JP2019145770A - Plasma processing apparatus - Google Patents

Abstract

To seal an insertion hole, to be inserted with a pin, appropriately.SOLUTION: A plasma processing apparatus includes an insertion member having a first face arranged on the vacuum space side and a second face arranged on the non-vacuum space side, and in which an insertion hole penetrating the first and second faces is formed, a pin inserted into the insertion hole and moving in the vertical direction, a movable member into which the pin is inserted, and provided in a recess formed in the wall surface facing the pin in the insertion hole, movably along a surface intersecting the axial direction of the pin in the recess, a first seal member placed between the movable member and the pin, and a second seal member placed between the movable member and the face of the recess, and when pressing force for locally compressing the first seal member acts from the pin to the first seal member, allowing movement of the movable member in the direction to release the pressing force.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to a plasma processing apparatus.

  2. Description of the Related Art Conventionally, plasma processing apparatuses that perform plasma processing on an object to be processed such as a wafer using plasma are known. Such a plasma processing apparatus has, for example, a mounting table that holds an object to be processed that also serves as an electrode in a processing container capable of forming a vacuum space. The plasma processing apparatus performs plasma processing on an object to be processed disposed on the mounting table by applying a predetermined high-frequency power to the mounting table in a vacuum space formed in the processing container. The mounting table is formed with an insertion hole penetrating the surface on the vacuum space side of the mounting table and the back surface thereof, and a pin is inserted into the insertion hole. In the plasma processing apparatus, when the object to be processed is transported, the pin is protruded from the insertion hole, and the object to be processed is supported from the back surface by the pin and detached from the mounting table.

  On the wall surface facing the pin of the insertion hole, a seal member such as an O-ring is provided along the circumferential direction of the insertion hole. The seal member seals the insertion hole by contacting the pin. In the plasma processing apparatus, the insertion hole is sealed by the sealing member, so that the airtightness of the vacuum space in the processing container is maintained.

JP 2013-42012 A

  The present disclosure provides a technique capable of appropriately sealing an insertion hole into which a pin is inserted.

  In one embodiment, the disclosed plasma processing apparatus has a first surface disposed on the vacuum space side and a second surface disposed on the non-vacuum space side, and the first surface and the second surface are provided. An insertion member having an insertion hole formed therethrough, a pin inserted into the insertion hole and moved in the vertical direction, and a recess formed in a wall surface of the insertion hole facing the pin, the pin being inserted. A movable member provided to be movable along a plane intersecting the axial direction of the pin, a first seal member disposed between the movable member and the pin, and the surface of the movable member and the recess. When a pressing force that locally compresses the first seal member acts from the pin to the first seal member, the movable member is allowed to move in a direction to release the pressing force. And a second seal member.

  According to one aspect of the disclosed plasma processing apparatus, it is possible to appropriately seal the insertion hole into which the pin is inserted.

FIG. 1 is a diagram showing a schematic configuration of a plasma processing apparatus according to the first embodiment. FIG. 2 is a schematic cross-sectional view showing the main configuration of the mounting table according to the first embodiment. FIG. 3 is a view for explaining a deviation between the shaft of the pin insertion hole of the mounting table and the shaft of the pin. FIG. 4 is a perspective view showing a main configuration of the mounting table according to the second embodiment. FIG. 5 is a schematic cross-sectional view showing the main configuration of the first mounting table and the second mounting table according to the second embodiment. FIG. 6 is a diagram illustrating a configuration example of the evaluation apparatus. FIG. 7 is a diagram illustrating an example of the relationship between the amount of pin shaft misalignment and the amount of leakage. FIG. 8 is a schematic cross-sectional view showing the configuration of the main part of the mounting table in the prior art.

  Hereinafter, embodiments of the disclosed plasma processing apparatus will be described in detail with reference to the drawings. Note that the disclosed technology is not limited by the present embodiment.

  2. Description of the Related Art Conventionally, plasma processing apparatuses that perform plasma processing on an object to be processed such as a wafer using plasma are known. Such a plasma processing apparatus has, for example, a mounting table that holds an object to be processed that also serves as an electrode in a processing container capable of forming a vacuum space. The plasma processing apparatus performs plasma processing on an object to be processed disposed on the mounting table by applying a predetermined high-frequency power to the mounting table in a vacuum space formed in the processing container.

  Here, with reference to FIG. 8, the principal part structure of the mounting base 130 in a prior art is demonstrated. FIG. 8 is a schematic cross-sectional view showing the main configuration of the mounting table 130 in the prior art. As shown in FIG. 8, the mounting table 130 is formed with an insertion hole 170 penetrating the surface on the vacuum space side of the mounting table 130 and the back surface thereof, and a pin 172 is inserted into the insertion hole 170. In the plasma processing apparatus, when a wafer as an object to be processed is transported, the pins 172 are protruded from the insertion holes 170, and the wafer is supported from the back surface by the pins 172 and detached from the mounting table 130.

  A seal member 286 such as an O-ring is provided along the circumferential direction of the insertion hole 170 on the wall surface of the insertion hole 170 facing the pin 172. The seal member 286 seals the insertion hole 170 by contacting the pin 172. In the plasma processing apparatus, the insertion hole 170 is sealed by the sealing member 286, so that the airtightness of the vacuum space in the processing container is maintained.

  By the way, in a plasma processing apparatus, when the temperature of a mounting base is controlled according to various plasma processes, a mounting base expands or contracts according to a temperature change. When the mounting table expands or contracts, the shaft of the insertion hole of the mounting table and the shaft of the pin are displaced from each other. Therefore, a pressing force for locally compressing the seal member acts from the pin to the seal member provided in the insertion hole. . When the seal member is locally compressed, a gap may be generated between the uncompressed portion of the seal member and the pin, and as a result, it is difficult to sufficiently seal the insertion hole. Invite. For example, in the example shown in FIG. 8, when the mounting table 130 expands in the radial direction of the mounting table 130 according to the temperature change, the seal member 286 is locally compressed, and the portion of the seal member 286 that is not compressed There may be a gap between the pins 172. Note that this problem is not limited to the mounting table, and may similarly occur in other components in which insertion holes into which pins are inserted are formed. If the insertion hole is not properly sealed, the airtightness of the vacuum space in the processing container may be reduced.

(First embodiment)
[Configuration of plasma processing apparatus]
FIG. 1 is a diagram showing a schematic configuration of a plasma processing apparatus according to the first embodiment. FIG. 1 shows a cross section of the plasma processing apparatus according to the first embodiment.

  As shown in FIG. 1, the plasma processing apparatus 10 is a parallel plate type plasma processing apparatus. The plasma processing apparatus 10 includes a processing container 12 configured to be airtight. The processing container 12 has a substantially cylindrical shape, and defines a processing space S in which plasma is generated as its internal space. The plasma processing apparatus 10 includes a mounting table 13 in the processing container 12. The upper surface of the mounting table 13 is formed as a mounting surface 54d on which a semiconductor wafer (hereinafter referred to as “wafer”) W, which is an object to be processed, is mounted. In the present embodiment, the mounting table 13 includes a base 14 and an electrostatic chuck 50. The base 14 has a substantially disk shape and is provided below the processing space S. The base 14 is made of, for example, aluminum and has a function as a lower electrode.

The electrostatic chuck 50 is provided on the upper surface of the base 14. The electrostatic chuck 50 has a disk shape with a flat upper surface, and the upper surface corresponds to the mounting surface 54 d on which the wafer W is mounted. The electrostatic chuck 50 includes an electrode 54a and an insulator 54b. The electrode 54a is provided inside the insulator 54b, and a DC power source 56 is connected to the electrode 54a via a switch SW. When a DC voltage is applied to the electrode 54a from the DC power source 56, a Coulomb force is generated, and the wafer W is attracted and held on the electrostatic chuck 50 by the Coulomb force. The electrostatic chuck 50 has a heater 54c inside the insulator 54b. The heater 54c heats the electrostatic chuck 50 when electric power is supplied from a power supply mechanism (not shown). Thereby, the temperature of the mounting table 13 and the wafer W is controlled.
And function.

  In the present embodiment, the plasma processing apparatus 10 further includes a cylindrical holding portion 16 and a cylindrical support portion 17. The cylindrical holding part 16 holds the base 14 in contact with the edges of the side surface and the bottom surface of the base 14. The cylindrical support portion 17 extends in the vertical direction from the bottom portion of the processing container 12 and supports the base 14 via the cylindrical holding portion 16.

  A focus ring 18 is provided on the upper surface of the peripheral portion of the base 14. The focus ring 18 is a member for improving the in-plane uniformity of the processing accuracy of the wafer W. The focus ring 18 is a plate-like member having a substantially ring shape, and is made of, for example, silicon, quartz, or silicon carbide.

  In the present embodiment, an exhaust path 20 is formed between the side wall of the processing container 12 and the cylindrical support portion 17. A baffle plate 22 is attached to the inlet of the exhaust passage 20 or in the middle thereof. An exhaust port 24 is provided at the bottom of the exhaust path 20. The exhaust port 24 is defined by an exhaust pipe 28 fitted in the bottom of the processing container 12. An exhaust device 26 is connected to the exhaust pipe 28. The exhaust device 26 includes a vacuum pump, and the processing space S in the processing container 12 can be decompressed to a predetermined degree of vacuum by operating the vacuum pump. Thereby, the processing space S in the processing container 12 is maintained in a vacuum atmosphere. The processing space S is an example of a vacuum space. A gate valve 30 for opening and closing the loading / unloading port for the wafer W is attached to the side wall of the processing chamber 12.

  A high frequency power supply 32 is electrically connected to the base 14 via a matching unit 34. The high frequency power source 32 is a power source for plasma generation, and applies high frequency power of a predetermined high frequency (for example, 13 MHz) to the lower electrode, that is, the base 14. In addition, a coolant channel (not shown) is formed inside the base 14, and the plasma processing apparatus 10 cools the mounting table 13 by circulating the coolant through the coolant channel. Thereby, the temperature of the mounting table 13 and the wafer W is controlled.

  The mounting table 13 is provided with a plurality of, for example, three pin insertion holes 70 (only two pin insertion holes 70 are shown in FIG. 1), and each of the pin insertion holes 70 has a pin 72. Has been inserted. The pin 72 is connected to the drive mechanism 74 and is driven in the vertical direction by the drive mechanism 74. The configuration of the mounting table 13 including the pin insertion hole 70 and the pin 72 will be described later.

  The plasma processing apparatus 10 further includes a shower head 38 in the processing container 12. The shower head 38 is provided above the processing space S. The shower head 38 includes an electrode plate 40 and an electrode support 42.

  The electrode plate 40 is a conductive plate having a substantially disc shape and constitutes an upper electrode. A high frequency power source 35 is electrically connected to the electrode plate 40 via a matching unit 36. The high frequency power source 35 is a power source for plasma generation, and applies high frequency power of a predetermined high frequency (for example, 60 MHz) to the electrode plate 40. When high frequency power is applied to the base 14 and the electrode plate 40 by the high frequency power supply 32 and the high frequency power supply 35, respectively, a high frequency electric field is formed in the space between the base 14 and the electrode plate 40, that is, the processing space S. Plasma is generated.

  A plurality of gas vent holes 40 h are formed in the electrode plate 40. The electrode plate 40 is detachably supported by an electrode support 42. A buffer chamber 42 a is provided inside the electrode support 42. The plasma processing apparatus 10 further includes a gas supply unit 44, and the gas supply unit 44 is connected to the gas introduction port 25 of the buffer chamber 42 a through a gas supply conduit 46. The gas supply unit 44 supplies a processing gas to the processing space S. This processing gas may be, for example, an etching processing gas or a film forming processing gas. The electrode support 42 is formed with a plurality of holes each continuous with the plurality of gas vent holes 40h, and the plurality of holes communicate with the buffer chamber 42a. The gas supplied from the gas supply unit 44 is supplied to the processing space S via the buffer chamber 42a and the gas vent hole 40h.

  In the present embodiment, a magnetic field forming mechanism 48 extending annularly or concentrically is provided on the ceiling of the processing container 12. The magnetic field forming mechanism 48 functions to facilitate the start of high-frequency discharge (plasma ignition) in the processing space S and maintain stable discharge.

  In the present embodiment, the plasma processing apparatus 10 further includes a gas supply line 58 and a heat transfer gas supply unit 62. The heat transfer gas supply unit 62 is connected to a gas supply line 58. The gas supply line 58 extends to the upper surface of the electrostatic chuck 50 and extends annularly on the upper surface. The heat transfer gas supply unit 62 supplies a heat transfer gas such as He gas between the upper surface of the electrostatic chuck 50 and the wafer W, for example.

  The operation of the plasma processing apparatus 10 having the above configuration is comprehensively controlled by the control unit 90. The control unit 90 includes a process controller 91 that includes a CPU (Central Processing Unit) and controls each unit of the plasma processing apparatus 10, a user interface 92, and a storage unit 93.

  The user interface 92 includes a keyboard that allows a process manager to input commands to manage the plasma processing apparatus 10, a display that visualizes and displays the operating status of the plasma processing apparatus 10, and the like.

  The storage unit 93 stores a recipe that stores a control program (software), processing condition data, and the like for realizing various processes executed by the plasma processing apparatus 10 under the control of the process controller 91. Then, if necessary, an arbitrary recipe is called from the storage unit 93 by an instruction from the user interface 92 and is executed by the process controller 91, so that a desired process in the plasma processing apparatus 10 can be performed under the control of the process controller 91. Is performed. In addition, recipes such as control programs and processing condition data may be stored in computer-readable computer storage media (for example, hard disks, CDs, flexible disks, semiconductor memories, etc.). Is possible. Also, recipes such as control programs and processing condition data can be transmitted from other devices as needed via, for example, a dedicated line and used online.

[Configuration of Mounting Table 13]
Next, with reference to FIG. 2, the principal part structure of the mounting base 13 which concerns on 1st Embodiment is demonstrated. FIG. 2 is a schematic cross-sectional view showing the main configuration of the mounting table 13 according to the first embodiment. As described above, the mounting table 13 includes the base 14 and the electrostatic chuck 50, and is configured such that the pins 72 can be inserted from below the base 14 to above the electrostatic chuck 50. The mounting table 13 is an example of an insertion member.

  The electrostatic chuck 50 is formed in a disk shape and is supported by the base 14. An upper surface of the electrostatic chuck 50 forms a mounting surface 54d on which the wafer W is mounted. The upper surface of the base 14 is bonded to the lower surface of the electrostatic chuck 50. The lower surface of the base 14 forms a back surface 14a with respect to the mounting surface 54d.

  A pin insertion hole 70 into which the pin 72 is inserted is formed in the mounting surface 54d. The pin insertion hole 70 passes through the mounting surface 54d and the back surface 14a with respect to the mounting surface 54d. The pin insertion hole 70 is formed by a first through hole 76 and a second through hole 78. The first through hole 76 is formed in the electrostatic chuck 50, and the second through hole 78 is formed in the base 14. A recess 82 is formed on the wall surface of the pin insertion hole 70 facing the pin 72.

  The pin 72 is connected to the drive mechanism 74 shown in FIG. 1, and is moved up and down in the pin insertion hole 70 by driving by the drive mechanism 74, so that the pin 72 can freely move in and out from the mounting surface 54 d of the mounting table 13. . That is, in a state where the pins 72 are raised, the tip portions of the pins 72 protrude from the mounting surface 54 d of the mounting table 13 and support the wafer W. On the other hand, when the pins 72 are lowered, the tip ends of the pins 72 are accommodated in the pin insertion holes 70, and the wafer W is placed on the placement surface 54d.

  A movable member 84 is provided in the recess 82 of the pin insertion hole 70. The movable member 84 has an opening into which the pin 72 is inserted, and is provided in the recess 82 so as to be movable along an upper surface 82 a that intersects the axial direction of the pin 72 of the recess 82.

  A first seal member 86 is disposed between the movable member 84 and the pin 72. In the pin insertion hole 70, a gap formed by the movable member 84 and the pin 72 that moves in the vertical direction in the pin insertion hole 70 is sealed by the first seal member 86. The first seal member 86 is, for example, an omni seal (registered trademark) or an O-ring.

  A second seal member 88 is disposed between the movable member 84 and the upper surface 82 a of the recess 82. In the pin insertion hole 70, a gap formed by the movable member 84 and the upper surface 82 a of the recess 82 is sealed by the second seal member 88. The second seal member 88 is, for example, an omni seal (registered trademark) or an O-ring.

  The upper surface of the mounting table 13 is formed as a mounting surface 54d on which the wafer W is mounted, and the lower surface of the mounting table 13 is formed as a back surface 14a with respect to the mounting surface 54d. The mounting surface 54d of the mounting table 13 is disposed on the processing space S side, which is a vacuum space maintained in a vacuum atmosphere. On the other hand, the back surface 14a of the mounting table 13 is disposed on the non-vacuum space side maintained in an air atmosphere. The non-vacuum space is, for example, a space R that is surrounded by the inner surface of the cylindrical holding portion 16. The processing space S and the space R are communicated with each other through a pin insertion hole 70. The plasma processing apparatus 10 seals the pin insertion hole 70 with the first seal member 86 and the second seal member 88, so that the atmosphere on the space R side becomes the processing space S (that is, the vacuum space in the processing container 12). The inflow is suppressed.

  By the way, in the plasma processing apparatus 10, when the temperature of the mounting table 13 is controlled according to various plasma processes, the mounting table 13 expands or contracts according to the temperature change. When the mounting table 13 expands or contracts, the axis of the pin insertion hole 70 of the mounting table 13 and the axis of the pin 72 are shifted, and therefore the first seal member 86 is locally moved from the pin 72 to the first seal member 86. A pressing force to compress acts. When the first seal member 86 is locally compressed, a gap may be formed between the uncompressed portion of the first seal member 86 and the pin 72. As a result, the pin insertion hole 70 is sufficiently provided. It becomes difficult to seal.

  FIG. 3 is a diagram for explaining a deviation between the axis of the pin insertion hole 70 of the mounting table 13 and the axis of the pin 72. The mounting table 13 has a mounting surface 54d and a back surface 14a with respect to the mounting surface 54d. Further, the mounting table 13 is provided with a mounting surface 54d and a pin insertion hole 70 penetrating the back surface 14a with respect to the mounting surface 54d. The temperature of the mounting table 13 is controlled by the heater 54 c of the electrostatic chuck 50 and the refrigerant flow path (not shown) of the base 14. In the plasma processing apparatus 10, when the temperature of the mounting table 13 is controlled, the mounting table 13 expands or contracts according to a temperature change. In the present embodiment, it is assumed that the mounting table 13 expands according to a temperature change. For example, in the plasma processing apparatus 10, the mounting table 13 expands in the radial direction of the mounting table 13 according to a temperature change. In FIG. 3, the expansion direction of the mounting table 13 is indicated by a white arrow. When the mounting table 13 expands in the radial direction of the mounting table 13, the shaft 70 a of the pin insertion hole 70 of the mounting table 13 is shifted in the radial direction of the mounting table 13 with respect to the shaft 72 a of the pin 72. For this reason, the first seal member 86 is pressed against the pin 72 by the mounting table 13, the second seal member 88, and the movable member 84. Accordingly, a pressing force that locally compresses the first seal member 86 from the pin 72 to the first seal member 86 acts as a reaction force of the force with which the first seal member 86 is pressed against the pin 72. In FIG. 3, the pressing force for locally compressing the first seal member 86 acts in the direction opposite to the expansion direction of the mounting table 13 (that is, the direction indicated by the white arrow). The right-hand part at is locally compressed by the pin 72. When the right side portion of the first seal member 86 is locally compressed, a gap is generated between the uncompressed left side portion of the first seal member 86 and the pin 72, and air may flow from the gap. is there.

  Therefore, in the plasma processing apparatus 10, the second sealing member 88 releases the pressing force when a pressing force that locally compresses the first sealing member 86 acts from the pin 72 to the first sealing member 86. The movable member 84 is allowed to move. For example, as shown in FIG. 3, when the pressing force for locally compressing the first seal member 86 acts in the direction opposite to the expansion direction of the mounting table 13 (that is, the direction indicated by the white arrow). Is assumed. In this case, the second seal member 88 allows the movement of the movable member 84 by sliding in the direction opposite to the expansion direction of the mounting table 13 along the upper surface 82 a of the recess 82.

  As a result, the pressing force for locally compressing the first seal member 86 is released, so that it is possible to prevent a gap from being generated between the uncompressed left side portion of the first seal member 86 and the pin 72. it can. As a result, even if the axis of the pin insertion hole 70 of the mounting table 13 and the axis of the pin 72 are misaligned, the plasma processing apparatus 10 uses the first seal member 86 and the second seal member 88 to insert the pin insertion hole. 70 can be properly sealed.

  As described above, the plasma processing apparatus 10 according to the first embodiment includes the mounting table 13, the pin 72, the movable member 84, the first seal member 86, and the second seal member 88. The mounting table 13 has a mounting surface 54d disposed on the vacuum space side and a back surface 14a disposed on the non-vacuum space side, and a pin insertion hole 70 penetrating the mounting surface 54d and the back surface 14a is formed. ing. The pin 72 is inserted into the pin insertion hole 70 and moves in the vertical direction. The movable member 84 is inserted into the concave portion 82 formed on the wall surface facing the pin 72 of the pin insertion hole 70 along the upper surface 82a that intersects the axial direction of the pin 72 of the concave portion 82. Is provided. The first seal member 86 is disposed between the movable member 84 and the pin 72. The second seal member 88 is disposed between the movable member 84 and the upper surface 82 a of the recess 82, and when a pressing force that locally compresses the first seal member 86 acts from the pin 72 to the first seal member 86. Then, the movable member 84 is allowed to move in the direction in which the pressing force is released. Thereby, even if the axis of the pin insertion hole 70 of the mounting table 13 and the axis of the pin 72 are deviated as the mounting table 13 expands or contracts, the plasma processing apparatus 10 can The pin insertion hole 70 can be appropriately sealed by the second seal member 88.

  Hereinafter, an evaluation experiment performed to verify the effect of the plasma processing apparatus 10 according to the first embodiment will be described.

[Evaluation equipment]
First, the evaluation apparatus 500 used for the evaluation experiment will be described. FIG. 6 is a diagram illustrating a configuration example of the evaluation apparatus 500. An evaluation apparatus 500 illustrated in FIG. 6 includes an experimental container 121. The experimental container 121 is formed in a substantially cylindrical shape, and has an opening at the bottom. A sample 510 is attached to the opening of the experimental container 121. By attaching the sample 510 to the opening of the experimental container 121, a space Q is formed inside the experimental container 121.

  The sample 510 includes a base plate 141, a pin 72, a movable member 84, a first seal member 86, and a second seal member 88. The base plate 141, the pin 72, the movable member 84, the first seal member 86, and the second seal member 88 are respectively the mounting table 13, the pin 72, the movable member 84, the first seal member 86, and the second seal member shown in FIG. This corresponds to the seal member 88.

  Further, an exhaust port 121 a is formed in the side wall of the experimental container 121, and a vacuum pump 123 is connected to the exhaust port 121 a through an exhaust pipe 122. The exhaust pipe 122 is provided with an open / close valve 122a. The vacuum pump 123 is configured such that the inside of the experimental container 121 can be depressurized to a predetermined degree of vacuum. The degree of vacuum (pressure) of the experimental container 121 is measured by the pressure gauge 121b.

[Evaluation experiment]
In the evaluation experiment, the sample 510 is attached to the evaluation apparatus 500, and the following steps (1) to (6) are performed in order, whereby the amount of air flowing into the space Q from the pin insertion hole 70 of the base plate 141 (hereinafter referred to as the amount of air). "Leakage amount") was measured. The sample 510 corresponds to the plasma processing apparatus 10 according to the first embodiment.

Procedure (1): The vacuum degree of the experimental vessel 121 is reduced to about 2.5 Pa by the vacuum pump 123.
Procedure (2): The shaft 72 a of the pin 72 is shifted in the radial direction of the base plate 141 with respect to the shaft 70 a of the pin insertion hole 70 of the base plate 141.
Procedure (3): The on-off valve 122a is closed.
Procedure (4): The pin 72 is reciprocated 100 times for 10 minutes within a range of 5 mm in the vertical direction by the drive mechanism 74.
Procedure (5): After executing the procedure (4) for 10 minutes, the degree of vacuum (pressure) of the experimental container 121 is measured by the pressure gauge 121b.
Step (6): By multiplying the amount of increase in the degree of vacuum (pressure) of the experimental container 121 by the volume of the experimental container 121 in 10 minutes (= 600 seconds) in which the procedure (4) is executed, the leak amount ( Pa · m3 / sec) is calculated.

[Comparison experiment]
Moreover, in the comparative experiment, the leak amount was measured by attaching a comparative sample to the evaluation apparatus 500 and sequentially performing the procedures (1) to (6). The comparative sample corresponds to a plasma processing apparatus having a mounting table 130 (see FIG. 8) in the prior art, and instead of the movable member 84, the first seal member 86, and the second seal member 88, a single seal member 286 is used. It differs from the sample 510 in that it has around the pin 72.

  FIG. 7 is a diagram illustrating an example of the relationship between the deviation amount of the shaft 72a of the pin 72 and the leak amount. FIG. 7 shows the result of measuring the amount of leakage by changing the amount of displacement of the shaft 72a of the pin 72. FIG. In FIG. 7, “Comparative Example” is a leak amount corresponding to the comparative experiment, and “Example” is a leak amount corresponding to the evaluation experiment.

  As shown in FIG. 7, in the comparative experiment, when the deviation amount of the shaft 72a of the pin 72 is 0.1 mm, the leakage amount exceeds the predetermined allowable specification range. On the other hand, in the evaluation experiment, even when the deviation amount of the shaft 72a of the pin 72 is 0.9 mm, the leak amount is within the predetermined allowable specification range. That is, even if the shaft 70 a of the pin insertion hole 70 of the mounting table 13 and the shaft 72 a of the pin 72 are misaligned, the pin insertion hole 70 is appropriately sealed by the first seal member 86 and the second seal member 88. Confirmed that you can.

(Second Embodiment)
Next, a second embodiment will be described. The plasma processing apparatus 10 according to the second embodiment has the same configuration as the plasma processing apparatus 10 according to the first embodiment except for the configuration of the mounting table 13. Therefore, in 2nd Embodiment, while using the same referential mark as the same component as the said 1st Embodiment, the detailed description is abbreviate | omitted.

[Configuration of Mounting Table 13]
With reference to FIG. 4, FIG. 5, the principal part structure of the mounting base 13 which concerns on 2nd Embodiment is demonstrated. FIG. 4 is a perspective view showing a main configuration of the mounting table 13 according to the second embodiment. As shown in FIG. 4, the mounting table 13 includes a first mounting table 102 and a second mounting table 107 provided on the outer periphery of the first mounting table 102. The first mounting table 102 and the second mounting table 107 are arranged so as to be coaxial with each other.

  The first mounting table 102 includes a base 103. The base 103 is formed in a cylindrical shape, and the above-described electrostatic chuck 50 is disposed on one surface 103a in the axial direction. Further, the base 103 is provided with a flange portion 200 that protrudes outward along the outer periphery. The base 103 according to the present embodiment is formed with an overhanging portion 201 that protrudes outward from the center portion of the outer peripheral side surface with a larger outer diameter, and outwards further below the side overhanging portion. A protruding flange portion 200 is provided. In the flange portion 200, through holes 210 penetrating in the axial direction are formed at three or more positions in the circumferential direction of the upper surface. In the flange portion 200 according to this embodiment, three through holes 210 are formed at equal intervals in the circumferential direction. The through hole 210 has a function as a pin insertion hole into which a pin 220 described later is inserted. The first mounting table 102 is an example of an insertion member.

  The second mounting table 107 includes a base 108. The base 108 is formed in a cylindrical shape whose inner diameter is a predetermined size larger than the outer diameter of the surface 103a of the base 103, and the above-described focus ring 18 is disposed on one surface 108a in the axial direction. In addition, the base 108 is provided with pins 220 on the lower surface at the same intervals as the through holes 210 of the flange portion 200. In the base 108 according to this embodiment, three pins 220 are fixed to the lower surface at equal intervals in the circumferential direction. The base 108 is an example of a common member.

  The base 108 has the same axis as the base 103 and is arranged on the flange portion 200 of the base 103 so that the pins 220 are inserted into the through holes 210 and aligned in the circumferential direction.

  FIG. 5 is a schematic cross-sectional view showing the main configuration of the first mounting table 102 and the second mounting table 107 according to the second embodiment. The example of FIG. 5 is a view showing a cross section of the first mounting table 102 and the second mounting table 107 at the position of the through hole 210.

  The base 103 is supported by an insulating support 104. A through hole 210 is formed in the base 103 and the support base 104.

  The through-hole 210 is formed with a diameter smaller from the center to the lower part than the upper part, and a step 211 is formed. Corresponding to the through-hole 210, the pin 220 is formed with a smaller diameter from the vicinity of the center to the lower portion than the upper portion.

  The base 108 is disposed on the flange portion 200 of the base 103. The base 108 is formed to have an outer diameter larger than that of the base 103, and an annular portion 221 that protrudes downward is formed on a portion of the lower surface facing the base 103 that is larger than the outer diameter of the base 103. ing. When the base 108 is disposed on the flange portion 200 of the base 103, the annular portion 221 is formed so as to cover the side surface of the flange portion 200.

  A pin 220 is inserted into the through hole 210. Each through-hole 210 is provided with a lifting mechanism 120 that lifts and lowers the second mounting table 107. For example, the base 103 is provided with an elevating mechanism 120 that elevates and lowers the pins 220 at the bottom of each through hole 210. The elevating mechanism 120 includes an actuator, and elevates and lowers the pin 220 by extending and contracting the rod 120a by the driving force of the actuator. The pin 220 moves up and down in the through hole 210 by the lifting and lowering by the lifting mechanism 120.

  A recess 182 is formed on the wall surface of the through-hole 210 facing the pin 220. A movable member 184 is provided in the recess 182. The movable member 184 has an opening into which the pin 220 is inserted, and is provided in the recess 182 so as to be movable along an upper surface 182 a that intersects the axial direction of the pin 220 of the recess 182.

  A first seal member 186 is disposed between the movable member 184 and the pin 220. In the through hole 210, a gap formed by the movable member 184 and the pin 220 that moves in the up and down direction in the through hole 210 is sealed by the first seal member 186. The first seal member 186 is, for example, an omni seal (registered trademark) or an O-ring.

  A second seal member 188 is disposed between the movable member 184 and the upper surface 182 a of the recess 182. In the through hole 210, a gap formed by the movable member 184 and the upper surface 182 a of the recess 182 is sealed by the second seal member 188. The second seal member 188 is, for example, an omni seal (registered trademark) or an O-ring.

  In the first mounting table 102, the lower space is maintained in an air atmosphere. For example, in the support base 104, a space 270 is formed in an inner lower portion, and the space 270 is maintained in an air atmosphere. The upper surface of the first mounting table 102 (for example, the upper surface of the flange portion 200 of the base 103) is disposed on the processing space S side that is a vacuum space maintained in a vacuum atmosphere. On the other hand, the lower surface of the first mounting table 102 (for example, the lower surface of the support table 104) is disposed on the space 270 side, which is a non-vacuum space maintained in an air atmosphere. The processing space S and the space 270 are communicated with each other through the through hole 210. The plasma processing apparatus 10 seals the through hole 210 with the first seal member 186 and the second seal member 188, so that the atmosphere on the space 270 side flows into the processing space S (that is, the vacuum space in the processing container 12). That is restrained.

  By the way, in the plasma processing apparatus 10, when the three pins 220 are fixed to the lower surface of the base 108 by machining, an arbitrary pin 220 of the three pins 220 is inserted into the arbitrary pin 220. May be displaced with respect to the axis of the through-hole 210. When the axis of any pin 220 is offset with respect to the axis of the through hole 210 into which the arbitrary pin 220 is inserted, the first seal member 186 is locally compressed from the arbitrary pin 220 to the first seal member 186. The pressing force is applied. When the first seal member 186 is locally compressed, a gap may be generated between the uncompressed portion of the first seal member 186 and the arbitrary pin 220, and as a result, the through hole 210 is sufficiently formed. It becomes difficult to seal.

  Therefore, in the plasma processing apparatus 10, when the pressing force that locally compresses the first seal member 186 acts from the pin 220 to the first seal member 186, the second seal member 188 releases the pressing force. The movable member 184 is allowed to move. For example, it is assumed that the pressing force for locally compressing the first seal member 186 acts in the same direction as the direction of the axial deviation of the arbitrary pin 220. In this case, the second seal member 188 allows the movement of the movable member 184 by sliding along the upper surface 182a of the recess 182 in the same direction as the direction of the axial deviation of the arbitrary pin 220.

  As a result, the pressing force that locally compresses the first seal member 186 is released, so that it is possible to prevent a gap from being generated between the uncompressed portion of the first seal member 186 and the pin 220. . As a result, the plasma processing apparatus 10 is penetrated by the first seal member 186 and the second seal member 188 even when the axis of the through hole 210 of the first mounting table 102 and the axis of the pin 220 are shifted. The hole 210 can be properly sealed.

DESCRIPTION OF SYMBOLS 10 Plasma processing apparatus 13 Mounting base 14 Base 14a Back surface 50 Electrostatic chuck 54d Mounting surface 70 Pin insertion hole 70a, 72a Shaft 72, 220 Pin 82, 182 Recessed part 82a, 182a Upper surface 84, 184 Movable member 86, 186 1st 1 seal member 88, 188 2nd seal member 102 1st mounting table 200 Flange part 210 Through hole

Claims (4)

An insertion member having a first surface disposed on the vacuum space side and a second surface disposed on the non-vacuum space side, and having an insertion hole penetrating the first surface and the second surface;
A pin that is inserted into the insertion hole and moves in the vertical direction;
A movable member provided in a concave portion formed on a wall surface of the insertion hole facing the pin in which the pin is inserted, movably along a surface of the concave portion that intersects the axial direction of the pin;
A first seal member disposed between the movable member and the pin;
When the pressing force that is disposed between the movable member and the surface of the recess and locally compresses the first seal member from the pin acts on the first seal member, the pressing force is released. A second seal member that allows movement of the movable member in a direction;
A plasma processing apparatus comprising: The insertion member expands or contracts according to a temperature change,
The pressing force for locally compressing the first seal member acts in a direction opposite to an expansion direction or a contraction direction of the insertion member,
The second seal member allows movement of the movable member by sliding along the surface of the recess in a direction opposite to an expansion direction or a contraction direction of the insertion member. The plasma processing apparatus according to claim 1. A plurality of the insertion holes are formed in the insertion member,
The plurality of pins are provided, and the plurality of pins are fixed to a common member,
Of the plurality of pins, the axis of an arbitrary pin is deviated from the axis of the insertion hole into which the arbitrary pin is inserted,
The pressing force for locally compressing the first seal member acts in the same direction as the direction of the axis deviation of the arbitrary pin,
The second seal member allows movement of the movable member by sliding along the surface of the recess in the same direction as the direction of axial displacement of the arbitrary pin. The plasma processing apparatus according to claim 1.   The plasma processing apparatus according to claim 1, wherein the first seal member and the second seal member are an omni seal (registered trademark) or an O-ring.

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