply a heat transfer gas, for example, He gas, to the gap between the first electrostatic chuck region 21 and the back surface of the substrate W. The gas supply line 25 is connected to a gas supply mechanism that is a source of the heat transfer gas.

[0057] The second electrostatic chuck region 22 is provided so as to surround the first electrostatic chuck region 21. The second electrostatic chuck region 22 is a substantially annular region. The central axis of the second electrostatic chuck region 22 substantially coincides with the axis AX. The second electrostatic chuck region 22 is configured to hold an edge ring ER placed thereon (i.e., above its upper surface). The second electrostatic chuck region 22 shares the dielectric part 20d with the first electrostatic chuck region 21.

[0058] The second electrostatic chuck region 22 has one or more electrodes. The one or more electrodes are provided in the second electrostatic chuck region 22 to generate an electrostatic attraction between the edge ring ER and the second electrostatic chuck region 22 and to supply bias power to the edge ring ER through the second electrostatic chuck region 22. The one or more electrodes are provided in the dielectric part 20d in the second electrostatic chuck region 22.

[0059] In one embodiment, the second electrostatic chuck region 22 includes a first electrode and a second electrode. The first electrode is an electrode to which a voltage is applied to generate an electrostatic attraction force. The second electrode is an electrode to which a bias power is supplied.

[0060] In one embodiment, the second electrostatic chuck region 22 constitutes a bipolar electrostatic chuck. That is, the second electrostatic chuck region 22 includes a pair of electrodes that constitute a bipolar electrode. Specifically, in the substrate support 16 of the plasma processing apparatus 1, the second electrostatic chuck region 22 has electrodes 22a and 22b as a pair of first electrodes that constitute a bipolar electrode. Each of the electrodes 22a and 22b is a film-like electrode. The electrodes 22a and 22b may extend at substantially the same height position in the vertical direction.

[0061] A DC power supply 71 is connected to the electrode 22a via a switch 72 and a filter 73. The filter 73 is an electrical filter that blocks or reduces high-frequency power and bias power. The filter 73 prevents high-frequency power and bias power from flowing into the DC power supply 71, or reduces the high-frequency power and bias power flowing into the DC power supply 71.

[0062] A DC power supply 74 is connected to the electrode 22b via a switch 75 and a filter 76. The filter 76 is an electrical filter that blocks or reduces high-frequency power and bias power. The filter 76 prevents high-frequency power and bias power from flowing into the DC power supply 74, or reduces the high-frequency power and bias power flowing into the DC power supply 74.

[0063] The DC power supplies 71 and 74 apply DC voltages to the electrodes 22a and 22b, respectively, so that a potential difference is generated between the electrodes 22a and 22b. Note that the set potential of each of the electrodes 22a and 22b may be any of a positive potential, a negative potential, and 0V. For example, the potential of the electrode 22a may be set to a positive potential and the potential of the electrode 22b may be set to a negative potential. Also, the potential difference between the electrodes 22a and 22b may be formed using a single DC power supply instead of two DC power supplies.

[0064] When a potential difference is generated between the electrodes 22a and 22b, an electrostatic attraction force is generated between the second electrostatic chuck region 22 and the edge ring ER. The edge ring ER is attracted to the second electrostatic chuck region 22 by the generated electrostatic attraction force and is held by the second electrostatic chuck region 22.

[0065] The second electrostatic chuck region 22 further has an electrode 22c as a second electrode. The electrode 22c is a film-like electrode and is provided in the dielectric part 20d in the second electrostatic chuck region 22. Note that the electrodes 22a and 22b may extend closer to the upper surface of the second electrostatic chuck region 22 than the electrode 22c in the vertical direction. A bias power supply 81 is connected to the electrode 22c via a matcher 82 and a filter 83.

[0066] The bias power supply 81 is a power supply that generates bias power. The bias power generated by the bias power supply 81 can be high-frequency power having the same frequency as the high-frequency power that is the bias power generated by the bias power supply 63. Alternatively, the bias power supply 81 may periodically generate a pulsed negative-polarity DC voltage as the bias power, similar to the bias power supply 63. The matcher 82 is configured to match the output impedance of the bias power supply 81 and the impedance on the load side (electrode 22c side). The filter 83 is connected between the matcher 82 and the electrode 22c. The filter 83 is an electrical filter that blocks or reduces the high-frequency power generated by the high-frequency power supply 61. The filter 83 prevents the high-frequency power generated by the high-frequency power supply 61 from flowing into the bias power supply 81, or reduces the high-frequency power flowing into the bias power supply 81.

[0067] The second electrostatic chuck region 22 may further include a heater 22h. The heater 22h is provided in the dielectric portion 20d in the second electrostatic chuck region 22. Note that the electrodes 22a, 22b, and 22c may extend closer to the upper surface of the second electrostatic chuck region 22 than the heater 22h in the vertical direction. The heater 22h can be a resistance heating element. A heater controller 85 is connected to the heater 22h. The heater controller 85 supplies power to the heater 22h. The heater controller 85 is configured to control the level of power supplied to the heater 22h. Note that the second electrostatic chuck region 22 may have a plurality of heaters. Also, power may be supplied to the heater 21h and the heater 22h from the same and single heater controller.

[0068] The second electrostatic chuck region 22 may further include a gas line 22g. The gas line 22g is a gas line provided to supply a heat transfer gas, such as He gas, between the second electrostatic chuck region 22 and the edge ring ER. The gas line 22g is connected to a gas supply mechanism 86 that is a source of the heat transfer gas.

[0069] In one embodiment, as shown in FIG. 2, the plasma processing apparatus 1 may further include a control unit MC. The control unit MC is a computer including a processor, a storage device, an input device, a display device, etc., and controls each part of the plasma processing apparatus 1. Specifically, the control unit MC executes a control program stored in the storage device, and controls each part of the plasma processing apparatus 1 based on recipe data stored in the storage device. By the control of the control unit MC, the process specified by the recipe data is executed in the plasma processing apparatus 1.

[0070] In the substrate support 16 of the plasma processing apparatus 1, the electrodes 22a, 22b, and 22c are provided in the second electrostatic chuck region 22. Therefore, it is possible to supply bias power to the edge ring ER through the second electrostatic chuck region 22 while holding the edge ring ER in the second electrostatic chuck region 22. Therefore, the substrate support 16 of the plasma processing apparatus 1 provides a structure capable of independently and stably supplying bias power to the edge ring ER.

[0071] Also, in the substrate support 16 of the plasma processing apparatus 1, the first electrostatic chuck region 21 has the electrode 21c, and the second electrostatic chuck region 22 has the electrode 22c. Bias power is supplied to the electrodes 21c and 22c individually. Therefore, it is possible to independently control the bias power supplied to the substrate W through the first electrostatic chuck region 21 and the bias power supplied to the edge ring ER through the second electrostatic chuck region 22.

[0072] Hereinafter, refer to FIG. 3. FIG. 3 is a diagram schematically showing a plasma processing apparatus according to another exemplary embodiment. Hereinafter, the plasma processing apparatus 1B shown in FIG. 3 will be described from the viewpoint of the differences between the plasma processing apparatus 1 and the plasma processing apparatus 1B.

[0073] In the plasma processing apparatus 1B, the electrodes to which voltage is applied to generate electrostatic attraction between the second electrostatic chuck region 22 and the edge ring ER and the electrodes to which bias power is supplied are common electrodes. Specifically, in the plasma processing apparatus 1B, the bias power supply 81 is connected to both the electrode 22a and the electrode 22b via the matcher 82 and the filter 83. In the plasma processing apparatus 1B, the bias power from the bias power supply 81 is distributed to the electrode 22a and the electrode 22b.

[0074] The bias power supply 81 may be connected to the electrode 22a via the blocking capacitor 87. Also, the bias power supply 81 may be connected to the electrode 22b via the blocking capacitor 88. The blocking capacitor 87 and the blocking capacitor 88 prevent a direct current from flowing into the bias power supply 81 or reduce the direct current flowing into the bias power supply 81.

[0075] In the substrate support 16 of the plasma processing apparatus 1B, bias power is supplied to the electrodes 22a and 22b to which voltage is applied to generate electrostatic attraction. Therefore, a dedicated electrode 22c to which bias power is supplied can be omitted from the second electrostatic chuck region 22. Thus, the structure of the second electrostatic chuck region 22 can be a simple structure. As a result, the substrate support 16 of the plasma processing apparatus 1B can be manufactured at low cost and easily.

[0076] Also, in the substrate support 16 of the plasma processing apparatus 1B, the distance between each of the electrodes 22a and 22b to which bias power is supplied and the edge ring ER can be shortened. Therefore, the capacitance between each of the electrodes 22a and 22b and the edge ring ER increases. Thus, the bias power supplied to the electrodes 22a and 22b and coupled to the edge ring ER increases. On the other hand, the bias power supplied to the electrodes 22a and 22b and supplied to the substrate W decreases. Therefore, the independent controllability of the bias power supplied to the edge ring ER is enhanced.

[0077] Refer to FIG. 4 below. FIG. 4 is a diagram schematically showing a plasma processing apparatus according to yet another exemplary embodiment. Hereinafter, the plasma processing apparatus 1C shown in FIG. 4 will be described from the viewpoint of the differences between the plasma processing apparatus 1B and the plasma processing apparatus 1C.

[0078] In the plasma processing apparatus 1C, the bias power supply 63 is connected to the base 18 via the matcher 64. In the plasma processing apparatus 1C, the bias power from the bias power supply 63 and the bias power from the bias power supply 81 are supplied to the edge ring ER via the second electrostatic chuck region 22. Therefore, it is possible to reduce the bias power supplied from the bias power supply 81.

[0079] Refer to FIG. 5 below. FIG. 5 is a diagram schematically showing a plasma processing apparatus according to yet another exemplary embodiment. Hereinafter, the plasma processing apparatus 1D shown in FIG. 5 will be described from the viewpoint of the differences between the plasma processing apparatus 1C and the plasma processing apparatus 1D.

[0080] The plasma processing apparatus 1D further includes a high-frequency power supply 91. The high-frequency power supply 91 is connected to the electrode 22a via the matcher 92, the filter 83, and the blocking capacitor 87. Also, the high-frequency power supply 91 is connected to the electrode 22b via the matcher 92, the filter 83, and the blocking capacitor 88. The high-frequency power supply 91 generates high-frequency power having the same frequency as the frequency of the high-frequency power generated by the high-frequency power supply 61. In the plasma processing apparatus 1D, the high-frequency power from the high-frequency power supply 91 is coupled to the plasma via the second electrostatic chuck region 22 and the edge ring ER. As a result, it becomes possible to independently control the density of the plasma in the region above the edge ring with respect to the density of the plasma in the region above the substrate W.

[0081] Note that in the plasma processing apparatus 1D, when the second electrostatic chuck region 22 has the electrode 22c, the high-frequency power supply 91 and the bias power supply 81 may be connected to the electrode 22c.

[0082] Refer to FIG. 6 below. FIG. 6 is a diagram schematically showing a plasma processing apparatus according to yet another exemplary embodiment. Hereinafter, the plasma processing apparatus 1E shown in FIG. 6 will be described from the viewpoint of the differences between the plasma processing apparatus 1C and the plasma processing apparatus 1E.

[0083] The plasma processing apparatus 1E includes a common electrical path 100, a first electrical path 101, and a second electrical path 102. The common electrical path 100 is connected to a high-frequency power source 61 and a bias power source 63. The first electrical path 101 and the second electrical path 102 are branched from the common electrical path 100. The first electrical path 101 is connected to the base 18. The second electrical path 102 is connected to the electrode 22a via a blocking capacitor 87. Also, the second electrical path 102 is connected to the electrode 22b via a blocking capacitor 88. In the plasma processing apparatus 1E, the high-frequency power from the high-frequency power source 61 and the bias power from the bias power source 63 are distributed to the base 18, the electrode 22a, and the electrode 22b. Therefore, the plasma processing apparatus 1E does not include a bias power source 81, a matcher 82, and a filter 83.

[0084] An impedance circuit 103 is provided on the second electrical path 102. The impedance circuit 103 may have a variable impedance element. As the variable impedance element, a variable capacitance capacitor is exemplified. By adjusting the impedance of the impedance circuit 103, the ratio of the bias power supplied from the bias power source 63 to the electrode 22a and the electrode 22b with respect to the bias power supplied from the bias power source 63 to the base 18 can be adjusted. Also, by adjusting the impedance of the impedance circuit 103, the ratio of the high-frequency power supplied from the high-frequency power source 61 to the electrode 22a and the electrode 22b with respect to the high-frequency power supplied from the high-frequency power source 61 to the base 18 can be adjusted. In such a plasma processing apparatus 1E, the number of bias power sources can be reduced compared to the plasma processing apparatus 1C. Therefore, the plasma processing apparatus 1E can be provided at a relatively low cost.

[0085] Note that an impedance circuit similar to the impedance circuit 103 may be provided on the first electrical path 101. When an impedance circuit is provided on the first electrical path 101, the impedance circuit 103 may or may not be provided on the second electrical path 102.

[0086] In addition, in the plasma processing apparatus 1E, when the second electrostatic chuck region 22 has the electrode 22c, the high-frequency power supply 61 and the bias power supply 63 may be connected to the electrode 22c via the second electrical path 102.

[0087] Hereinafter, refer to FIG. 7. FIG. 7 is a diagram schematically showing a plasma processing apparatus according to still another exemplary embodiment. Hereinafter, the plasma processing apparatus 1F shown in FIG. 7 will be described from the viewpoint of the differences between the plasma processing apparatus 1D and the plasma processing apparatus 1F.

[0088] In the substrate support 16 of the plasma processing apparatus 1F, the first electrostatic chuck region 21 has the first dielectric part 21d, and the second electrostatic chuck region 22 has the second dielectric part 22d. Each of the first dielectric part 21d and the second dielectric part 22d is formed of a dielectric such as aluminum nitride or aluminum oxide.

[0089] The first dielectric part 21d has a substantially disk shape. The central axis of the first dielectric part 21d substantially coincides with the axis AX. An electrode 21a and a heater 21h are provided in the first dielectric part 21d.

[0090] The second dielectric part 22d extends so as to surround the first dielectric part 21d. The second dielectric part 22d is a substantially annular plate. The central axis of the second dielectric part 22d substantially coincides with the axis AX. An electrode 22a, an electrode 22b, and a heater 22h are provided in the second dielectric part 22d. In one embodiment, the thickness of the second dielectric part 22d is smaller than the thickness of the first dielectric part 21d. The position of the upper surface of the second dielectric part 22d in the vertical direction may be lower than the position of the upper surface of the first dielectric part 21d in the vertical direction.

[0091] In the substrate support 16 of the plasma processing apparatus 1F, the first dielectric part 21d and the second dielectric part 22d are separated from each other. That is, there is a gap between the first dielectric part 21d and the second dielectric part 22d.

[0092] Also, in the substrate support 16 of the plasma processing apparatus 1F, the base 18 is separated into a first part 181 and a second part 182. That is, there is a gap between the first part 181 and the second part 182. A high-frequency power source 61 and a bias power source 63 are electrically connected to the first part 181. The first part 181 supports the first electrostatic chuck region 21 provided thereon. The second part 182 supports the second electrostatic chuck region 22 provided thereon.

[0093] When an electrode 21c is provided in the first dielectric part 21d of the substrate support 16 of the plasma processing apparatus 1F, the high-frequency power source 61 and the bias power source 63 may be connected to the electrode 21c.

[0094] Hereinafter, refer to FIG. 8. FIG. 8 is a diagram schematically showing a plasma processing apparatus according to still another exemplary embodiment. Hereinafter, the plasma processing apparatus 1G shown in FIG. 8 will be described from the viewpoint of the differences between the plasma processing apparatus 1E and the plasma processing apparatus 1G.

[0095] In the substrate support 16 of the plasma processing apparatus 1G, similar to the substrate support 16 of the plasma processing apparatus 1F, the first electrostatic chuck region 21 has the first dielectric part 21d, and the second electrostatic chuck region 22 has the second dielectric part 22d. However, in the substrate support 16 of the plasma processing apparatus 1G, the base 18 is not separated into two parts (the first part 181 and the second part 182), unlike the base 18 of the substrate support 16 of the plasma processing apparatus 1F. A groove 18g may be formed in the base 18 of the substrate support 16 of the plasma processing apparatus 1G. The groove 18g opens on the upper surface of the base 18. The bottom of the groove 18g is located between the upper end opening of the groove 18g and the lower surface of the base 18. The groove 18g extends between the region of the base 18 where the first electrostatic chuck region 21 extends and the region of the base 18 where the second electrostatic chuck region 22 extends.

[0096] Hereinafter, refer to FIG. 9. FIG. 9 is a diagram schematically showing a plasma processing apparatus according to still another exemplary embodiment. Hereinafter, the plasma processing apparatus 1H shown in FIG. 9 will be described from the viewpoint of the differences between the plasma processing apparatus 1E and the plasma processing apparatus 1H.

[0097] In the plasma processing apparatus 1H, the first electrical path 101 is connected to the electrode 21a. The first electrical path 101 includes a capacitor 110. The capacitor 110 can be a fixed capacitor or a variable capacitor. The capacitor 110 can prevent a direct current from flowing into the bias power supply 81 or reduce the direct current flowing into the bias power supply 81. Also, the capacitor 110 can adjust the distribution ratio of each of the high-frequency power and the bias power between each of the electrodes 22a and 22b and the electrode 21a.

[0098] Also, in the plasma processing apparatus 1H, the filter 112 may be connected between the DC power supply 55 and the electrode 21a. The filter 112 is an electrical filter that blocks or reduces the high-frequency power generated by the high-frequency power supply 61 and the bias power generated by the bias power supply 63. The filter 112 prevents the high-frequency power generated by the high-frequency power supply 61 and the bias power generated by the bias power supply 63 from flowing into the DC power supply 55, or reduces the high-frequency power and the bias power flowing into the DC power supply 55.

[0099] Hereinafter, refer to FIG. 10. FIG. 10 is a diagram schematically showing a plasma processing apparatus according to yet another exemplary embodiment. Hereinafter, the plasma processing apparatus 1J shown in FIG. 10 is different from the plasma processing apparatus 1H in that the high-frequency power supply 61 is electrically connected to the base 18. Other configurations of the plasma processing apparatus 1J are the same as the corresponding configurations of the plasma processing apparatus 1H.

[0100] Hereinafter, refer to FIG. 11. FIG. 11 is a diagram schematically showing a plasma processing apparatus according to yet another exemplary embodiment. Hereinafter, the plasma processing apparatus 1K shown in FIG. 11 is different from the plasma processing apparatus 1J in that the bias power supply 63 is electrically connected to the heaters 21h and 22h. Other configurations of the plasma processing apparatus 1H are the same as the corresponding configurations of the plasma processing apparatus 1J.

[0101] Refer to FIGS. 12(a), 12(b), and 12(c) below. FIG. 12(a) is a partial enlarged view showing another example of the first electrostatic chuck region, and each of FIGS. 12(b) and 12(c) is a partial enlarged view showing another example of the second electrostatic chuck region. As shown in FIG. 12(a), in the first electrostatic chuck region 21 of the substrate support 16 according to the various embodiments described above, the height-direction positions of the electrodes 21a and 21c may be the same as each other. Also, as shown in FIGS. 12(b) and 12(c), in the second electrostatic chuck region 22 of the substrate support 16 according to the various embodiments described above, the height-direction positions of the electrodes 22a, 22b, and 22c may be the same as each other. As shown in FIG. 12(b), the electrode 22c may be provided between the electrodes 22a and 22b in the horizontal direction. Alternatively, as shown in FIG. 12(c), the electrode 22b may be provided between the electrodes 22a and 22c in the horizontal direction. Note that, in the substrate support 16 having the second electrostatic chuck region 22 shown in FIGS. 12(b) and 12(c), the electrode 21c of the first electrostatic chuck region 21 may extend at the same height-direction position as the electrode 22c.

[0102] As described above, various exemplary embodiments have been described. However, without being limited to the above-described exemplary embodiments, various additions, omissions, substitutions, and changes may be made. Also, it is possible to form other embodiments by combining elements in different embodiments.

[0103] For example, the substrate support 16 may have only one of the above-described first electrostatic chuck region 21 and second electrostatic chuck region 22, or may have both of them. That is, the substrate support 16 only needs to include a dielectric part and at least one electrode. The at least one electrode is provided in the dielectric part to supply bias power to an object placed on the dielectric part. The object is at least one of the substrate W and the edge ring ER. The at least one electrode may include only the electrode provided in the dielectric part in the first electrostatic chuck region 21. Alternatively, the at least one electrode may include only the electrode provided in the dielectric part in the second electrostatic chuck region 22. Alternatively, the at least one electrode may include both the electrode provided in the dielectric part in the first electrostatic chuck region 21 and the electrode provided in the dielectric part in the second electrostatic chuck region 22. Examples of the electrode provided in the dielectric part in the first electrostatic chuck region 21 include electrodes such as electrode 21a, electrode 21c, or heater 21h. Examples of the electrode provided in the dielectric part in the second electrostatic chuck region 22 include electrodes such as electrode 22a, electrode 22b, electrode 22c, or heater 22h.

[0104] Also, the second electrostatic chuck region 22 may be a monopolar type electrostatic chuck. That is, the second electrostatic chuck region 22 may have one or more electrodes to which a single voltage is applied to generate an electrostatic attraction, instead of a pair of electrodes constituting a bipolar electrode.

[0105] Also, the first and second electrostatic chuck regions 21 and 22 and the base 18 of each of the plasma processing apparatuses 1E and 1H may be configured in the same manner as the first and second electrostatic chuck regions 21 and 22 and the base 18 of the plasma processing apparatus 1F.

[0106] Further, each of the first and second electrostatic chuck regions 21 and 22 and the base 18 of the plasma processing apparatuses 1, 1B, 1C, 1D, 1E, 1H, 1J, and 1K may be configured in the same manner as the first and second electrostatic chuck regions 21 and 22 and the base 18 of the plasma processing apparatus 1G.

[0107] Also, the plasma processing apparatus including the substrate support 16 of the various embodiments described above may be any type of plasma processing apparatus. Such a plasma processing apparatus is, for example, an inductively coupled plasma processing apparatus, an electron cyclotron resonance (ECR) plasma processing apparatus, or a plasma processing apparatus that generates plasma by a surface wave such as a microwave.

[0108] From the above description, it will be understood that the various embodiments of the present disclosure have been described herein for purposes of illustration and that various changes can 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, and the true scope and spirit are indicated by the appended claims.

Explanation of Reference Numerals

[0109] 16... Substrate support, 21... First electrostatic chuck region, 22... Second electrostatic chuck region, 22a, 22b, 22c... Electrodes, W... Substrate, ER... Edge ring.

Claims

1. A chamber; a substrate support disposed within the chamber, the substrate support including a first portion having a substrate support surface and a second portion disposed surrounding the first portion and having a ring support surface, a gap being present between the first portion and the second portion, the first portion including a substrate bias electrode, and the second portion including a ring bias electrode; an edge ring disposed on the ring support surface to surround a substrate on the substrate support surface; a first voltage pulse generator electrically connected to the substrate bias electrode and configured to generate a first pulsed voltage; a second voltage pulse generator electrically connected to the ring bias electrode and configured to generate a second pulsed voltage; A plasma processing apparatus comprising:

2. The plasma processing apparatus of claim 1 , wherein a vertical position of the ring support surface is lower than a vertical position of the substrate support surface.

3. the first portion includes a first dielectric portion, the second portion includes a second dielectric portion; The plasma processing apparatus of claim 1 , wherein the second dielectric portion includes the ring bias electrode.

4. The plasma processing apparatus according to claim 3 , wherein the second dielectric portion has a thickness smaller than a thickness of the first dielectric portion.

5. The plasma processing apparatus of claim 3 , wherein the second dielectric portion includes a heater disposed below the ring bias electrode.

6. Further comprising a substrate chuck power supply; the first portion includes a substrate chuck electrode disposed between the substrate support surface and the substrate bias electrode; the substrate chuck power supply is electrically connected to the substrate chuck electrode; The plasma processing apparatus according to claim 1 .

7. The plasma processing apparatus of claim 1 , further comprising a ring chuck power supply electrically connected to the ring bias electrode.

8. 8. The plasma processing apparatus according to claim 1, wherein the first pulsed voltage and the second pulsed voltage have negative polarity.

9. 9. The plasma processing apparatus of claim 8, wherein the first pulsed voltage and the second pulsed voltage have a pulse frequency of 400 kHz.

10. A chamber; a substrate support disposed within the chamber, the substrate support including a first dielectric portion having a substrate support surface, and a second dielectric portion disposed to surround the first dielectric portion and having a ring support surface, a gap being present between the first dielectric portion and the second dielectric portion, the second dielectric portion including a ring bias electrode; an edge ring disposed on the ring support surface to surround a substrate on the substrate support surface; a ring voltage pulse generator electrically connected to the ring bias electrode and configured to generate a pulsed ring voltage; A plasma processing apparatus comprising:

11. The plasma processing apparatus of claim 10 , wherein a vertical position of the ring support surface is lower than a vertical position of the substrate support surface.

12. The plasma processing apparatus according to claim 10 , wherein the second dielectric portion has a thickness smaller than a thickness of the first dielectric portion.

13. The plasma processing apparatus of claim 10 , wherein the second dielectric portion includes a heater disposed below the ring bias electrode.

14. The plasma processing apparatus of claim 10 , further comprising a ring chuck power supply electrically connected to the ring bias electrode.

15. 15. The plasma processing apparatus according to claim 10, wherein the pulsed ring voltage has a negative polarity.

16. The plasma processing apparatus of claim 15 , wherein the pulsed ring voltage has a pulse frequency of 400 kHz.

17. a first dielectric portion having a substrate support surface; a second dielectric portion disposed so as to surround the first dielectric portion and having a ring support surface, the second dielectric portion having a gap between the first dielectric portion and the second dielectric portion; a substrate electrode disposed within the first dielectric portion and to which a pulsed substrate voltage is applied; a ring electrode disposed within the second dielectric portion and to which a pulsed ring voltage is applied; A substrate support comprising:

18. A first base; a second base disposed so as to surround the first base, and a gap being present between the first base and the second base; Further comprising: the first dielectric portion is disposed on the first base, The second dielectric portion is disposed on the second base. The substrate support of claim 17.

19. Further comprising a base; The first dielectric portion and the second dielectric portion are disposed on the base. The substrate support of claim 17.

20. The substrate support according to any one of claims 17 to 19, wherein a thickness of the second dielectric portion is smaller than a thickness of the first dielectric portion.

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