Gas supply, showerhead, and piping

Abstract

This gas supply device comprises: a first member which is formed from a conductive material; a second member which is formed from a conductive material and is set to a potential different from that of the first member; and piping which is formed of a dielectric and through which gas flows between the first member and the second member. One end of the piping is inserted into an opening formed in the second member. In the interior of the piping, a flow path is formed in a direction that is oblique with respect to the direction running from the first member to the second member. In the flow path in the piping at a portion thereof stretching between the first member and the second member, there is a portion where the length of the cross-section of the flow path in the direction running from the first member to the second member is shorter than the flow path in the piping at a portion thereof inserted into the opening in the second member.

Description

[Technical Field]

[0001] Various aspects and embodiments of the present disclosure relate to gas distribution systems, showerheads, and plumbing. [Background technology]

[0002] Patent Document 1 listed below discloses that "in a plasma etching apparatus 100 in which high frequency power is applied to a lower electrode 110 of a pair of electrodes arranged opposite each other in an airtight processing vessel 102, a processing gas introduced between the electrodes is converted into plasma to perform a predetermined processing on the surface of a processing object, an electrostatic chuck 112 that attracts and holds the processing object, and a heat transfer gas supply unit 120 that supplies a heat transfer gas to a minute space S between the electrostatic chuck 112 and the processing object to control the processing object to a predetermined temperature, are composed of a heat transfer gas supply pipe 162 and a heat transfer gas supply pipe support 164 that are inclined with respect to the direction of the electric field generated by the high frequency power supplied to the electrodes." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2003 / 046969 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a gas supply device, a showerhead, and piping that can increase the conductance of a flow path while preventing discharge of gas within the flow path. [Means for solving the problem]

[0005] A gas supply device according to one aspect of the present disclosure includes a first member made of a conductive material, a second member made of a conductive material and set to a different potential than the first member, and a pipe made of a dielectric material for circulating gas between the first member and the second member. One end of the pipe is inserted into an opening formed in the second member. A flow path is formed inside the pipe in a direction oblique to the direction from the first member to the second member. The flow path of the pipe between the first member and the second member has a portion where the cross-sectional length of the flow path in the direction from the first member to the second member is shorter than the flow path of the pipe inserted into the opening of the second member. [Effects of the Invention]

[0006] According to various aspects and embodiments of the present disclosure, the conductance of a flow channel can be increased while preventing discharge of gas within the flow channel. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of a plasma processing system. [Figure 2] FIG. 2 is an enlarged cross-sectional view showing an example of the structure of a pipe. [Figure 3] FIG. 3 is a diagram showing an example of the distribution of equipotential lines in the piping of Reference Example 1. In FIG. [Figure 4] FIG. 4 is a diagram showing an example of the distribution of equipotential lines in the piping of Reference Example 2. In FIG. [Figure 5] FIG. 5 is a diagram showing an example of the relationship between the distance from the top plate and the potential. [Figure 6] FIG. 6 is a diagram showing an example of the relationship between the distance from the top plate and the cross-sectional length of the flow channel. [Figure 7] FIG. 7 is a diagram showing an example of the distribution of equipotential lines in the piping of this embodiment. [Figure 8] FIG. 8 is a diagram showing a comparison of the conductance in the pipes of Reference Example 1, Reference Example 2, and this embodiment. [Figure 9]FIG. 9 is a diagram showing another example of the relationship between the distance from the top plate and the cross-sectional length of the flow channel. [Figure 10] FIG. 10 is an enlarged cross-sectional view showing another example of the structure of the piping. [Figure 11] FIG. 11 is an enlarged cross-sectional view showing another example of a flow path in a pipe. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of a gas supply device, a shower head, and piping will be described in detail with reference to the drawings. Note that the disclosed gas supply device, shower head, and piping are not limited to the following embodiments.

[0009] When a pipe is placed between two conductors with a potential difference and gas is circulated through the pipe, if the cross-sectional length of the gas flow path in the direction of the electric field generated by the potential difference is long, the gas molecules flowing through the path may be accelerated by the electric field and discharge may occur. If a discharge occurs inside the pipe, the inner wall of the pipe may be damaged, and particles generated from the damaged area may be scattered into the processing chamber along with the gas. To suppress such discharge inside the pipe, the cross-sectional length of the gas flow path in the direction of the electric field may be shortened.

[0010] However, when the cross-sectional length of the flow path in the direction of the electric field becomes shorter, the conductance within the flow path decreases, making it difficult to increase the flow rate of gas flowing through the piping or to quickly switch gases in the space to which gas is supplied via the piping.

[0011] Therefore, the present disclosure provides a technique that can increase the conductance of a flow channel while preventing discharge of gas within the flow channel.

[0012] [Configuration of plasma processing system] An example of the configuration of a plasma processing system will be described below. FIG. 1 is a schematic diagram illustrating an example of a plasma processing system. The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a control unit 2. 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 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 part 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 has at least one gas inlet for supplying at least one processing gas to the plasma processing space 10s and at least one gas outlet for exhausting gas from the plasma processing space 10s. The plasma processing chamber 10 is made of a conductor such as aluminum and is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0013] 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.

[0014] 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 (Radio Frequency) power supply 31 and / or a DC (Direct Current) power supply 32 (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 (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 the lower electrode. Therefore, the substrate support 11 includes at least one lower electrode.

[0015] 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.

[0016] 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.

[0017] The shower head 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The shower head 13 is an example of a gas supply device. The shower head 13 has at least one gas supply port 13a, a top plate 13b, an insulating member 13c, a holder 13d, at least one gas diffusion chamber 13e, a shower plate 13f, and piping 130. The top plate 13b is an example of a first member, and the holder 13d is an example of a second member.

[0018] The shower plate 13f has a plurality of gas inlet ports 13g formed therein, which are through-holes. The top plate 13b is made of a conductive material such as aluminum and is grounded via the sidewall 10a of the plasma processing chamber 10. The holder 13d and the shower plate 13f are also made of a conductive material such as aluminum. An insulating member 13c is disposed between a lower surface 13b1 of the top plate 13b and an upper surface 13d1 of the holder 13d, insulating the top plate 13b from the holder 13d. The holder 13d is supported on the sidewall 10a of the plasma processing chamber 10 via an insulating member 13h, and is insulated from the plasma processing chamber 10 by the insulating member 13h. The holder 13d detachably holds the shower plate 13f. The holder 13d is connected to a power supply 30, and the holder 13d and the shower plate 13f are maintained at a predetermined potential (e.g., −1.2 kV).

[0019] The processing gas supplied to the gas supply port 13a is supplied into the gas diffusion chamber 13e via the pipe 130. The processing gas supplied into the gas diffusion chamber 13e diffuses within the gas diffusion chamber 13e and is introduced into the plasma processing space 10s through the gas inlet port 13g of the shower plate 13f. The holder 13d and the shower plate 13f function as at least one upper electrode. In addition to the shower head 13, the gas inlet may include one or more side gas injectors (SGIs) attached to one or more openings formed in the side wall 10a.

[0020] 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 one or more flow modulation devices to modulate or pulse the flow rate of the at least one process gas.

[0021] 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 process gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of a plasma generating unit configured to generate a plasma from one or more process gases in the plasma processing chamber 10. In addition, 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.

[0022] 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.

[0023] 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.

[0024] 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 bias 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.

[0025] In various embodiments, at least one of 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 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.

[0026] 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.

[0027] 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).

[0028] [Structure of piping 130] 2 is an enlarged cross-sectional view showing an example of the structure of the pipe 130. In this embodiment, the pipe 130 is made of a dielectric material such as polyimide or PCTFE (polychlorotrifluoroethylene), and is disposed between the top plate 13b and the holder 13d. In this embodiment, one end of the pipe 130 on the holder 13d side is inserted into an opening 13d2 formed in the holder 13d. Sealing members 131 such as O-rings are disposed between the top plate 13b and the pipe 130 and between the holder 13d and the pipe 130.

[0029] A flow path 132 through which gas flows is formed within the piping 130. The flow path 132 is formed to extend in a direction oblique to the direction from the top plate 13b toward the holder 13d (the direction of the arrow in FIG. 2). In this embodiment, the flow path 132 is formed in a spiral shape within the piping 130. One end of the flow path 132 on the holder 13d side communicates with the gas diffusion chamber 13e via a flow path 13d3, and the other end of the flow path 132 on the top plate 13b side communicates with the gas supply port 13a via a flow path 13b2 of the gas supply port 13a.

[0030] In the portion of the flow path 132 of the piping 130 between the top plate 13b and the holder 13d, there is a portion where the cross-sectional length L1 of the flow path 132 in the direction of the arrow in Fig. 2 is shorter than the cross-sectional length L2 of the flow path 132 of the portion of the piping 130 inserted into the opening 13d2 of the holder 13d. In the example of Fig. 2, the cross-sectional length L1 of the flow path 132a of the piping 130 in the portion corresponding to the region R1 in Fig. 2 is shorter than the cross-sectional length L2 of the flow path 132b of the piping 130 inserted into the opening 13d2 of the holder 13d (the portion corresponding to the region R2 in Fig. 2). For example, the flow path 132 of the piping 130 is configured so that the cross-sectional length of the flow path 132 in the direction of the arrow in Fig. 2 continuously increases as it progresses along the flow path from the top plate 13b side to the holder 13d side. In addition, the portion of piping 130 corresponding to region R1 in Figure 2 may have a portion of flow path 132 in which the cross-sectional length of flow path 132 in the direction of the arrow in Figure 2 is approximately the same as the cross-sectional length of flow path 132b of the portion of piping 130 inserted into opening 13d2 of holder 13d.

[0031] In this embodiment, the cross-sectional length of the flow path 132 in the direction of the arrow in Fig. 2 is a length such that the potential difference between the wall surface of the flow path 132 on the top plate 13b side and the wall surface of the flow path 132 on the holder 13d side is less than the discharge inception voltage of Ar gas. Among gases, Ar gas has a low discharge inception voltage. Therefore, by setting the cross-sectional length of the flow path 132 in the direction of the arrow in Fig. 2 to a length such that no discharge occurs in Ar gas, it is possible to suppress the occurrence of discharge in the flow path 132 even when Ar gas and other gases are flowing.

[0032] [Reference example 1] Here, consider a pipe 130' that is disposed only in the region R1 between the top plate 13b and the holder 13d, and one end of which is not inserted into the opening of the holder 13d, as Reference Example 1. FIG. 3 is a diagram showing an example of the distribution of equipotential lines 133 in the pipe 130' of Reference Example 1. Only half of the pipe 130' is shown in FIG. 3. Also, the seal member 131 is not shown in FIG.

[0033] 3, the density of equipotential lines 133 in the piping 130′ of Reference Example 1 is high. Therefore, when the cross-sectional length of the flow path 132 in the direction from the top plate 13b toward the holder 13d (the direction of the arrow in FIG. 3) is increased, the potential difference between the wall surface of the flow path 132 on the top plate 13b side and the wall surface of the flow path 132 on the holder 13d side increases. When the potential difference between the wall surface of the flow path 132 on the top plate 13b side and the wall surface of the flow path 132 on the holder 13d side exceeds the discharge inception voltage of the gas flowing through the flow path 132, a discharge occurs in the flow path 132.

[0034] Therefore, in order to suppress gas discharge in the flow path 132, it is necessary to shorten the cross-sectional length of the flow path 132 in the direction of the arrow in Fig. 3. If the cross-sectional length of the flow path 132 in the direction of the arrow in Fig. 3 is shortened, the conductance of the flow path 132 decreases, making it difficult to increase the flow rate of gas flowing through the flow path 132 or to quickly switch gases in the plasma processing space 10s to which gas is supplied via the flow path 132.

[0035] [Reference example 2] Next, consider a pipe 130" as Reference Example 2, which has a portion disposed in the region R1 between the top plate 13b and the holder 13d and a portion inserted into the opening 13d2 of the holder 13d. FIG. 4 is a diagram showing an example of the distribution of equipotential lines 133 in the pipe 130" of Reference Example 2. Only half of the pipe 130" is shown in FIG. 4. Also, the seal member 131 is not shown in FIG.

[0036] As illustrated in FIG. 4, in the piping 130″ of Reference Example 2, the density of the equipotential lines 133 in the portion of the piping 130″ corresponding to region R2 in FIG. 4 is lower than the density of the equipotential lines 133 in the portion of the piping 130″ corresponding to region R1 in FIG. 4. Furthermore, in the example of FIG. 4, the equipotential lines 133 protrude into the portion of the piping 130″ corresponding to region R2 in FIG. 4. As a result, the density of the equipotential lines 133 in the portion of the piping 130″ on the holder 13d side in region R1 in FIG. 4 is lower than the density of the equipotential lines 133 in the portion of the piping 130″ on the top plate 13b side in region R1 in FIG. 3.

[0037] In the pipe 130" of Reference Example 2, the relationship between the distance from the top plate 13b and the potential in the direction of the arrow in FIG. 4 is illustrated, for example, as shown in FIG. 5, with the surface of the top plate 13b facing the holder 13d as the reference point. In the example of FIG. 5, a DC voltage of -1.2 kV is applied to the holder 13d, and a potential difference of 1.2 kV occurs between the top plate 13b and the holder 13d.

[0038] 5, the electric potential changes greatly with the change in distance from holder 13d near holder 13d, and the change in electric potential with the change in distance from holder 13d becomes smaller as the distance from holder 13d increases. That is, the change in the electric field is large near holder 13d, and the change in the electric field becomes smaller as the distance from holder 13d increases.

[0039] Here, when the cross-sectional length of the flow path 132 at which the potential difference between the wall surface of the flow path 132 on the top plate 13b side and the wall surface of the flow path 132 on the holder 13d side is constant is plotted against the distance from the top plate 13b in the direction of the arrow in Fig. 4, the result is, for example, as shown in Fig. 6. As illustrated in Fig. 6, the cross-sectional length of the flow path 132 at which the potential difference between the wall surface of the flow path 132 on the top plate 13b side and the wall surface of the flow path 132 on the holder 13d side is constant increases with increasing distance from the holder 13d. That is, in Reference Example 2, the cross-sectional length of the flow path 132 in the direction of the arrow in Fig. 4 can be increased with increasing distance from the holder 13d, within a range equal to or shorter than the cross-sectional length of the flow path 132 illustrated in Fig. 6.

[0040] FIG. 7 is a diagram showing an example of the distribution of equipotential lines 133 in piping 130 of this embodiment. Only half of piping 130 is shown in FIG. 7. Furthermore, sealing member 131 is not shown in FIG. 7. In this embodiment, as shown in FIG. 7, for example, the cross-sectional length of flow path 132 in the direction from top plate 13b toward holder 13d (the direction of the arrow in FIG. 7) increases with increasing distance from holder 13d. This allows the cross-sectional area of ​​flow path 132 to be increased within a range in which the potential difference between the wall surface of flow path 132 on the top plate 13b side and the wall surface of flow path 132 on the holder 13d side is equal to or less than a certain value, thereby increasing the conductance of flow path 132.

[0041] [Comparison of conductance of flow channel 132] 8 is a diagram showing a comparison of the conductance in the piping of Reference Example 1, Reference Example 2, and this embodiment. In the piping 130′ of Reference Example 1 (see FIG. 3), the cross-sectional length of the flow path 132 in the direction from the top plate 13b toward the holder 13d is set to 1 mm regardless of the distance from the holder 13d, and the maximum value of the voltage applied to the flow path 132 is 148 V. In addition, in the pipe 130″ of Reference Example 2 (see FIG. 4), the cross-sectional length of the flow path 132 in the direction from the top plate 13b toward the holder 13d is set to 1.6 mm regardless of the distance from the holder 13d, and the maximum value of the voltage applied to the flow path 132 is 144.3 V. In addition, in the pipe 130 of this embodiment (see FIGS. 2 and 7), the cross-sectional length of the flow path 132 in the direction from the top plate 13b toward the holder 13d is set to a minimum of 1.6 mm and a maximum of 4.0 mm, and the maximum value of the voltage applied to the flow path 132 is 144.3 V. In FIG. 8, in all of Reference Example 1, Reference Example 2, and this embodiment, the cross-sectional length of the flow path 132 in the direction from the top plate 13b toward the holder 13d is set to a length that results in a potential difference that is lower than 178 V, which is the discharge start voltage of Ar gas.

[0042] For example, as shown in FIG. 8 , among Reference Example 1, Reference Example 2, and this embodiment, the flow path 132 of this embodiment has the highest conductance. Therefore, in the piping 130 of this embodiment, the conductance of the flow path 132 can be increased while preventing discharge of gas in the flow path 132. Furthermore, comparing Reference Example 2 with this embodiment, the rise time, which is the time it takes for gas to be introduced into the plasma processing chamber 10 at a predetermined flow rate, is shorter in the piping 130 of this embodiment than in the piping 130″ of Reference Example 2. As a result, the piping 130 of this embodiment allows for rapid switching of gas in the plasma processing chamber 10 via the piping 130. Furthermore, in order to increase the conductance of the flow path 132, the cross-sectional length of the flow path 132 in a direction intersecting the direction from the top plate 13b toward the holder 13d (the width of the flow path 132) may be increased.

[0043] The above describes the embodiment. As described above, the showerhead 13 in this embodiment includes a top plate 13b made of a conductive material, a holder 13d also made of a conductive material and set to a different potential than the top plate 13b, and a pipe 130 made of a dielectric material for circulating gas between the top plate 13b and the holder 13d. One end of the pipe 130 is inserted into an opening 13d2 formed in the holder 13d. A flow path is formed inside the pipe 130 in a direction oblique to the direction from the top plate 13b to the holder 13d. The flow path 132 of the pipe 130 between the top plate 13b and the holder 13d has a portion where the cross-sectional length of the flow path 132 in the direction from the top plate 13b to the holder 13d is shorter than the flow path 132 of the pipe 130 inserted into the opening 13d2 of the holder 13d. This prevents discharge of gas within the flow path 132 while increasing the conductance of the flow path 132.

[0044] In the above embodiment, the cross-sectional length of the flow path 132 of the piping 130 in the direction from the top plate 13b to the holder 13d increases continuously from the top plate 13b side to the holder 13d side along the extension direction of the flow path 132. This makes it possible to prevent gas from accumulating in the flow path 132 and to create a smooth gas flow.

[0045] Furthermore, in the above-described embodiment, the flow path 132 is formed in a spiral shape inside the pipe 130. This allows the pipe 130 to be made smaller.

[0046] Furthermore, in the above-described embodiment, the cross-sectional length of the flow path 132 of the piping 130 in the direction from the top plate 13b toward the holder 13d is a length such that the potential difference between the wall surface of the flow path 132 on the top plate 13b side and the wall surface of the flow path 132 on the holder 13d side is less than the discharge inception voltage of Ar gas. Among gases, Ar gas has a low discharge inception voltage. Therefore, the piping 130 of this embodiment can increase the conductance of the flow path 132 while preventing discharge of the gas in the flow path 132, even when any gas is passed through it.

[0047] In the above embodiment, the pipe 130 is made of polyimide, which makes it easy to fabricate the pipe 130.

[0048] The above-described embodiment of the showerhead 13 includes a top plate 13b, a holder 13d, a shower plate 13f, and piping 130. The top plate 13b is made of a conductive material and is grounded. The holder 13d is made of a conductive material and is insulated from the top plate 13b. The shower plate 13f is made of a conductive material, has a plurality of through-holes, and is held by the holder 13d. The piping 130 is made of a dielectric material and is disposed between the top plate 13b and the holder 13d. The piping 130 supplies gas to the gas diffusion chamber 13e between the holder 13d and the shower plate 13f via the top plate 13b. A voltage of a predetermined magnitude is applied to the top plate 13b and the shower plate 13f. One end of the piping 130 is inserted into an opening 13d2 formed in the holder 13d, and a flow path is formed inside the piping 130 in a direction oblique to the direction from the top plate 13b to the holder 13d. In the portion of flow path 132 of piping 130 between top plate 13b and holder 13d, there is a portion where the cross-sectional length of flow path 132 in the direction from top plate 13b to holder 13d is shorter than that of flow path 132 of piping 130 inserted into opening 13d2 of holder 13d. This makes it possible to increase the conductance of flow path 132 while preventing discharge of gas within flow path 132.

[0049] [others] The technology disclosed in this application is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist thereof.

[0050] For example, in the above-described embodiment, the flow path 132 of the piping 130 is configured so that the cross-sectional length of the flow path 132 in the direction from the top plate 13b to the holder 13d continuously increases as the flow path advances from the top plate 13b side to the holder 13d side. However, the disclosed technology is not limited to this. As another embodiment, the cross-sectional length of the flow path 132 in the direction from the top plate 13b to the holder 13d may be configured so that the length increases in steps as the flow path advances from the top plate 13b side to the holder 13d side, as shown by the dashed line in FIG. 9 . This allows the piping 130 to be easily manufactured.

[0051] Furthermore, in the above-described embodiment, one flow path 132 is formed in the pipe 130, but the disclosed technology is not limited to this, and multiple flow paths 132 may be formed in the pipe 130. This makes it possible to supply multiple different gases using one pipe 130. Note that the same gas may flow through each of the multiple flow paths 132 formed in the pipe 130.

[0052] In the above-described embodiment, one end of the pipe 130 is inserted into the opening 13d2 formed in the holder 13d. However, the disclosed technology is not limited to this. Alternatively, the other end of the pipe 130 may be inserted into an opening formed in the top plate 13b. Furthermore, the flow path 132 of the pipe 130 between the top plate 13b and the holder 13d has a portion where the cross-sectional length of the flow path 132 in the direction from the top plate 13b to the holder 13d is shorter than the cross-sectional length of the flow path 132 of the pipe 130 inserted into the opening of the top plate 13b. Even in this configuration, the electric field applied to the flow path 132 of the pipe 130 inserted into the opening of the top plate 13b is weakened. Therefore, in the portion of the pipe 130 inserted into the opening of the top plate 13b, the cross-sectional length of the flow path 132 in the direction from the top plate 13b to the holder 13d can be increased, thereby increasing the conductance of the flow path 132. Alternatively, one end of the pipe 130 may be inserted into the opening 13d2 formed in the holder 13d, and the other end of the pipe 130 may be inserted into the opening formed in the top plate 13b.

[0053] Furthermore, in the above-described embodiment, the piping 130 is formed of a single dielectric material. However, the disclosed technology is not limited to this. The piping 130 may be formed of multiple materials with different dielectric constants. For example, as shown in FIG. 10, the piping 130 may be formed of materials with different dielectric constants. In the example of FIG. 10, the piping 130 has a first dielectric 130a and a second dielectric 130b having a higher dielectric constant than the first dielectric 130a. In the example of FIG. 10, at least a portion of the piping 130 between the top plate 13b and the holder 13d (region R1) is formed of the first dielectric 130a. This weakens the electric field applied to the flow path 132 of the piping 130 in region R1 compared to when the piping 130 is formed of the same dielectric. Therefore, the cross-sectional length of the flow path 132 in region R1 in the direction from the top plate 13b to the holder 13d can be increased, thereby increasing the conductance of the flow path 132.

[0054] Furthermore, in the above-described embodiment, a spiral flow path 132 is formed within the piping 130, but the disclosed technology is not limited to this. The shape of the flow path 132 formed within the piping 130 does not have to be spiral as long as it extends in a direction oblique to the direction from the top plate 13b toward the holder 13d. For example, as shown in FIG. 11, the flow path 132 may be linear. However, even in the example of FIG. 11, the cross-sectional length of the flow path 132 in the direction from the top plate 13b toward the holder 13d is configured to gradually increase as the flow path advances from the top plate 13b side toward the holder 13d side. Also in the example of FIG. 11, the cross-sectional length of the flow path 132 in the direction from the top plate 13b toward the holder 13d is a length such that the potential difference between the wall surface of the flow path 132 on the top plate 13b side and the wall surface of the flow path 132 on the holder 13d side is less than the discharge start voltage of Ar gas. Even with the flow channel 132 having such a shape, the conductance of the flow channel 132 can be increased while preventing discharge of the gas within the flow channel 132 .

[0055] In the above-described embodiment, the piping 130 is provided inside the shower head 13, but the disclosed technology is not limited to this. The piping may be provided in a portion other than the shower head 13, such as a piping for supplying a heat transfer gas between the substrate W and the electrostatic chuck 1111, as long as the piping allows a gas to flow between two conductive members having a potential difference therebetween.

[0056] In the above embodiment, the plasma processing apparatus 1 is described as using a capacitively coupled plasma (CCP) as an example of a plasma source, but the plasma source is not limited to the capacitively coupled plasma. Examples of plasma sources other than the capacitively coupled plasma include an inductively coupled plasma (ICP), a microwave-excited surface wave plasma (SWP), an electron cyclotron resonance plasma (ECP), and a helicon wave-excited plasma (HWP).

[0057] 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.

[0058] Furthermore, the following supplementary notes are disclosed regarding the above-described embodiment.

[0059] (Appendix 1) a first member formed of a conductive material; a second member formed of a conductive material and set to a potential different from that of the first member; a pipe formed of a dielectric material and allowing a gas to flow between the first member and the second member; Equipped with One end of the pipe is inserted into an opening formed in the second member, a flow path is formed inside the pipe in a direction oblique to a direction from the first member to the second member, A gas supply device in which the flow path of the piping in the portion between the first member and the second member has a portion where the cross-sectional length of the flow path in the direction from the first member to the second member is shorter than the flow path of the piping in the portion inserted into the opening of the second member. (Appendix 2) A gas supply device as described in Appendix 1, wherein the cross-sectional length of the flow path of the piping in the direction from the first member to the second member increases continuously from the first member side to the second member side along the extension direction of the flow path. (Appendix 3) A gas supply device as described in Appendix 1, wherein the cross-sectional length of the flow path of the piping in the direction from the first member to the second member increases stepwise from the first member side to the second member side along the extension direction of the flow path. (Appendix 4) 4. The gas supply device according to claim 1, wherein the flow path is formed in a spiral shape within the piping. (Appendix 5) 5. The gas supply device according to claim 1, wherein the piping has a plurality of the flow paths formed therein. (Appendix 6) the other end of the pipe is inserted into an opening formed in the first member, 6. A gas supply device according to any one of claims 1 to 5, wherein the flow path of the piping in the portion between the first member and the second member has a portion where the cross-sectional length of the flow path in the direction from the first member to the second member is shorter than the flow path of the piping in the portion inserted into the opening of the first member. (Appendix 7) The length of the cross section of the flow path of the pipe in the direction from the first member to the second member is 7. The gas supply device according to claim 1, wherein the length is such that a potential difference between a wall surface of the flow path on the first member side and a wall surface of the flow path on the second member side is less than a discharge start voltage of Ar gas. (Appendix 8) 8. The gas supply device according to claim 1, wherein the piping is made of polyimide. (Appendix 9) the piping is formed of a first dielectric and a second dielectric having a higher dielectric constant than the first dielectric, At least a portion of the piping between the first member and the second member is formed of the first dielectric material, 8. The gas supply device according to claim 1, wherein the portion of the piping inserted into the second member is formed from the second dielectric material. (Appendix 10) a top plate formed of a conductive material and grounded; a holder formed of a conductive material and insulated from the top plate; a shower plate made of a conductive material, having a plurality of through holes, and held by the holder; a pipe formed of a dielectric material and disposed between the top plate and the holder, for supplying a gas to a space between the holder and the shower plate via the top plate; Equipped with a voltage of a predetermined magnitude is applied to the holder and the shower plate; One end of the pipe is inserted into an opening formed in the holder, a flow path is formed inside the piping in a direction oblique to a direction from the top plate toward the holder, A showerhead in which the flow path of the piping in the portion between the top plate and the holder has a portion where the cross-sectional length of the flow path in the direction from the top plate to the holder is shorter than the flow path of the piping in the portion inserted into the opening of the holder. (Appendix 11) A pipe made of a dielectric material, which allows a gas to flow between a first member made of a conductive material and a second member made of a conductive material and set to a potential different from that of the first member, One end of the pipe is inserted into an opening formed in the second member, a flow path is formed inside the pipe in a direction oblique to a direction from the first member to the second member, A pipe in which the flow path of the pipe in the portion between the first member and the second member has a portion where the cross-sectional length of the flow path in the direction from the first member to the second member is shorter than the flow path of the pipe in the portion inserted into the opening of the second member. [Explanation of symbols]

[0060] R region W substrate 1. Plasma processing equipment 10 Plasma Processing Chamber 10a side wall 10e Gas outlet 10s Plasma treatment space 11 Substrate support 111 Main body 111a Central area 111b Annular region 1110 Foundation 1110a flow channel 1111 Electrostatic chuck 1111a Ceramic components 1111b Electrostatic electrode 112 Ring Assembly 13. Shower head 13a Gas supply port 13b Top Plate 13b1 Bottom surface 13b2 Flow path 13c Insulating material 13d Holder 13d1 Top surface 13d2 opening 13d3 Flow path 13e Gas diffusion chamber 13f Shower Plate 13g Gas inlet 13h Insulating material 130 Piping 130a first dielectric 130b Second dielectric 131 Sealing material 132 Channel 20 Gas supply unit 21 Gas Source 22 Flow Controller 30 power supply 31 RF power supply 31a First RF generation unit 31b Second RF generation unit 32 DC power supply 32a First DC generation unit 32b Second DC generation unit 40 Exhaust system 2. Control Unit 2a Computer 2a1 Processing section 2a2 Storage section 2a3 communication interface

Claims

1. a first member formed of a conductive material; a second member formed of a conductive material and set to a potential different from that of the first member; a pipe formed of a dielectric material and allowing a gas to flow between the first member and the second member; Equipped with One end of the pipe is inserted into an opening formed in the second member, a flow path is formed inside the pipe in a direction oblique to a direction from the first member to the second member, A gas supply device in which the flow path of the piping in the portion between the first member and the second member has a portion where the cross-sectional length of the flow path in the direction from the first member to the second member is shorter than the flow path of the piping in the portion inserted into the opening of the second member.

2. 2. The gas supply device according to claim 1, wherein the cross-sectional length of the flow path of the piping in the direction from the first member to the second member increases continuously from the first member side to the second member side along the extension direction of the flow path.

3. 2. The gas supply device according to claim 1, wherein the cross-sectional length of the flow path of the piping in the direction from the first member to the second member increases stepwise from the first member side to the second member side along the extension direction of the flow path.

4. The gas supply device according to claim 1 , wherein the flow path is formed in a spiral shape within the piping.

5. The gas supply device according to claim 1 , wherein the piping has a plurality of the flow paths formed therein.

6. the other end of the pipe is inserted into an opening formed in the first member, 2. The gas supply device according to claim 1, wherein the flow path of the piping in the portion between the first member and the second member has a portion in which the cross-sectional length of the flow path in the direction from the first member to the second member is shorter than the flow path of the piping in the portion inserted into the opening of the first member.

7. The cross-sectional length of the flow path of the piping in the direction from the first member to the second member is 2. The gas supply device according to claim 1, wherein the length is such that a potential difference between a wall surface of the flow path on the first member side and a wall surface of the flow path on the second member side is less than a discharge start voltage of Ar gas.

8. 2. The gas supply device according to claim 1, wherein the piping is made of polyimide.

9. the piping is formed of a first dielectric and a second dielectric having a higher dielectric constant than the first dielectric, at least a portion of the piping between the first member and the second member is formed of the first dielectric; 2. The gas supply device according to claim 1, wherein the portion of the pipe inserted into the second member is formed from the second dielectric material.

10. a top plate formed of a conductive material and grounded; a holder formed of a conductive material and insulated from the top plate; a shower plate made of a conductive material, having a plurality of through holes, and held by the holder; a pipe formed of a dielectric material and disposed between the top plate and the holder, for supplying a gas to a space between the holder and the shower plate via the top plate; Equipped with a voltage of a predetermined magnitude is applied to the holder and the shower plate; One end of the pipe is inserted into an opening formed in the holder, a flow path is formed inside the piping in a direction oblique to a direction from the top plate toward the holder, A showerhead in which the flow path of the piping in the portion between the top plate and the holder has a portion where the cross-sectional length of the flow path in the direction from the top plate to the holder is shorter than the flow path of the piping in the portion inserted into the opening of the holder.

11. A pipe made of a dielectric material, which allows a gas to flow between a first member made of a conductive material and a second member made of a conductive material and set to a potential different from that of the first member, One end of the pipe is inserted into an opening formed in the second member, a flow path is formed inside the pipe in a direction oblique to a direction from the first member to the second member, A piping in which the flow path of the piping in the portion between the first member and the second member has a portion where the cross-sectional length of the flow path in the direction from the first member to the second member is shorter than the flow path of the piping in the portion inserted into the opening of the second member.

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