Substrate support and plasma processing apparatus

Abstract

A substrate support according to the present invention includes a first region, a second region, a first electrode, and a second electrode. The first region is configured to hold a substrate placed thereon. The second region is disposed in a manner surrounding the first region and is configured to hold a edge ring placed thereon. The first electrode is disposed within the first region and is configured to receive a first electrical bias. The second electrode is disposed at least within the second region and is configured to receive a second electrical bias. The second electrode extends below the first electrode in a manner opposing the first electrode within the first region.

Description

Technical Field

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

[0002] A plasma processing apparatus is used for plasma processing of a substrate. The substrate is disposed within a region on a bias electrode and surrounded by an edge ring within the chamber of the plasma processing apparatus. The edge ring is disposed on an annular electrode. U.S. Patent Application Publication No. 2018 / 0082824 (Patent Document 1) discloses such a plasma processing apparatus. The plasma processing apparatus disclosed in Patent Document 1 includes two bias power supplies. The two bias power supplies are respectively connected to the bias electrode and the annular electrode for forming a flat plasma sheath on the substrate. Summary of the Invention

[0003] This invention provides a technique to mitigate the effect of the phase difference between the first electrical bias of the substrate and the second electrical bias of the edge ring on plasma processing.

[0004] In one exemplary embodiment, a substrate support is provided. The substrate support includes a first region, a second region, a first electrode, and a second electrode. The first region is configured to hold a substrate mounted thereon. The second region is disposed surrounding the first region and configured to hold an edge ring mounted thereon. The first electrode is disposed in the first region for receiving a first electrical bias. The second electrode is disposed at least in the second region for receiving a second electrical bias. The second electrode extends below the first electrode in the first region, opposite to the first electrode.

[0005] According to an exemplary embodiment, the effect of the phase difference between the first electrical bias of the substrate and the electrical bias of the edge ring on plasma processing is mitigated. Attached Figure Description

[0006] Figure 1 This is a schematic diagram illustrating a plasma processing apparatus according to an exemplary embodiment.

[0007] Figure 2 This is a diagram illustrating the structure within the chamber of a plasma processing apparatus according to an exemplary embodiment.

[0008] Figure 3 This is a top view schematically illustrating a first region, a second region, a first electrode, and a second electrode in a substrate support according to an exemplary embodiment.

[0009] Figure 4 This is a timing diagram of an example of the first electrical bias, the second electrical bias, the potential of the first electrode, and the potential of the second electrode.

[0010] Figure 5 This is a partially enlarged cross-sectional view of a substrate support according to another exemplary embodiment.

[0011] Figure 6 This is a diagram that schematically illustrates a plasma processing apparatus according to another exemplary embodiment.

[0012] Figure 7 This is a top view schematically representing the first region, second region, first electrode, and second electrode in a substrate support according to yet another exemplary embodiment.

[0013] Figure 8 This is a schematic diagram illustrating a plasma processing apparatus according to yet another exemplary embodiment.

[0014] Figure 9 This is a schematic diagram illustrating a plasma processing apparatus according to yet another exemplary embodiment. Detailed Implementation

[0015] The following describes various exemplary embodiments.

[0016] In one exemplary embodiment, a substrate support is provided. The substrate support includes a first region, a second region, a first electrode, and a second electrode. The first region is configured to hold a substrate mounted thereon. The second region is disposed surrounding the first region and configured to hold an edge ring mounted thereon. The first electrode is disposed in the first region for receiving a first electrical bias. The second electrode is disposed at least in the second region for receiving a second electrical bias. The second electrode extends below the first electrode in the first region, opposite to the first electrode.

[0017] In the substrate support of the above embodiment, the first electrode and the second electrode are opposite to each other in a first region, and therefore capacitively coupled in the first region. Therefore, a portion of a second electrical bias is applied to the first electrode, and a portion of a first electrical bias is applied to the second electrode. Thus, the potential difference between the first and second electrodes caused by the phase difference between the first and second electrical biases is mitigated, and the potential difference between the substrate and the edge ring caused by this phase difference is mitigated. As a result, the effect of the phase difference between the first and second electrical biases on plasma processing is mitigated.

[0018] In one exemplary embodiment, the first region may constitute a first electrostatic chuck configured to hold a substrate mounted thereon. The second region may constitute a second electrostatic chuck configured to hold an edge ring mounted thereon.

[0019] In one exemplary embodiment, the first region may have a first dielectric portion and a second dielectric portion. The first dielectric portion extends around the first electrode. The second dielectric portion is formed of a dielectric different from the dielectric forming the first dielectric portion. The second dielectric portion is disposed between the first electrode and the second electrode.

[0020] In one exemplary embodiment, at least a portion of the second electrode may protrude from the second region into the first region.

[0021] In another exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber and a substrate support. The substrate support is any one of the substrate supports described in the various exemplary embodiments above. The substrate support is configured to support a substrate and an edge ring within the chamber.

[0022] In one exemplary embodiment, the plasma processing apparatus may further include a first bias power supply and a second bias power supply. The first bias power supply is configured to generate a first electrical bias and is electrically connected to a first electrode. The second bias power supply is configured to generate a second electrical bias and is electrically connected to a second electrode.

[0023] In one exemplary embodiment, the first electrical bias and the second electrical bias can each be high-frequency power. In another exemplary embodiment, the first electrical bias and the second electrical bias can each be a pulse wave containing a negative DC voltage and generated periodically.

[0024] In another exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a first bias power supply, a second bias power supply, a substrate support, a first electrical path, a second electrical path, and a capacitor. The first bias power supply is configured to generate a first electrical bias. The second bias power supply is configured to generate a second electrical bias. The substrate support is configured to support a substrate and an edge ring within the chamber. The substrate support has a first region, a second region, a first electrode, and a second electrode. The first region is configured to hold a substrate mounted thereon. The second region is disposed surrounding the first region and configured to hold an edge ring mounted thereon. The first electrode is disposed within the first region for receiving the first electrical bias. The second electrode is disposed within the second region for receiving the second electrical bias. The first electrical path connects the first bias power supply and the first electrode. The second electrical path connects the second bias power supply and the second electrode. The capacitor is connected between the first electrical path and the second electrical path.

[0025] In the plasma processing apparatus of the above embodiment, the first electrode and the second electrode are capacitively coupled via a capacitor. Therefore, a portion of a second electrical bias is applied to the first electrode, and a portion of a first electrical bias is applied to the second electrode. Consequently, the potential difference between the first and second electrodes caused by the phase difference between the first and second electrical biases is mitigated, and the potential difference between the substrate and the edge ring caused by this phase difference is also mitigated. As a result, the effect of the phase difference between the first and second electrical biases on plasma processing is mitigated.

[0026] In one exemplary embodiment, the first electrical bias and the second electrical bias can each be high-frequency power. In another exemplary embodiment, the first electrical bias and the second electrical bias can each be a pulse wave containing a negative DC voltage and generated periodically.

[0027] In one exemplary embodiment, the capacitor may be a variable capacitor.

[0028] Hereinafter, various exemplary embodiments will be described in detail with reference to the accompanying drawings. Furthermore, in the drawings, the same or equivalent parts are labeled with the same symbols.

[0029] Figure 1 This is a schematic diagram illustrating a plasma processing apparatus according to an exemplary embodiment. Figure 1 The plasma processing device 1 shown includes a chamber 10. Figure 2 This is a diagram illustrating the structure within the chamber of a plasma processing apparatus according to an exemplary embodiment. (As shown...) Figure 2 As shown, the plasma processing device 1 can be a capacitively coupled plasma processing device.

[0030] An internal space 10s is provided within the chamber 10. The central axis of the internal space 10s is an axis AX extending vertically. In one embodiment, the chamber 10 includes a chamber body 12. The chamber body 12 has a generally cylindrical shape. The internal space 10s is disposed within the chamber body 12. The chamber body 12 is formed, for example, of aluminum. The chamber body 12 is electrically grounded. A plasma-resistant membrane is formed on the inner wall surface of the chamber body 12, i.e., the wall surface dividing the internal space 10s. This membrane may be a ceramic membrane formed by anodizing or by yttrium oxide.

[0031] A channel 12p is formed on the side wall of the chamber body 12. When the substrate W is transported between the internal space 10s and the outside of the chamber 10, it passes through the channel 12p. A gate valve 12g is provided along the side wall of the chamber body 12 for opening and closing the channel 12p.

[0032] The plasma processing apparatus 1 also includes a substrate support 16. The substrate support 16 is configured to support a substrate W placed thereon within the chamber 10. The substrate W has a generally disc-shaped form. 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 generally cylindrical shape. The support portion 17 is formed of an insulating material such as quartz.

[0033] The substrate support 16 has a lower electrode 18 and an electrostatic chuck 20. The lower electrode 18 and the electrostatic chuck 20 are disposed in the chamber 10. The lower electrode 18 is formed of a conductive material such as aluminum and has a generally disc-shaped form.

[0034] A flow path 18f is formed within the lower electrode 18. 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 (e.g., a cooling unit) for the heat exchange medium is connected to flow path 18f. This supply device is located outside the chamber 10. The heat exchange medium is supplied from the supply device to flow path 18f via pipe 23a. The heat exchange medium supplied to flow path 18f returns to the supply device via pipe 23b.

[0035] The electrostatic chuck 20 is mounted on the lower electrode 18. For example... Figure 1 As shown, the electrostatic chuck 20 has a dielectric portion 20d and an electrode 21a. The dielectric portion 20d is formed of a dielectric material. For example, the dielectric portion 20d is formed of aluminum nitride or aluminum oxide. The electrostatic chuck 20 also has electrodes 22a and 22b. When processed in the internal space for 10 seconds, the substrate W is placed on the electrostatic chuck 20 and held by it. Furthermore, an edge ring ER is mounted on the substrate support 16. The edge ring ER is a plate having a generally ring shape. The edge ring ER is formed, for example, of silicon, silicon carbide, or quartz. Figure 2 As shown, the edge ring ER is mounted on the substrate support 16 with its central axis aligned with the axis AX. The substrate W, housed within the chamber 10, is positioned on the electrostatic chuck 20 within the area surrounded by the edge ring ER.

[0036] The plasma processing apparatus 1 may also include a gas line 25. The gas line 25 supplies heat transfer gas, such as He gas, from the gas supply mechanism to the gap between the upper surface of the electrostatic chuck 20 (the first region described later) and the back surface (lower surface) of the substrate W.

[0037] The plasma processing apparatus 1 may also 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 generally cylindrical shape and extends along the outer periphery of the support portion 17. The outer peripheral portion 28 is formed of a conductive material. 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 formed by anodizing or a film formed of yttrium oxide.

[0038] An outer peripheral portion 29 is disposed on the outer peripheral portion 28. The outer peripheral portion 29 is formed of an insulating material. For example, the outer peripheral portion 29 is formed of ceramic such as quartz. The outer peripheral portion 29 has a generally cylindrical shape. The outer peripheral portion 29 extends along the outer periphery of the lower electrode 18 and the electrostatic chuck 20.

[0039] The plasma processing apparatus 1 also includes an upper electrode 30. The upper electrode 30 is disposed above the substrate support 16. The upper electrode 30, together with the component 32, seals the upper opening of the chamber body 12. The component 32 is insulating. The upper electrode 30 is supported on the upper part of the chamber body 12 via the component 32.

[0040] The upper electrode 30 includes a top plate 34 and a support 36. The lower surface of the top plate 34 divides an internal space 10s. A plurality of vent holes 34a are formed on the top plate 34. The plurality of vent holes 34a penetrate the top plate 34 along the thickness direction (vertical direction). The top plate 34 is formed, for example, of silicon. Alternatively, the top plate 34 may have a structure in which a plasma-resistant film is provided on the surface of an aluminum component. This film may be a ceramic film formed by anodizing or formed of yttrium oxide.

[0041] The support body 36 detachably supports the top plate 34. The support body 36 is formed of a conductive material, such as aluminum. A gas diffusion chamber 36a is provided inside the support body 36. Multiple gas holes 36b extend downward from the gas diffusion chamber 36a. The multiple gas holes 36b communicate with multiple exhaust holes 34a. A gas inlet port 36c is formed in the support body 36. The gas inlet port 36c is connected to the gas diffusion chamber 36a. A gas supply pipe 38 is connected to the gas inlet port 36c.

[0042] A gas source group 40 is connected to the gas supply pipe 38 via a valve group 41, a flow controller group 42, and a valve group 43. The gas supply unit comprises the gas source group 40, valve group 41, flow controller group 42, and valve group 43. The gas source group 40 includes multiple gas sources. Valve groups 41 and 43 each include multiple valves (e.g., on / off valves). The flow controller group 42 includes multiple flow controllers. These flow controllers are either mass flow controllers or pressure-controlled flow controllers. The multiple gas sources of the gas source group 40 are connected to the gas supply pipe 38 via valves corresponding to valve group 41, flow controllers corresponding to flow controller group 42, and valves corresponding to valve group 43. The plasma processing apparatus 1 can supply gas from one or more gas sources selected from the multiple gas sources of the gas source group 40 at individually adjusted flow rates to the internal space for 10 seconds.

[0043] A baffle 48 is provided between the outer peripheral portion 28 and the side wall of the chamber body 12. The baffle 48 can be constructed, for example, by coating an aluminum component with a ceramic such as yttrium oxide. Multiple through holes are formed in the baffle 48. Below the baffle 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 turbomolecular pump, which can reduce the pressure in the internal space 10s.

[0044] The substrate support 16 will now be described in detail. As described above, the substrate support 16 includes a lower electrode 18 and an electrostatic chuck 20. Figure 1 As shown, the plasma processing apparatus 1 includes a high-frequency power supply 57. The high-frequency power supply 57 is connected to the lower electrode 18 via a matching adapter 58. The high-frequency power supply 57 is a power source for generating high-frequency electricity for plasma generation. The high-frequency electricity generated by the high-frequency power supply 57 has a first frequency. The first frequency can be a frequency in the range of 27 to 100 MHz. For example, the first frequency is a frequency of 40 MHz or 60 MHz. The matching adapter 58 has a matching circuit for matching the impedance of the load side (lower electrode 18 side) of the high-frequency power supply 57 with the output impedance of the high-frequency power supply 57. Alternatively, the high-frequency power supply 57 may not be electrically connected to the lower electrode 18, but may be connected to the upper electrode 30 via the matching adapter 58.

[0045] In the plasma processing apparatus 1, a high-frequency electric field is generated within a chamber 10 using high-frequency power from a high-frequency power source 57. The gas within the chamber 10 is excited by the generated high-frequency electric field. As a result, plasma is generated within the chamber 10. The substrate W is treated with chemical species such as ions and / or free radicals from the generated plasma. The treatment of the substrate W based on the chemical species from the plasma is, for example, etching.

[0046] The substrate support 16 has a first region 21 and a second region 22. Figure 3 This is a top view schematically illustrating a first region, a second region, a first electrode, and a second electrode in a substrate support according to an exemplary embodiment. Hereinafter, [the following is a continuation of the previous paragraph]. Figure 1 and Figure 2 For reference Figure 3 Region 21 is the central region of the substrate support 16. Region 21 includes the central region of the electrostatic chuck 20. Region 22 extends radially outward and circumferentially relative to Region 21. Region 22 includes the peripheral region of the electrostatic chuck 20. In the plasma processing apparatus 1, Region 21 and Region 22 are constituted by a single electrostatic chuck 20 and are integrated with each other. Furthermore, in... Figure 1 In the diagram, the boundary between region 21 (first region) and region 22 (second region) is represented by a dashed line. Furthermore, in... Figure 3 In the diagram, a single-dotted line represents the boundary between region 21 (region 1) and region 22 (region 22).

[0047] The first region 21 is configured to support a substrate W placed thereon (i.e., on its upper surface). The first region 21 is a region having a disk shape. The central axis of the first region 21 is substantially aligned with the axis AX. The first region 21 and the second region 22 share a dielectric portion 20d. The dielectric portion 20d has a substantially disk shape. In one embodiment, the thickness of the dielectric portion 20d in the second region 22 is less than the thickness of the dielectric portion 20d in the first region 21. The upper surface of the dielectric portion 20d in the second region 22 may be positioned lower in the vertical direction than the upper surface of the dielectric portion 20d in the first region 21.

[0048] The first region 21 has an electrode 21a (chuck electrode). Electrode 21a is a film-like electrode disposed within the dielectric portion 20d of the first region 21. The planar shape of electrode 21a may be circular. The central axis of electrode 21a is approximately aligned with axis AX. A DC power supply 55 is connected to electrode 21a via a switch 56. When a DC voltage from the DC power supply 55 is applied to electrode 21a, an electrostatic attraction is generated between the first region 21 and the substrate W. Through this electrostatic attraction, the substrate W is attracted to and held by the first region 21. That is, the first region 21 constitutes a first electrostatic chuck configured to hold the substrate W placed thereon.

[0049] The substrate support 16 has a first electrode 211. The first electrode 211 is a film-shaped electrode disposed in the dielectric portion 20d within the first region 21. The planar shape of the first electrode 211 may be circular. The central axis of the first electrode 211 is approximately aligned with the axis AX. In addition, the electrode 21a may extend in the vertical direction closer to the upper surface of the first region 21 than the first electrode 211.

[0050] The plasma processing apparatus 1 also includes a first bias power supply 61. The first bias power supply 61 is electrically connected to the first electrode 211 via a circuit 62. The first bias power supply 61 generates a first electrical bias. The first electrical bias is applied to the first electrode 211.

[0051] In one embodiment, the first electrical bias is a high-frequency bias power. The high-frequency bias power has a second frequency. The second frequency can be lower than the first frequency. The second frequency can be a frequency in the range of 100 kHz to 13.56 MHz. The second frequency is, for example, 400 kHz. When the first electrical bias is a high-frequency bias power, circuit 62 is a matching circuit. Circuit 62 is configured to match the impedance on the load side of the first bias power supply 61 with the output impedance of the first bias power supply 61.

[0052] In another embodiment, the first electrical bias is a pulse wave generated periodically at the second frequency described above. In each cycle, the pulse wave contains a pulse of negative DC voltage. The level of the pulse wave may also be 0V during periods other than the duration of the negative DC voltage pulse within the cycle. Alternatively, the voltage of the pulse wave may have an absolute value lower than the absolute value of the pulse voltage during periods other than the duration of the negative DC voltage pulse within the cycle. Furthermore, the level of the pulse may vary with time within the cycle. When the first electrical bias is a periodically generated pulse wave, circuit 62 may be an electrical filter configured to block or attenuate the high-frequency power from the high-frequency power supply 57.

[0053] The second region 22 extends in a manner that surrounds the first region 21. The second region 22 is a generally annular region. The central axis of the second region 22 is approximately aligned with the axis AX. The second region 22 is configured to support the edge ring ER placed thereon (i.e., on its upper surface). The second region 22 and the first region 21 share a dielectric portion 20d.

[0054] In one embodiment, the second region 22 can also retain the edge ring ER by electrostatic attraction. That is, the second region 22 can constitute a second electrostatic chuck configured to retain the edge ring ER placed thereon. In this embodiment, the second region 22 can have more than one electrode (chuck electrode). In one embodiment, the second region 22 has a pair of electrodes, namely electrode 22a and electrode 22b. Electrodes 22a and 22b are disposed in the dielectric portion 20d within the second region 22. Electrodes 22a and 22b constitute bipolar electrodes. That is, in one embodiment, the second region 22 constitutes a bipolar type electrostatic chuck. Electrodes 22a and 22b are both film-shaped electrodes. The planar shape of each electrode 22a and 22b is, for example, a ring shape. Electrode 22a can extend inside electrode 22b. Electrodes 22a and 22b can extend at approximately the same height in the vertical direction. In addition, electrodes 22a and 22b can extend in the vertical direction closer to the upper surface of the second region 22 than the second electrode 222 described later.

[0055] DC power supply 71 is connected to electrode 22a via switch 72 and filter 73. Filter 73 is an electrical filter configured to block or attenuate high-frequency power and to apply a first electrical bias and a second electrical bias. DC power supply 74 is connected to electrode 22b via switch 75 and filter 76. Filter 76 is an electrical filter configured to block or reduce high-frequency power and to apply a first electrical bias and a second electrical bias.

[0056] DC power supplies 71 and 74 apply DC voltages to electrodes 22a and 22b respectively to generate a potential difference between them. Furthermore, the set potentials of electrodes 22a and 22b can be any one of positive, negative, or 0V. For example, the potential of electrode 22a can be set to positive, and the potential of electrode 22b can be set to negative. Moreover, the potential difference between electrodes 22a and 22b can also be formed using a single DC power supply instead of two separate DC power supplies.

[0057] When a potential difference is generated between electrodes 22a and 22b, an electrostatic attraction is generated between the second region 22 and the edge ring ER. The edge ring ER is attracted to and held by the second region 22 by the generated electrostatic attraction. Alternatively, the second region 22 can also be configured as a unipolar electrostatic chuck. In the case where the second region 22 is a unipolar electrostatic chuck, a DC voltage is applied to one or more chuck electrodes within the second region 22.

[0058] The substrate support 16 also has a second electrode 222. The second electrode 222 is a film-like electrode. The second electrode 222 is disposed in the dielectric portion 20d. The second electrode 222 is disposed at least in the second region 22. The second electrode 222 is separate from the first electrode 211. The second electrode 222 extends below the first electrode 211 in a manner opposite to the first electrode 211 within the first region 21. In one embodiment, the planar shape of the second electrode 222 may be annular. In this embodiment, the central axis of the second electrode 222 is substantially aligned with the axis AX. In this embodiment, the radius of the inner edge 222i of the second electrode 222 is smaller than the radius of the outer edge 211e of the first electrode 211, and the radius of the outer edge 222o of the second electrode 222 is larger than the radius of the outer edge 211e of the first electrode 211.

[0059] The plasma processing apparatus 1 also includes a second bias power supply 81. The second bias power supply 81 is electrically connected to the second electrode 222 via a circuit 82. The second bias power supply 81 generates a second electrical bias. The second electrical bias is applied to the second electrode 222.

[0060] In one embodiment, the second electrical bias is a high-frequency bias power. The high-frequency bias power has the aforementioned second frequency. When the second electrical bias is a high-frequency bias power, circuit 82 is a matching circuit. Circuit 82 is configured to match the impedance on the load side of the second bias power supply 81 with the output impedance of the second bias power supply 81.

[0061] In another embodiment, the second electrical bias is a pulse wave generated periodically at the aforementioned second frequency. In each cycle, the pulse wave contains a pulse of negative DC voltage. The level of the pulse wave may also be 0V during periods other than the duration of the negative DC voltage pulse within the cycle. Alternatively, the voltage of the pulse wave may have an absolute value lower than the absolute value of the pulse voltage during periods other than the duration of the negative DC voltage pulse within the cycle. Furthermore, the pulse level may vary with time within the cycle. When the second electrical bias is a periodically generated pulse wave, circuit 82 may be an electrical filter configured to block or attenuate the high-frequency power from the high-frequency power supply 57.

[0062] The second region 22 may also have a gas conduit 22g. The gas conduit 22g is provided for supplying heat transfer gas, such as He gas, to the gap between the second region 22 and the edge ring ER. The gas conduit 22g is connected to a gas supply mechanism 86, which serves as a heat transfer gas source.

[0063] In one implementation, such as Figure 2As shown, the plasma processing apparatus 1 may also include a control unit MC. The control unit MC is a computer equipped with a processor, storage device, input device, 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 according to process data stored in the storage device. Through the control of the control unit MC, the process specified by the process data is executed in the plasma processing apparatus 1.

[0064] As described above, in the substrate support 16, the first electrode 211 and the second electrode 222 are opposite to each other in the first region 21, and therefore capacitively coupled within the first region 21. Therefore, a portion of the second electrical bias is applied to the first electrode 211, and a portion of the first electrical bias is applied to the second electrode 222. Thus, the potential difference between the first electrode 211 and the second electrode 222 caused by the phase difference between the first and second electrical biases is mitigated, and the potential difference between the substrate W and the edge ring ER is mitigated. As a result, the effect of the phase difference between the first and second electrical biases on plasma processing is mitigated.

[0065] refer to Figure 4 . Figure 4 This is a timing diagram of an example of the first bias, second bias, the potential of the first electrode, and the potential of the second electrode. Figure 4 In the example shown, the first and second electrical biases are pulse waves. Figure 4 In the example shown, the phase of the second electrical bias is delayed relative to the phase of the first electrical bias, but even during the period when the second electrical bias is not applied to the second electrode 222, a portion of the first electrical bias is applied to the second electrode 222. Furthermore, even during the period when the first electrical bias is not applied to the first electrode 211, a portion of the second electrical bias is applied to the first electrode 211. Therefore, the potential difference between the first electrode 211 and the second electrode 222 caused by the phase difference between the first and second electrical biases is mitigated, and the potential difference between the substrate W and the edge ring ER is mitigated.

[0066] refer to Figure 5 . Figure 5 This is a partially enlarged cross-sectional view of a substrate support according to another exemplary embodiment. Instead of the substrate support 16, it is possible to employ [a different type of support] in the plasma processing apparatus 1. Figure 5The substrate support 16B is shown. In addition to the dielectric portion 20d, i.e., the first dielectric portion, the substrate support 16B also has a dielectric portion 20m, i.e., the second dielectric portion. Other structures of the substrate support 16B can be the same as the corresponding structures of the substrate support 16. The dielectric portion 20d extends around the first electrode 211. The dielectric portion 20m is formed of a dielectric material different from the dielectric material forming the dielectric portion 20d. The dielectric portion 20m is disposed between the first electrode 211 and the second electrode 222. According to this embodiment, by appropriately selecting the dielectric material forming the dielectric portion 20m, the electrostatic capacitance of the capacitor formed between the first electrode 211 and the second electrode 222 can be set. In one embodiment, the dielectric portion 20m may also be formed of a dielectric material having a higher dielectric constant and higher insulating strength than the dielectric material forming the dielectric portion 20d. The dielectric portion 20m is formed, for example, of zirconium oxide (ZrO2).

[0067] refer to Figure 6 . Figure 6 This is a diagram that schematically illustrates a plasma processing apparatus according to another exemplary embodiment. Figure 6 The plasma processing apparatus 1C shown includes a substrate support 16C. The electrode 21a also serves as the first electrode 211; in this respect, the substrate support 16C differs from the substrate support 16. Other structures of the substrate support 16C can be the same as the corresponding structure of the substrate support 16. Furthermore, other structures of the plasma processing apparatus 1C can be the same as the corresponding structure of the plasma processing apparatus 1. Additionally, similar to the substrate support 16B, a dielectric section 20m, different from the dielectric section 20d, can be provided between the first electrode 211 and the second electrode 222 in the substrate support 16C.

[0068] refer to Figure 7 . Figure 7 This is a top view schematically showing the first region, second region, first electrode, and second electrode in a substrate support according to another exemplary embodiment. Instead of the substrate support 16, it can be used in the plasma processing apparatus 1 or 1C. Figure 7 The substrate support 16D is shown. The substrate support 16D has a second electrode 222D replacing the second electrode 222. Multiple portions of the inner edge side of the second electrode 222D protrude from the second region 22 into the first region 21; in this respect, the second electrode 222D differs from the second electrode 222. Other structures of the substrate support 16D can be the same as the corresponding structure of the substrate support 16. Like the second electrode 222D in the substrate support 16D, more than one portion of the inner edge side of the second electrode of the substrate support can protrude into the first region and extend below the first electrode.

[0069] Furthermore, similarly to the substrate support 16B, a dielectric portion 20m, different from the dielectric portion 20d, may be provided between the first electrode 211 and the second electrode 222D in the substrate support 16D. Also, in the substrate support 16D, electrode 21a may also serve as the first electrode 211.

[0070] refer to Figure 8 . Figure 8 This is a schematic diagram illustrating a plasma processing apparatus according to yet another exemplary embodiment. Figure 8 The plasma processing apparatus 1E shown includes a substrate support 16E. The second electrode 222 extends within the second region 22 but does not extend into the first region 21; in this respect, the substrate support 16E differs from the substrate support 16. Other structures of the substrate support 16E may be identical to the corresponding structure of the substrate support 16. In the plasma processing apparatus 1E, a capacitor 90 is connected between the first electrical path 63 and the second electrical path 83. The first electrical path 63 is connected between the first bias power supply 61 and the first electrode 211. The second electrical path 83 is connected between the second bias power supply 81 and the second electrode 222. The capacitor 90 may be a fixed capacitor or a variable capacitor. Furthermore, other structures of the plasma processing apparatus 1E may be identical to the corresponding structure of the plasma processing apparatus 1.

[0071] In the plasma processing apparatus 1E, the first electrode 211 and the second electrode 222 are capacitively coupled via a capacitor 90. Therefore, a portion of a second electrical bias is applied to the first electrode 211, and a portion of a first electrical bias is applied to the second electrode 222. Consequently, the potential difference between the first electrode 211 and the second electrode 222 caused by the phase difference between the first and second electrical biases is mitigated, and the potential difference between the substrate W and the edge ring ER is mitigated. As a result, the effect of the phase difference between the first and second electrical biases on plasma processing is mitigated.

[0072] refer to Figure 9 . Figure 9 This is a schematic diagram illustrating a plasma processing apparatus according to yet another exemplary embodiment. Figure 9The plasma processing apparatus 1F shown includes a substrate support 16F. Electrode 21a also serves as the first electrode 211, and electrodes 22a and 22b also serve as the second electrode 222. In this respect, the substrate support 16F differs from the substrate support 16E. Other structures of the substrate support 16F can be the same as the corresponding structures of the substrate support 16E. Furthermore, other structures of the plasma processing apparatus 1F can be the same as the corresponding structures of the plasma processing apparatus 1E. Additionally, in the substrate support 16F, the first electrode 211 can be a different electrode than electrode 21a. Alternatively, the second electrode 222 can be a different electrode than electrodes 22a and 22b.

[0073] The above descriptions of various exemplary embodiments are not limited to these exemplary embodiments, and various additions, omissions, substitutions, and modifications can be made. Furthermore, elements from different embodiments can be combined to form other embodiments.

[0074] In another embodiment, the plasma processing apparatus can be another type of plasma processing apparatus. This other type of plasma processing apparatus includes, for example, an inductively coupled plasma processing apparatus, an electron cyclotron resonance (ECR) plasma processing apparatus, or a plasma processing apparatus that generates plasma using surface waves such as microwaves.

[0075] As can be understood from the above description, the various embodiments of the present invention have been described in this specification for illustrative purposes, and various modifications can be made without departing from the scope and spirit of the present invention. Therefore, the various embodiments disclosed in this specification are not intended to be limiting, and the true scope and spirit can be shown by the scope of the appended technical solutions.

Claims

1. A substrate support, comprising: The first region constitutes the central region of the electrostatic chuck, which is configured to hold the substrate placed thereon. The second region is arranged to surround the first region and is configured to hold the edge ring placed thereon; The first electrode is disposed in the first region and is used to receive the first electrical bias; A second electrode, at least disposed in the second region, is used to receive a second electrical bias; and The lower electrode, made of conductive material, is located below the electrostatic chuck. The second electrode extends below the first electrode in a manner opposite to the first electrode within the first region.

2. The substrate support according to claim 1, wherein, The electrostatic chuck comprises a single dielectric section. The first electrode and the second electrode are disposed within the single dielectric portion.

3. The substrate support according to claim 1, wherein, The first region has: The first dielectric portion extends around the first electrode; and The second dielectric portion is formed of a dielectric material different from the dielectric material forming the first dielectric portion and is disposed between the first electrode and the second electrode.

4. The substrate support according to any one of claims 1 to 3, wherein, At least a portion of the second electrode protrudes from the second region into the first region.

5. The substrate support according to any one of claims 1 to 3, wherein, The chuck electrode, which is equipped with the electrostatic chuck, extends closer to the upper surface of the first region than the first electrode.

6. The substrate support according to any one of claims 1 to 3, wherein, The second electrode has a ring shape.

7. A plasma processing apparatus, comprising: Chambers; and The substrate support according to any one of claims 1 to 6 is configured to support the substrate and the edge ring in the cavity.

8. The plasma processing apparatus according to claim 7, further comprising: A first bias power supply is configured to generate the first electrical bias and is electrically connected to the first electrode; and The second bias power supply is configured to generate the second electrical bias and is electrically connected to the second electrode.

9. The plasma processing apparatus according to claim 8, wherein, The first electrical bias and the second electrical bias are both high-frequency electrical biases.

10. The plasma processing apparatus according to claim 8, wherein, The first electrical bias and the second electrical bias are pulse waves that contain negative DC voltage pulses and are generated periodically.

11. The plasma processing apparatus according to claim 10, wherein, The pulse wave contains pulses of DC voltage.

12. The plasma processing apparatus according to claim 10, wherein, A filter is provided between the first bias power supply and the first electrode, and a filter is provided between the second bias power supply and the second electrode.

13. The plasma processing apparatus according to claim 7, wherein, It also has a high-frequency power supply, configured to generate high-frequency power for plasma generation, and is electrically connected to the lower electrode.

14. A plasma processing apparatus comprising: chamber; The first bias power supply is configured to generate the first electrical bias. The second bias power supply is configured to generate the second electrical bias. A substrate support is configured to support a substrate and an edge ring within a cavity. The substrate support has: a first region configured to hold the substrate placed thereon; a second region disposed around the first region and configured to hold the edge ring placed thereon; a first electrode disposed in the first region for receiving a first electrical bias; and a second electrode disposed in the second region for receiving a second electrical bias. The first electrical path is connected between the first bias power supply and the first electrode; The second electrical path is connected between the second bias power supply and the second electrode; and A capacitor is connected between the first electrical path and the second electrical path.

15. The plasma processing apparatus according to claim 14, wherein, The first electrical bias and the second electrical bias are both high-frequency electrical biases.

16. The plasma processing apparatus according to claim 14, wherein, The first electrical bias and the second electrical bias are pulse waves that contain negative DC voltage pulses and are generated periodically.

17. The plasma processing apparatus according to any one of claims 14 to 16, wherein, The capacitor is a variable capacitor.

Images