Plasma processing device

Abstract

This plasma processing device comprises: a chamber; a plasma generation unit; a first conductive member; a second conductive member; and piping. The chamber houses a substrate. The plasma generation unit generates plasma inside the chamber by supplying electromagnetic waves into the chamber, and processes the substrate using the plasma. The first conductive member is disposed inside the chamber. The second conductive member has a predetermined potential difference with the first conductive member. The piping is formed of a first dielectric, is disposed between the first conductive member and the second conductive member, and circulates a gas between the first conductive member and the second conductive member. The piping has a body and a porous member. The body is formed of the first dielectric and has a hollow shape. The porous member is formed of a second dielectric and is used to fill the body.

Description

Plasma processing equipment

[0001] Various aspects and embodiments of the present disclosure relate to plasma processing apparatuses.

[0002] The following Patent Document 1 discloses "a plasma processing apparatus that converts a processing gas introduced through a gas inlet hole of a gas inlet section disposed within a processing chamber into plasma and performs plasma processing on an object to be processed disposed within the processing chamber, wherein an embedded member that prevents charged particles in the plasma generated within the processing chamber from entering the gas inlet hole of the gas inlet section is replaceably attached to the gas inlet hole of the gas inlet section."

[0003] Japanese Patent Application Laid-Open No. 2004-356531

[0004] The present disclosure provides a plasma processing apparatus capable of suppressing discharge inside a pipe.

[0005] One aspect of the present disclosure is a plasma processing apparatus comprising a chamber, a plasma generating unit, a first conductive member, a second conductive member, and piping. The chamber accommodates a substrate. The plasma generating unit generates plasma in the chamber by supplying electromagnetic waves into the chamber, and processes the substrate with the plasma. The first conductive member is disposed in the chamber. The second conductive member has a predetermined potential difference between it and the first conductive member. The piping is formed of a first dielectric and is disposed between the first conductive member and the second conductive member, and allows gas to flow between the first conductive member and the second conductive member. The piping has a main body and a porous member. The main body is hollow and formed of the first dielectric. The porous member is formed of the second dielectric and filled within the main body.

[0006] According to various aspects and embodiments of the present disclosure, discharge in a pipe can be suppressed.

[0007] FIG. 1 is a system configuration diagram showing an example of the configuration of a plasma processing system according to an embodiment of the present disclosure. FIG. 2 is a schematic cross-sectional view showing an example of the structure of a plasma processing apparatus according to an embodiment of the present disclosure. FIG. 3 is a cross-sectional view showing an example of the structure of a piping. FIG. 4 is an enlarged cross-sectional view illustrating an example of the state of pores in a porous member. FIG. 5 is a cross-sectional view showing an example of a piping in a comparative example. FIG. 6 is an enlarged cross-sectional view illustrating an example of the size of pores in a porous member. FIG. 7 is an enlarged view illustrating an example of a gap between a base and a piping. FIG. 8 is a diagram showing an example of the relationship between the dielectric constant, porosity, and discharge voltage of a porous member.

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the plasma processing apparatus will be described in detail below with reference to the accompanying drawings. However, the disclosed plasma processing apparatus is not limited to the following embodiments.

[0009] Recently, high-performance, high-density semiconductor devices have required the formation of trenches with high aspect ratios. To form trenches with high aspect ratios, processing using high-voltage, high-power RF (Radio Frequency) power is required. When high-voltage, high-power RF power is used in plasma processing, the electric field generated in the piping that supplies gas to the chamber also becomes stronger. This causes charged particles in the piping to be accelerated over a shorter distance, making discharges more likely to occur in the piping. Therefore, there is a need to further suppress discharges in the piping.

[0010] Therefore, the present disclosure provides a technique capable of suppressing discharge in a pipe.

[0011] [Configuration of Plasma Processing System 100] FIG. 1 is a system configuration diagram illustrating an example of the configuration of a plasma processing system 100 according to an embodiment of the present disclosure. In this embodiment, the plasma processing system 100 includes a plasma processing apparatus 1 and a controller 2. The plasma processing system 100 is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 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.

[0012] 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, AC signals include radio frequency (RF) signals and microwave signals. The AC signal is an example of an electromagnetic wave. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0013] 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).

[0014] [Configuration of Plasma Processing Apparatus 1] A configuration example of a capacitively coupled plasma processing apparatus will be described below as an example of the plasma processing apparatus 1. Fig. 2 is a schematic cross-sectional view showing an example of the structure of the plasma processing apparatus 1 according to an embodiment of the present disclosure.

[0015] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 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 and supported by an insulating member 113. 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.

[0016] 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.

[0017] 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. Furthermore, the electrostatic electrode 1111b may function as a lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0018] 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.

[0019] The substrate support 11 also has a heat transfer gas supply unit configured to supply a heat transfer gas between the substrate W and the substrate support surface 111a. In this embodiment, the heat transfer gas is a rare gas such as helium gas. The heat transfer gas supply unit includes a pipe 50 formed of a dielectric material and for circulating the heat transfer gas. The pipe 50 is disposed between the main body 111 and the bottom wall 10b of the plasma processing chamber 10, and circulates the heat transfer gas between the main body 111 and the bottom wall 10b. The heat transfer gas supplied into the pipe 50 via the pipe 14 flows through the pipe 50 and is supplied between the substrate support surface 111a and the substrate W via a flow path 111c formed in the main body 111.

[0020] The main body 111 and the bottom wall 10b of the plasma processing chamber 10 are electrically insulated via an insulating member 113, and an RF signal (RF power) is supplied to the main body 111 from a power supply 30. Because the bottom wall 10b of the plasma processing chamber 10 is grounded, a potential difference occurs between the main body 111 and the bottom wall 10b of the plasma processing chamber 10. The main body 111 is an example of a first conductive member, and the bottom wall 10b of the plasma processing chamber 10 is an example of a second conductive member.

[0021] The substrate support 11 may also include a temperature control 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 control module may include a heater, 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 within the ceramic member 1111a of the electrostatic chuck 1111.

[0022] The showerhead 13 is configured to introduce at least one process 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 process 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 inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0023] 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.

[0024] 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, thereby attracting ion components in the formed plasma to the substrate W.

[0025] 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.

[0026] The second RF generator 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is 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 generator 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.

[0027] 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 the 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 the 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.

[0028] 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 pulse waveform. In one embodiment, a waveform generator for generating the 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.

[0029] 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 in the plasma processing space 10s is regulated by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0030] [Structure of the Pipe 50] FIG. 3 is a cross-sectional view showing an example of the structure of the pipe 50. The pipe 50 has a hollow, cylindrical main body 51. The main body 51 of the pipe 50 is filled with a porous member 52 made of a dielectric material. A plurality of pores 520 are formed in the porous member 52. The pores 520 are connected to one another, as shown in FIG. 4, for example, and gas flows from the bottom wall 10b to the main body 111 through the pores 520. In this embodiment, the main body 51 and the porous member 52 are made of a dielectric material such as quartz, alumina, PCTFE (Poly Chloro Tri Fluoro Ethylene), or PTFE (Poly Tetra Fluoro Ethylene). The dielectric material used in the main body 51 is an example of a first dielectric material, and the dielectric material used in the porous member 52 is an example of a second dielectric material.

[0031] Here, when there is a potential difference between both ends of a pipe and an electric field is generated along the extension direction of the pipe, if the length of the flow path in the electric field direction is long, charged particles contained in the gas flowing through the flow path accelerate along the electric field direction and eventually discharge. Therefore, it is conceivable to suppress the acceleration of charged particles along the electric field direction by shortening the length of the flow path in the electric field direction. For example, as shown in the comparative example in FIG. 5, it is conceivable to form a spiral flow path 61 along the electric field direction within the pipe 60. FIG. 5 is a cross-sectional view showing an example of the pipe 60 in the comparative example. By using the pipe 60 illustrated in FIG. 5, the length ΔL1 of the flow path 61 in the electric field direction can be shortened.

[0032] However, with the recent trend toward higher voltages in semiconductor manufacturing processes, the potential difference between both ends of the pipe 60 tends to increase. Furthermore, with the miniaturization of semiconductor manufacturing equipment, there is a demand for shortening the pipe 60. This demands further shortening the length ΔL1 of the flow path 61 in the direction of the electric field. However, due to limitations in processing technology, it is difficult to reduce the length ΔL1 of the flow path 61 in the direction of the electric field to 0.4 mm or less. Therefore, it is difficult to suppress discharge within the flow path 61 in the pipe 60 illustrated in FIG. 5 .

[0033] In contrast, in the piping 50 of this embodiment, as shown in Figures 3 and 4, for example, gas flows through pores 520 of a porous member 52 formed of a dielectric material within a main body 51. In addition, in this embodiment, the average diameter of the pores 520 formed in the porous member 52 is 0.2 mm or less. Therefore, even if two pores 520a and 520b are connected along the direction of the electric field, as shown in Figure 6, for example, the length ΔL2 of the space along the direction of the electric field can be set to 0.4 mm or less. This makes it possible to suppress discharge within the piping 50.

[0034] Even if the average diameter of the pores 520 is 0.2 mm or less, there may be pores 520 with a diameter of 0.2 mm or more among the plurality of pores 520. If two pores 520 with a diameter of 0.2 mm or more are connected along the direction of the electric field, discharge may occur due to charged particles contained in the gas in the two pores 520. Therefore, it is preferable that the maximum diameter of the pores 520 is 0.2 mm or less. Furthermore, there is a possibility that three or more pores 520 are connected along the direction of the electric field among the plurality of pores 520. Therefore, it is more preferable that the maximum diameter of the pores 520 is 0.1 mm or less.

[0035] [Relationship between Dielectric Constant, Porosity, and Discharge Voltage] Fig. 7 is an enlarged view illustrating an example of a gap between the base 1110 and the pipe 50. The base 1110 includes a conductive member, and the main body 51 and the porous member 52 of the pipe 50 are formed of a dielectric material, so that the base 1110 and the pipe 50 have different thermal expansion coefficients. Therefore, a gap ΔL3 of a predetermined width is provided between the base 1110 and the pipe 50, as shown in Fig. 7, for example. The width of the gap ΔL3 is 0.2 mm, for example.

[0036] The heat transfer gas flows through the space within the gap ΔL3 via the porous member 52. Furthermore, an electric field is generated in the space within the gap ΔL3 according to the potential difference between the base 1110 and the pipe 50. If the potential difference in the space within the gap ΔL3 exceeds 136 V, the heat transfer gas may discharge within the gap ΔL3. In order to suppress the discharge of the heat transfer gas within the gap ΔL3, for example, it is possible to prevent the potential difference in the space within the gap ΔL3 from exceeding 136 V.

[0037] Here, the potential difference in the space within the gap ΔL3 changes depending on the dielectric constant and porosity of the porous member 52, as shown in Fig. 8, for example. Fig. 8 is a diagram showing an example of the relationship between the dielectric constant, porosity, and discharge voltage of the porous member 52. For example, as shown in Fig. 8, the smaller the dielectric constant and porosity of the porous member 52, the smaller the potential difference in the space within the gap ΔL3.

[0038] For example, when the porous member 52 is made of PTFE, which has a relative dielectric constant of approximately 2.1, the potential difference in the space within the gap ΔL3 is below 136 V at any porosity, as shown in Figure 8. Therefore, when the porous member 52 is made of PTFE, discharge in the space within the gap ΔL3 can be suppressed. However, because PTFE has a large coefficient of thermal expansion, it is preferable to use it in an apparatus that performs a process in which temperature changes are not so great.

[0039] Furthermore, when the porous member 52 is made of quartz, which has a relative dielectric constant of approximately 4.2, if the porosity is below 10%, the potential difference in the space within the gap ΔL3 may exceed 136 V, as shown in Fig. 8. Therefore, when the porous member 52 is made of quartz, it is preferable that the porosity of the porous member 52 be 10% or more and 90% or less. This makes it possible to suppress discharge in the space within the gap ΔL3.

[0040] Furthermore, when the porous member 52 is made of alumina, which has a relative dielectric constant of approximately 10, if the porosity is below 60%, the potential difference in the space within the gap ΔL3 may exceed 136 V, as shown in Fig. 8. Therefore, when the porous member 52 is made of alumina, it is preferable that the porosity of the porous member 52 be 60% or more and 90% or less. This makes it possible to suppress discharge in the space within the gap ΔL3.

[0041] Since quartz and alumina have a smaller coefficient of thermal expansion than PTFE, the porous member 52 made of quartz or alumina can also be used in an apparatus that performs a process in which the temperature changes greatly.

[0042] One embodiment has been described above. As described above, the plasma processing apparatus (plasma processing apparatus 1) in this embodiment includes a chamber (plasma processing chamber 10), a plasma generating unit (plasma generating unit 12), a first conductive member (main body 111), a second conductive member (bottom wall 10b), and piping (piping 50). The chamber accommodates a substrate (W). The plasma generating unit generates plasma in the chamber by supplying electromagnetic waves into the chamber, and processes the substrate with the plasma. The first conductive member is disposed in the chamber. The second conductive member has a predetermined potential difference with the first conductive member. The piping is formed of a first dielectric, is disposed between the first conductive member and the second conductive member, and allows gas to flow between the first conductive member and the second conductive member. The piping includes a main body (main body 51) and a porous member (porous member 52). The main body is hollow and formed of the first dielectric. The porous member is made of a second dielectric material and is filled in the body, thereby making it possible to suppress discharge in the piping that supplies gas into the chamber.

[0043] In the above embodiment, the second dielectric is quartz, and the porosity of the porous member is 10% or more and 90% or less. This makes it possible to suppress discharge within the pipe 50.

[0044] In the above embodiment, the second dielectric is alumina, and the porosity of the porous member is 60% or more and 90% or less. This makes it possible to suppress discharge within the pipe 50.

[0045] In the above-described embodiment, the first conductive member is a substrate support portion on which a substrate is placed, and the second conductive member is a bottom wall of the chamber, thereby making it possible to suppress discharge in the piping when gas is supplied from the bottom wall of the chamber to the substrate support portion.

[0046] In the above-described embodiment, the gas flowing through the pipe 50 is a rare gas such as helium gas, which can suppress discharge within the pipe when gas is supplied between the first conductive member and the second conductive member.

[0047] In the above embodiment, the average diameter of the pores in the porous member is 0.2 mm or less. More preferably, the maximum diameter of the pores in the porous member is 0.1 mm or less. This makes it possible to suppress discharge in the pipe 50.

[0048] [Others] The technology disclosed in the present application is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist thereof.

[0049] For example, in the above-described embodiment, the main body 111 is described as an example of a first conductive member, and the bottom wall 10b of the plasma processing chamber 10 is described as an example of a second conductive member, but the disclosed technology is not limited thereto. The disclosed technology can be applied to any conductive member provided in the plasma processing apparatus 1, other than the main body 111 and the bottom wall 10b of the plasma processing chamber 10, as long as the two conductive members have a potential difference. For example, the disclosed technology can be applied to a case in which the shower head 13 is the first conductive member and the housing covering the shower head 13 is the second conductive member.

[0050] In the above embodiment, a capacitively coupled plasma has been described as an example of a plasma source used in the plasma processing apparatus 1, but the plasma source is not limited to this. Examples of plasma sources other than the capacitively coupled plasma include inductively coupled plasma (ICP), microwave-excited surface wave plasma (SWP), electron cyclotron resonance plasma (ECP), and helicon wave-excited plasma (HWP).

[0051] It should be noted that the disclosed embodiments are illustrative in all respects and should not be considered limiting. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

[0052] Furthermore, the following supplementary notes are disclosed regarding the above-described embodiment.

[0053] (Supplementary Note 1) A plasma processing apparatus comprising: a chamber for accommodating a substrate; a plasma generating unit for generating plasma in the chamber by supplying electromagnetic waves into the chamber and processing the substrate with the plasma; a first conductive member disposed in the chamber; a second conductive member having a predetermined potential difference between itself and the first conductive member; and a pipe formed of a first dielectric, disposed between the first conductive member and the second conductive member, and for circulating a gas between the first conductive member and the second conductive member, the pipe having: a hollow body formed of the first dielectric; and a porous member formed of the second dielectric and filled in the body. (Supplementary Note 2) The plasma processing apparatus according to Supplementary Note 1, wherein the second dielectric is quartz. (Supplementary Note 3) The plasma processing apparatus according to Supplementary Note 2, wherein the porosity of the porous member is 10% or more and 90% or less. (Supplementary Note 4) The plasma processing apparatus according to Supplementary Note 1, wherein the second dielectric is alumina. (Appendix 5) The plasma processing apparatus according to Appendices 4, wherein the porosity of the porous member is 60% or more and 90% or less. (Appendix 6) The plasma processing apparatus according to any one of Appendices 1 to 5, wherein the first conductive member is a substrate support portion on which the substrate is placed, and the second conductive member is a bottom wall of the chamber. (Appendix 7) The plasma processing apparatus according to any one of Appendices 1 to 6, wherein the gas is a rare gas. (Appendix 8) The plasma processing apparatus according to Appendices 7, wherein the gas is helium gas. (Appendix 9) The plasma processing apparatus according to any one of Appendices 1 to 8, wherein the average diameter of the pores in the porous member is 0.2 mm or less. (Appendix 10) The plasma processing apparatus according to any one of Appendices 1 to 9, wherein the maximum diameter of the pores in the porous member is 0.1 mm or less.

[0054] W substrate 100 plasma processing system 1 plasma processing apparatus 2 control unit 10 plasma processing chamber 10a side wall 10b bottom wall 10e gas outlet 10s plasma processing space 11 substrate support unit 111 main body 112 ring assembly 12 plasma generation unit 13 shower head 14 piping 20 gas supply unit 30 power supply 31 RF power supply 32 DC power supply 40 exhaust system 50 piping 51 main body 52 porous member 520 fine pores 60 piping 61 flow path

Claims

1. A plasma processing apparatus comprising: a chamber for accommodating a substrate; a plasma generating unit for generating plasma in the chamber by supplying electromagnetic waves into the chamber and processing the substrate with the plasma; a first conductive member disposed in the chamber; a second conductive member having a predetermined potential difference between itself and the first conductive member; and a piping formed of a first dielectric and disposed between the first conductive member and the second conductive member for circulating gas between the first conductive member and the second conductive member, the piping having a hollow body formed of the first dielectric, and a porous member formed of a second dielectric and filled within the body.

2. The plasma processing apparatus according to claim 1, wherein the second dielectric is quartz.

3. The plasma processing apparatus according to claim 2, wherein the porosity of the porous member is 10% or more and 90% or less.

4. The plasma processing apparatus according to claim 1, wherein said second dielectric is alumina.

5. The plasma processing apparatus according to claim 4, wherein the porosity of said porous member is not less than 60% and not more than 90%.

6. The plasma processing apparatus according to claim 1, wherein the first conductive member is a substrate support portion on which the substrate is placed, and the second conductive member is a bottom wall of the chamber.

7. The plasma processing apparatus according to claim 1, wherein the gas is a rare gas.

8. The plasma processing apparatus according to claim 7, wherein the gas is helium gas.

9. The plasma processing apparatus according to claim 1, wherein the average diameter of the pores in said porous member is 0.2 mm or less.

10. The plasma processing apparatus according to claim 1, wherein the maximum diameter of the pores of said porous member is 0.1 mm or less.

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