Plasma processing apparatus and electrostatic chuck

Abstract

To provide a technique for suppressing occurrence of abnormal discharge in a through hole of an electrostatic chuck.SOLUTION: There is provided a plasma processing apparatus including a plasma processing chamber, a base disposed in the plasma processing chamber, and an electrostatic chuck. The electrostatic chuck includes a placing table, an electrostatic electrode, a bias electrode, an embedding member, and a conductive member. The mounting table includes an upper surface, a lower surface opposite to the upper surface, and a through hole penetrating the upper surface and the lower surface. The embedded member is disposed in the through hole and has a diameter smaller than a hole diameter of the through hole. The conductive member is spaced apart from the electrostatic electrode and the bias electrode within the mounting table. The conductive member includes a tubular portion surrounding the through hole, and a flange portion extending radially outward from an upper end of the tubular portion in parallel with the upper surface.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] Exemplary embodiments of the present disclosure relate to plasma processing apparatuses and electrostatic chucks. [Background technology]

[0002] Patent Documents 1 and 2 disclose electrostatic chucks with through holes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2023 / 074475 [Patent Document 2] International Publication No. 2023 / 095707 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for suppressing the occurrence of abnormal discharge in a through-hole of an electrostatic chuck. [Means for solving the problem]

[0005] In one exemplary embodiment of the present disclosure, there is provided a plasma processing apparatus including: a plasma processing chamber; a base disposed within the plasma processing chamber; and an electrostatic chuck, the electrostatic chuck including a mounting table having an upper surface, a lower surface opposite the upper surface, and a through hole penetrating the upper and lower surfaces; an embedded member disposed within the through hole and having a diameter smaller than the diameter of the through hole; an electrostatic electrode and a bias electrode disposed inside the mounting table; and a conductive member disposed within the mounting table and spaced apart from the electrostatic electrode and the bias electrode, the conductive member having a cylindrical portion surrounding the through hole and a flange portion extending radially outward from the upper end of the cylindrical portion parallel to the upper surface. [Effects of the Invention]

[0006] According to one exemplary embodiment of the present disclosure, a technique for suppressing the occurrence of abnormal discharge in a through-hole of an electrostatic chuck can be provided. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a plasma processing system. [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of a capacitively coupled plasma processing apparatus. [Figure 3] 4 is a schematic cross-sectional view for explaining an example of the configuration of a substrate support portion. FIG. [Figure 4] FIG. 4 is an enlarged view of area A in FIG. 3. [Figure 5] FIG. 2 is a perspective view illustrating an example of a conductive member. [Figure 6] FIG. 4 is a diagram illustrating an example of a voltage pulse signal. [Figure 7A] 10A and 10B are diagrams for explaining a potential difference between a substrate and a filling member; [Figure 7B] 10A and 10B are diagrams for explaining a potential difference between a substrate and a filling member; DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, each embodiment of the present disclosure will be described.

[0009] In one exemplary embodiment, a plasma processing apparatus is provided, comprising: a plasma processing chamber; a base disposed within the plasma processing chamber; and an electrostatic chuck, the electrostatic chuck comprising: a mounting base having an upper surface, a lower surface opposite the upper surface, and a through hole penetrating the upper and lower surfaces; an embedded member disposed within the through hole and having a diameter smaller than the diameter of the through hole; an electrostatic electrode and a bias electrode disposed inside the mounting base; and a conductive member disposed within the mounting base and spaced apart from the electrostatic electrode and the bias electrode, the conductive member having a cylindrical portion surrounding the through hole and a flange portion extending radially outward from the upper end of the cylindrical portion parallel to the upper surface.

[0010] In one exemplary embodiment, the electrostatic electrode is positioned below and parallel to the top surface, and the bias electrode is positioned below the electrostatic electrode and parallel to the top surface.

[0011] In one exemplary embodiment, the electrostatic electrode is disposed so as not to overlap the flange portion in a plan view.

[0012] In one exemplary embodiment, the bias electrode is arranged so as not to overlap the flange portion in a plan view.

[0013] In one exemplary embodiment, the distance from the upper surface to the flange portion is equal to or less than the distance from the upper surface to the electrostatic electrode.

[0014] In one exemplary embodiment, the distance from the upper surface to the lower end of the barrel is equal to or greater than the distance from the upper surface to the bias electrode.

[0015] In one exemplary embodiment, a flow path for heat transfer gas is formed in the gap between the inner wall of the through-hole and the embedded member.

[0016] In one exemplary embodiment, the device further comprises a voltage pulse generator electrically connected to the bias electrode and configured to generate a voltage pulse signal, the voltage pulse signal having a sequence of voltage pulses, each of the voltage pulses having a negative voltage level.

[0017] In one exemplary embodiment, the upper surface constitutes a substrate support surface.

[0018] In one exemplary embodiment, the upper surface defines a ring support surface that surrounds the periphery of the substrate support surface.

[0019] In one exemplary embodiment, an electrostatic chuck is provided that includes: a mounting table having an upper surface, a lower surface opposite the upper surface, and a through hole penetrating the upper and lower surfaces; an embedded member disposed in the through hole and having a diameter smaller than the diameter of the through hole; an electrostatic electrode and a bias electrode disposed inside the mounting table; and a conductive member disposed inside the mounting table and spaced apart from the electrostatic electrode and the bias electrode, the conductive member having a cylindrical portion surrounding the through hole and a flange portion extending radially outward from the upper end of the cylindrical portion parallel to the upper surface.

[0020] In one exemplary embodiment, the electrostatic electrode is positioned below and parallel to the top surface, and the bias electrode is positioned below the electrostatic electrode and parallel to the top surface.

[0021] In one exemplary embodiment, the electrostatic electrode is disposed so as not to overlap the flange portion in a plan view.

[0022] In one exemplary embodiment, the bias electrode is arranged so as not to overlap the flange portion in a plan view.

[0023] In one exemplary embodiment, the distance from the upper surface to the flange portion is equal to or less than the distance from the upper surface to the electrostatic electrode.

[0024] In one exemplary embodiment, the distance from the upper surface to the lower end of the barrel is equal to or greater than the distance from the upper surface to the bias electrode.

[0025] In one exemplary embodiment, a flow path for heat transfer gas is formed in the gap between the inner wall of the through-hole and the embedded member.

[0026] In one exemplary embodiment, the bias electrode is configured to be supplied with a voltage pulse signal, the voltage pulse signal having a sequence of voltage pulses, each of the voltage pulses having a negative voltage level.

[0027] In one exemplary embodiment, the upper surface constitutes a substrate support surface.

[0028] In one exemplary embodiment, the upper surface defines a ring support surface that surrounds the periphery of the substrate support surface.

[0029] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or similar elements are designated by the same reference numerals, and redundant explanations will be omitted. Unless otherwise specified, the positional relationships, such as up, down, left, and right, will be described based on the positional relationships shown in the drawings. The dimensional ratios in the drawings do not represent actual ratios, and the actual ratios are not limited to the ratios shown in the drawings.

[0030] <Configuration example of plasma processing system> FIG. 1 is a diagram illustrating an exemplary configuration of a plasma processing system. In one embodiment, the plasma processing system includes a plasma processing device 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing device 1 is an example of a substrate processing device. 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.

[0031] 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 100 kHz to 150 MHz.

[0032] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 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 control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. The program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). 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).

[0033] The following describes a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1. Fig. 2 is a diagram for explaining a configuration example of a capacitively coupled plasma processing apparatus.

[0034] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply 20, a power supply 30, 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 process 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 plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0035] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0036] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that the annular region 111b may also be provided by another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Furthermore, at least one RF / DC electrode coupled to an RF power supply 31 and / or a DC power supply 32, which will be described later, may be disposed within the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal, which will be described later, is supplied to the at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple lower electrodes. Alternatively, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0037] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0038] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow passage 1110a, or a combination thereof. A heat transfer fluid such as brine or a gas flows through the flow passage 1110a. In one embodiment, the flow passage 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply configured to supply a heat transfer gas to a gap between the backside of the substrate W and the central region 111a.

[0039] 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 at least one 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.

[0040] 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.

[0041] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. This generates a plasma from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generation unit 12. Furthermore, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, and ion components in the formed plasma can be attracted to the substrate W.

[0042] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0043] The second RF generating unit 31b is coupled to at least one lower electrode via at least one impedance matching circuit and configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generating unit 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0044] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0045] In various embodiments, the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or combination thereof. In one embodiment, a waveform generator for generating a sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0046] 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.

[0047] <Example of a substrate support part> Fig. 3 is a schematic cross-sectional view for explaining an example of the configuration of a substrate support portion, Fig. 4 is an enlarged view of an area A in Fig. 3, and Fig. 5 is a perspective view showing an example of a conductive member.

[0048] As shown in FIG. 3, the main body 111 of the substrate support 11 includes a base 1110 and an electrostatic chuck 1111 .

[0049] The base 1110 is made of a conductive material such as aluminum. A flow path 1110a is formed in the base 1110. A heat transfer fluid such as brine or gas flows through the flow path 1110a. In one embodiment, the base 1110 and the electrostatic chuck 1111 are integrated with each other by, for example, an adhesive layer. The base 1110 may be made of an insulating ceramic such as SiC. In this case, the base 1110 does not function as a lower electrode.

[0050] The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a is an example of the "mounting table" in the present disclosure. The ceramic member 1111a is formed in a substantially circular plate shape. The ceramic member 1111a is formed of a ceramic material such as aluminum oxide or aluminum nitride. The ceramic member 1111a has a central region 111a and an annular region 111b on its upper surface. The ceramic member 1111a may be formed by thermal spraying of the ceramic material. The ceramic member 1111a has a through-hole 114a penetrating from its lower surface to the central region 111a. The ceramic member 1111a also has a through-hole 118a penetrating from its lower surface to the annular region 111b.

[0051] In one embodiment, the central region 111a has a diameter smaller than the diameter of the substrate W and is positioned higher than the annular region 111b. Therefore, when the substrate W is supported on the central region 111a, a peripheral portion of the substrate W extends horizontally beyond the central region 111a.

[0052] In the example of FIG. 3, an integrally formed ceramic member 1111a has a central region 111a and an annular region 111b. The ceramic member 1111a may be divided into a central portion and an annular portion. In this case, the central portion may have the central region 111a, and the annular portion may have the annular region 111b. In the example of FIG. 3, the central portion and the annular portion are integrally formed. The central portion and the annular portion may also be formed as separate bodies.

[0053] In the example of FIG. 3, the electrostatic chuck 1111 includes a bias electrode 1111c in addition to the electrostatic electrode 1111b. Both the electrostatic electrode 1111b and the bias electrode 1111c are disposed within the ceramic member 1111a and below the central region 111a. Power is applied to the electrostatic electrode 1111b from an AC power source or a DC power source (not shown). The electrostatic force generated thereby attracts and holds the substrate W to the central region 111a. That is, the electrostatic electrode 1111b functions as an attraction electrode for the substrate W. In one embodiment, the electrostatic electrode 1111b is formed in a circular shape in a plan view. The electrostatic electrode 1111b may also have a plurality of electrode segments divided, for example, in the radial and / or circumferential directions.

[0054] The bias electrode 1111c is disposed below the electrostatic electrode 1111b. A bias RF signal and / or a DC signal is applied to the bias electrode 1111c from an RF power supply or a DC power supply (not shown), i.e., a bias power supply. This causes ions in the plasma to be attracted toward the substrate W in the central region 111a. In one embodiment, the bias electrode 1111c is formed in a circular shape in a plan view. The bias electrode 1111c may have a plurality of electrode segments divided, for example, in the radial and / or circumferential directions. The bias power supply may be the second RF generator 31b or the first DC generator 32a described above.

[0055] The base 1110 includes a sleeve 113. The sleeve 113 is disposed in a through-hole that penetrates the base 1110 from the lower surface to the upper surface below the central region 111a. The sleeve 113 is formed of an insulating material. The sleeve 113 has a substantially cylindrical shape and has a through-hole 114b. The through-hole 114b of the sleeve 113 communicates with the through-hole 114a of the ceramic member 1111a. Hereinafter, the through-holes 114a and 114b will be collectively referred to as the through-holes 114. In one embodiment, the through-holes 114 are provided at multiple locations in the central region 111a.

[0056] The electrostatic chuck 1111 includes an embedding member 115 disposed inside the through-hole 114. In one embodiment, the vertical cross section of the embedding member 115 has a convex shape. The diameter of the embedding member 115 is smaller than the diameter of the through-hole 114. A heat transfer gas flow path through which a heat transfer gas flows is formed in the gap between the inner wall of the through-hole 114 and the embedding member 115.

[0057] The embedding member 115 may be made of, for example, any one of quartz, silicon carbide, silicon nitride, aluminum oxide, aluminum nitride, yttria, titanium oxide, and tungsten carbide. The embedding member 115 may also be made of any one of silicon, tungsten, titanium, silicone, Teflon (registered trademark), elastomer, and fluororesin. The embedding member 115 may be composed of multiple members divided in the radial and / or vertical directions. Each member constituting the embedding member 115 may be made of the same or different materials.

[0058] The electrostatic chuck 1111 includes a conductive member 116. The conductive member 116 is disposed within the ceramic member 1111a. The conductive member 116 is disposed below the central region 111a and spaced apart from the electrostatic electrode 1111b and the bias electrode 1111c. The conductive member 116 is formed of a conductive material. Examples of conductive materials include metals and conductive ceramics. In one embodiment, the conductive member 116 is completely embedded within the ceramic member 1111a and is not exposed to the through-holes 114a.

[0059] As shown in FIGS. 4 and 5, the conductive member 116 includes a tubular portion 116a and a flange portion 116b. The tubular portion 116a has a generally cylindrical shape. The tubular portion 116a extends in the vertical direction so as to surround the periphery of the through-hole 114a. The flange portion 116b has a generally annular shape. The flange portion 116b extends in the horizontal direction from the upper end of the tubular portion 116a toward the radially outer side of the tubular portion 116a. In other words, the flange portion 116b is disposed parallel to the central region 111a and the substrate W on the central region 111a. The thickness (horizontal length) of the tubular portion 116a and the thickness (vertical length) of the flange portion 116b may be the same or different.

[0060] The cylindrical portion 116a functions to shield the through hole 114 and the embedding member 115 from the influence of the electric field generated around the electrostatic electrode 1111b and / or the bias electrode 1111c. The flange portion 116b also functions to ensure electrostatic capacitance with the substrate W and to bring the potential of the conductive member 116 closer to the potential of the substrate W. Due to the above function of the conductive member 116, the potential of the through hole 114 surrounded by the conductive member 116 and the embedding member 115 inside the through hole 114 approaches the potential of the substrate W. Furthermore, even if the potential of the substrate W fluctuates, the potential of the through hole 114 and the embedding member 115 follows the fluctuation. This can prevent a potential difference equal to or greater than the discharge start voltage from occurring between the substrate W and the upper surface of the embedding member 115, causing an abnormal discharge.

[0061] 4, the distance h1 from the central region 111a to the flange portion 116b may be equal to or smaller than the distance h3 from the central region 111a to the electrostatic electrode 1111b. That is, h1≦h3 may be satisfied. By reducing the distance h1 from the central region 111a to the flange portion 116b, the capacitance with the substrate W increases, and the potential of the conductive member 116 and the potential of the through-hole 114 and the embedded member 115 surrounded by the conductive member 116 become closer to the potential of the substrate W.

[0062] 4, the electrostatic electrode 1111b and the bias electrode 1111c may be arranged so as not to overlap the flange portion 116b in a plan view. In other words, the electrostatic electrode 1111b and the bias electrode 1111c do not need to be arranged below the flange portion 116b. This allows the cylindrical portion 116a to be arranged further away from the electrostatic electrode 1111b and the bias electrode 1111c, making it less susceptible to the influence of the electric fields of the electrostatic electrode 1111b and the bias electrode 1111c. This makes the potential of the conductive member 116 and the potential of the through hole 114 and the embedded member 115 surrounded by the conductive member 116 closer to the potential of the substrate W.

[0063] 4, the distance h2 from the central region 111a to the lower end of the cylindrical portion 116a may be equal to or greater than the distance h4 from the central region 111a to the bias electrode 1111c. That is, h2≧h4 may be satisfied. Since the cylindrical portion 116a extends to the horizontal plane on which the bias electrode 1111c is disposed or below the horizontal plane, the shielding function of the cylindrical portion 116a can be further enhanced.

[0064] As shown in FIG. 3, the ceramic member 1111a includes a ring electrostatic electrode 1111d and a ring bias electrode 1111e. The ring electrostatic electrode 1111d and the ring bias electrode 1111e are disposed below the annular region 111b. Power is applied to the ring electrostatic electrode 1111d from an AC power supply or a DC power supply (not shown). The resulting electrostatic force attracts and holds the ring assembly 112 (edge ​​ring) to the annular region 111b. That is, the ring electrostatic electrode 1111d functions as an attraction electrode for the edge ring. In one embodiment, the ring electrostatic electrode 1111d is formed in an annular shape in a plan view. The ring electrostatic electrode 1111d may also have multiple electrode segments divided, for example, in the radial and / or circumferential directions. Note that, although both the ring electrostatic electrode 1111d and the ring bias electrode 1111e are disposed within the ceramic member 1111a in the example of FIG. 3, this is not limiting. For example, only one of the ring electrostatic electrode 1111d and the ring bias electrode 1111e may be disposed within the ceramic member 1111a.

[0065] The ring bias electrode 1111e is disposed below the ring electrostatic electrode 1111d. A bias RF signal and / or a DC signal is applied to the ring bias electrode 1111e from an RF power supply or a DC power supply (not shown). This adjusts the plasma sheath in the outer peripheral region of the substrate W and above the edge ring, thereby improving the in-plane uniformity of the plasma processing. In one embodiment, the ring bias electrode 1111e is formed in an annular shape in a plan view. The ring bias electrode 1111e may also have a plurality of electrode segments divided, for example, in the radial and / or circumferential directions.

[0066] The base 1110 includes a sleeve 117. The sleeve 117 is disposed in a through-hole that penetrates the base 1110 from the lower surface to the upper surface below the annular region 111b. The sleeve 117 is formed of an insulating material. The sleeve 117 has a substantially cylindrical shape and has a through-hole 118b. The through-hole 118b of the sleeve 117 communicates with the through-hole 118a of the ceramic member 1111a. Hereinafter, the through-holes 118a and 118b will be collectively referred to as the through-holes 118. In one embodiment, the through-holes 118 are provided at multiple locations in the annular region 111b.

[0067] The electrostatic chuck 1111 includes an embedding member 119 disposed inside the through-hole 118. In one embodiment, the embedding member 119 has a convex cross section. The diameter of the embedding member 119 is smaller than the diameter of the through-hole 118. This forms a heat transfer gas flow path through which a heat transfer gas flows in the gap between the embedding member 119 and the inner wall of the through-hole 118. The embedding member 119 may be configured similarly to the embedding member 115 described above.

[0068] The electrostatic chuck 1111 includes a conductive member 120 disposed within the ceramic member 1111a and spaced apart from the ring electrostatic electrode 1111d and the ring bias electrode 1111e below the annular region 111b. The conductive member 120 may have a configuration similar to that of the conductive member 116 described above. The conductive member 120 functions to bring the potential of the through hole 118 surrounded by the conductive member 120 and the filler member 119 within the through hole 118 closer to the potential of the substrate W. Even if the potential of the substrate W fluctuates, the potential of the through hole 114 and the filler member 115 follows the fluctuation. This can prevent a potential difference greater than a discharge inception voltage from occurring between the ring assembly 112 (edge ​​ring) and the filler member 119, causing an abnormal discharge.

[0069] <An example of a plasma processing method> In one embodiment, the plasma processing method includes an etching process that uses plasma to etch a film on the substrate W. In one embodiment, the plasma processing method is performed by the control unit 2 in the plasma processing apparatus 1.

[0070] First, the substrate W is carried into the chamber 10 by the transport arm, placed on the substrate support portion 11 by the lifter, and held by suction on the substrate support portion 11 as shown in FIG.

[0071] Next, the processing gas is supplied to the shower head 13 by the gas supply unit 20, and is then supplied to the plasma processing space 10s from the shower head 13. The processing gas supplied at this time includes a gas that generates active species necessary for etching the substrate W.

[0072] A source RF signal is supplied from an RF power supply 31 to the upper electrode or the lower electrode. A voltage pulse signal is supplied from a DC power supply 32 to the lower electrode. The atmosphere in the plasma processing space 10s is exhausted from the gas exhaust port 10e, and the pressure inside the plasma processing space 10s is reduced. As a result, plasma is generated from the processing gas on the substrate support 11 in the plasma processing space 10s, and the substrate W is etched.

[0073] In the example of the etching process described above, when plasma is generated, a voltage pulse signal may be supplied to the bias electrode 1111c shown in Fig. 3. Similarly, when plasma is generated, a voltage pulse signal may be supplied to the ring bias electrode 1111c shown in Fig. 3. The voltage pulse signal supplied to the bias electrode 1111c and the voltage pulse signal supplied to the ring bias electrode 1111e may be different.

[0074] FIG. 6 is a diagram illustrating an example of a voltage pulse signal. As shown in FIG. 6, the voltage pulse signal PV includes a plurality of voltage pulses P(n) (n is an integer). The plurality of voltage pulses P(n) are a sequence of voltage pulses that alternately include a first voltage level V1 and a second voltage level V2. The absolute value of the first voltage level V1 is smaller than the absolute value of the second voltage level V2. In one embodiment, the second voltage level V2 has a negative voltage level. In one embodiment, the first voltage level has a zero voltage level. As shown in FIG. 6, in one embodiment, the voltage pulse P(n) may have a rectangular pulse waveform. Note that the voltage pulse P(n) may have various pulse waveforms other than rectangular, such as trapezoidal, triangular, or a combination thereof.

[0075] 7A and 7B are diagrams for explaining the potential difference between the substrate and the embedding member. FIGS. 7A and 7B respectively show an example of the potential Pb of the bias electrode 1111c, the potential Pr of the upper surface of the embedding member 115, and the potential Pw of the substrate W when a voltage pulse signal is supplied to the bias electrode 1111c. FIG. 7A shows an example in which the electrostatic chuck 1111 does not include the conductive member 116 described above. FIG. 7B shows an example in which the electrostatic chuck 1111 includes the conductive member 116 described above.

[0076] If the electrostatic chuck 1111 does not include a conductive member 116, the embedding member 115 is directly affected by the electric field generated around the bias electrode 1111c. Therefore, as shown in FIG. 7A, the potential Pr of the top surface of the embedding member 115 follows the potential Pb of the bias electrode 1111c. Meanwhile, the potential of the substrate W increases due to the incidence of ions caused by the voltage pulse signal. Therefore, the potential difference VA between the potential Pr of the top surface of the embedding member 115 and the substrate W increases. The potential difference VA increases as the voltage level of the voltage pulse increases, increasing the number of ions incident on the substrate W and as the plasma density in the chamber increases. If the potential difference VA exceeds the discharge inception voltage, an abnormal discharge may occur.

[0077] In contrast, when the electrostatic chuck 1111 includes the conductive member 116, as described above, the conductive member 116 functions to bring the potential of the embedding member 115 in the through hole 114 closer to the potential of the substrate W. As a result, as shown in FIG. 7B , the potential Pr of the upper surface of the embedding member 115 fluctuates following the potential Pw of the substrate W, rather than the potential Pb of the bias electrode 1111c. Therefore, the potential difference VB between the potential Pw of the substrate W and the potential Pr of the upper surface of the embedding member 115 is prevented from increasing. As a result, the occurrence of abnormal discharge can be prevented.

[0078] According to one embodiment, a technique for suppressing the occurrence of abnormal discharge in a through-hole of an electrostatic chuck can be provided.

[0079] Although the above embodiment has been described as a capacitively coupled plasma processing apparatus, the present invention is not limited to this and may be applied to other plasma processing apparatuses. For example, an inductively coupled plasma processing apparatus may be used instead of the capacitively coupled plasma processing apparatus.

[0080] Embodiments of the present disclosure further include the following aspects.

[0081] [Appendix 1] a plasma processing chamber; a base disposed within the plasma processing chamber; an electrostatic chuck; The electrostatic chuck comprises: a mounting table having an upper surface, a lower surface opposite to the upper surface, and a through hole penetrating the upper surface and the lower surface; an embedding member disposed in the through hole and having a diameter smaller than the diameter of the through hole; an electrostatic electrode and a bias electrode disposed inside the mounting table; a conductive member disposed inside the mounting table at a distance from the electrostatic electrode and the bias electrode, the conductive member having a cylindrical portion surrounding the through hole and a flange portion extending radially outward from an upper end of the cylindrical portion in parallel to the upper surface. Plasma processing equipment.

[0082] [Appendix 2] 2. The plasma processing apparatus of claim 1, wherein the electrostatic electrode is disposed below the upper surface and parallel to the upper surface, and the bias electrode is disposed below the electrostatic electrode and parallel to the upper surface.

[0083] [Appendix 3] 3. The plasma processing apparatus according to claim 1, wherein the electrostatic electrode is disposed so as not to overlap the flange portion in a plan view.

[0084] [Appendix 4] 4. The plasma processing apparatus according to claim 1, wherein the bias electrode is disposed so as not to overlap the flange portion in a plan view.

[0085] [Appendix 5] 5. The plasma processing apparatus according to claim 1, wherein the distance from the upper surface to the flange portion is equal to or less than the distance from the upper surface to the electrostatic electrode.

[0086] [Appendix 6] 6. The plasma processing apparatus according to claim 1, wherein the distance from the upper surface to the lower end of the cylindrical portion is equal to or greater than the distance from the upper surface to the bias electrode.

[0087] [Appendix 7] 7. The plasma processing apparatus according to claim 1, wherein a flow path for a heat transfer gas is formed in a gap between an inner wall of the through hole and the embedding member.

[0088] [Appendix 8] 8. The plasma processing apparatus of claim 1, further comprising a voltage pulse generating unit electrically connected to the bias electrode and configured to generate a voltage pulse signal, the voltage pulse signal having a sequence of voltage pulses, each of the voltage pulses having a negative voltage level.

[0089] [Appendix 9] 9. The plasma processing apparatus of claim 1, wherein the upper surface forms a substrate support surface.

[0090] [Appendix 10] 10. The plasma processing apparatus of claim 1, wherein the upper surface forms a ring support surface that surrounds a periphery of a substrate support surface.

[0091] [Appendix 11] a mounting table having an upper surface, a lower surface opposite to the upper surface, and a through hole penetrating the upper surface and the lower surface; an embedding member disposed in the through hole and having a diameter smaller than the diameter of the through hole; an electrostatic electrode and a bias electrode disposed inside the mounting table; a conductive member disposed inside the mounting table at a distance from the electrostatic electrode and the bias electrode, the conductive member having a cylindrical portion surrounding the through hole and a flange portion extending radially outward from an upper end of the cylindrical portion in parallel to the upper surface. Electrostatic chuck.

[0092] [Appendix 12] 12. The electrostatic chuck of claim 11, wherein the electrostatic electrode is disposed below and parallel to the upper surface, and the bias electrode is disposed below and parallel to the upper surface.

[0093] [Appendix 13] 13. The electrostatic chuck according to claim 11, wherein the electrostatic electrode is disposed so as not to overlap the flange portion in a plan view.

[0094] [Appendix 14] 14. The electrostatic chuck according to claim 11, wherein the bias electrode is disposed so as not to overlap the flange portion in a plan view.

[0095] [Appendix 15] 15. The electrostatic chuck according to claim 11, wherein a distance from the upper surface to the flange portion is equal to or less than a distance from the upper surface to the electrostatic electrode.

[0096] [Appendix 16] 16. The electrostatic chuck according to claim 11, wherein a distance from the upper surface to a lower end of the cylindrical portion is equal to or greater than a distance from the upper surface to the bias electrode.

[0097] [Appendix 17] 17. The electrostatic chuck according to claim 11, wherein a flow path for a heat transfer gas is formed in a gap between an inner wall of the through hole and the embedded member.

[0098] [Appendix 18] 18. The electrostatic chuck of any one of Claims 11 to 17, wherein the bias electrode is configured to be supplied with a voltage pulse signal, the voltage pulse signal having a sequence of voltage pulses, each of the voltage pulses having a negative voltage level.

[0099] [Appendix 19] 19. The electrostatic chuck of any one of claims 11 to 18, wherein the upper surface forms a substrate support surface.

[0100] [Appendix 20] 20. The electrostatic chuck of claim 11, wherein the upper surface forms a ring support surface that circumscribes a substrate support surface.

[0101] The above embodiments are described for the purpose of explanation and are not intended to limit the scope of the present disclosure. Various modifications can be made to the above embodiments without departing from the scope and spirit of the present disclosure. For example, some components in one embodiment can be added to other embodiments. Also, some components in one embodiment can be replaced with corresponding components in other embodiments. [Explanation of symbols]

[0102] 1... plasma processing apparatus, 2... control unit, 10... plasma processing chamber, 11... substrate support portion, 1111... electrostatic chuck, 1110... base, 111a... central region, 111b... annular region, 112... ring assembly, 114... through hole, 115... embedded member, 116... conductive member, 116a... cylindrical portion, 116b... flange portion, 118... through hole, 119... embedded member, 120... conductive member, 1111b... electrostatic electrode, 1111c... bias electrode, 1111c ring bias electrode

Claims

1. a plasma processing chamber; a base disposed within the plasma processing chamber; an electrostatic chuck; The electrostatic chuck comprises: a mounting table having an upper surface, a lower surface opposite to the upper surface, and a through hole penetrating the upper surface and the lower surface; an embedding member disposed in the through hole and having a diameter smaller than the diameter of the through hole; an electrostatic electrode and a bias electrode disposed inside the mounting table; a conductive member disposed inside the mounting table at a distance from the electrostatic electrode and the bias electrode, the conductive member having a cylindrical portion surrounding the through hole and a flange portion extending radially outward from an upper end of the cylindrical portion in parallel to the upper surface. Plasma processing equipment.

2. The plasma processing apparatus according to claim 1 , wherein the electrostatic electrode is disposed below the upper surface and parallel to the upper surface, and the bias electrode is disposed below the electrostatic electrode and parallel to the upper surface.

3. The plasma processing apparatus according to claim 2 , wherein the electrostatic electrode is disposed so as not to overlap the flange portion in a plan view.

4. The plasma processing apparatus according to claim 3 , wherein the bias electrode is disposed so as not to overlap the flange portion in a plan view.

5. The plasma processing apparatus according to claim 2 , wherein the distance from the upper surface to the flange portion is equal to or less than the distance from the upper surface to the electrostatic electrode.

6. The plasma processing apparatus according to claim 5 , wherein the distance from the upper surface to the lower end of the cylindrical portion is equal to or greater than the distance from the upper surface to the bias electrode.

7. The plasma processing apparatus according to claim 1 , wherein a flow path for a heat transfer gas is formed in a gap between an inner wall of the through hole and the embedding member.

8. 10. The plasma processing apparatus of claim 1, further comprising: a voltage pulse generator electrically connected to the bias electrode and configured to generate a voltage pulse signal, the voltage pulse signal having a sequence of voltage pulses, each of the voltage pulses having a negative voltage level.

9. The plasma processing apparatus of claim 1 , wherein the upper surface comprises a substrate support surface.

10. The plasma processing apparatus of claim 1 , wherein the upper surface forms a ring support surface surrounding a periphery of a substrate support surface.

11. a mounting table having an upper surface, a lower surface opposite to the upper surface, and a through hole penetrating the upper surface and the lower surface; an embedding member disposed in the through hole and having a diameter smaller than the diameter of the through hole; an electrostatic electrode and a bias electrode disposed inside the mounting table; a conductive member disposed inside the mounting table at a distance from the electrostatic electrode and the bias electrode, the conductive member having a cylindrical portion surrounding the through hole and a flange portion extending radially outward from an upper end of the cylindrical portion in parallel to the upper surface. Electrostatic chuck.

12. 12. The electrostatic chuck of claim 11, wherein the electrostatic electrode is disposed below and parallel to the upper surface, and the bias electrode is disposed below and parallel to the upper surface.

13. The electrostatic chuck according to claim 12 , wherein the electrostatic electrode is disposed so as not to overlap the flange portion in a plan view.

14. The electrostatic chuck according to claim 13 , wherein the bias electrode is disposed so as not to overlap the flange portion in a plan view.

15. The electrostatic chuck according to claim 12 , wherein the distance from the upper surface to the flange portion is equal to or less than the distance from the upper surface to the electrostatic electrode.

16. 16. The electrostatic chuck according to claim 15, wherein the distance from the upper surface to the lower end of the cylindrical portion is equal to or greater than the distance from the upper surface to the bias electrode.

17. The electrostatic chuck according to claim 11 , wherein a flow path for a heat transfer gas is formed in a gap between an inner wall of the through hole and the embedding member.

18. 12. The electrostatic chuck of claim 11, wherein the bias electrode is configured to be supplied with a voltage pulse signal, the voltage pulse signal having a sequence of voltage pulses, each of the voltage pulses having a negative voltage level.

19. The electrostatic chuck of claim 11 , wherein the upper surface comprises a substrate support surface.

20. 12. The electrostatic chuck of claim 11, wherein the upper surface defines a ring support surface that circumscribes a periphery of the substrate support surface.

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