Plasma processing apparatus and inner chamber

Abstract

To provide a technique for reducing variations in gas flow velocity in a radial direction within a substrate processing space.SOLUTION: A plasma processing apparatus disclosed herein includes a substrate support, an upper electrode, an inner chamber, and an exhaust device in an outer chamber. The substrate support is provided in the outer chamber. The upper electrode is provided above the substrate support. The inner chamber defines a substrate processing space above the substrate support. The exhaust device is connected to an exhaust port provided at the bottom of the outer chamber. The inner chamber includes a ceiling and a sidewall. The ceiling extends above the substrate processing space, provides a plurality of gas holes, and constitutes a showerhead together with the upper electrode. The sidewall extends in a circumferential direction so as to surround the substrate processing space, and provides a plurality of through holes. The sidewall has an opening area that increases stepwise or continuously along a direction from its lower end to its upper end.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] SUMMARY Exemplary embodiments of the present disclosure relate to a plasma processing apparatus and an inner chamber. [Background technology]

[0002] A capacitively coupled plasma processing apparatus is used as a type of plasma processing apparatus. The capacitively coupled plasma processing apparatus described in Patent Document 1 and Patent Document 2 has a chamber, a substrate support, an upper electrode, and a baffle plate. The substrate support includes a lower electrode and is provided in the chamber. The substrate support supports a substrate placed on its upper surface. The upper electrode is provided on the substrate support and constitutes a shower head. The baffle plate is provided so as to surround the substrate support below the upper surface of the substrate support. The baffle plate provides a plurality of through holes. The bottom of the chamber provides an exhaust port below the baffle plate, and the exhaust port is connected to an exhaust device. The baffle plate is formed so that the opening area becomes wider from its inner periphery toward its outer periphery. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-200460 A [Patent Document 2] Japanese Patent Application Publication No. 11-317397 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for reducing variations in gas flow velocity in a radial direction within a substrate processing space. [Means for solving the problem]

[0005] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes an outer chamber, a substrate support, an upper electrode, an inner chamber, and an exhaust device. The outer chamber provides an exhaust port at its bottom. The substrate support includes a lower electrode and is provided in the outer chamber. The upper electrode is provided above the substrate support. The inner chamber, together with the substrate support, defines a substrate processing space on the substrate support in the outer chamber. The exhaust device connects to a space provided in the outer chamber and outside the inner chamber through the exhaust port of the outer chamber. The inner chamber is detachable from the upper electrode. The inner chamber includes a ceiling portion and a sidewall portion. The ceiling portion extends over the substrate processing space and provides a plurality of gas holes. The ceiling portion and the upper electrode form a shower head. The sidewall portion extends in a circumferential direction to surround the substrate processing space. The sidewall portion provides a plurality of through holes. The sidewall portion has an opening area that increases stepwise or continuously along a direction from its lower end to its upper end. Effect of the Invention

[0006] According to one exemplary embodiment, it is possible to reduce variations in gas flow velocity in a radial direction within a substrate processing space. [Brief description of the drawings]

[0007] [Figure 1] 1 is a schematic diagram illustrating a plasma processing apparatus according to an exemplary embodiment; [Diagram 2] Each of Fig. 2(a), Fig. 2(b), and Fig. 2(c) is an exemplary plan view of an upper portion and a lower portion of the inner chamber, respectively. [Diagram 3] Each of Fig. 3(a), Fig. 3(b), and Fig. 3(c) is an exemplary plan view of an upper portion and a lower portion of the inner chamber, respectively. [Figure 4] FIGS. 4(a) and 4(b) are diagrams showing the results of a first simulation and a second simulation, respectively. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Various exemplary embodiments are described below.

[0009] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes an outer chamber, a substrate support, an upper electrode, an inner chamber, and an exhaust device. The outer chamber provides an exhaust port at its bottom. The substrate support includes a lower electrode and is provided in the outer chamber. The upper electrode is provided above the substrate support. The inner chamber, together with the substrate support, defines a substrate processing space on the substrate support in the outer chamber. The exhaust device connects to a space provided in the outer chamber and outside the inner chamber through the exhaust port of the outer chamber. The inner chamber is detachable from the upper electrode. The inner chamber includes a ceiling portion and a sidewall portion. The ceiling portion extends over the substrate processing space and provides a plurality of gas holes. The ceiling portion and the upper electrode form a shower head (gas shower head). The sidewall portion extends in a circumferential direction so as to surround the substrate processing space. The sidewall portion provides a plurality of through holes. The sidewall portion has an opening area that increases stepwise or continuously along a direction from its lower end to its upper end.

[0010] In another exemplary embodiment, an inner chamber for use in an outer chamber of a plasma processing apparatus is provided. The inner chamber includes a ceiling portion and a sidewall portion. The ceiling portion extends over a substrate processing space and provides a plurality of gas holes. The sidewall portion extends in a circumferential direction on a side of the substrate processing space so as to surround the substrate processing space. The sidewall portion provides a plurality of through holes and has an opening area that increases stepwise or continuously along a direction from a lower end to an upper end thereof.

[0011] According to the above embodiment, the variation in gas pressure in the radial direction within the substrate processing space is reduced, and therefore the variation in gas flow velocity in the radial direction within the substrate processing space is reduced.

[0012] In one exemplary embodiment, the sidewall may include an upper portion and a lower portion, the upper portion having a larger open area than the lower portion.

[0013] In one exemplary embodiment, the upper portion may be a portion of the sidewall between the upper end and the lower end from the center to the upper end. That is, the upper portion may be a portion of the upper half of the sidewall. The lower portion may be a portion of the sidewall from the center to the lower end. That is, the lower portion may be a portion of the lower half of the sidewall.

[0014] In one exemplary embodiment, the plurality of through holes may have a circular or oval shape.

[0015] In one exemplary embodiment, the maximum width (diameter or major axis width) of each of the plurality of first through holes provided in the upper portion of the plurality of through holes may be greater than the maximum width (diameter or major axis width) of each of the plurality of second through holes provided in the lower portion of the plurality of through holes.

[0016] In one exemplary embodiment, the density of the plurality of through holes in the upper portion may be greater than the density of the plurality of through holes in the lower portion.

[0017] In one exemplary embodiment, each of the plurality of through holes may have a maximum width (diameter or major axis width) that is greater than the maximum width (diameter or major axis width) of a through hole in the plurality of through holes that is located closer to its lower end.

[0018] In one exemplary embodiment, the density of the plurality of through holes may increase along a direction from the bottom to the top.

[0019] In one exemplary embodiment, the sidewall may have a bulging shape between its upper and lower ends, or the sidewall may have a cylindrical shape.

[0020] Various exemplary embodiments will now be described in detail with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0021] Fig. 1 is a schematic diagram of a plasma processing apparatus according to an exemplary embodiment. The plasma processing apparatus 1 shown in Fig. 1 is a capacitively coupled plasma processing apparatus. The plasma processing apparatus 1 includes an outer chamber 10, a substrate support 12, an upper electrode 14, an inner chamber 16, and an exhaust device 11.

[0022] The outer chamber 10 provides an internal space therein. The outer chamber 10 is made of a metal such as aluminum. The outer chamber 10 is electrically grounded. A corrosion-resistant film may be formed on the surface of the outer chamber 10. The corrosion-resistant film may be formed of a material such as aluminum oxide or yttrium oxide.

[0023] The outer chamber 10 includes a side wall 10s. The side wall 10s has a substantially cylindrical shape. A central axis of the side wall 10s extends in a vertical direction and is shown as an axis AX in FIG. 1. The side wall 10s provides a passage 10p. The passage 10p can be opened and closed by a gate valve 10g. The substrate W passes through the passage 10p when being transferred between the internal space of the outer chamber 10 and the outside of the outer chamber 10 by a transfer device.

[0024] The side wall 10s further provides an opening 10o. The opening 10o has a size that allows the inner chamber 16 to pass through. The opening 10o can be opened and closed by a gate valve 10v. The inner chamber 16 passes through the opening 10o when it is transferred between the internal space of the outer chamber 10 and the outside of the outer chamber 10 by a transfer device.

[0025] The outer chamber 10 may further include an upper portion 10u. The upper portion 10u extends from the upper end of the side wall 10s in a direction intersecting with the axis line AX. The upper portion 10u provides an opening in a region intersecting with the axis line AX.

[0026] The outer chamber 10 provides an exhaust port 10e at its bottom. An exhaust pipe 13 is attached to the bottom of the outer chamber 10 so as to connect to the exhaust port 10e. The exhaust device 11 is connected to a space (exhaust space) provided inside the outer chamber 10 and outside the inner chamber 16 via the exhaust pipe 13 and the exhaust port 10e. The exhaust device 11 includes a pressure regulator such as an automatic pressure control valve and a pressure reducing pump such as a turbo molecular pump.

[0027] The substrate support 12 is provided in the outer chamber 10. The substrate support 12 is configured to support a substrate W placed thereon. The substrate support 12 provides a lower electrode. The substrate support 12 may include a base 22 and an electrostatic chuck 24. The base 22 has a substantially disk shape. The central axis of the base 22 substantially coincides with the axis AX. The base 22 is formed of a conductor such as aluminum. The base 22 may constitute a lower electrode. The base 22 provides a flow path 22f therein. The flow path 22f extends, for example, in a spiral shape. The flow path 22f is connected to a chiller unit 23. The chiller unit 23 is provided outside the outer chamber 10. The chiller unit 23 supplies a heat medium (for example, a refrigerant) to the flow path 22f. The heat medium supplied to the flow path 22f flows through the flow path 22f and is returned to the chiller unit 23.

[0028] The electrostatic chuck 24 is provided on the base 22. The electrostatic chuck 24 includes a main body and an electrode chuck. The main body of the electrostatic chuck 24 has a substantially disk shape. The central axis of the electrostatic chuck 24 substantially coincides with the axis AX. The main body of the electrostatic chuck 24 is formed of ceramic. The substrate W is placed on the upper surface of the main body of the electrostatic chuck 24. The chuck electrode is a film formed of a conductor. The chuck electrode is provided in the main body of the electrostatic chuck 24. The chuck electrode is connected to a DC power supply via a switch. When a voltage from the DC power supply is applied to the chuck electrode, an electrostatic attractive force is generated between the electrostatic chuck 24 and the substrate W. The generated electrostatic attractive force attracts the substrate W to the electrostatic chuck 24 and the substrate W is held by the electrostatic chuck 24. The plasma processing apparatus 1 may provide a gas line for supplying a heat transfer gas (e.g., helium gas) to the gap between the electrostatic chuck 24 and the rear surface of the substrate W.

[0029] The substrate support 12 may further support an edge ring ER disposed thereon. The substrate W is placed on the electrostatic chuck 24 within a region surrounded by the edge ring ER. The edge ring ER is made of, for example, silicon, quartz, or silicon carbide.

[0030] The plasma processing apparatus 1 may further include an insulating portion 26. The insulating portion 26 is made of an insulator such as quartz. The insulating portion 26 may have a substantially cylindrical shape. The insulating portion 26 extends along the outer periphery of the base 22 and the outer periphery of the electrostatic chuck 24.

[0031] The plasma processing apparatus 1 may further include a conductor 28. The conductor 28 is formed of a conductor such as aluminum. The conductor 28 may have a substantially cylindrical shape. The conductor 28 extends along the outer circumferential surface of the insulating portion 26. The conductor 28 extends in the circumferential direction radially outside the insulating portion 26. Note that the radial direction and the circumferential direction are each a direction based on the axis AX. The conductor 28 is connected to the ground. In one example, the conductor 28 is connected to the ground via the outer chamber 10. The conductor 28 may be a part of the outer chamber 10.

[0032] The plasma processing apparatus 1 may further include a high-frequency power supply 31 and a bias power supply 32. The high-frequency power supply 31 is a power supply that generates a source high-frequency power. The source high-frequency power has a frequency suitable for generating plasma. The frequency of the source high-frequency power is, for example, 27 MHz or more. The high-frequency power supply 31 is electrically connected to a lower electrode in the substrate support 12 via a matching device 31m. The high-frequency power supply 31 may be electrically connected to the base 22. The matching device 31m has a matching circuit for matching the impedance of the load side of the high-frequency power supply 31 to the output impedance of the high-frequency power supply 31. The high-frequency power supply 31 may be electrically connected to another electrode in the substrate support 12. Alternatively, the high-frequency power supply 31 may be connected to an upper electrode via the matching device 31m.

[0033] The bias power supply 32 is a power supply that generates electric bias energy. The electric bias energy is supplied to the lower electrode of the substrate support 12 to attract ions from the plasma to the substrate W. The electric bias energy may be bias RF power. The waveform of the bias RF power is a sine wave having a bias frequency. The bias frequency is, for example, 13.56 MHz or less. In this case, the bias power supply 32 is electrically connected to the lower electrode of the substrate support 12 via a matching device 32m. The bias power supply 32 may be electrically connected to the base 22. The matching device 32m has a matching circuit for matching the impedance of the load side of the bias power supply 32 to the output impedance of the bias power supply 32. The bias power supply 32 may be electrically connected to another electrode in the substrate support 12.

[0034] Alternatively, the electrical bias energy may be a pulse of voltage periodically generated at a time interval equal to the inverse of the bias frequency. The pulse of voltage may have a negative polarity. The pulse of voltage may be a pulse generated from a negative DC voltage.

[0035] The upper electrode 14 is provided above the substrate support 12. The upper electrode 14 is provided below the upper portion 10u of the outer chamber 10 and inside the side wall 10s. The upper electrode 14 is configured to be movable upward and downward within the outer chamber 10.

[0036] The plasma processing apparatus 1 may further include a lift mechanism 34. The lift mechanism 34 is configured to move the upper electrode 14 upward and downward. The lift mechanism 34 includes a drive device (e.g., a motor) that generates power for moving the upper electrode 14. The lift mechanism 34 may be provided outside the outer chamber 10 and above or on the upper portion 10u.

[0037] The plasma processing apparatus 1 may further include a bellows 36. The bellows 36 is provided between the upper electrode 14 and the upper portion 10u. The bellows 36 separates the internal space of the outer chamber 10 from the outside of the outer chamber 10. A lower end of the bellows 36 is fixed to the upper electrode 14. An upper end of the bellows 36 is fixed to the upper portion 10u.

[0038] The upper electrode 14 has a substantially disk shape. The central axis of the upper electrode 14 is an axis AX. The upper electrode 14 is made of a conductor such as aluminum. In one embodiment, the upper electrode 14 may be grounded when the high frequency power supply 31 is electrically connected to the lower electrode in the substrate support 12. In this case, the upper electrode 14 may be in contact with the inner wall surface of the outer chamber 10 via a connection member 37.

[0039] The upper electrode 14 constitutes a shower head together with a ceiling part of the inner chamber 16, which will be described later. The shower head is configured to supply gas to a substrate processing space S, which will be described later. To this end, the upper electrode 14 provides a gas diffusion chamber 14d and a plurality of gas holes 14h.

[0040] The gas diffusion chamber 14d is provided in the upper electrode 14. A gas supply unit 38 is connected to the gas diffusion chamber 14d. The gas supply unit 38 is provided outside the outer chamber 10. The gas supply unit 38 includes one or more gas sources used in the plasma processing apparatus 1, one or more flow rate controllers, and one or more valves. Each of the one or more gas sources is connected to the gas diffusion chamber 14d via a corresponding flow rate controller and a corresponding valve. A plurality of gas holes 14h extend downward from the gas diffusion chamber 14d.

[0041] In one embodiment, the upper electrode 14 may provide a flow path 14f therein. The flow path 14f is connected to a chiller unit 40. The chiller unit 40 is provided outside the outer chamber 10. The chiller unit 40 supplies a heat medium (e.g., a refrigerant) to the flow path 14f. The heat medium supplied to the flow path 14f flows through the flow path 14f and is returned to the chiller unit 40.

[0042] The inner chamber 16, together with the substrate support 12, defines a substrate processing space S above the substrate support 12 within the outer chamber 10. The inner chamber 16 may be made of a metal such as aluminum. A corrosion-resistant film may be formed on the surface of the inner chamber 16. The corrosion-resistant film may be formed of a material such as aluminum oxide or yttrium oxide.

[0043] The inner chamber 16 is detachably attached to the upper electrode 14. The inner chamber 16 or its top portion 16c is detachably fixed to the upper electrode 14 by one or more contact members 18. The inner chamber 16 is configured to be transportable between the inside and outside of the outer chamber 10.

[0044] The plasma processing apparatus 1 may further include an actuator 20 for releasing the fixation of the inner chamber 16 from the upper electrode 14. The actuator 20 is configured to move the inner chamber 16 downward. In one embodiment, the actuator 20 includes a driving device 20d. The actuator 20 may include a plurality of rods 20r.

[0045] The driving device 20d is provided outside the outer chamber 10. The driving device 20d generates power to move the driving shaft 20m up and down. The driving device 20d may include a power cylinder such as an air cylinder or a motor. The driving device 20d is fixed to the upper electrode 14 outside the outer chamber 10.

[0046] The rods 20r are coupled to the drive shaft 20m. The rods 20r extend downward from the drive shaft 20m. The rods 20r are arranged in a circumferential direction around the axis AX. The rods 20r may be arranged at equal intervals.

[0047] The upper electrode 14 provides a plurality of through holes extending in the vertical direction. The plurality of through holes penetrate the upper electrode 14 from the upper surface of the upper electrode 14 through the gas diffusion chamber 14d to the lower surface of the upper electrode 14. The plurality of rods 20r are inserted into the plurality of through holes of the upper electrode 14. A sealing member 48 such as an O-ring is provided between the upper electrode 14 and each of the plurality of rods 20r. In addition, the plurality of rods 20r pass through the inner hole of the cylindrical member 46 in the gas diffusion chamber 14d.

[0048] The rods 20r are moved up and down by a driving device 20d. When the inner chamber 16 is fixed to the upper electrode 14, the rods 20r are arranged such that their lower ends are at the same horizontal level as the upper surface of the top part 16c of the inner chamber 16 or are located higher than the upper surface. When the inner chamber 16 is removed from the upper electrode 14, the rods 20r are moved by the driving device 20d so as to move the inner chamber 16 downward with their lower ends in contact with the upper surface of the top part 16c of the inner chamber 16.

[0049] The inner chamber 16 includes a top portion 16c and a side wall portion 16s. The top portion 16c can be disposed above the substrate support portion 12 and below the upper electrode 14. The top portion 16c is plate-like and has a substantially disk shape. The top portion 16c is disposed in the outer chamber 10 such that its central axis is located on the axis line AX. The top portion 16c may be disposed directly below the upper electrode 14 in the outer chamber 10. Alternatively, a heat transfer sheet may be sandwiched between the lower surface of the upper electrode 14 and the inner chamber 16.

[0050] As described above, the ceiling portion 16c and the upper electrode 14 form a shower head. The ceiling portion 16c provides a plurality of gas holes 16g. The plurality of gas holes 16g penetrate the ceiling portion 16c. The ceiling portion 16c is disposed in the outer chamber 10 such that the plurality of gas holes 16g communicate with the plurality of gas holes 14h, respectively. The gas from the gas supply unit 38 described above is supplied to the substrate processing space S via the gas diffusion chamber 14d, the plurality of gas holes 14h, and the plurality of gas holes 16g.

[0051] The sidewall portion 16s extends in the circumferential direction so as to surround the substrate processing space S. The sidewall portion 16s extends downward from the peripheral edge portion of the ceiling portion 16c. The sidewall portion 16s is disposed in the outer chamber 10 so that its central axis is positioned on the axis line AX. The lower end 16b of the sidewall portion 16s may be configured to contact the conductor portion 28.

[0052] In one embodiment, the side wall portion 16s may have a shape that bulges in the radial direction between its upper end 16u and its lower end 16b. In this case, the distance between the plasma generated in the substrate processing space S and the side wall portion 16s is made more uniform. In another embodiment, the side wall portion 16s may have a cylindrical shape.

[0053] Reference will now be made to Figures 2(a), 2(b), 2(c), 3(a), 3(b), and 3(c) in addition to Figure 1. Each of Figures 2(a), 2(b), 2(c), 3(a), 3(b), and 3(c) is an exemplary plan view of an upper portion and a lower portion of the inner chamber, respectively.

[0054] The sidewall portion 16s provides a plurality of through holes 16h. The through holes 16h communicate the substrate processing space S with a space (exhaust space) outside the sidewall portion 16s. Gas in the substrate processing space S is exhausted by the exhaust device 11 through the through holes 16h and the space (exhaust space) outside the sidewall portion 16s. The through holes 16h are uniformly distributed in the circumferential direction to provide uniform exhaust. The opening area of ​​the sidewall portion 16s provided by the through holes 16h increases stepwise or continuously along the direction from the lower end 16b to the upper end 16u.

[0055] In one embodiment, the side wall portion 16s includes an upper portion 161 and a lower portion 162. The upper portion 161 includes an upper end 16u and extends above the lower portion 162. The upper portion 161 may be a portion of the side wall portion 16s from the center between the upper end 16u and the lower end 16b to the upper end 16u. That is, the upper portion 161 may be a portion of the upper half of the side wall portion 16s. The lower portion 162 includes the lower end 16b and extends below the upper portion 161. The lower portion 162 may be a portion of the side wall portion 16s from the center between the upper end 16u and the lower end 16b to the lower end 16b. That is, the lower portion 162 may be a portion of the lower half of the side wall portion 16s. In one embodiment, the opening area of ​​the upper portion 161 may be larger than the opening area of ​​the lower portion 162.

[0056] In one embodiment, the plurality of through holes 16h may include a plurality of first through holes 161h formed in the upper portion 161. The plurality of through holes 16h may also include a plurality of second through holes 162h formed in the lower portion 162.

[0057] In one embodiment, as shown in Fig. 2(a), the plurality of through holes 16h may have a circular shape. In this case, the diameter of each of the plurality of first through holes 161h may be larger than the diameter of each of the plurality of second through holes 162h.

[0058] In one embodiment, as shown in FIG. 2(b), the plurality of through holes 16h may have an elliptical shape. The major axis of each of the plurality of through holes 16h may extend in a direction perpendicular to the vertical direction and the radial direction. In this case, the maximum width (major axis width) of each of the plurality of first through holes 161h may be larger than the maximum width (major axis width) of each of the plurality of second through holes 162h.

[0059] In one embodiment, as shown in FIG. 2(c), the density of the first through holes 161h in the upper portion 161 may be higher than the density of the second through holes 162h in the lower portion 162. In this case, the first through holes 161h and the second through holes 162h may have a circular or elliptical shape. The maximum width (diameter or major axis width) of each of the first through holes 161h may be the same as or different from the maximum width (diameter or major axis width) of each of the second through holes 162h. The maximum width (diameter or major axis width) of each of the first through holes 161h may be larger than the maximum width (diameter or major axis width) of each of the second through holes 162h. The upper portion 161 may provide the first through holes 161h having different maximum widths. Although not shown, the density of the plurality of through holes 16h may continuously increase along the direction from the lower end 16b toward the upper end 16u.

[0060] In one embodiment, as shown in (a) of FIG. 3, the plurality of through holes 16h may have a circular shape. Also, in one embodiment, as shown in (b) of FIG. 3, the plurality of through holes 16h may have an oval shape. As shown in (a) and (b) of FIG. 3, each of the plurality of through holes 16h may have a maximum width (diameter or major axis width) larger than the maximum width (diameter or major axis width) of the through hole 16h provided closer to the lower end 16b among the plurality of through holes 16h. That is, the maximum width (diameter or major axis width) of the plurality of through holes 16h may continuously increase along the direction from the lower end 16b toward the upper end 16u.

[0061] In one embodiment, as shown in Fig. 3(c), each of the plurality of through holes 16h may extend long in a direction from the lower end 16b toward the upper end 16u. In this case, the width of each of the plurality of through holes 16h increases continuously along the direction from the lower end 16b toward the upper end 16u.

[0062] The plasma processing apparatus 1 and the inner chamber 16 described above reduce variations in gas pressure in the radial direction within the substrate processing space S. Therefore, variations in gas flow velocity in the radial direction within the substrate processing space S are reduced.

[0063] Hereinafter, a first simulation #1 and a second simulation #2 performed for evaluating the plasma processing apparatus 1 will be described. In the first simulation #1, the sidewall portion 16s had a plurality of through holes 16h as shown in FIG. 2(a). In the first simulation #1, the upper portion 161 was the upper half of the sidewall portion 16s, and the lower portion 162 was the lower half of the sidewall portion 16s. In the first simulation #1, the diameter of the plurality of first through holes 161h was 4 mm, and the diameter of the plurality of second through holes 162h was 3 mm. The conditions of the second simulation #2 were different from the conditions of the first simulation #1 only in that the diameters of the plurality of first through holes 161h and the plurality of second through holes 162h were both 3 mm. In the first simulation #1 and the second simulation #2, the standard deviation of the gas pressure and the standard deviation of the gas flow rate in the substrate processing space S were obtained.

[0064] 4(a) and 4(b) are diagrams showing the results of the first and second simulations, respectively. As shown in FIG. 4(a) and FIG. 4(b), in the first simulation #1, the standard deviation of the gas pressure and the standard deviation of the gas flow rate in the substrate processing space S were smaller than those in the second simulation #2. Therefore, it was confirmed that the plasma processing apparatus 1 can reduce the variation in the gas flow rate in the radial direction in the substrate processing space S.

[0065] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. In addition, elements in different embodiments can be combined to form other embodiments.

[0066] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims. [Explanation of symbols]

[0067] Reference Signs List 1: plasma processing apparatus, 10: outer chamber, 11: exhaust device, 12: substrate support, 14: upper electrode, 16: inner chamber, 16c: ceiling, 16s: side wall, 16h: through hole.

Claims

1. An outer chamber; a substrate support disposed within the outer chamber and including a lower electrode; an upper electrode provided above the substrate support; an inner chamber that, together with the substrate support, defines a substrate processing space within the outer chamber and above the substrate support; an exhaust device that is connected to a space provided inside the outer chamber and outside the inner chamber through an exhaust port provided at the bottom of the outer chamber; Equipped with the inner chamber is detachable from the upper electrode; a top portion extending above the substrate processing space, providing a plurality of gas holes, and constituting a shower head together with the upper electrode; a sidewall portion extending in a circumferential direction so as to surround the substrate processing space; Including, The side wall portion has a plurality of through holes, and has an opening area that increases stepwise or continuously along a direction from a lower end to an upper end thereof. Plasma processing equipment.

2. The sidewall includes an upper portion and a lower portion, The opening area of ​​the upper portion is larger than the opening area of ​​the lower portion. The plasma processing apparatus according to claim 1 .

3. the upper portion is a portion of the side wall portion from a center between the upper end and the lower end to the upper end, The lower portion is a portion of the side wall portion from the center to the lower end. The plasma processing apparatus according to claim 2 .

4. The plasma processing apparatus according to claim 2 , wherein the plurality of through holes have a circular or elliptical shape.

5. 5. The plasma processing apparatus of claim 4, wherein a maximum width of each of the first through holes provided in the upper portion of the plurality of through holes is greater than a maximum width of each of the second through holes provided in the lower portion of the plurality of through holes.

6. The plasma processing apparatus of claim 4 , wherein a density of the plurality of through holes in the upper portion is higher than a density of the plurality of through holes in the lower portion.

7. The plasma processing apparatus according to claim 1 , wherein the plurality of through holes have a circular or elliptical shape.

8. The plasma processing apparatus according to claim 7 , wherein each of the plurality of through holes has a maximum width greater than a maximum width of a through hole of the plurality of through holes that is provided closer to the lower end than the each of the plurality of through holes.

9. The plasma processing apparatus of claim 7 , wherein a density of the plurality of through holes increases along a direction from the lower end to the upper end.

10. 10. The plasma processing apparatus according to claim 1, wherein the side wall portion has a shape that bulges between the upper end and the lower end.

11. An inner chamber used in an outer chamber of a plasma processing apparatus, comprising: a top portion extending above a substrate processing space and providing a plurality of gas holes; a sidewall portion extending in a circumferential direction on a side of the substrate processing space so as to surround the substrate processing space; Equipped with The side wall portion has a plurality of through holes, and has an opening area that increases stepwise or continuously along a direction from a lower end to an upper end thereof. Inner chamber.

12. The sidewall includes an upper portion and a lower portion, The opening area of ​​the upper portion is larger than the opening area of ​​the lower portion. The inner chamber according to claim 11.

13. the upper portion is a portion of the side wall portion from a center between the upper end and the lower end to the upper end, The lower portion is a portion of the side wall portion from the center to the lower end. The inner chamber of claim 12.

14. The inner chamber according to claim 12 or 13, wherein the plurality of through holes have a circular or oval shape.

15. The inner chamber of claim 14, wherein the maximum width of each of the first through holes provided in the upper portion of the plurality of through holes is greater than the maximum width of each of the second through holes provided in the lower portion of the plurality of through holes.

16. The inner chamber of claim 14 , wherein a density of the plurality of through holes in the upper portion is greater than a density of the plurality of through holes in the lower portion.

17. The inner chamber according to claim 11 , wherein the plurality of through holes have a circular or oval shape.

18. The inner chamber according to claim 17 , wherein each of the plurality of through holes has a maximum width greater than a maximum width of a through hole of the plurality of through holes that is closer to the bottom end than the each of the plurality of through holes.

19. The inner chamber according to claim 17 , wherein a density of the plurality of through holes increases along a direction from the lower end to the upper end.

20. The inner chamber according to any one of claims 11 to 19, wherein the side wall portion has a bulging shape between the upper end and the lower end.

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