JP2017224697A - Gas transport tube and plasma processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress occurrence of discharge in a gas transport tube provided between electrodes, without increasing the length of the gas transport tube.SOLUTION: A gas transport tube 60 transports process gas, introduced from the side of a ground member 61 facing an upper electrode 42 applied with a DC voltage, to gas diffusion chambers 54, 55. A tubular member 160 of the gas transport tube 60 has an inlet 161, and an outlet 162. A passage formation member 170 forms a first gas passage 171, multiple second gas passages 172, multiple third gas passages 173, and a fourth gas passage 174 in the tubular member 160. The first gas passage 171 elongates in the direction of the outlet 162. The multiple second gas passages 172 branch from the terminal of the first gas passage 171. The multiple third gas passages 173 meander between the inlet 161 and outlet 162. The fourth gas passage 174 merges the terminals of the multiple third gas passages 173 with the outlet 162.SELECTED DRAWING: Figure 2

Description

  Various aspects and embodiments of the present invention relate to a gas transport tube and a plasma processing apparatus.

  2. Description of the Related Art Conventionally, plasma processing apparatuses that perform processing such as etching on an object to be processed using plasma are known. In such a plasma processing apparatus, an object to be processed is mounted on a lower electrode as a mounting table disposed inside the processing container, and a processing gas is supplied into the processing container. Then, high-frequency power is applied from the upper electrode disposed above the lower electrode so as to face the object to be processed on the lower electrode, thereby generating plasma of the processing gas in the processing container. Is done. Then, a predetermined plasma process such as etching is performed on the surface of the object to be processed by ions or radicals in the plasma. In addition, a positive or negative DC voltage may be applied to the upper electrode.

  Further, in many cases, a grounding member that faces the upper electrode and functions as a grounding electrode is provided near the upper electrode. When the ground member is provided in the vicinity of the upper electrode, a gas transport pipe for transporting the processing gas introduced from the ground member side to the gas diffusion chamber inside the upper electrode is provided between the upper electrode and the ground member. . The gas transport pipe is formed of an insulating material and insulates the upper electrode and the ground member. The processing gas supplied to the gas diffusion chamber inside the upper electrode by the gas transport pipe is supplied into the processing container from a gas supply port formed on the lower surface of the upper electrode.

  By the way, when a positive or negative DC voltage is applied to the upper electrode, if the absolute value of the applied DC voltage exceeds a certain value, inside the gas transport pipe provided between the upper electrode and the ground member. Electric discharge occurs and the inner wall of the gas transport pipe is damaged. In order to avoid this, a technique is known in which the gas flow path inside the gas transport pipe is formed in a spiral shape or a zigzag shape to increase the distance that the processing gas flows inside the gas transport pipe. As a result, the distance between the electrodes (that is, the distance between the upper electrode and the ground member), which is a factor that determines the discharge start voltage, can be substantially increased, so that the discharge inside the gas transport tube can be prevented. Can be suppressed.

JP 2013-149865 A JP 2006-351435 A JP-A-7-273038

  However, when the gas flow path inside the gas transport pipe is formed in a spiral or zigzag shape, if the gas pressure between the electrodes, which is another factor that determines the discharge start voltage, becomes lower than a certain value, the gas transport is still Discharge occurs inside the tube. In order to avoid this, a method of increasing the length of the spiral or zigzag gas flow path by increasing the length of the gas transport pipe itself can be considered. However, an increase in the length of the gas transport pipe itself is not realistic because it involves a change in the arrangement of other parts in the vicinity of the gas transport pipe.

  In one embodiment, the disclosed gas transport pipe transports a processing gas introduced from the side of a grounding member facing the electrode to which a DC voltage is applied and functioning as a grounding electrode to a gas diffusion chamber inside the electrode. The gas transport pipe includes a tubular member and a flow path forming member. The tubular member has an inflow port through which a processing gas introduced from the grounding member side flows, and an outflow port through which the processing gas flows out into a gas diffusion chamber inside the electrode. The flow path forming member is provided inside the tubular member, and includes a first gas flow path, a plurality of second gas flow paths, a plurality of third gas flow paths, and a fourth gas flow path. It is formed inside the member. The first gas channel is connected to the inlet and extends in the direction of the outlet. The plurality of second gas flow paths branch from the end of the first gas flow path. The plurality of third gas flow paths are respectively connected to the plurality of second gas flow paths and meander between the inflow port and the outflow port. The fourth gas flow path joins the ends of the plurality of third gas flow paths to the outlet.

  According to one aspect of the disclosed gas transport tube, it is possible to suppress the occurrence of discharge inside the gas transport tube without increasing the length of the gas transport tube provided between the electrodes. Play.

FIG. 1 is a longitudinal sectional view showing a schematic configuration of a plasma processing apparatus according to the present embodiment. FIG. 2 is an enlarged longitudinal sectional view showing the gas transport pipe according to this embodiment. FIG. 3 is a cross-sectional view taken along line AA of the tubular member and the flow path forming member shown in FIG. FIG. 4 is a perspective view of the flow path forming member according to the present embodiment as viewed from the inlet side of the tubular member. FIG. 5 is a perspective view of the flow path forming member according to the present embodiment as viewed from the outlet side of the tubular member. FIG. 6 is a diagram for explaining the effect (increase in discharge start voltage) by the gas transport tube according to the present embodiment. FIG. 7 is a diagram showing a simulation result of pressure distribution in the gas flow path when a gas transport pipe having an internal gas flow path formed in a spiral shape is used for comparison with the gas transport pipe of the present embodiment. It is. FIG. 8 is a diagram showing a simulation result of the pressure distribution in the gas flow path when the gas transport pipe of this embodiment is used. FIG. 9 is a perspective view of the flow path forming member according to the modification as viewed from the inlet side of the tubular member. FIG. 10 is a perspective view of the flow path forming member according to the modification as seen from the outlet side of the tubular member.

  Hereinafter, embodiments of a gas transport pipe and a plasma processing apparatus disclosed in the present application will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals. Moreover, the invention disclosed by this embodiment is not limited.

(Plasma processing equipment)
FIG. 1 is a longitudinal sectional view showing a schematic configuration of a plasma processing apparatus 1 according to the present embodiment. The plasma processing apparatus 1 according to the present embodiment is, for example, a parallel plate type plasma etching processing apparatus.

  The plasma processing apparatus 1 includes a substantially cylindrical processing container 11 provided with a wafer chuck 10 that holds a wafer W that is a silicon substrate. The processing container 11 is electrically connected to the ground line 12 and grounded. An electrode (not shown) is provided inside the wafer chuck 10 so that the wafer W can be adsorbed and held by an electrostatic force generated by applying a DC voltage to the electrode.

  The lower surface of the wafer chuck 10 is supported by a susceptor 13 serving as a lower electrode. The susceptor 13 is formed in a substantially disk shape from a metal such as aluminum. A support base 15 is provided at the bottom of the processing container 11 via an insulating plate 14, and the susceptor 13 is supported on the upper surface of the support base 15.

  A conductive correction ring 20 made of, for example, silicon is provided on the upper surface of the susceptor 13 and on the outer peripheral portion of the wafer chuck 10 to improve the uniformity of plasma processing. The outer surface of the susceptor 13, the support base 15, and the correction ring 20 is covered with a cylindrical member 21 made of, for example, quartz.

  A coolant path 15a through which a coolant flows is provided in the support base 15 in, for example, an annular shape. By controlling the temperature of the coolant supplied by the coolant path 15a, the wafer W held by the wafer chuck 10 is controlled. The temperature can be controlled. Further, a heat transfer gas pipe 22 for supplying, for example, helium gas as a heat transfer gas between the wafer chuck 10 and the wafer W held by the wafer chuck 10, for example, connects the susceptor 13, the support base 15, and the insulating plate 14. It is provided through.

  The susceptor 13 is electrically connected via a first matching unit 31 to a first high frequency power supply 30 for supplying high frequency power to the susceptor 13 to generate plasma. The first high frequency power supply 30 is configured to output a high frequency power of 27 to 100 MHz, for example, 40 MHz in the present embodiment, for example. The first matching unit 31 matches the internal impedance of the first high-frequency power source 30 and the load impedance, and when the plasma is generated in the processing container 11, the internal impedance of the first high-frequency power source 30. And the load impedance seem to coincide with each other.

  The susceptor 13 is provided with a second high-frequency power supply 40 for supplying ions to the wafer W by supplying a high-frequency power to the susceptor 13 and applying a bias to the wafer W via a second matching unit 41. Are electrically connected. The second high frequency power supply 40 is configured to output a high frequency power of, for example, 400 kHz to 13.56 MHz, and in this embodiment, for example, 3.2 MHz. Similar to the first matching unit 31, the second matching unit 41 matches the internal impedance of the second high-frequency power source 40 with the load impedance.

  Above the susceptor 13, which is the lower electrode, an upper electrode 42 is provided in parallel to face the susceptor 13. The upper electrode 42 is supported on the upper portion of the processing container 11 via an insulating shielding member 50. The upper electrode 42 includes an electrode plate 51 that forms a surface facing the wafer W held by the wafer chuck 10, and an electrode support 52 that supports the electrode plate 51 from above. In the electrode plate 51, a plurality of gas supply ports 53 for supplying a processing gas into the processing container 11 are formed so as to penetrate the electrode plate 51. The electrode plate 51 is made of, for example, a low-resistance conductor or semiconductor with little Joule heat, and silicon is used in the present embodiment, for example. Moreover, the electrode support body 52 is comprised with the conductor, and aluminum is used in this embodiment, for example.

  A DC power supply 81 is electrically connected to the upper electrode 42 through a low-pass filter 80 that traps high frequencies from the first high frequency power supply 30 and the second high frequency power supply 40. A positive or negative DC voltage can be applied. In the present embodiment, a negative DC voltage is applied, and the negative DC voltage is −1200 V, for example.

  A gas diffusion chamber 54 formed in a substantially disk shape is provided in the center portion inside the electrode support 52. A gas diffusion chamber 55 formed in an annular shape is further provided outside the gas diffusion chamber 54. A plurality of gas holes 56 extending downward from the gas diffusion chambers 54 and 55 are formed in the lower part of the electrode support 52, and the gas supply port 53 is connected to the gas diffusion chambers 54 and 55 through the gas holes 56. ing. The gas diffusion chamber 54 and the gas diffusion chamber 55 are provided separately by adjusting the internal pressures of the gas diffusion chamber 54 and the gas diffusion chamber 55, respectively, and the gas hole 56 near the center of the electrode support 52 and the vicinity of the outer periphery. This is for independently adjusting the flow rate of the processing gas flowing from the gas holes 56, and the arrangement and shape of the gas diffusion chambers 54 and 55 are not limited to those of the present embodiment.

  A grounding member 61 is provided above the upper electrode 42 (electrode support 52) so as to face the upper electrode 42 (electrode support 52). The ground member 61 functions as a ground electrode with respect to the upper electrode 42. The ground member 61 is made of a conductor, and in this embodiment, for example, aluminum is used.

  A gas transport pipe 60 is provided between the upper electrode 42 and the ground member 61. The gas transport pipe 60 is formed of an insulating material and insulates the upper electrode 42 and the ground member 61. The gas transport pipe 60 transports the processing gas introduced from the grounding member 61 side to the gas diffusion chambers 54 and 55 inside the upper electrode 42. Details of the gas transport pipe 60 will be described later.

A gas introduction port 70 is formed in the grounding member 61 at a position corresponding to the gas transport pipe 60 so as to penetrate the grounding member 61. A gas supply pipe 71 is connected to the gas inlet 70. A processing gas supply source 72 is connected to the gas supply pipe 71 as shown in FIG. 1, and the processing gas supplied from the processing gas supply source 72 passes through the gas supply pipe 71 and the gas transport pipe 60. It is supplied to the diffusion chambers 54 and 55. Then, the processing gas supplied to the gas diffusion chambers 54 and 55 is introduced into the processing container 11 through the gas hole 56 and the gas supply port 53. That is, the upper electrode 42 functions as a shower head that supplies a processing gas into the processing container 11. As the processing gas, various gases used in conventional plasma etching can be employed. For example, a fluorocarbon gas such as C ₄ F ₈ may be used, and other gases such as Ar and O ₂ may be used. Gas may be included.

  The gas supply pipe 71 is provided with a flow rate adjusting mechanism 73, and the amount of gas supplied from the processing gas supply source 72 to the gas diffusion chambers 54 and 55 can be controlled. The flow rate adjusting mechanism 73 is configured by, for example, a mass flow controller and a valve.

  An exhaust port 90 is provided on the bottom surface of the processing container 11. An exhaust device 92 is connected to the exhaust port 90 via an exhaust pipe 91. By driving the exhaust device 92, the atmosphere in the processing container 11 can be decompressed to a predetermined degree of vacuum. In addition, the inner wall of the processing vessel 11 is covered with a liner 93 having a sprayed coating made of a plasma-resistant material formed on the surface.

(Gas transport pipe)
FIG. 2 is an enlarged longitudinal sectional view showing the gas transport pipe 60 according to the present embodiment. As shown in FIG. 2, the gas transport pipe 60 includes a tubular member 160 and a flow path forming member 170. The tubular member 160 includes an inflow port 161 through which the processing gas introduced from the gas introduction port 70 of the grounding member 61 flows, and an outflow port 162 through which the processing gas flows out to the gas diffusion chambers 54 and 55 inside the upper electrode 42. Have.

  The flow path forming member 170 is provided inside the tubular member 160. The flow path forming member 170 forms a first gas flow path 171, a plurality of second gas flow paths 172, a plurality of third gas flow paths 173, and a fourth gas flow path 174 inside the tubular member 160. To do.

  Here, with reference to FIG. 2 to FIG. 5, the first gas channel 171, the second gas channel 172, the third gas channel 173, and the fourth gas formed by the channel forming member 170 according to the present embodiment. Details of the flow path 174 will be described. FIG. 3 is a cross-sectional view taken along line AA of the tubular member 160 and the flow path forming member 170 shown in FIG. FIG. 4 is a perspective view of the flow path forming member 170 according to the present embodiment as viewed from the inflow port 161 side of the tubular member 160. FIG. 5 is a perspective view of the flow path forming member 170 according to the present embodiment as viewed from the outlet 162 side of the tubular member 160.

  As shown in FIGS. 2 and 4, the first gas flow channel 171 is connected to the inlet 161 of the tubular member 160 and extends in the direction of the outlet 162 of the tubular member 160.

  As shown in FIGS. 2 to 5, the plurality of second gas flow paths 172 branch from the end of the first gas flow path 171 in the radial direction of the tubular member 160. For example, the plurality of second gas flow paths 172 are arranged so that the angle between the second gas flow paths 172 adjacent in the circumferential direction of the tubular member 160 is equal from the end of the first gas flow path 171 to the tubular member 160. Branch in the radial direction. In the present embodiment, the three second gas passages 172 have the first gas passage 171 so that the angle between the second gas passages 172 adjacent in the circumferential direction of the tubular member 160 is 60 °. Branches in the radial direction of the tubular member 160 from the end.

  As shown in FIGS. 2, 4, and 5, the plurality of third gas flow paths 173 are respectively connected to the plurality of second gas flow paths 172 and are formed between the inlet 161 and the outlet 162 of the tubular member 160. Meander. Specifically, the plurality of third gas flow paths 173 meander between the inlet 161 and the outlet 162 of the tubular member 160 along the circumferential direction of the tubular member 160. In the present embodiment, the three third gas flow paths 173 are connected to the three second gas flow paths 172, respectively, and flow along the inlet 161 of the tubular member 160 along the circumferential direction of the tubular member 160. Serpentine between the outlet 162. In addition, at least a part of the inner wall of the folded portion of each third gas channel 173 is a curved surface. Thereby, the pressure loss in the folding | turning part of each 3rd gas flow path 173 is reduced.

  As shown in FIGS. 2 and 5, the fourth gas passage 174 joins the terminal ends of the plurality of third gas passages 173 to the outlet 162 of the tubular member 160. The fourth gas channel 174 has a convex rectifying portion 174 a that guides the processing gas flowing in from the terminal ends of the plurality of third gas channels 173 toward the outlet 162 of the tubular member 160.

  By providing the flow path forming member 170 inside the tubular member 160 like the gas transport pipe 60 of the present embodiment, the gas flow is compared with a gas transport pipe in which the internal gas flow path is formed in a spiral or zigzag shape. The channel length of the channel can be increased. For example, the case where the length of the gas transport pipe 60 of this embodiment and the length of the gas transport pipe which formed the internal gas flow path in the shape of a spiral or a zigzag are equal is assumed. In this case, in the gas transport pipe in which the internal gas channel is formed in a spiral shape or a zigzag shape, the channel length of the gas channel (measured along the channel wall of the gas channel) is 80 mm. Become. On the other hand, in the gas transport pipe 60 of the present embodiment, the length of the first gas channel 171, the length of each second gas channel 172, the length of each third gas channel 173, and the fourth gas The channel length (the length measured along the channel wall of the gas channel) which is the sum of the lengths of the channels 174 is 200 mm. According to the gas transport pipe 60 of the present embodiment, by providing the flow path forming member 170 inside the tubular member 160, the distance between the electrodes that is a factor that determines the discharge start voltage (that is, the upper electrode 42 and the grounding member). 61) can be substantially increased, so that the discharge start voltage can be increased. As a result, the occurrence of discharge inside the gas transport tube 60 can be suppressed without increasing the length of the gas transport tube 60 provided between the upper electrode 42 and the ground member 61.

  In the gas transport pipe 60 of the present embodiment, the plurality of second gas channels 172 branch from the end of the first gas channel 171 and are connected to the plurality of second gas channels 172. The end of the channel 173 joins the outlet 162 of the tubular member 160 via the fourth gas channel 174. Thereby, while suppressing generation | occurrence | production of the discharge inside the gas transport pipe 60, the reduction | decrease in the flow volume of the process gas conveyed by the gas transport pipe 60 can be suppressed.

  Next, with reference to FIGS. 6-8, the effect by the gas transport pipe 60 which concerns on this embodiment is further demonstrated. FIG. 6 is a diagram for explaining the effect (increase in discharge start voltage) by the gas transport tube 60 according to the present embodiment.

  FIG. 6 shows a Paschen curve when the processing gas transported by the gas transport pipe 60 is Ar gas. In FIG. 6, the horizontal axis represents the gas pressure between the electrodes (that is, the pressure of the processing gas inside the gas transport pipe 60) P × the distance between the electrodes (that is, between the upper electrode 42 and the ground member 61. Distance) d [cm × Torr], and the vertical axis represents the discharge start voltage [V]. Moreover, in FIG. 6, the discharge start voltage at the time of using the gas transport pipe | tube 60 of this embodiment is represented as an "Example." On the other hand, in FIG. 6, the discharge start voltage in the case of using a gas transport tube having an internal gas flow path formed in a spiral shape is represented as “comparative example”. In FIG. 6, it is assumed that 1.3 Torr is used as the gas pressure between the electrodes (that is, the pressure of the processing gas inside the gas transport pipe 60) P.

  As shown in FIG. 6, the discharge start voltage was 675.83 V when a gas transport tube having an internal gas flow path formed in a spiral shape was used. On the other hand, the discharge start voltage in the case of using the gas transport tube 60 of the present embodiment was 1348.03V. That is, the discharge start voltage when the gas transport tube 60 of the present embodiment is used is about twice as high as the discharge start voltage when the gas transport tube in which the internal gas flow path is formed in a spiral shape is used. It became.

  FIG. 7 shows a simulation result of the pressure distribution in the gas flow path when a gas transport pipe having an internal gas flow path formed in a spiral shape is used for comparison with the gas transport pipe 60 of the present embodiment. FIG. FIG. 8 is a diagram showing a simulation result of the pressure distribution in the gas flow path when the gas transport pipe 60 of the present embodiment is used.

  The horizontal axis of FIG. 7 shows the position (mm) inside the gas flow path with reference to the starting end of the spiral gas flow path. The vertical axis | shaft of FIG. 7 shows the pressure in each position inside a spiral gas flow path. The horizontal axis of FIG. 8 indicates the first gas flow path 171, each second gas flow path 172, each third gas flow path 173, and the fourth gas flow path 174 with reference to the start end of the first gas flow path 171. The internal position (mm) is shown. The vertical axis in FIG. 8 indicates the pressure at each position inside the first gas channel 171, the second gas channel 172, the third gas channel 173, and the fourth gas channel 174. In the simulations of FIGS. 7 and 8, the processing conditions are: processing gas: Ar, processing gas flow rate: 200 sccm, pressure at the end of the spiral gas flow path or the end of the fourth gas flow path 174: 1.3 Torr. Was used.

  As is apparent from the simulation results of FIGS. 7 and 8, in the gas transport pipe in which the internal gas flow path is formed in a spiral shape, the pressure at the starting end of the spiral gas flow path is about 1.85 Torr. On the other hand, in the gas transport pipe 60 of the present embodiment in which the flow path forming member 170 is provided inside the tubular member 160, the pressure at the start end of the first gas flow path 171 is about 2.63 Torr. As is apparent from the simulation results of FIGS. 7 and 8, by providing the flow path forming member 170 inside the tubular member 160, the pressure distribution of the processing gas inside the gas transport pipe 60 generally increases. That is, by providing the flow path forming member 170 inside the tubular member 160 as in the gas transport pipe 60 of the embodiment, the pressure of the gas between the electrodes (that is, the gas transport), which is another factor that determines the discharge start voltage. The pressure of the processing gas inside the pipe 60 can be increased. Therefore, it has been found that also from the viewpoint of pressure, the occurrence of discharge inside the gas transport tube 60 is suppressed.

  As described above, according to the gas transport pipe 60 and the plasma processing apparatus 1 of the present embodiment, by providing the flow path forming member 170 inside the tubular member 160, the gas in which the internal gas flow path is formed in a spiral shape or a zigzag shape. Compared with the transport pipe, the length of the gas channel can be increased. As a result, the distance between the electrodes (that is, the distance between the upper electrode 42 and the ground member 61), which is a factor that determines the discharge start voltage, can be substantially increased, so that the discharge start voltage is increased. Can do. As a result, the occurrence of discharge inside the gas transport tube 60 can be suppressed without increasing the length of the gas transport tube 60 provided between the upper electrode 42 and the ground member 61.

  In addition, although illustration is abbreviate | omitted, the some 2nd gas flow path 172 may take the structure branched in the radial direction of the tubular member 160, and diagonally upward.

(Modification)
Next, a modified example will be described. The gas transport pipe according to the modified example has the same configuration as the gas transport pipe 60 according to the above-described embodiment except for the shape of the plurality of second gas flow paths 172 formed by the flow path forming member 170. Therefore, in the modified example, the same reference numerals are used for components common to the above-described embodiment, and detailed description thereof is omitted.

  In the gas transport pipe 60 according to the modification, the flow path forming member 170 includes a first gas flow path 171, a plurality of second gas flow paths 172, a plurality of third gas flow paths 173, and a fourth gas flow path. 174 is formed inside the tubular member 160.

  FIG. 9 is a perspective view of the flow path forming member 170 according to the modification as viewed from the inflow port 161 side of the tubular member 160. FIG. 10 is a perspective view of the flow path forming member 170 according to the modification as viewed from the outlet 162 side of the tubular member 160.

  As shown in FIG. 9, the first gas flow path 171 is connected to the inlet 161 of the tubular member 160 and extends in the direction of the outlet 162 of the tubular member 160.

  As shown in FIG. 9, the plurality of second gas flow paths 172 branch from the end of the first gas flow path 171 in the circumferential direction of the tubular member 160. In this modification, the two second gas flow paths 172 branch from the end of the one gas flow path 171 in the circumferential direction of the tubular member 160.

  As shown in FIGS. 9 and 10, the plurality of third gas flow paths 173 are respectively connected to the plurality of second gas flow paths 172 and meander between the inlet 161 and the outlet 162 of the tubular member 160. . In the present embodiment, the two second gas flow paths 172 are connected to the two second gas flow paths 172, respectively, and flow along the inlet 161 of the tubular member 160 along the circumferential direction of the tubular member 160. Serpentine between the outlet 162. In addition, at least a part of the inner wall of the folded portion of each third gas channel 173 is a curved surface. Thereby, the pressure loss in the folding | turning part of each 3rd gas flow path 173 is reduced.

  The fourth gas channel 174 joins the terminal ends of the plurality of third gas channels 173 to the outlet 162 of the tubular member 160.

  As described above, according to the gas transport pipe 60 and the plasma processing apparatus 1 of the modification, the length of the gas transport pipe 60 provided between the upper electrode 42 and the ground member 61 is increased as in the above embodiment. In addition, the occurrence of discharge inside the gas transport tube 60 can be suppressed.

DESCRIPTION OF SYMBOLS 1 Plasma processing apparatus 11 Processing container 13 Susceptor (lower electrode)
42 Upper electrode 51 Electrode plate 52 Electrode support 53 Gas supply port 54, 55 Gas diffusion chamber 56 Gas hole 60 Gas transport pipe 61 Grounding member 70 Gas inlet 71 Gas supply pipe 81 DC power supply 160 Tubular member 161 Inlet 162 Outlet 170 Channel forming member 171 First gas channel 172 Second gas channel 173 Third gas channel 174 Fourth gas channel

Claims (8)

A gas transport pipe for transporting a processing gas introduced from the side of the ground member facing the electrode to which a DC voltage is applied and functioning as a ground electrode, to the gas diffusion chamber inside the electrode;
A tubular member having an inflow port for introducing a processing gas introduced from the grounding member side, and an outflow port for allowing the processing gas to flow into a gas diffusion chamber inside the electrode;
A first gas flow path provided in the tubular member, connected to the inflow port and extending in the direction of the outflow port, and a plurality of second gas flow paths branched from the end of the first gas flow path; A plurality of third gas passages connected to the plurality of second gas passages and meandering between the inflow port and the outflow port, respectively, and ends of the plurality of third gas passages are connected to the outflow port. A gas transport pipe, comprising: a fourth gas flow path that merges with the flow path forming member that forms inside the tubular member.   2. The gas transport pipe according to claim 1, wherein the plurality of second gas flow paths are branched in a radial direction of the tubular member from an end of the first gas flow path.   2. The gas transport pipe according to claim 1, wherein the plurality of second gas flow paths branch from a terminal end of the first gas flow path in a circumferential direction of the tubular member.   2. The gas transport pipe according to claim 1, wherein the plurality of second gas flow paths branch from a terminal end of the first gas flow path in a radial direction of the tubular member and obliquely upward. A processing container for performing plasma processing on an object to be processed;
A lower electrode provided inside the processing container and on which a target object is placed;
An upper electrode provided above the lower electrode to which a DC voltage is applied;
A ground member facing the upper electrode and functioning as a ground electrode;
A plasma processing apparatus having a gas transport pipe for transporting a processing gas introduced from the ground member side to a gas diffusion chamber inside the upper electrode,
The gas transport pipe is
A tubular member having an inflow port for introducing a processing gas introduced from the grounding member side, and an outflow port for allowing the processing gas to flow into a gas diffusion chamber inside the upper electrode;
A first gas flow path provided in the tubular member, connected to the inflow port and extending in the direction of the outflow port, and a plurality of second gas flow paths branched from the end of the first gas flow path; A plurality of third gas passages that are respectively connected to the plurality of second gas passages and meander between the inflow port and the outflow port; A plasma processing apparatus, comprising: a channel forming member that forms a fourth gas channel to be joined to the inside of the tubular member.   The plasma processing apparatus according to claim 5, wherein the plurality of second gas flow paths branch from a terminal end of the first gas flow path in a radial direction of the tubular member.   The plasma processing apparatus according to claim 5, wherein the plurality of second gas flow paths branch from a terminal end of the first gas flow path in a circumferential direction of the tubular member.   The plasma processing apparatus according to claim 5, wherein the plurality of second gas flow paths branch from a terminal end of the first gas flow path in a radial direction of the tubular member and obliquely upward.

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