JP3169134U - Plasma processing equipment - Google Patents

Abstract

A plasma processing apparatus capable of facilitating maintenance of parts is provided. In a plasma processing apparatus, a dielectric window defines an accommodation space and a supply hole in order from the top along an axis. The supply source 18 introduces the microwave into the processing space in the processing container through the dielectric window. A conduit 20 supplies a gas for plasma processing. The conduit includes one end housed in the housing space. The injector 22 has a first surface on one end side and a second surface on the processing space side. The injector is formed with one or more holes extending from the first surface to the second surface. The injector is housed below the one end in the processing space, is separated from the one end, and is placed on the bottom surface that defines the housing space. An annular sealing member is in contact with the bottom surface and the second surface of the injector. [Selection] Figure 1

Description

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

  Patent Document 1 below describes a kind of plasma processing apparatus. The plasma processing apparatus described in Patent Document 1 includes a processing container, a stage, a microwave generator, an antenna, a dielectric window coaxial waveguide, and an injector base.

  The stage holds the substrate to be processed and is accommodated in the processing container. The antenna is provided above the stage. The antenna is connected to the microwave generator via a coaxial waveguide. The antenna includes a slot plate in which slots are formed. The dielectric window is provided between the antenna and the processing space above the stage.

  The dielectric window is formed with a housing space for housing the injector base, and further has a gas supply hole extending from the housing space toward the processing space. An O-ring is provided between the lower surface of the injector base and the surface of the dielectric window that defines the accommodation space. The injector base is not explicitly disclosed in Patent Document 1, but is fixed to another member such as a waveguide.

  In this plasma processing apparatus, a plasma processing gas is supplied into the processing space via the injector base hole and the gas supply hole of the dielectric window.

JP 2010-21243

  The injector base and O-ring described in Patent Document 1 are exposed to a plasma processing gas.

  Under such circumstances, in this technical field, it is required to facilitate the maintenance and management of parts in the plasma processing apparatus.

  A plasma processing apparatus according to one aspect of the present invention includes a processing container, a dielectric window, a supply source, a conduit, an injector, and a sealing member. The dielectric window includes an inner surface, and the inner surface defines an accommodation space and a supply hole in order from above along the axis. The inner surface includes a bottom surface that defines the accommodation space from below. The supply source introduces microwaves into the processing space in the processing container through a dielectric window. The conduit supplies a gas for plasma processing. The conduit includes one end housed in the housing space. The injector has a first surface on one end side and a second surface on the processing space side. The injector is formed with one or more holes extending from the first surface to the second surface. The injector is accommodated below the one end in the processing space, separated from the one end, and placed on the bottom surface. The sealing member has an annular shape and has elasticity. The sealing member is in contact with the bottom surface and the second surface of the injector.

  In this plasma processing apparatus, since the injector is placed on the bottom surface of the dielectric member and separated from the conduit, the injector can be easily replaced. Further, since the injector is not coupled to another member and is placed on the bottom surface, the gap between the bottom surface and the injector can be prevented from changing due to the displacement of the other member. Therefore, it is possible to suppress deterioration of the sealing member due to the gas flowing through the gap between the bottom surface and the injector. Therefore, maintenance of the injector and the sealing member can be facilitated.

  In one embodiment, the source includes a coaxial waveguide, a slot plate, a cooling jacket, and a dielectric plate. The slot plate has conductivity. A plurality of slot pairs are formed on the slot plate. The slot plate is electrically connected to the coaxial waveguide. The cooling jacket has a conductive surface and is electrically connected to the coaxial waveguide. The dielectric plate is provided between the cooling jacket and the slot plate. The dielectric window is provided directly below the slot plate. When the coolant flows through the cooling jacket, the cooling jacket expands, and accordingly, one end of the conduit may move upward. According to this embodiment, since the injector is separated from the conduit, the injector remains placed on the bottom surface of the dielectric window as one end of the conduit moves. Therefore, an increase in the gap between the bottom surface and the injector can be suppressed.

  In one embodiment, the conduit can be electrically conductive and is electrically connected to the slot plate. The injector can also be conductive. The plasma processing apparatus may further include a conductive member having elasticity and conductivity. The conductive member may be provided between the first surface and one end of the conduit, and may be in contact with the first surface and the one end. According to this embodiment, the potential of the conduit and the injector can be set to the same potential as that of the slot plate.

  In one embodiment, the second face of the injector may include a first region that intersects the axis and a second region that surrounds the first region. One or more holes of the injector may extend from the first surface to the first region, and the sealing member may be in contact with the bottom surface and the second region. According to this embodiment, the distance between the gas supply path, that is, one or more holes of the injector, and the supply hole defined by the dielectric window and the sealing member can be increased. Thereby, deterioration of a sealing member is further suppressed.

  In one embodiment, the distance in the axial direction between the first surface and the second region (hereinafter referred to as “axial direction”) is the distance between the first surface and the first region. The bottom surface may extend along the peripheral portion of the first region and the second region, which is larger than the distance in the axial direction. According to this embodiment, the distance between the gas supply path and the sealing member can be further increased. Thereby, deterioration of a sealing member is further suppressed.

  In one embodiment, the plasma processing apparatus may further include another sealing member. The sealing member has elasticity and may have a ring shape. The sealing member is provided between the first surface and one end portion of the conduit, and is in contact with the first surface and the one end portion. According to this embodiment, it is possible to ensure airtightness between the one end portion of the conduits separated from each other and the sealing member.

  As described above, according to various aspects and embodiments of the present invention, the maintenance and management of parts in the plasma processing apparatus can be facilitated.

It is a figure showing roughly the plasma treatment apparatus concerning one embodiment. It is the top view which looked at the slot board concerning one embodiment from the axis line X direction. It is sectional drawing which expands and shows the principal part containing the injector shown in FIG. It is sectional drawing which expands and shows the accommodation space and supply port of the dielectric material window which concern on one Embodiment. It is sectional drawing which shows the injector which concerns on one Embodiment. It is a disassembled perspective view which shows a conduit | pipe, two sealing members, and an electrically-conductive member with the injector which concerns on one Embodiment.

  Hereinafter, various embodiments 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.

  FIG. 1 is a cross-sectional view schematically showing a plasma processing apparatus according to an embodiment. A plasma processing apparatus 10 shown in FIG. 1 includes a processing container 12, a stage 14, a dielectric window 16, a supply source 18, a conduit 20, and an injector 22.

  The processing container 12 defines a processing space S for performing plasma processing on the substrate W to be processed. The processing container 12 may include a side wall 12a and a bottom 12b. The side wall 12a has a substantially cylindrical shape extending in the axis X direction. The bottom 12b is provided on the lower end side of the side wall 12a. The bottom 12b is provided with an exhaust hole 12h for exhaust. The upper end of the side wall 12a is open.

  The upper end opening of the side wall 12a is closed by a dielectric window 16 so as to hermetically seal the processing space S. An O-ring 28 may be interposed between the dielectric window 16 and the upper end of the side wall 12a. The O-ring 28 ensures the sealing of the processing container 12 more reliably.

  The supply source 18 introduces microwaves into the processing space S through the dielectric window 16. In one embodiment, source 18 includes a coaxial waveguide 24, a slot plate 26, a cooling jacket 30, and a dielectric plate 32. The source 18 may further include a microwave generator 34, a tuner 36, a waveguide 38, and a mode converter 40.

  The microwave generator 34 generates a microwave having a frequency of 2.45 GHz, for example. The microwave generator 34 is connected to a waveguide 38 via a tuner 36. The waveguide 38 is a rectangular waveguide, for example. The waveguide 38 is connected to a mode converter 40, and the mode converter 40 is connected to the upper end of the coaxial waveguide 24.

  The coaxial waveguide 24 extends along the axis X. The coaxial waveguide 24 includes an outer conductor 24a and an inner conductor 24b. The outer conductor 24a has a cylindrical shape extending in the axis X direction. The lower end of the outer conductor 24 a can be electrically connected to the upper surface of the cooling jacket 30. The surface of the cooling jacket 30 may have conductivity. The cooling jacket 30 cools the dielectric plate 32 and the slot plate 26. Therefore, a coolant channel is formed in the cooling jacket 30.

  The inner conductor 24b is provided inside the outer conductor 24a. The inner conductor 24b has a cylindrical shape extending along the axis X. The lower end of the inner conductor 24 b passes through the cooling jacket 30 and the central portion of the dielectric plate 32 and is connected to the slot plate 26.

  FIG. 2 is a plan view of the slot plate according to the embodiment as viewed from the direction of the axis X. As shown in FIG. 2, the slot plate 26 may be a slot plate constituting a radial line slot antenna in one embodiment. The slot plate 26 can be made of a metal disc having conductivity. A plurality of slot pairs 26 a are formed on the slot plate 26. Each slot pair 26a includes a slot 26b and a slot 26c extending in a direction intersecting or orthogonal to each other. The plurality of slot pairs 26a are arranged at predetermined intervals in the radial direction, and are arranged at predetermined intervals in the circumferential direction.

  As shown in FIG. 1, a dielectric window 16 is provided immediately below the slot plate 26. A dielectric plate 32 is provided between the slot plate 26 and the lower surface of the cooling jacket 30. The dielectric plate 32 is made of, for example, quartz and has a substantially disk shape. The microwave generated by the microwave generator 34 is propagated to the dielectric plate 32 through the coaxial waveguide 24 and introduced into the processing space S from the slot of the slot plate 26 through the dielectric window 16. Is done.

  The conduit 20 passes through the inner hole of the inner conductor 24 b of the coaxial waveguide 24. The conduit 20 extends along the axis X, and its end is connected to a gas supply system 42. The end connected to the gas supply system 42 is the end opposite to one end of the conduit described later. The gas supply system 42 supplies a gas for plasma processing. The gas supply system 42 includes a flow rate controller 42a such as a mass flow controller and an on-off valve 42b. The gas from the gas supply system 42 is supplied to the injector 22 through the conduit 20. The gas supplied to the injector 22 is supplied to the processing space S through the supply holes formed in the injector 22 and the dielectric window 16.

  In the plasma processing apparatus 10, plasma processing gas is supplied into the processing space S, and an electric field is generated directly below the dielectric window 16 by the microwave introduced into the processing space S as described above. As a result, plasma is generated in the processing space S. Thus, the plasma processing apparatus 10 can generate plasma using a microwave without applying a magnetic field.

  In one embodiment, the plasma processing apparatus 10 may further include a conduit 44. The conduit 44 extends annularly around the axis X between the dielectric window 16 and the stage 14. The conduit 44 is provided with a plurality of gas injection holes 44b that inject gas in a direction toward the axis X. The conduit 44 is connected to a gas supply system 46.

  The gas supply system 46 includes a conduit 46a, an on-off valve 46b, and a flow rate controller 46c such as a mass flow controller. Process gas is supplied to the conduit 44 via the flow rate controller 46c, the on-off valve 46b, and the conduit 46a.

  The stage 14 is provided so that the processing space S is sandwiched between the dielectric window 16 and the stage 14. A substrate W to be processed is placed on the stage 14. In one embodiment, the stage 14 may include a table 14a, a focus ring 14b, and an electrostatic chuck 14c.

  The base 14a is supported by a cylindrical support portion 48. The cylindrical support portion 48 is made of an insulating material and extends vertically upward from the bottom portion 12b. A conductive cylindrical support 50 is provided on the outer periphery of the cylindrical support 48. The cylindrical support portion 50 extends vertically upward from the bottom portion 12 b of the processing container 12 along the outer periphery of the cylindrical support portion 48. An annular exhaust passage 51 is formed between the cylindrical support portion 50 and the side wall 12a.

  An annular baffle plate 52 provided with a plurality of through holes is attached to the upper portion of the exhaust passage 51. An exhaust device 56 is connected to the lower portion of the exhaust hole 12 h via an exhaust pipe 54. The exhaust device 56 has a vacuum pump such as a turbo molecular pump. The exhaust device 56 can depressurize the processing space S in the processing container 12 to a desired degree of vacuum.

  The base 14a also serves as a high-frequency electrode. A high frequency power source 58 for RF bias is electrically connected to the base 14 a via a matching unit 60 and a power feeding rod 62. The high frequency power supply 58 outputs a predetermined frequency suitable for controlling the energy of ions drawn into the substrate W to be processed, for example, high frequency power of 13.65 MHz at a predetermined power. The matching unit 60 accommodates a matching unit for matching between the impedance on the high-frequency power source 58 side and the impedance on the load side such as electrodes, plasma, and the processing container 12. This matching unit includes a blocking capacitor for generating a self-bias.

  An electrostatic chuck 14c is provided on the upper surface of the table 14a. The electrostatic chuck 14c holds the substrate to be processed W with an electrostatic attraction force. A focus ring 14b that surrounds the periphery of the substrate W to be processed is provided on the outer side in the radial direction of the electrostatic chuck 14c. The electrostatic chuck 14c includes an electrode 14d, an insulating film 14e, and an insulating film 14f. The electrode 14d is made of a conductive film, and is provided between the insulating film 14e and the insulating film 14f. A high-voltage DC power supply 64 is electrically connected to the electrode 14 d via a switch 66 and a covered wire 68. The electrostatic chuck 14c can attract and hold the substrate W to be processed by the Coulomb force generated by the DC voltage applied from the DC power source 64.

  An annular refrigerant chamber 14g extending in the circumferential direction is provided inside the table 14a. A refrigerant having a predetermined temperature, for example, cooling water, is circulated and supplied to the refrigerant chamber 14g from a chiller unit (not shown) via pipes 70 and 72. Depending on the temperature of the refrigerant, the heat transfer gas of the electrostatic chuck 14 c, for example, He gas, is supplied between the upper surface of the electrostatic chuck 14 c and the rear surface of the substrate W to be processed via the gas supply pipe 74.

  Hereinafter, the injector 22 and the configuration around it will be described in more detail with reference to FIGS. 3, 4, 5, and 6. FIG. 3 is an enlarged cross-sectional view showing a main part including the injector shown in FIG. FIG. 4 is an enlarged cross-sectional view illustrating the accommodation space and the supply port of the dielectric window according to the embodiment. FIG. 5 is a cross-sectional view showing an injector according to an embodiment. FIG. 6 is an exploded perspective view showing a conduit, two sealing members, and a conductive member together with the injector according to the embodiment.

  The dielectric window 16 has a substantially disc shape and is made of a dielectric material such as quartz. As shown in FIGS. 3 and 4, the dielectric window 16 includes an inner side surface 16f. The inner surface 16f defines an accommodation space 16s and a supply hole 16h. The accommodation space 16s is provided above the supply hole 16h. The supply hole 16 h extends from the accommodation space 16 s to the lower surface of the dielectric window 16.

  The inner side surface 16f includes a surface 16f1, a surface (bottom surface) 16f2, and a surface 16f3. The surface 16f1 defines an accommodation space 16s from the side with respect to the axis X. The bottom surface 16f2 defines the accommodation space 16s from below. Further, the surface 16f3 defines a supply hole 16h. In one embodiment, the supply hole 16h has a tapered shape whose diameter decreases toward the lower side.

  As shown in FIG. 3, the injector 22 is accommodated in the accommodating space 16s. The injector 22 has conductivity and has a substantially disk shape. The injector 22 is made of, for example, aluminum or stainless steel.

As shown in FIGS. 3 and 5, the injector 22 includes a first surface 22a and a second surface 22b. The second surface 22b is provided on the opposite side in the axis X direction with respect to the first surface 22a, and is provided on the processing space S side (downward) with respect to the first surface 22a. The second surface 22b faces the supply hole 16h. In one embodiment, a film of Y ₂ O ₃ may be formed on the second surface 22b. This film may be formed by coating Y ₂ O ₃ on the second surface 22b and then melting the coated film with an electron beam.

The injector 22 has a plurality of holes 22h extending in the direction of the axis X. These holes 22h penetrate from the first surface 22a to the second surface 22b. In one embodiment, the injector 22 is chamfered at the boundary between the surface defining the hole 22h and the first surface 22a and at the boundary between the surface defining the hole 22h and the second surface 22b. May have been made.
By chamfering, concentration of the electric field at the boundary portion can be suppressed, and abnormal discharge can be suppressed. The second surface 22b defines a groove 22c that extends annularly about the axis X. The groove 22c is provided so as to surround the openings on the second surface 22b side of the plurality of holes 22h. A sealing member 84 is fitted in the groove 22c. The sealing member 84 is an annular member having elasticity, and is, for example, an O-ring. The sealing member 84 is in contact with the second surface 22b and the bottom surface 16f2 to ensure airtightness between the injector 22 and the dielectric window 16.

  In one embodiment, the second surface 22b includes a first region R1 and a second region R2. The first region R1 intersects the axis X, and openings on the second surface 22b side of the plurality of holes 22h are provided in the first region R1. The second region R2 surrounds the first region R1. In one embodiment, the groove 22c described above may be defined by the second region R2. Thereby, the distance from the supply hole 16h to the sealing member 84 becomes long. As a result, deterioration of the sealing member 84 can be suppressed.

  The distance in the axis X direction from the second region R2 to the first surface 22a may be larger than the distance in the axis X direction from the first region R1 to the first surface 22b. In this case, the bottom surface 16f2 of the dielectric window 16 is configured as a stepped surface along the peripheral portion of the first region R1 and the second region R2. This further increases the distance from the supply hole 16h to the sealing member 84. As a result, deterioration of the sealing member 84 can be further suppressed.

  As shown in FIG. 3, the injector 22 is placed on the bottom surface 16f2 that defines the accommodation space 16s. In the accommodating space 16s, the one end 20b of the conduit 20 is accommodated above the injector 22.

  In one embodiment, the conduit 20 is made of a conductive metal. The conduit 20 includes a main body portion 20a and one end portion 20b. The main body portion 20a has a cylindrical shape extending along the axis X. The one end portion 20b has a substantially disk shape and has an outer diameter larger than that of the main body portion 20a. The conduit 20 is provided with a gas supply inner hole penetrating through the main body 20a and the one end 20b. The main body portion 20a of the conduit 20 passes through the inner hole of the inner conductor 24b.

  The inner conductor 24b is connected to the slot plate 26 as described above. In one embodiment, the slot plate 26 is formed with a through hole provided along the axis X. The inner edge of the slot plate 26 that defines the through hole is held between the lower end of the inner conductor 24 b and the metal member 80. The member 80 is fixed to the lower end of the inner conductor 24b with a screw 82. Further, the upper surface of the one end portion 20 b of the conduit 20 is in contact with the lower surface of the slot plate 26. Thus, the inner conductor 24b, the slot plate 26, and the conduit 20 are electrically connected.

  As shown in FIG. 3, the injector 22 is placed on the bottom surface 16 f 2, but is separated from the one end 20 b of the conduit 20. Therefore, the injector 22 can be easily replaced. In addition, the injector 22 can suppress an increase in the gap (clearance) between the second surface 22b and the bottom surface 16f2 even if other members are displaced. For example, when the refrigerant is supplied to the cooling jacket 30 and the pressure in the cooling jacket 30 increases, the cooling jacket 30 may expand. This expansion may raise the conduit 20 upward. Even if such other members are displaced, the position of the injector 22 is not affected. Therefore, an increase in the gap (clearance) between the second surface 22b and the bottom surface 16f2 can be suppressed. As a result, it is possible to suppress the deterioration of the sealing member 84 due to the processing gas that can flow in through the gap.

  In one embodiment, as shown in FIGS. 3, 5, and 6, the first surface 22 a of the injector 22 may define a groove 22 d that extends annularly about the axis X. The grooves 22d are provided so as to surround the openings on the first surface 22a side of the plurality of holes 22h. A sealing member 88 is fitted in the groove 22d. The sealing member 88 is an annular member having elasticity, and is, for example, an O-ring. The sealing member 88 is in contact with the first surface 22 a of the injector 22 and the lower surface of the one end portion 20 b of the conduit 20. Thereby, the airtightness between the 1st surface 22a of the injector 22 isolate | separated mutually and the lower surface of the one end part 20b of the conduit | pipe 20 is securable.

  Further, the first surface 22a can further define another groove 22e extending annularly about the axis X. The groove 22e can be provided outside the groove 22d. A conductive member 86 is fitted into the groove 22e. The conductive member 86 has conductivity and elasticity, and can extend along an annular closed curve with the axis X as the center. As shown in FIG. 6, the conductive member 86 may be, for example, a metal member provided in a spiral shape along an annular closed curve with the axis X as the center. This conductive member 86 electrically connects the injector 22 to the conduit 20. As a result, the inner conductor 24b, the slot plate 26, the conduit 20, and the injector 22 are electrically connected to each other. The inner conductor 24b, the slot plate 26, the conduit 20, and the injector 22 are maintained at a ground potential, for example. Thereby, generation of plasma in the hole 22h of the injector 22 is suppressed.

  Although various embodiments have been described above, the present invention is not limited to these embodiments, and various modifications can be configured. For example, in the plasma processing apparatus 10 described above, a supply source 18 having a radial line slot antenna is used as a supply source. However, a microwave supply source adopted in another type of plasma processing apparatus is used. Also good. For example, a microwave supply source in a plasma processing apparatus of a SWP (Surface Wave Plasma) type may be used.

  DESCRIPTION OF SYMBOLS 10 ... Plasma processing apparatus, 12 ... Processing container, 14 ... Stage, 16 ... Dielectric window, 16s ... Storage space, 16h ... Supply hole, 16f ... Inner side surface, 16f2 ... Bottom surface, 18 ... Supply source, 20 ... Conduit, 20a ... Main body, 20b ... One end, 22 ... Injector, 22a ... First surface, 22b ... Second surface, R1 ... First region, R2 ... Second region, 22c ... Groove, 22d ... Groove, 22e ... groove, 22h ... hole, 24 ... coaxial waveguide, 26 ... slot plate, 30 ... cooling jacket, 32 ... dielectric plate, 34 ... microwave generator, 36 ... tuner, 38 ... waveguide, 40 ... mode Converter: 42 ... Gas supply system, 84 ... Sealing member, 86 ... Conductive member, 88 ... Sealing member, S ... Processing space, W ... Substrate to be processed.

Claims (6)

A processing vessel;
The dielectric window, including an inner surface defining an accommodation space and a supply hole in order from above along an axis, the inner surface including a bottom surface defining the accommodation space from below;
A supply source for introducing microwaves into the processing space in the processing vessel via the dielectric window;
A conduit for supplying a plasma processing gas, the conduit including one end accommodated in the accommodating space;
The first surface on the one end portion side and the second surface on the processing space side are formed, and one or more holes extending from the first surface to the second surface are formed in the processing space. An injector that is housed below the one end and is separated from the one end and placed on the bottom surface;
An annular sealing member having elasticity and contacting the bottom surface and the second surface of the injector;
A plasma processing apparatus comprising: The source is
A coaxial waveguide;
A conductive slot plate formed with a plurality of slot pairs, the slot plate electrically connected to the coaxial waveguide;
A cooling jacket having a conductive surface and electrically connected to the coaxial waveguide;
A dielectric plate provided between the cooling jacket and the slot plate;
Including
The dielectric window is provided immediately below the slot plate,
The plasma processing apparatus according to claim 1. The conduit has electrical conductivity and is electrically connected to the slot plate;
The injector has electrical conductivity;
A conductive member provided between the first surface and the one end portion of the conduit, and having contact with the first surface and the one end portion, and having elasticity and conductivity;
The plasma processing apparatus according to claim 2. The second surface of the injector includes a first region that intersects the axis, and a second region that surrounds the first region;
The one or more holes extend from the first surface to the first region;
The sealing member is in contact with the bottom surface and the second region;
The plasma processing apparatus as described in any one of Claims 1-3. The distance in the extension direction of the axis between the first surface and the second region is greater than the distance in the extension direction of the axis between the first surface and the first region. big,
The bottom surface extends along a peripheral portion of the second region and the first region.
The plasma processing apparatus according to claim 4.   Another sealing member having an annular shape having elasticity, provided between the first surface and the one end of the conduit, and the other sealing member in contact with the first surface and the one end The plasma processing apparatus according to any one of claims 1 to 5, further comprising:

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