Plasma processing apparatus and substrate processing method

Abstract

The disclosed plasma treatment device is such that a substrate support part has a base and a dielectric part. The base includes a base member and an electrode. The base member is formed from a dielectric or an insulator. The electrode is formed on an upper surface of the base member. The electrode constitutes an upper surface of the base. The dielectric part provides a support surface having a substrate placed thereon. The dielectric part extends from the upper surface of the base to the support surface and is formed only from a dielectric. A bias power supply and a chuck power supply are electrically connected to the electrode of the base.

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION Exemplary embodiments of the present disclosure relate to a plasma processing apparatus and a method for processing a substrate. [Background technology]

[0002] A plasma processing apparatus is used in plasma processing of a substrate. The plasma processing apparatus includes a chamber and a substrate support. The substrate support includes a base and an electrostatic chuck. The base constitutes a lower electrode. A bias power supply is connected to the base. The electrostatic chuck is provided on the base. The electrostatic chuck includes an insulating layer and an electrode provided in the insulating layer. A DC power supply is connected to the electrode of the electrostatic chuck. Patent Documents 1 and 2 listed below disclose such plasma processing apparatuses. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-169635 [Patent Document 2] Japanese Patent Publication No. 2020-205444 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides techniques for efficiently delivering bias energy from a bias power supply to a substrate. [Means for solving the problem]

[0005] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, a plasma generating unit, a bias power supply, and a chuck power supply. The substrate support is provided within the chamber. The plasma generating unit is configured to generate plasma within the chamber. The bias power supply is configured to generate bias energy to attract ions from the plasma to the substrate. The chuck power supply is configured to generate a voltage applied to the substrate support to hold the substrate by electrostatic attraction. The bias energy is high-frequency power or a periodically generated voltage pulse. The substrate support includes a base and a dielectric portion. The base includes a base member and an electrode. The base member is formed from a dielectric or insulator. The electrode is formed on an upper surface of the base member. The electrode constitutes the upper surface of the base. The dielectric portion provides a support surface on which the substrate is placed. The dielectric portion extends from the upper surface of the base to the support surface and is formed solely from a dielectric. The bias power supply and the chuck power supply are electrically connected to the electrode of the base. [Effects of the Invention]

[0006] According to one exemplary embodiment, bias energy from a bias power supply can be efficiently delivered to a substrate. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram illustrating a schematic diagram of a plasma processing apparatus according to an exemplary embodiment; [Figure 2] 1 is a diagram illustrating a schematic diagram of a plasma processing apparatus according to an exemplary embodiment; [Figure 3] 1 illustrates a substrate support and multiple power supplies of a plasma processing apparatus according to an exemplary embodiment. [Figure 4] FIG. 10 illustrates a substrate support and multiple power supplies of a plasma processing apparatus according to another exemplary embodiment. [Figure 5] FIG. 10 illustrates a substrate support and multiple power supplies of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 6] FIG. 10 illustrates a substrate support and multiple power supplies of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 7] FIG. 10 illustrates a substrate support and multiple power supplies of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 8] FIG. 10 illustrates a substrate support and multiple power supplies of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 9] FIG. 10 illustrates a substrate support and multiple power supplies of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 10] FIG. 10 illustrates a substrate support and multiple power supplies of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 11] FIG. 10 illustrates a substrate support and multiple power supplies of a plasma processing apparatus according to yet another exemplary embodiment. [Figure 12] 1 is a flow diagram of a substrate processing method according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Various exemplary embodiments are described below.

[0009] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, a plasma generating unit, a bias power supply, and a chuck power supply. The substrate support is provided within the chamber. The plasma generating unit is configured to generate plasma within the chamber. The bias power supply is configured to generate bias energy to attract ions from the plasma to the substrate. The chuck power supply is configured to generate a voltage applied to the substrate support to hold the substrate by electrostatic attraction. The bias energy is high-frequency power or a periodically generated voltage pulse. The substrate support includes a base and a dielectric portion. The base includes a base member and an electrode. The base member is formed from a dielectric or insulator. The electrode is formed on an upper surface of the base member. The electrode constitutes the upper surface of the base. The dielectric portion provides a support surface on which the substrate is placed. The dielectric portion extends from the upper surface of the base to the support surface and is formed solely from a dielectric. The bias power supply and the chuck power supply are electrically connected to the electrode of the base.

[0010] In the above embodiment, since the electrodes are not provided within the dielectric portion, the thickness of the dielectric portion can be reduced. This reduces the impedance between the electrodes of the base and the substrate. As a result, bias energy is efficiently supplied to the substrate.

[0011] In one exemplary embodiment, the bias power supply may be electrically connected to the pedestal electrode through a capacitor, the bias power supply being galvanically isolated from the chuck power supply by the capacitor.

[0012] In one exemplary embodiment, the bias power supply and the chuck power supply may be electrically connected to the electrodes via wiring extending between the upper and lower surfaces of the base member.

[0013] In one exemplary embodiment, the plasma generating unit may include a high frequency power source electrically connected to an electrode on the base.

[0014] In one exemplary embodiment, the support surface of the dielectric portion may include a first region on which the substrate is placed and a second region on which the edge ring is placed. In this embodiment, the electrode of the base is a first electrode provided below the first region. The base may further include a second electrode. The second electrode is provided below the second region, constitutes the upper surface of the base, and is separated from the first electrode. A bias power supply or a separate bias power supply and a separate chuck power supply are electrically connected to the second electrode.

[0015] In one exemplary embodiment, the second electrode may include two electrodes forming a bipolar electrode, and the separate chuck power supply may include two power supplies connected to the two electrodes, respectively.

[0016] In one exemplary embodiment, the bias power supply or another bias power supply may be electrically connected to the second electrode through a capacitor, and the bias power supply or another bias power supply may be galvanically isolated from the other chuck power supply by the capacitor.

[0017] In one exemplary embodiment, the bias power supply or a separate bias power supply and a separate chuck power supply may be electrically connected to the second electrode via wiring extending between the upper and lower surfaces of the base member.

[0018] In another exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, a plasma generating unit, a bias power supply, and a chuck power supply. The substrate support is provided within the chamber. The plasma generating unit is configured to generate plasma within the chamber. The bias power supply is configured to generate bias energy to attract ions from the plasma to the substrate. The chuck power supply is configured to generate a voltage applied to the substrate support to hold the substrate by electrostatic attraction. The bias energy is high-frequency power or a periodically generated voltage pulse. The substrate support includes a base and a dielectric portion. The dielectric portion provides a support surface on which the substrate is placed, extends from the upper surface of the base to the support surface, and is made entirely of a dielectric material. The support surface includes a first region on which the substrate is placed and a second region on which an edge ring is placed. The base includes a first portion and a second portion. The first portion is made of a conductive material and is provided below the first portion. The second portion is formed from a conductive material and is disposed below the second region and separated from the first portion. The bias power supply and the chuck power supply are electrically connected to the first portion. The bias power supply or a separate bias power supply and a separate chuck power supply are electrically connected to the second portion.

[0019] In the above embodiment, since the electrodes are not provided within the dielectric portion, the thickness of the dielectric portion can be reduced. Therefore, the impedance between the first portion of the base and the substrate and the impedance between the second portion of the base and the edge ring are reduced. As a result, bias energy is efficiently supplied to the substrate and the edge ring.

[0020] In one exemplary embodiment, the second portion may include two portions that form a bipolar electrode, and the separate chuck power supply may include two power supplies connected to the two portions, respectively.

[0021] In one exemplary embodiment, the bias power supply may be electrically connected to the first portion through a capacitor. The bias power supply is galvanically isolated from the chuck power supply by the capacitor. The bias power supply or another bias power supply may be electrically connected to the second portion through a capacitor. The bias power supply or another bias power supply is galvanically isolated from the other chuck power supply by the capacitor.

[0022] In one exemplary embodiment, the plasma generating portion may include a high frequency power source electrically connected to the first portion of the base.

[0023] In yet another exemplary embodiment, there is provided a substrate processing method using the plasma processing apparatus of any of the above exemplary embodiments. The substrate processing method includes placing a substrate on a dielectric portion of a substrate support. The substrate processing method further includes generating a plasma in the chamber using the plasma generating unit. The substrate processing method further includes holding the substrate by the substrate support by supplying a voltage from a chuck power supply. The substrate processing method further includes attracting ions from the plasma to the substrate by supplying bias energy from a bias power supply.

[0024] Various exemplary embodiments will be described in detail below with reference to the drawings, in which the same or equivalent parts are designated by the same reference numerals.

[0025] 1 and 2 are diagrams schematically illustrating a plasma processing apparatus according to an exemplary embodiment.

[0026] In one embodiment, the plasma processing system includes a plasma processing device 1 and a controller 2. The plasma processing device 1 includes a plasma processing chamber 10, a substrate support 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0027] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), or surface wave plasma (SWP). Various types of plasma generating units may be used, including alternating current (AC) plasma generating units and direct current (DC) plasma generating units. In one embodiment, the AC signal (AC power) used in the AC plasma generating unit has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal includes a radio frequency (RF) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 200 kHz to 150 MHz.

[0028] The controller 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The controller 2 may be configured to control each element of the plasma processing apparatus 1 to perform various processes described herein. In one embodiment, part or all of the controller 2 may be included in the plasma processing apparatus 1. The controller 2 may include, for example, a computer 2a. The computer 2a may include, for example, a processing unit (CPU: Central Processing Unit) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 may be configured to perform various control operations based on programs stored in the storage unit 2a2. The storage unit 2a2 may include a random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0029] An exemplary configuration of a capacitively coupled plasma processing apparatus is described below as an example of the plasma processing apparatus 1. The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, multiple power sources, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The sidewall 10a is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0030] The substrate support 11 is configured to support a substrate W placed thereon. The substrate support 11 is further configured to support an edge ring ER placed thereon. The edge ring ER is an annular member formed of a material such as silicon or silicon carbide. The substrate W is disposed on the substrate support 11 within a region surrounded by the edge ring ER. The substrate support 11 may include a temperature control module configured to adjust at least one of the edge ring ER and the substrate W to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas between the back surface of the substrate W and the substrate support surface 111a.

[0031] The showerhead 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes a conductive member. The conductive member of the showerhead 13 functions as an upper electrode. In addition to the showerhead 13, the gas introduction unit may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0032] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0033] The multiple power sources include one or more high frequency power sources that constitute a plasma generating unit, one or more bias power sources that generate bias energy for attracting ions to the substrate, and one or more chuck power sources that hold the substrate W and edge ring ER by electrostatic attraction. These power sources will be described later.

[0034] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the pressure in the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0035]

[0033] Hereinafter, reference will be made to Fig. 3. Fig. 3 is a diagram showing a substrate support and a plurality of power supplies of a plasma processing apparatus according to one exemplary embodiment. The substrate support 11A shown in Fig. 3 can be employed as the substrate support 11 of the plasma processing apparatus 1.

[0036] The substrate support 11A includes a base 16 and a dielectric portion 18. The base 16 includes a base member 16b and one or more electrodes. The base member 16b is made of a dielectric or insulator. The base member 16b has a substantially disk shape. The base member 16b is made of a ceramic such as aluminum nitride or aluminum oxide.

[0037] One or more electrodes of the base 16 are formed on the upper surface of the base member 16b. The one or more electrodes of the base 16 constitute the upper surface 16u of the base 16. The one or more electrodes of the base 16 may be conductive films. In one embodiment, the base 16 may include a first electrode 161 and a second electrode 162 as the one or more electrodes. The first electrode 161 includes the center of the upper surface 16u and has a substantially circular shape. The second electrode 162 is separated from the first electrode 161. The second electrode 162 may extend in the circumferential direction so as to surround the first electrode 161. That is, the second electrode 162 may have a ring shape.

[0038] In one embodiment, the second electrode 162 may include two electrodes 162a and 162b that constitute a bipolar electrode. The two electrodes 162a and 162b are separated from each other. Each of the two electrodes 162a and 162b may have a ring shape. One of the two electrodes 162a and 162b may be radially outward of the other and extend circumferentially. Alternatively, each of the two electrodes 162a and 162b may be composed of multiple electrodes that are separated from each other and arranged circumferentially.

[0039] In one embodiment, the base 16 may include an electrode 163. The electrode 163 may be a conductive film formed on the lower surface of the base member 16b. In one embodiment, the base 16 may include a plurality of wirings 165, 166a, and 166b. The plurality of wirings 165, 166a, and 166b extend between the upper and lower surfaces of the base member 16b. The one or more wirings 165 connect the first electrode 161 and the electrode 163 to each other. The one or more wirings 166a connect to the electrode 162a. The one or more wirings 166b connect to the electrode 162b. Each of the plurality of wirings 165, 166a, and 166b may be a via hole formed in the base member 16b. Alternatively, each of the plurality of wirings 165, 166a, and 166b may be a conductor line formed along the surface of the base member 16b. The electrode 163 may be a planar electrode, or may be a wiring that connects the power supply points for the first electrode 161, the electrode 162a, and the electrode 162b to the wirings 165, 166a, and 166b, respectively.

[0040] The dielectric portion 18 provides a support surface 18s on which the substrate W is placed. The dielectric portion 18 extends from the upper surface 16u of the base 16 to the support surface 18s and is made solely of a dielectric. The dielectric portion 18 is made of a ceramic such as aluminum nitride or aluminum oxide.

[0041] In one embodiment, the support surface 18s of the dielectric portion 18 may include a first region 181 and a second region 182. The first region 181 includes the center of the support surface 18s and has a substantially circular shape. The substrate W is placed on the first region 181. The first region 181 extends above the first electrode 161 of the base 16. That is, the first electrode 161 is provided below the first region 181.

[0042] The second region 182 extends in the circumferential direction radially outward from the first region 181. That is, the second region 182 has an annular shape. The edge ring ER is placed on the second region 182. The second region 182 extends above the second electrode 162 of the base 16. That is, the second electrode 162 (electrodes 162a and 162b) is provided below the second region 182.

[0043] In one embodiment, the substrate support 11 may further include an insulator portion 11i. The insulator portion 11i covers the end face (outer peripheral surface) of the first electrode 161 and the inner end face (inner peripheral surface) of the second electrode 162 so as to hide them from plasma. In one embodiment, the dielectric portion 18 may be separated into a portion that provides the first region 181 and a portion that provides the second region 182. The insulator portion 11i may be interposed between the outer peripheral surface of the portion that provides the first region 181 and the inner peripheral surface of the portion that provides the second region 182.

[0044] The multiple power supplies of the plasma processing apparatus 1 may include chuck power supplies 31, 32, and 33. Each of the chuck power supplies 31, 32, and 33 is a DC power supply or a variable DC power supply. The chuck power supply 31 is connected to the first electrode 161 via a switch 31s, an electrode 163, and one or more wirings 165. When a DC voltage from the chuck power supply 31 is applied to the first electrode 161, the substrate W is attracted to the first region 181 by electrostatic attraction and held by the substrate support 11A.

[0045] The chuck power supply 32 is connected to the electrode 162a via a switch 32s and one or more wirings 166a. The chuck power supply 33 is connected to the electrode 162b via a switch 33s and one or more wirings 166b. When a DC voltage from the chuck power supply 32 is applied to the electrode 162a and a DC voltage from the chuck power supply 33 is applied to the electrode 162b, the edge ring ER is attracted to the second region 182 by electrostatic attraction and held by the substrate support 11A.

[0046] The multiple power sources of the plasma processing apparatus 1 include one or more radio frequency power sources and one or more bias power sources. In the example shown in Fig. 3, the multiple power sources include a radio frequency power source 51, a radio frequency power source 52, a bias power source 53, and a bias power source 54.

[0047] The high frequency power supplies 51 and 52 constitute a plasma generating unit in one embodiment. Each of the high frequency power supplies 51 and 52 generates high frequency power having a frequency suitable for generating plasma from the gas in the chamber 10. The high frequency power generated by each of the high frequency power supplies 51 and 52 has a frequency within a range of, for example, 13 MHz to 150 MHz.

[0048] The high frequency power supply 51 is connected to the first electrode 161 via a matching box 51m, an electrode 163, and one or more wirings 165. The matching box 51m includes a matching circuit for matching the impedance of the load of the high frequency power supply 51 to the output impedance of the high frequency power supply 51.

[0049] The high frequency power supply 52 is connected to the electrode 162a via a matching device 52m, a capacitor 54ca, and one or more wirings 166a. The high frequency power supply 52 is also connected to the electrode 162b via a matching device 52m, a capacitor 54cb, and one or more wirings 166b. The matching device 52m includes a matching circuit for matching the impedance of the load of the high frequency power supply 52 to the output impedance of the high frequency power supply 52. The capacitor 54ca DC-isolates the high frequency power supply 52 from the chuck power supply 32. The capacitor 54cb DC-isolates the high frequency power supply 52 from the chuck power supply 33.

[0050] The bias power supplies 53 and 54 generate bias energy for attracting ions to the substrate W and the edge ring ER. The bias energy may be high-frequency bias power. The high-frequency bias power has a frequency within a range of, for example, 100 kHz to 13.56 MHz. Alternatively, the bias energy may be periodically generated voltage pulses. The voltage pulses have positive or negative polarity. The voltage pulses may be pulses having any waveform. The voltage pulses may be negative DC voltage pulses. The voltage pulses are periodically generated at a repetition frequency within a range of 100 kHz to 13.56 MHz.

[0051] The bias power supply 53 is connected to the first electrode 161 via a matching box 53m, a capacitor 53c, an electrode 163, and one or more wirings 165. The matching box 53m includes a matching circuit for matching the impedance of the load of the bias power supply 53 to the output impedance of the bias power supply 53. The capacitor 53c is provided to DC-isolate the bias power supply 53 from the chuck power supply 31.

[0052] The bias power supply 54 is connected to the electrode 162a via a matching device 54m, a capacitor 54ca, and one or more wirings 166a. The bias power supply 54 is also connected to the electrode 162b via a matching device 54m, a capacitor 54cb, and one or more wirings 166b. The matching device 54m includes a matching circuit for matching the impedance of the load of the bias power supply 54 to the output impedance of the bias power supply 54. The capacitor 54ca is provided to DC-isolate the bias power supply 54 from the chuck power supply 32. The capacitor 54cb is provided to DC-isolate the bias power supply 54 from the chuck power supply 33.

[0053] In the plasma processing apparatus 1, since the electrodes are not provided within the dielectric portion 18, the thickness of the dielectric portion 18 can be reduced. Therefore, the impedance between the first electrode 161 of the base 16 and the substrate W is reduced. Furthermore, the impedance between each of the electrodes 162a and 162b of the base 16 and the edge ring ER is reduced. As a result, bias energy is efficiently supplied to the substrate W. Furthermore, bias energy is efficiently supplied to the edge ring ER. Furthermore, high-frequency power is efficiently coupled to the plasma via the substrate W and the edge ring ER. Therefore, it is possible to reduce the bias energy. Furthermore, it is possible to reduce the high-frequency power. Therefore, heat generation in the electrodes, contacts, etc. of the substrate support portion 11A is suppressed.

[0054] Furthermore, since the base member 16b of the base 16 is formed from a dielectric or an insulator, there is a small difference in the thermal expansion coefficient between the base 16 and the dielectric portion 18. Therefore, damage to the substrate support portion 11A caused by the difference in the thermal expansion coefficient between the base 16 and the dielectric portion 18 is suppressed.

[0055] In one embodiment, the dielectric portion 18 may satisfy the following (1). 0.5×C W0 / S W < C FO / S F < 1.5×C W0 / S W …(1) In formula (1), C W0 is the capacitance between the base 16 and the substrate W. W is the area of one main surface of the substrate W (for example, the bottom surface or the surface in contact with the plasma). FO is the capacitance between the base 16 and the edge ring ER. F is the area of one main surface of the edge ring (e.g., the lower surface or the surface in contact with the plasma). By satisfying formula (1), the difference between the power density of the high-frequency power coupled to the plasma through the substrate W and the power density of the high-frequency power coupled to the plasma through the edge ring ER is reduced. Therefore, variations in the plasma density in the chamber are suppressed.

[0056] In one embodiment, the substrate support 11A may be configured so that the capacitance between the substrate W and the edge ring ER is 10 nF or less, or 3 nF or less, thereby suppressing electrical coupling between the substrate W and the edge ring ER.

[0057] Reference is now made to FIG. 4, which illustrates a substrate support and multiple power supplies of a plasma processing apparatus according to another exemplary embodiment. The substrate support 11B illustrated in FIG. 4 can be employed as the substrate support 11 of the plasma processing apparatus 1. The substrate support 11B further includes one or more wirings 165a and one or more wirings 165b. The one or more wirings 165a and the one or more wirings 165b extend between the upper and lower surfaces of the base member 16b. The one or more wirings 165a connect the electrode 163 and the electrode 162a to each other. The one or more wirings 165b connect the electrode 163 and the electrode 162b to each other.

[0058] Each of the one or more wirings 165a and the one or more wirings 165b may be a via hole formed in the base member 16b, or each of the one or more wirings 165a and the one or more wirings 165b may be a conductor line formed along the surface of the base member 16b.

[0059] In the example shown in Fig. 4, the plasma processing apparatus 1 does not include a high-frequency power supply 52 and a matching box 52m. In the example shown in Fig. 4, the high-frequency power supply 51 is connected to the electrode 162a via a matching box 51m, an electrode 163, and one or more wirings 165a. The high-frequency power supply 51 is also connected to the electrode 162b via a matching box 51m, an electrode 163, and one or more wirings 165b. In the example shown in Fig. 4, high-frequency power from the single high-frequency power supply 51 is distributed to the first electrode 161 and the second electrode 162. Note that each of the other components in the example shown in Fig. 4 is the same as the corresponding components in the example shown in Fig. 3.

[0060]

[0043] Referring now to Figure 5, which is a diagram illustrating a substrate support and multiple power supplies in a plasma processing apparatus according to yet another exemplary embodiment. As shown in Figure 5, the plasma processing apparatus 1 does not necessarily have to include the high-frequency power supply 52, the matching box 52m, the bias power supply 54, and the matching box 54m.

[0061] As shown in FIG. 5 , the high-frequency power supply 51 is connected to the electrode 162a via a matching device 51m, an impedance circuit 56, a capacitor 53ca, and a wiring 166a. The high-frequency power supply 51 is also connected to the electrode 162b via a matching device 51m, an impedance circuit 56, a capacitor 53cb, and a wiring 166b. The bias power supply 53 is also connected to the electrode 162a via a matching device 53m, an impedance circuit 56, a capacitor 53ca, and a wiring 166a. The bias power supply 53 is also connected to the electrode 162b via a matching device 53m, an impedance circuit 56, a capacitor 53cb, and a wiring 166b. The capacitor 53ca is provided to DC-isolate the high-frequency power supply 51 and the bias power supply 53 from the chuck power supply 32. The capacitor 53cb is provided to DC-isolate the high-frequency power supply 51 and the bias power supply 53 from the chuck power supply 33.

[0062] The impedance circuit 56 has a variable impedance. The impedance circuit includes a variable impedance element such as a variable capacitor. In the plasma processing apparatus 1 of the example shown in FIG. 5, high-frequency power from a single high-frequency power supply 51 is distributed to a first electrode 161 and a second electrode 162. In the plasma processing apparatus 1 of the example shown in FIG. 5, bias energy from a single bias power supply 53 is distributed to the first electrode 161 and the second electrode 162. The distribution ratio of the high-frequency power and the bias energy is set by adjusting the variable impedance of the impedance circuit 56. Note that each of the other components in the example shown in FIG. 5 is the same as the corresponding components in the example shown in FIG. 3.

[0063] Reference will now be made to FIG. 6, which is a diagram illustrating a substrate support and a plurality of power supplies of a plasma processing apparatus according to yet another exemplary embodiment. A substrate support 11D shown in FIG. 6 can be employed as the substrate support 11 of the plasma processing apparatus 1. The substrate support 11D has a base 16D instead of the base 16. The base 16D includes a first portion 161D and a second portion 162D.

[0064] Each of the first portion 161D and the second portion 162D is made of a conductive material, such as a metal, such as aluminum, or a metal-ceramic composite material.

[0065] The first portion 161D is provided below the first region 181. The first portion 161D includes the center of the base 16D and has a generally disk shape. The second portion 162D is provided below the second region 182. The second portion 162D extends in the circumferential direction radially outside the first portion 161D. The second portion 162D may have a generally ring shape in a plan view. The second portion 162D is separated from the first portion 161D. The gap between the first portion 161D and the second portion 162D may be filled with an insulating material (insulating portion 11i) or a dielectric material.

[0066] In one embodiment, the second portion 162D may include portions 162e and 162f. The portions 162e and 162f constitute a bipolar electrode. Each of the portions 162e and 162f extends circumferentially radially outward from the first portion 161D. Each of the portions 162e and 162f may have a generally annular shape in a plan view. The portion 162f may extend circumferentially radially outward from the portion 162e. The portions 162e and 162f are separated from each other. A gap between the portions 162e and 162f may be filled with an insulating material or a dielectric material.

[0067] The chuck power supply 31 is connected to the first portion 161D via the switch 31s. When a DC voltage from the chuck power supply 31 is applied to the first portion 161D, the substrate W is attracted to the first region 181 by electrostatic attraction and held by the substrate support portion 11D.

[0068] The chuck power supply 32 is connected to the portion 162e via a switch 32s. The chuck power supply 33 is connected to the portion 162f via a switch 33s. When a DC voltage from the chuck power supply 32 is applied to the portion 162e and a DC voltage from the chuck power supply 33 is applied to the portion 162f, the edge ring ER is attracted to the second region 182 by electrostatic attraction and held by the substrate support 11D.

[0069] The high frequency power supply 51 is connected to the first section 161D via a matching device 51m. The high frequency power supply 52 is connected to the section 162e via a matching device 52m and a capacitor 54ca. The high frequency power supply 52 is also connected to the section 162f via a matching device 52m and a capacitor 54cb.

[0070] The bias power supply 53 is connected to the first section 161D via a matching device 53m and a capacitor 53c. The bias power supply 54 is connected to the section 162e via a matching device 54m and a capacitor 54ca. The bias power supply 54 is also connected to the section 162f via a matching device 54m and a capacitor 54cb.

[0071] In the substrate support 11D, since no electrodes are provided within the dielectric portion 18, the thickness of the dielectric portion 18 can be reduced. Therefore, the impedance between the first portion 161D of the base 16D and the substrate W and the impedance between the second portion 162D of the base 16D and the edge ring ER are reduced. As a result, bias energy is efficiently supplied to the substrate W and the edge ring ER.

[0072] In one embodiment, the dielectric portion 18 may satisfy the following (2). 0.5×CW0 / S W < C FO / S F < 1.5×C W0 / S W …(2) In equation (2), C W0 is the capacitance between the base 16D and the substrate W. W is the area of one main surface of the substrate W (for example, the bottom surface or the surface in contact with the plasma). FO is the capacitance between the base 16D and the edge ring ER. F is the area of one main surface of the edge ring ER (e.g., the lower surface or the surface in contact with the plasma). When formula (2) is satisfied, the difference between the power density of the high-frequency power coupled to the plasma through the substrate W and the power density of the high-frequency power coupled to the plasma through the edge ring ER is reduced. Therefore, variations in the plasma density in the chamber are suppressed.

[0073] In one embodiment, the substrate support 11D may be configured so that the capacitance between the substrate W and the edge ring ER is 10 nF or less, or 3 nF or less, thereby suppressing electrical coupling between the substrate W and the edge ring ER.

[0074]

[0043] Referring now to Figure 7, which is a diagram showing a substrate support and a plurality of power supplies of a plasma processing apparatus according to yet another exemplary embodiment. As shown in Figure 7, the plasma processing apparatus 1 does not necessarily have to include the high-frequency power supply 52, the matching box 52m, the bias power supply 54, and the matching box 54m.

[0075] 7, the high frequency power supply 51 is connected to the portion 162e via a matching device 51m, an impedance circuit 56, and a capacitor 53ca. The high frequency power supply 51 is also connected to the portion 162f via a matching device 51m, an impedance circuit 56, and a capacitor 53cb. The bias power supply 53 is also connected to the portion 162e via a matching device 53m, an impedance circuit 56, and a capacitor 53ca. The bias power supply 53 is also connected to the portion 162f via a matching device 53m, an impedance circuit 56, and a capacitor 53cb.

[0076] In the plasma processing apparatus 1 of the example shown in Fig. 7, high-frequency power from a single high-frequency power supply 51 is distributed to a first portion 161D and a second portion 162D. Also, in the plasma processing apparatus 1 of the example shown in Fig. 7, bias energy from a single bias power supply 53 is distributed to the first portion 161D and a second portion 162D. The distribution ratio of the high-frequency power and the bias energy is set by adjusting the variable impedance of the impedance circuit 56. Note that each of the other components in the example shown in Fig. 7 is the same as the corresponding components in the example shown in Fig. 6.

[0077] Reference is now made to FIG. 8, which illustrates a substrate support and multiple power supplies of a plasma processing apparatus according to yet another exemplary embodiment. In the substrate support 11A and the substrate support 11B described above, the second electrode 162 includes two electrodes, whereas in the substrate support 11E shown in FIG. 8, the second electrode 162E is configured as a single electrode. A wiring 166 extending from the lower surface of the base member 16b through the end surface is connected to the second electrode 162E. Each of the one or more wirings 165 may connect the electrode 163 and the first electrode 161 via a groove formed in the peripheral portion of the base member 16b.

[0078] The chuck power supply 32 is connected to the second electrode 162E via a switch 32s and a wiring 166. The high-frequency power supply 52 is connected to the second electrode 162E via a matching device 52m, a capacitor 54c, and a wiring 166. The bias power supply 54 is connected to the second electrode 162E via a matching device 54m, a capacitor 54c, and a wiring 166. The high-frequency power from the high-frequency power supply 51 may be distributed to the first electrode 161 and the second electrode 162E. The bias energy from the bias power supply 53 may be distributed to the first electrode 161 and the second electrode 162E.

[0079]

[0093] Reference will now be made to Fig. 9, which is a diagram illustrating a substrate support and a plurality of power supplies of a plasma processing apparatus according to yet another exemplary embodiment. In the above-described substrate support 11D, the second portion 162D includes two portions 162e and 162f, whereas in the base 16F of the substrate support 11F shown in Fig. 9, the second portion 162F is configured as a single portion.

[0080] The chuck power supply 32 is connected to the second section 162F via a switch 32s. The high-frequency power supply 52 is connected to the second section 162F via a matching device 52m and a capacitor 54c. The bias power supply 54 is connected to the second section 162F via a matching device 54m and a capacitor 54c. The high-frequency power from the high-frequency power supply 51 may be distributed to the first section 161D and the second section 162F. The bias energy from the bias power supply 53 may be distributed to the first section 161D and the second section 162F.

[0081] Reference will now be made to FIG. 10 . FIG. 10 is a diagram illustrating a substrate support and a plurality of power supplies of a plasma processing apparatus according to yet another exemplary embodiment. The example illustrated in FIG. 10 is a modified example of the example illustrated in FIG. 3 . In the example illustrated in FIG. 10 , a flow path 16f is formed in the base 16. A heat transfer medium (e.g., a refrigerant) is supplied to the flow path 16f from a supplier. The heat transfer medium flows through the flow path 16f and is returned to the supplier. The flow path 16f may be formed to have a large cross-sectional area as long as the mechanical strength of the base 16 is not impaired. Note that the flow path 16f may also be formed in the base 16 in the above-described examples other than the example illustrated in FIG. 3 .

[0082] Reference will now be made to FIG. 11 . FIG. 11 illustrates a substrate support and a plurality of power supplies of a plasma processing apparatus according to yet another exemplary embodiment. The example illustrated in FIG. 11 is a modification of the example illustrated in FIG. 6 . In the example illustrated in FIG. 11 , a flow path 16f is formed in a base 16D. A heat transfer medium (e.g., a refrigerant) is supplied from a supplier to the flow path 16f. The heat transfer medium flows through the flow path 16f and is returned to the supplier. The flow path 16f may be formed to have a large cross-sectional area as long as it does not impair the mechanical strength of the base 16D. Note that the flow path 16f may be formed in the base 16D in the above-described examples other than the example illustrated in FIG. 6 . The flow path 16f may also be formed in the base 16F in the example illustrated in FIG. 9 .

[0083] Reference will now be made to FIG. 12. FIG. 12 is a flowchart of a substrate processing method according to one exemplary embodiment. The substrate processing method shown in FIG. 12 (hereinafter referred to as "method MT") can be performed using the above-described plasma processing apparatus 1. In method MT, each part of the plasma processing apparatus 1 can be controlled by a control unit 2. Method MT includes steps STa, STb, STc, and STd.

[0084] In step STa, the substrate W is placed on the dielectric portion 18 of the substrate support portion. Steps STb, STc, and STd are performed in a state in which the substrate W is placed on the dielectric portion 18.

[0085] In step STb, plasma is generated in the chamber 10 using the plasma generation unit. In step STb, a processing gas is supplied from the gas supply unit 20 into the chamber 10. Also, in step STb, the pressure in the chamber 10 is reduced to a specified pressure by the exhaust system 40. Also, in step STb, high-frequency power is supplied to generate plasma from the processing gas.

[0086] In step STc, the substrate W is held by the substrate support by applying a voltage from the chuck power supply 31. Note that the edge ring ER may be held by the substrate support in step STc by applying a voltage from the chuck power supplies 32 and 33. Alternatively, the edge ring ER may be held by the substrate support at a time point before step STb.

[0087] Step STd is performed while the plasma is being generated in step STb. In step STd, bias energy is supplied to attract ions from the plasma to the substrate W.

[0088] 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. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0089] For example, the RF power from the RF power supply may be supplied to the upper electrode rather than to the substrate support. In another embodiment, the plasma processing apparatus may be a type of plasma processing apparatus other than a capacitively coupled type. Such a plasma processing apparatus may be an inductively coupled type 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.

[0090] 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]

[0091] 1...plasma processing apparatus, 11...substrate support portion, 16...base, 18...dielectric portion, 51...high frequency power supply, 53...bias power supply, 31...chuck power supply.

Claims

1. a chamber; a substrate support disposed within the chamber; a plasma generating unit configured to generate plasma within the chamber; a bias power supply configured to generate bias energy to attract ions from the plasma to a substrate; a chuck power supply configured to generate a voltage applied to the substrate support to hold the substrate by electrostatic attraction; Equipped with the bias energy is a high frequency power or a periodically generated voltage pulse; The substrate support includes: a base including a base member made of a dielectric or an insulator and an electrode formed on an upper surface of the base member, the electrode constituting an upper surface of the base; a dielectric portion that provides a support surface on which a substrate is placed, extends from the upper surface of the base to the support surface, and is made solely of a dielectric material; Including, the bias power supply and the chuck power supply are electrically connected to the electrode of the base; the support surface includes a first region on which a substrate is placed and a second region on which an edge ring is placed; the electrode is a first electrode provided below the first region, the base further includes a second electrode; the second electrode is provided below the second region, forms the upper surface of the base, and is separated from the first electrode; the bias power supply or a separate bias power supply and a separate chuck power supply are electrically connected to the second electrode; The dielectric portion satisfies formula (1), 0.5×C W0 / S W < C FO / S F < 1.5×C W0 / S W …(1) In the formula (1), C W0 is the capacitance between the base and the substrate, S W is the area of one main surface of the substrate, C FO is the capacitance between the base and the edge ring, and S F is the area of one main surface of the edge ring. Plasma processing equipment.

2. 2. The plasma processing apparatus of claim 1, wherein the bias power supply is electrically connected to the electrode through a capacitor and is DC isolated from the chuck power supply.

3. 3. The plasma processing apparatus according to claim 1, wherein the bias power supply and the chuck power supply are electrically connected to the electrodes via wiring extending between the upper and lower surfaces of the base member.

4. 4. The plasma processing apparatus according to claim 1, wherein the plasma generating unit includes a high frequency power source electrically connected to the electrode of the base.

5. the second electrode includes two electrodes constituting a bipolar electrode; the separate chuck power supply includes two power supplies connected to the two electrodes, respectively; The plasma processing apparatus according to any one of claims 1 to 4.

6. 6. The plasma processing apparatus of claim 1, wherein the bias power supply or another bias power supply is electrically connected to the second electrode via a capacitor and is DC-isolated from the other chuck power supply.

7. 7. The plasma processing apparatus according to claim 1, wherein the bias power supply or the other bias power supply and the other chuck power supply are electrically connected to the second electrode via wiring extending between the upper and lower surfaces of the base member.

8. A plasma processing apparatus described in any one of claims 1 to 7, wherein the substrate support portion is configured so that the electrostatic capacitance between the substrate and the edge ring is 10 nF or less.

9. A plasma processing apparatus described in any one of claims 1 to 7, wherein the substrate support portion is configured so that the electrostatic capacitance between the substrate and the edge ring is 3 nF or less.

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