Plasma Processing Equipment

Abstract

To provide technology that efficiently supplies bias power to an object mounted on a substrate support.SOLUTION: A disclosed plasma processing device comprises a chamber, a substrate support, and a voltage pulse generator. The substrate support is provided inside of the chamber. The substrate support includes first and second electrostatic chuck parts. The first electrostatic chuck part is constituted so as to support the substrate that is mounted thereon. The second electrostatic chuck part is constituted so as to enclose the first electrostatic chuck part and hold an edge ring that is mounted thereon. The second electrostatic chuck part includes one or more edge chuck electrodes and an edge bias electrode. The one or more edge chuck electrodes are arranged on top of the edge bias electrode inside of the second electrostatic chuck part. The voltage pulse generator is electrically connected to the edge bias electrode and is constituted so as to generate a DC voltage in pulse form.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] A plasma processing apparatus is used in processing 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 a substrate placed thereon. A bias power is supplied to the base from a high frequency power source to attract ions from the plasma generated in the chamber to the substrate.

[0003] An edge ring is mounted on the substrate support. The substrate is placed 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 supporters configured to hold the edge ring by electrostatic attraction are described in the following Patent Documents 1 to 3. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-33376 A [Patent Document 2] Special Publication No. 2004-511901 [Patent Document 3] JP 2016-122740 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides techniques for efficiently providing bias power to an object mounted on a substrate support. [Means for solving the problem]

[0006] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, and a voltage pulse generator. The substrate support is disposed within the chamber. The substrate support includes a first electrostatic chuck portion and a second electrostatic chuck portion. The first electrostatic chuck portion is configured to hold a substrate disposed thereon. The second electrostatic chuck portion surrounds the first electrostatic chuck portion and is configured to hold an edge ring disposed thereon. The second electrostatic chuck portion includes one or more edge chuck electrodes and an edge bias electrode. The one or more edge chuck electrodes are disposed within the second electrostatic chuck portion above the edge bias electrode. The voltage pulse generator is electrically connected to the edge bias electrode and configured to generate a pulsed DC voltage. Effect 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] 1 is a schematic diagram illustrating a plasma processing apparatus according to an exemplary embodiment; [Diagram 2] FIG. 2 is a detailed diagram illustrating a configuration inside a chamber of a plasma processing apparatus according to an exemplary embodiment. [Diagram 3] FIG. 13 is a schematic diagram of a plasma processing apparatus according to another exemplary embodiment. [Figure 4] FIG. 13 is a schematic diagram of a plasma processing apparatus according to yet another exemplary embodiment. [Diagram 5] FIG. 13 is a schematic diagram of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 6] FIG. 13 is a schematic diagram of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 7]FIG. 13 is a schematic diagram of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 8] FIG. 13 is a schematic diagram of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 9] FIG. 13 is a schematic diagram of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 10] FIG. 13 is a schematic diagram of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 11] FIG. 13 is a schematic diagram of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 12] FIG. 12(a) is a partially enlarged view showing another example of the first electrostatic chuck region, and FIG. 12(b) and FIG. 12(c) are each a partially enlarged view showing another example of the second electrostatic chuck region. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Various exemplary embodiments are described below.

[0010] In one exemplary embodiment, a substrate support is provided. The substrate support includes a dielectric portion and at least one electrode. The at least one electrode is provided in the dielectric portion to supply bias power to an object placed on the dielectric portion. In the substrate support according to this embodiment, the electrode to which the bias power is supplied is provided in the dielectric portion on which the object is placed. Thus, 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 disposed thereon. The second electrostatic chuck region is configured to surround the first electrostatic chuck region and to hold an edge ring disposed thereon. The second electrostatic chuck region has one or more electrodes disposed therein for generating an electrostatic attraction between the second electrostatic chuck region and the edge ring and for providing bias power to the edge ring via the second electrostatic chuck region. In this embodiment, the one or more electrodes include at least one of the electrodes described above.

[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 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 between the second electrostatic chuck region and the edge ring and an electrode to which bias power is supplied. Since the one or more electrodes are provided in the second electrostatic chuck region, it is possible to supply bias power to the edge ring via the second electrostatic chuck region while the edge ring is held in the second electrostatic chuck region. Therefore, the substrate support provides a structure that can independently and stably supply bias power to the edge ring.

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

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

[0015] In one exemplary embodiment, the second electrostatic chuck region may be a bipolar electrostatic chuck, i.e., the one or more electrodes may include a pair of electrodes that form a bipolar electrode, while in another exemplary embodiment, the second electrostatic chuck region may be a monopolar electrostatic chuck.

[0016] In one exemplary embodiment, the second electrostatic chucking region can further include at least a portion of the dielectric portion, wherein one or more electrodes are disposed within at least a portion of the dielectric portion.

[0017] In one exemplary embodiment, the first and second electrostatic chucking regions may share the dielectric portion. The first electrostatic chucking region may have a chucking electrode disposed within the dielectric portion, the chucking electrode being an electrode to which a voltage is applied to attract the substrate to the first electrostatic chucking region.

[0018] In one exemplary embodiment, the first electrostatic chucking region may have a first dielectric portion and a chucking electrode, the chucking electrode being an electrode to which a voltage is applied to attract the substrate to the first electrostatic chucking region, and disposed within the first dielectric portion. The second electrostatic chucking region may have a second dielectric portion that is separate from the first dielectric portion.

[0019] In one exemplary embodiment, the substrate support may further include a heater disposed within 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 chucking region and the edge ring.

[0021] In one exemplary embodiment, the first electrostatic chuck region may further include another electrode, the another electrode being an electrode to which bias power is supplied, disposed within the first electrostatic chuck region, such that 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 can be controlled independently of each other.

[0022] In an exemplary embodiment, the substrate support may further include a base. The base is electrically conductive. A 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 further exemplary embodiments, a plasma processing apparatus is provided.

[0024] According to one exemplary embodiment, a plasma processing apparatus includes a chamber and a substrate support, the substrate support being any of the substrate support of the various exemplary embodiments described above. The substrate support is disposed within the chamber.

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

[0026] In one exemplary embodiment of the plasma processing apparatus, the substrate support is a substrate support having the separate electrode disposed in the first electrostatic chuck region, and the plasma processing apparatus may further include a separate bias power supply configured to generate a bias power supplied to the separate electrode.

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

[0028] 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 separate electrode disposed in the first electrostatic chuck region. The substrate support is disposed 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 a bias power. The common electrical path is connected to the bias power supply. The first electrical path and the second electrical path are branched from the common electrical path. The first electrical path is an electrical path for bias power supplied to the separate electrode. 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 disposed 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 separate electrode are generated by distributing bias power generated by a bias power supply to a first electrical path and a 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 above-mentioned 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 a bias power. The common electrical path is connected to the bias power supply. The first electrical path and the second electrical path are branched 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 and the bias power supplied to the pedestal via the second electrostatic chuck region are generated by distributing bias power generated by a bias power supply to a first electrical path and a second electrical path.

[0030] Various exemplary embodiments will now be described in detail with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0031] Fig. 1 is a diagram illustrating a schematic configuration of a plasma processing apparatus according to an exemplary embodiment. The plasma processing apparatus 1 illustrated in Fig. 1 includes a chamber 10. Fig. 2 is a diagram illustrating in detail the configuration inside the chamber of the plasma processing apparatus according to an exemplary embodiment. As illustrated in Fig. 2, the plasma processing apparatus 1 may be a capacitively coupled plasma processing apparatus.

[0032] The 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, the chamber 10 includes a chamber body 12. The chamber body 12 has a substantially cylindrical shape. The internal space 10s is provided in 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, i.e., the wall surface defining the internal space 10s. This film may be a ceramic film, such as a film formed by anodizing or a film formed from yttrium oxide.

[0033] A passage 12p is formed in the sidewall of the chamber body 12. The substrate W passes through the passage 12p when being transferred between the internal space 10s and the outside of the chamber 10. A gate valve 12g is provided along the sidewall of the chamber body 12 to open and close the passage 12p.

[0034] The plasma processing apparatus 1 further includes a substrate support 16 according to an exemplary embodiment. The substrate support 16 is configured to support a substrate W placed thereon in the chamber 10. The substrate W has a substantially disk-like 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 made 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 in the chamber 10. The base 18 is made of a conductive material such as aluminum, and has a substantially disk shape.

[0036] A flow path 18f is formed in the base 18. The flow path 18f is a flow path for a heat exchange medium. For example, a liquid refrigerant is used as the heat exchange medium. 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 from the supply device through a pipe 23a to the flow path 18f. The heat exchange medium supplied to the flow path 18f is returned to the supply device through 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, the substrate W is placed on the electrostatic chuck 20 and held by the electrostatic chuck 20. An edge ring ER is mounted on the substrate support 16. The edge ring ER is a plate having a substantially ring shape. The edge ring ER is conductive. The edge ring ER is made of, for example, silicon or silicon carbide. The edge ring ER is mounted on the substrate support 16 so 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 in 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, for example, He gas, from a gas supply mechanism to a gap between an upper surface of the electrostatic chuck 20 (a first electrostatic chuck region described later) and a rear surface (lower surface) of the substrate W.

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

[0040] The outer peripheral portion 29 is provided on the outer peripheral portion 28. The outer peripheral portion 29 is made of an insulating material. The outer peripheral portion 29 is made of a ceramic such as quartz. The outer peripheral portion 29 has a substantially cylindrical shape. The outer peripheral portion 29 extends along the outer periphery 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 a member 32. The member 32 has insulating properties. The upper electrode 30 is supported by the upper part of the chamber body 12 via the 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 an 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). The top plate 34 is made of, but is not limited to, silicon, for example. Alternatively, the top plate 34 may have a structure in which a plasma-resistant film is provided on the surface of an aluminum member. The film may be a ceramic film, such as a film formed by anodizing or a film formed from yttrium oxide.

[0043] The support 36 detachably supports the top plate 34. The support 36 is made of a conductive material such as aluminum. 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 are connected to 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] The gas source group 40 is connected to the gas supply pipe 38 via the valve group 41, the flow rate controller group 42, and the valve group 43. The gas source group 40, the valve group 41, the flow rate 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 rate controller group 42 includes a plurality of flow rate controllers. Each of the plurality of flow rate controllers of the flow rate controller group 42 is a mass flow controller or a pressure control type flow rate controller. Each of the plurality of gas sources of the gas source group 40 is connected to the gas supply pipe 38 via a corresponding valve of the valve group 41, a corresponding flow rate controller of the flow rate controller group 42, and a corresponding valve of the valve group 43. The plasma processing apparatus 1 can supply gas from one or more gas sources selected from the plurality of gas sources of 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 periphery 28 and the side wall of the chamber body 12. The baffle plate 48 can be formed, for example, by coating an aluminum member 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 the 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] The substrate support 16 will be described in detail below. As described above, the substrate support 16 has the base 18 and the electrostatic chuck 20. As shown in FIG. 1, the high frequency power supply 61 is connected to the base 18 via a matching device 62. The high frequency power supply 61 is a power supply that generates high frequency power for generating plasma. 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 matching device 62 has a matching circuit for matching the output impedance of the high frequency power supply 61 with the impedance on the load side (the base 18 side). The high frequency power supply 61 does not have to be electrically connected to the base 18, and may be connected to the upper electrode 30 via the matching device 62.

[0047] In the plasma processing apparatus 1, when high frequency power is supplied from the high frequency power supply 61, gas is excited in the chamber 10, 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 a base 18. In the substrate support 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 are 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 a substrate W placed thereon (i.e., on 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 approximately coincides with the axis AX. The first electrostatic chuck region 21 and the second electrostatic chuck region 22 share a dielectric portion 20d. The dielectric portion 20d is made of a dielectric material such as aluminum nitride or aluminum oxide. The dielectric portion 20d has an approximately disk shape. In one embodiment, the thickness of the dielectric portion 20d in the second electrostatic chuck region 22 is smaller than the thickness of the dielectric portion 20d in the first electrostatic chuck region 21. The vertical position of the upper surface of the dielectric portion 20d in the second electrostatic chuck region 22 may be lower than the vertical position of the upper surface of the dielectric portion 20d in the first electrostatic chuck region 21.

[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 portion 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 attractive force is generated between the first electrostatic chuck region 21 and the substrate W. The generated electrostatic attractive force attracts the substrate W to the first electrostatic chuck region 21 and the substrate W is held by the first electrostatic chuck region 21.

[0051] The first electrostatic chuck region 21 may further include an electrode 21c. The electrode 21c is a film-like electrode and is provided in the dielectric portion 20d of the first electrostatic chuck region 21. The electrode 21a may extend closer to the upper surface of the first electrostatic chuck region 21 in the vertical direction than the electrode 21c. A bias power supply 63 is connected to the electrode 21c via a matching device 64 and a filter 65. The bias power supply 63 may be electrically connected to the base 18 via the matching device 64 and the filter 65. In this case, the first electrostatic chuck region 21 may not include 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 a high-frequency power. In this case, the bias power generated by the bias power supply 63 has a lower frequency 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 within a range of 400 kHz to 13.56 MHz, for example, 400 kHz.

[0053] The matching box 64 is connected between the bias power supply 63 and the electrode 21c. The matching box 64 is configured to match the output impedance of the bias power supply 63 with the impedance on the load side (the electrode 21c side). The filter 65 is connected between the matching box 64 and the electrode 21c. The filter 65 is an electric 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 a pulsed high-frequency power that is generated periodically. That is, the supply and stop of the high-frequency power from the bias power supply 63 to the electrode 21c may be alternately switched. In yet another embodiment, the bias power supply 63 may be configured to periodically apply a pulsed negative DC voltage to the electrode 21c as the bias power. In this case, the bias power supply 63 may periodically generate a pulsed negative DC voltage at a period defined by a frequency of, for example, 400 kHz. The level of the pulsed negative DC voltage may change during the period in which the pulsed negative 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 portion 20d of the first electrostatic chuck region 21. The electrodes 21a and 21c may extend closer to the top surface of the first electrostatic chuck region 21 in the vertical direction than the heater 21h. The heater 21h may be a resistive 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. The first electrostatic chuck region 21 may include 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 rear 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 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., on the upper surface thereof). The second electrostatic chuck region 22 and the first electrostatic chuck region 21 share the dielectric portion 20d.

[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 attractive force between the edge ring ER and the second electrostatic chuck region 22 and to supply bias power to the edge ring ER via the second electrostatic chuck region 22. The one or more electrodes are provided in the dielectric portion 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 the electrode to which a voltage is applied to generate an electrostatic attractive force. The second electrode is the 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 constituting a bipolar electrode. Specifically, in the substrate support 16 of the plasma processing apparatus 1, the second electrostatic chuck region 22 has an electrode 22a and an electrode 22b as a pair of first electrodes constituting a bipolar electrode. Each of the electrode 22a and the electrode 22b is a film-like electrode. The electrode 22a and the electrode 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 electric filter that blocks or reduces the RF power and bias power. The filter 73 blocks the RF power and bias power from flowing into the DC power supply 71, or reduces the RF 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 electric filter that blocks or reduces the RF power and bias power. The filter 76 blocks the RF power and bias power from flowing into the DC power supply 74, or reduces the RF 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. The set potentials 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. 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 attractive 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 attractive force and is held by the second electrostatic chuck region 22.

[0065] The second electrostatic chuck region 22 further includes an electrode 22c as a second electrode. The electrode 22c is a film-like electrode and is provided in the dielectric portion 20d in the second electrostatic chuck region 22. The electrodes 22a and 22b may extend closer to the upper surface of the second electrostatic chuck region 22 in the vertical direction than the electrode 22c. A bias power supply 81 is connected to the electrode 22c via a matching unit 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 may 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 DC voltage as the bias power, similar to the bias power supply 63. The matching device 82 is configured to match the output impedance of the bias power supply 81 with the impedance on the load side (the electrode 22c side). The filter 83 is connected between the matching device 82 and the electrode 22c. The filter 83 is an electric 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 of the second electrostatic chuck region 22. The electrodes 22a, 22b, and 22c may extend closer to the top surface of the second electrostatic chuck region 22 in the vertical direction than the heater 22h. The heater 22h may be a resistive 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. The second electrostatic chuck region 22 may include a plurality of heaters. The heaters 21h and 22h may be supplied with power 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, for example, 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] 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. Under the control of the control unit MC, a 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, while the edge ring ER is held in the second electrostatic chuck region 22, it is possible to supply bias power to the edge ring ER via the second electrostatic chuck region 22. Therefore, the substrate support 16 of the plasma processing apparatus 1 provides a structure that can independently and stably supply bias power to the edge ring ER.

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

[0072] Reference will now be made to Fig. 3. Fig. 3 is a diagram illustrating a plasma processing apparatus according to another exemplary embodiment. Hereinafter, the plasma processing apparatus 1B illustrated in Fig. 3 will be described from the viewpoint of differences between the plasma processing apparatus 1 and the plasma processing apparatus 1B.

[0073] In the plasma processing apparatus 1B, the electrode to which a voltage is applied to generate an electrostatic attractive force between the second electrostatic chuck region 22 and the edge ring ER and the electrode 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 a matching device 82 and a 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 a blocking capacitor 87. The bias power supply 81 may be connected to the electrode 22b via a blocking capacitor 88. The blocking capacitors 87 and 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 a voltage is applied to generate an electrostatic attraction force. Therefore, the dedicated electrode 22c to which the bias power is supplied can be omitted from the second electrostatic chuck region 22. Therefore, the structure of the second electrostatic chuck region 22 can be simplified. As a result, the substrate support 16 of the plasma processing apparatus 1B can be easily manufactured at low cost.

[0076] Furthermore, 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 electrostatic capacitance between each of the electrodes 22a and 22b and the edge ring ER increases. Therefore, 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 improved.

[0077] Reference will now be made to Fig. 4, which is a schematic diagram of a plasma processing apparatus according to yet another exemplary embodiment. Hereinafter, the plasma processing apparatus 1C shown in Fig. 4 will be described in terms of 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 a matching unit 64. In the plasma processing apparatus 1C, bias power from the bias power supply 63 and 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] Reference will now be made to Fig. 5. Fig. 5 is a diagram illustrating a plasma processing apparatus according to yet another exemplary embodiment. Hereinafter, the plasma processing apparatus 1D illustrated in Fig. 5 will be described from the viewpoint of 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 a matching unit 92, a filter 83, and a blocking capacitor 87. The high-frequency power supply 91 is also connected to the electrode 22b via a matching unit 92, a filter 83, and a 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 control the density of the plasma in the region above the edge ring independently of the density of the plasma in the region above the substrate W.

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

[0082] Reference will now be made to Fig. 6. Fig. 6 is a diagram illustrating a plasma processing apparatus according to yet another exemplary embodiment. Hereinafter, the plasma processing apparatus 1E illustrated in Fig. 6 will be described from the viewpoint of 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 supply 61 and a bias power supply 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 a base 18. The second electrical path 102 is connected to an electrode 22a via a blocking capacitor 87. The second electrical path 102 is connected to an electrode 22b via a blocking capacitor 88. In the plasma processing apparatus 1E, high frequency power from the high frequency power supply 61 and bias power from the bias power supply 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 supply 81, a matching unit 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. An example of the variable impedance element is a variable capacitance capacitor. By adjusting the impedance of the impedance circuit 103, it is possible to adjust the ratio of the bias power supplied from the bias power supply 63 to the electrodes 22a and 22b to the bias power supplied from the bias power supply 63 to the base 18. In addition, by adjusting the impedance of the impedance circuit 103, it is possible to adjust the ratio of the high frequency power supplied from the high frequency power supply 61 to the electrodes 22a and 22b to the high frequency power supplied from the high frequency power supply 61 to the base 18. In the plasma processing apparatus 1E, the number of bias power supplies 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] 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, if the second electrostatic chuck region 22 has an 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] Reference will now be made to Fig. 7, which is a schematic diagram of a plasma processing apparatus according to yet another exemplary embodiment. The plasma processing apparatus 1F shown in Fig. 7 will be described below from the viewpoint of 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 a first dielectric portion 21d, and the second electrostatic chuck region 22 has a second dielectric portion 22d. Each of the first dielectric portion 21d and the second dielectric portion 22d is formed of a dielectric material such as aluminum nitride or aluminum oxide.

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

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

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

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

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

[0094] Reference will now be made to Fig. 8. Fig. 8 is a diagram illustrating a plasma processing apparatus according to yet another exemplary embodiment. Hereinafter, the plasma processing apparatus 1G illustrated in Fig. 8 will be described from the viewpoint of 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, the first electrostatic chuck region 21 has a first dielectric portion 21d, and the second electrostatic chuck region 22 has a second dielectric portion 22d, similarly to the substrate support 16 of the plasma processing apparatus 1F. However, in the substrate support 16 of the plasma processing apparatus 1G, the base 18 is not separated into two parts (a first part 181 and a second part 182), unlike the base 18 of the substrate support 16 of the plasma processing apparatus 1F. The base 18 of the substrate support 16 of the plasma processing apparatus 1G may have a groove 18g formed therein. 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. Groove 18g extends between the region of base 18 over which first electrostatic chuck region 21 extends and the region of base 18 over which second electrostatic chuck region 22 extends.

[0096] Reference will now be made to Fig. 9. Fig. 9 is a diagram illustrating a plasma processing apparatus according to yet another exemplary embodiment. Hereinafter, the plasma processing apparatus 1H illustrated in Fig. 9 will be described from the viewpoint of 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 may be a fixed capacitance capacitor or a variable capacitance capacitor. The capacitor 110 may prevent a direct current from flowing into the bias power supply 81 or may reduce a direct current flowing into the bias power supply 81. The capacitor 110 may also adjust the distribution ratio of the high frequency power and the bias power between the electrode 22a and the electrode 21a and between the electrode 22b and the electrode 22a and the electrode 22b.

[0098] In the plasma processing apparatus 1H, a filter 112 may be connected between the DC power supply 55 and the electrode 21a. The filter 112 is an electric 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 bias power flowing into the DC power supply 55.

[0099] Reference will now be made to Fig. 10, which is a schematic diagram of a plasma processing apparatus according to yet another exemplary embodiment. Hereinafter, the plasma processing apparatus 1J shown in Fig. 10 differs from the plasma processing apparatus 1H in that a high-frequency power supply 61 is electrically connected to the base 18. The other configurations of the plasma processing apparatus 1J are the same as the corresponding configurations of the plasma processing apparatus 1H.

[0100] Reference will now be made to FIG. 11, which is a schematic diagram of a plasma processing apparatus according to yet another exemplary embodiment. The plasma processing apparatus 1K shown in FIG. 11 differs from the plasma processing apparatus 1J in that a bias power supply 63 is electrically connected to the heaters 21h and 22h. The other configurations of the plasma processing apparatus 1H are the same as the corresponding configurations of the plasma processing apparatus 1J.

[0101] Hereinafter, reference will be made to (a), (b), and (c) of FIG. 12. (a) of FIG. 12 is a partially enlarged view showing another example of the first electrostatic chuck region, and (b) and (c) of FIG. 12 are partially enlarged views showing another example of the second electrostatic chuck region. As shown in (a) of FIG. 12, in the first electrostatic chuck region 21 of the substrate support 16 according to the various embodiments described above, the positions in the height direction of the electrodes 21a and 21c may be the same as each other. Also, as shown in (b) and (c) of FIG. 12, in the second electrostatic chuck region 22 of the substrate support 16 according to the various embodiments described above, the positions in the height direction of the electrodes 22a, 22b, and 22c may be the same as each other. As shown in (b) of FIG. 12, 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. In the substrate support 16 having the second electrostatic chuck region 22 shown in Fig. 12(b) and Fig. 12(c), the electrode 21c of the first electrostatic chuck region 21 may extend at the same height position as the electrode 22c.

[0102] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. In addition, elements in different embodiments can be combined to form other embodiments.

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

[0104] The second electrostatic chuck region 22 may also be a monopolar electrostatic chuck, i.e., the second electrostatic chuck region 22 may have one or more electrodes to which a single voltage is applied to generate an electrostatic attractive force, rather than a pair of electrodes constituting a bipolar electrode.

[0105] Furthermore, the first and second electrostatic chuck regions 21, 22 and base 18 of each of the plasma processing apparatuses 1E and 1H may be configured similarly to the first and second electrostatic chuck regions 21, 22 and base 18 of the plasma processing apparatus 1F.

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

[0107] The plasma processing apparatus including the substrate support 16 according to the various embodiments described above may be any type of plasma processing apparatus, such as an inductively coupled plasma processing apparatus, an electron cyclotron resonance (ECR) plasma processing apparatus, or a plasma processing apparatus that generates plasma by surface waves such as microwaves.

[0108] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims. [Explanation of symbols]

[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, a first electrostatic chuck portion configured to hold a substrate disposed thereon; a second electrostatic chuck portion configured to surround the first electrostatic chuck portion and hold an edge ring disposed thereon, the second electrostatic chuck portion including one or more edge chuck electrodes and an edge bias electrode, the one or more edge chuck electrodes being disposed within the second electrostatic chuck portion above the edge bias electrode; a voltage pulse generator electrically connected to the edge bias electrode and configured to generate a pulsed DC voltage; A plasma processing apparatus comprising:

2. The plasma processing apparatus of claim 1 , wherein the pulsed DC voltage has a negative polarity.

3. The plasma processing apparatus of claim 2 , wherein the second electrostatic chuck portion includes a bipolar electrostatic chuck.

4. The second electrostatic chuck portion further includes a dielectric portion, the one or more edge chuck electrodes and the edge bias electrode are disposed within the dielectric portion. The plasma processing apparatus according to claim 2 .

5. the first electrostatic chuck portion and the second electrostatic chuck portion share the dielectric portion, the first electrostatic chuck portion includes a central chuck electrode disposed within the dielectric portion; The plasma processing apparatus according to claim 4 .

6. the dielectric portion includes a first dielectric portion and a second dielectric portion, The first electrostatic chuck portion includes: The first dielectric portion; a central chuck electrode disposed within the first dielectric portion; Including, the second electrostatic chuck portion includes the second dielectric portion, The plasma processing apparatus according to claim 4 .

7. The plasma processing apparatus according to claim 4 , further comprising a heater disposed within the dielectric portion included in the second electrostatic chuck portion.

8. 8. The plasma processing apparatus of claim 1, further comprising a gas line configured to supply a heat transfer gas between the second electrostatic chuck portion and the edge ring.

9. Further comprising a conductive base, the first electrostatic chuck portion and the second electrostatic chuck portion are disposed on the base. The plasma processing apparatus according to any one of claims 1 to 7.

10. The plasma processing apparatus of claim 6 , wherein the second electrostatic chuck portion has a thickness less than that of the first electrostatic chuck portion.

11. the first electrostatic chuck portion includes a first dielectric portion, the second electrostatic chuck portion includes a second dielectric portion, the first dielectric portion being separated from the second dielectric portion by a groove extending into the base; The plasma processing apparatus according to claim 9 .

12. The plasma processing apparatus of claim 11 , wherein the second dielectric portion has a thickness less than that of the first dielectric portion.

13. The plasma processing apparatus of claim 11 , wherein the groove has a bottom between an upper surface of the base and a lower surface of the base.

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