Load Locking Device

Abstract

The load lock device includes a load lock chamber and a substrate holding structure for holding a substrate in the load lock chamber. The substrate holding structure has an opposing surface facing the substrate, and is configured to allow gas to flow in the space between the substrate and the opposing surface. In a state where the substrate is held by the substrate holding structure, the distance between a portion located inside the outer edge of the opposing surface and the substrate is greater than the distance between the outer edge of the opposing surface and the substrate.

Description

Technical Field

[0001] The present invention relates to a load lock device. Background Art

[0002] In Patent Document 1, a vacuum processing apparatus is disclosed. The vacuum processing apparatus has a load lock chamber, a wafer stage disposed in the load lock chamber, and a mechanism for raising and lowering the wafer stage. The wafer stage has a convex shape.

[0003] In a substrate holding structure having a configuration such as a wafer stage described in Patent Document 1, when a gas flow is formed in the load lock chamber, standing vortices may be generated in the wafer stage. Such standing vortices may cause particles to fly from below the substrate to above the substrate, and thus particles may adhere to the substrate.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Laid-Open No. 5-140743 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] The present invention provides a technique that is advantageous for preventing particles from adhering to a substrate.

[0009] One aspect of the present invention is a load lock device including a load lock chamber and a substrate holding structure for holding a substrate in the load lock chamber. The substrate holding structure has a facing surface facing the substrate, and is configured to allow a gas to flow in a space between the substrate and the facing surface. In a state where the substrate is held by the substrate holding structure, a portion located inside the outer edge of the facing surface is farther from the substrate than the outer edge of the facing surface is from the substrate. Brief Description of the Drawings

[0010] Figure 1 FIG. schematically shows the structure of a processing apparatus including a load lock device according to a first embodiment of the present invention.

[0011] Figure 2 FIG. illustrates the operation of a processing apparatus including a load lock device according to a first embodiment of the present invention.

[0012] Figure 3 FIG. illustrates the operation of a processing apparatus including a load lock device according to a first embodiment of the present invention.

[0013] Figure 4It is a diagram illustrating the operation of a processing apparatus including a load lock device according to a first embodiment of the present invention.

[0014] Figure 5 It is a diagram illustrating the operation of a processing apparatus including a load lock device according to a first embodiment of the present invention.

[0015] Figure 6 It is a diagram illustrating the operation of a processing apparatus including a load lock device according to a second embodiment of the present invention.

[0016] Figure 7 It is a diagram illustrating the operation of a processing apparatus including a load lock device according to a third embodiment of the present invention.

[0017] Figure 8 It is a diagram illustrating the operation of a processing apparatus including a load lock device according to a fourth embodiment of the present invention.

[0018] Figure 9 It is a schematic top view of a first member in a load lock device according to a fifth embodiment of the present invention.

[0019] Figure 10 It is a schematic side view in which a substrate holding structure in a load lock device according to the first and fifth embodiments of the present invention is enlarged.

[0020] Figure 11 It is a diagram for explaining a problem.

[0021] Figure 12 It is a diagram for explaining a problem.

[0022] Figure 13A It is a diagram illustrating a substrate holding structure.

[0023] Figure 13B It is an illustration of Figure 13A a diagram of the shape of the first member or the opposing surface of the substrate holding structure.

[0024] Figure 14A It is a diagram showing an example of a substrate.

[0025] Figure 14B It is a diagram showing another example of a substrate.

[0026] Figure 15 It is a top view showing the arrangement of the load lock chamber, the extension chamber, and the gas dispersion section. Detailed Description

[0027] Hereinafter, embodiments will be described in detail with reference to the drawings. In addition, the following embodiments do not limit the invention described in the claims. A plurality of features are described in the embodiments, but not all of these features are essential components of the invention. In addition, the plurality of features can be arbitrarily combined. In the drawings, the same or similar structures are denoted by the same reference numerals, and redundant descriptions are omitted.

[0028] Figure 1 Schematically shows the structure of a processing apparatus including a load lock device 100 according to a first embodiment of the present invention. The load lock device 100 can have a load lock chamber 110 disposed between a loading chamber 30 and a transfer chamber 20. The loading chamber 30 can be maintained in an atmospheric environment. In the loading chamber 30, for example, a substrate S can be provided from a carrier. Alternatively, the substrate S can be provided from a pre-processing apparatus to the loading chamber 30. The loading chamber 30 can have a filter 32 at its top, and a downflow can be supplied to the internal space of the loading chamber 30 through the filter 32. A transfer robot 34 is disposed in the loading chamber 30, and the substrate S can be transferred by the transfer robot 34. The transfer robot 34 can transfer the substrate S from the loading chamber 30 to the load lock chamber 110 through a valve 50. The load lock chamber 110 having received the substrate S is sufficiently decompressed. Thereafter, a transfer robot 22 disposed in the transfer chamber 20 can transfer the substrate S from the load lock chamber 110 to the transfer chamber 20 through a valve 40. Thereafter, the transfer robot 22 can transfer the substrate S from the transfer chamber 20 to a decompression processing apparatus 10 through a valve 60. The decompression processing apparatus 10 can be, for example, any one of a CVD apparatus, a PVD apparatus, an etching apparatus, a plasma processing apparatus, and an electron beam lithography apparatus.

[0029] The load lock chamber 110 can have a first transfer port 111 connected to the transfer chamber 20 and a second transfer port 112 connected to the loading chamber 30, and the transfer chamber 20 is connected to the decompression processing apparatus 10. In one example, the height of the first transfer port 111 (for example, the height of the lower end of the first transfer port 111) is lower than the height of the second transfer port 112 (for example, the height of the lower end of the second transfer port 112). The first transfer port 111 is communicably disposed with the internal space of the transfer chamber 20 through a valve 40. The second transfer port 112 is communicably disposed with the internal space of the loading chamber 30 through a valve 50.

[0030] The load lock device 100 can include a gas introduction part 160 for introducing a gas (such as clean dry air or nitrogen) into the load lock chamber 110. The gas introduction part 160 can be disposed, for example, above the path between the substrate holding structure 120 and the transfer chamber 20 in a state where the substrate S is transferred to the transfer chamber 20 through the first transfer port 111. In one example, the gas introduction part 160 can be disposed above the first transfer port 111. The gas introduction part 160 can include a gas dispersion part 162 for dispersing the gas in the internal space of the load lock chamber 110. At least a part of the gas dispersion part 162 can be disposed inside the load lock chamber 110. The gas dispersion part 162 can be disposed at a position facing the second transfer port 112. The gas introduction part 160 can include a flow control valve 164 for adjusting the flow rate of the introduced gas. The gas dispersion part 162 can have a columnar part, and the inner side surface of the load lock chamber 110 can include a curved surface that is separated from the columnar part and extends along the columnar part. The columnar part can have a cylindrical shape, and the curved surface can form a part of a cylindrical surface.

[0031] The load lock device 100 can include a substrate holding structure 120 for holding the substrate S in the load lock chamber 110. The substrate holding structure 120 can have a facing surface OS facing the substrate S, and is configured to allow a gas to flow in the space between the substrate S and the facing surface OS. As Figure 10 As shown in the enlarged view, the substrate holding structure 120 can have the following structure: in a state where the substrate S is held by the substrate holding structure 120, the distance between a portion PP located inside the outer edge EE of the facing surface OS and the substrate S is greater than the distance between the outer edge EE of the facing surface OS and the substrate S. Through simulation, it is confirmed that: as Figure 10 schematically shown by the dashed arrow, the effect of suppressing the formation of a standing vortex in the gas flow in the internal space of the load lock chamber 110 is high for such a structure. Here, the gas flow can be formed by introducing a gas into the internal space of the load lock chamber 110 by the gas introduction part 160, and / or by discharging the gas from the internal space using a pump 150 or the like as described later. Therefore, in the load lock chamber 110 where the pressure varies over a wide range from atmospheric pressure to high vacuum, a gas flow can necessarily be formed.

[0032] On the other hand, as Figure 11 schematically shown by the dashed arrow, when the substrate holding structure SH for holding the substrate S has a wall that obstructs the gas flow, a standing vortex may be formed in the gas flow. Such a standing vortex may cause particles to fly and adhere to the substrate S. In addition, through simulation, it is confirmed that: as Figure 12As schematically shown by the dashed arrow, even when the substrate holding structure SH' of the substrate S maintains a facing surface OS' parallel to the lower surface of the substrate S, a standing vortex is formed in the gas flow. Such a standing vortex may cause particles to fly and adhere to the substrate S.

[0033] Return to Figure 1 Continue the description. The substrate holding structure 120 can include a first member 125 having a facing surface OS and a second member 126 having an upper surface US facing the lower surface LS of the first member 125. The substrate holding structure 120 can include a plurality of contact portions 124 that contact the substrate S in a manner of supporting the substrate S. The second member 126 can support the first member 125 and the plurality of contact portions 124. The upper surface US of the second member 126 can have a shape along the lower surface LS of the first member 125. Such a structure can enable the gas to flow smoothly. Here, in a structure where the space defined by the mutually facing first member 125 (lower surface LS) and second member 126 (upper surface US) does not exist as a gas flow path, that is, in a structure where the space is filled with a solid, the gas flow is obstructed and a standing vortex may be generated. On the other hand, the structure in which the first member 125 (lower surface LS) and the second member 126 (upper surface US) face each other is conducive to suppressing the generation of standing vortices.

[0034] The load lock device 100 can include a drive mechanism 130. The drive mechanism 130 can be disposed below the load lock chamber 110 in a manner of lifting and lowering the substrate holding structure 120. The drive mechanism 130 can be connected to the substrate holding structure 120 via a connecting member 122.

[0035] The load lock chamber 110 can include an extension chamber 140 extending laterally from the lower part of the load lock chamber 110 and a pump 150 disposed below the extension chamber 140 and discharging the gas in the load lock chamber 110 via the extension chamber 140. The extension chamber 140 can have a bottom surface 144 having an opening 142 at a position deviated from the vertical below the substrate holding structure 120. The pump 150 can be connected to the opening 142. Although not shown, a valve can be disposed between the pump 150 and the opening 142.

[0036] The pump 150 can include, for example, a rotary pump and a turbomolecular pump disposed between the rotary pump and the opening 142. The turbine of the turbomolecular pump rotates at high speed during operation. When the particles attracted by the turbomolecular pump collide with the turbine, they may bounce off the turbine. In addition, regardless of whether the pump 150 is a turbomolecular pump or not, the pump 150 itself may generate particles. Therefore, it is preferable to connect the pump 150 to the opening 142 provided on the bottom surface 144 of the extension chamber 140 extending laterally from the lower part of the load lock chamber 110. Thereby, the situation where the particles from the pump 150 reach the upper space of the substrate S through the gap G between the side surface of the substrate holding structure 120 and the inner side surface of the load lock chamber and adhere to the substrate S can be reduced.

[0037] A valve 50 disposed between the second transfer port 112 of the load lock chamber 110 and the loading chamber 30 can be connected to a gas discharge pipe 52. The gas in the space near the second transfer port 112 can be discharged to the external space of the load lock chamber 110 through the gas discharge pipe 52. A pump (not shown) can be connected to the gas discharge pipe 52.

[0038] At least a part of the second transfer port 112 can be disposed above (vertically above) the extension chamber 140. Alternatively, at least a part of the extension chamber 140 can be disposed between the second transfer port 112 and the pump 150. Such a structure is beneficial for reducing the occupied space of the load lock device 100.

[0039] At least a part of the loading chamber 30 can be disposed above (vertically above) the extension chamber 140. Alternatively, at least a part of the extension chamber 140 can be disposed between the loading chamber 30 and the pump 150. Such a structure is also beneficial for reducing the occupied space of the load lock device 100.

[0040] Figure 15 It is a top view showing the arrangement of the load lock chamber 110, the extension chamber 140, and the gas dispersion part 162. This top view can also be understood as a front projection with respect to the floor on which the load lock device 100 is disposed. The substrate holder 120 can be located between the gas dispersion part 162 and the extension chamber 140 in this top view or this front projection. Alternatively, the opening 142 can be located between the gas dispersion part 162 and the extension chamber 140 in this top view or this front projection.

[0041] The area of the gap G between the side surface of the substrate holding structure 120 and the inner side surface of the load lock chamber 110 is preferably smaller than the cross-sectional area of the second transfer port 112. More preferably, the area of the gap G is smaller than 1 / 2, 1 / 3, or 1 / 4 of the cross-sectional area of the second transfer port 112. Such a structure is beneficial for when transporting the substrate S from the loading chamber 30 to the inner space of the load lock chamber 110 through the second transfer port 112, making the amount of gas introduced into the inner space of the load lock chamber 110 from the gas dispersion portion 162 discharged through the second transfer port 112 and the gas discharge pipe 52 greater than the amount discharged from the space above the substrate S to the space below the substrate holding structure 120 through the gap G. This is effective in suppressing particles from invading the inner space of the load lock chamber 110 from the loading chamber 30 through the second transfer port 112.

[0042] The area of the gap G between the side surface of the substrate holding structure 120 and the inner side surface of the load lock chamber 110 is preferably smaller than the cross-sectional area of the opening 142 provided on the bottom surface 144 of the extension chamber 140. Such a structure is beneficial for reducing the situation where particles from the pump 150 reach the space above the substrate S through the gap G and adhere to the substrate S. The area of the gap G is preferably smaller than the cross-sectional area (cross-sectional area in the vertical plane) of the connection portion 146 between the load lock chamber 110 and the extension chamber 140. Such a structure is also beneficial for reducing the situation where particles from the pump 150 reach the space above the substrate S through the gap G and adhere to the substrate S.

[0043] In Figure 2 , Figure 3 , Figure 4 and Figure 5 , the operation of the processing apparatus shown in Figure 1 is illustratively shown. First, while introducing (supplying) gas from the gas introduction portion 160 into the inner space of the load lock chamber 110, the gas in this inner space can be discharged to the outer space of the load lock chamber 110 by the pump 150. At this time, the amount of gas introduced from the gas introduction portion 160 into this inner space can be made larger than the discharge amount of the gas by the pump 150 so that the pressure in this inner space rises. If the pressure in this inner space becomes above atmospheric pressure, as shown in Figure 2 , the valve 50 opens and the gas discharge using the gas discharge pipe 52 starts. After that, the substrate S can be transported from the loading chamber 30 to the substrate holding structure 120 in the inner space of the load lock chamber 110 by the transfer robot 34.

[0044] After that, as shown in Figure 3As shown, the valve 50 is closed, and the substrate holding structure 120 can be driven upward by the driving mechanism 130. Additionally, in a state where gas is introduced into the internal space of the load lock chamber 110 from the gas introduction portion 160, the discharge amount of gas from this internal space based on the pump 150 is increased, and this internal space is depressurized. After that, the introduction of gas into this internal space using the gas introduction portion 160 is stopped, and the discharge amount of gas from this internal space based on the pump 150 can be further increased.

[0045] If the pressure of the internal space of the load lock chamber 110 is sufficiently depressurized, then as Figure 4 shown, the substrate holding structure 120 can be driven downward by the driving mechanism 130 until the height for transferring the substrate S to the transfer chamber 20. After that, as Figure 5 shown, the valve 40 is opened, and the substrate S is transferred from the internal space of the load lock chamber 110 to the transfer chamber 20 using the transfer robot 22, and can further be transferred to the decompression processing device 10. Then, the valve 40 is closed, and the substrate S is processed in the decompression processing device 10.

[0046] After that, the valve 40 is opened, and as Figure 5 shown, the substrate S in the decompression processing device 10 can be transferred to the internal space of the load lock chamber 110 using the transfer robot 22. After that, the valve 40 can be closed.

[0047] After that, gas can be introduced into the internal space of the load lock chamber 110 from the gas introduction portion 160 while the gas in this internal space is discharged to the external space of the load lock chamber 110 using the pump 150. At this time, the amount of gas introduced from the gas introduction portion 160 into this internal space can be made larger than the discharge amount of gas based on the pump 150 so that the pressure of this internal space rises. If the pressure of this internal space becomes above atmospheric pressure, then as Figure 2 shown, the valve 50 is opened, and the discharge of gas using the gas discharge pipe 52 is started. After that, the substrate S can be transferred from the substrate holding structure 120 in the internal space of the load lock chamber 110 to the loading chamber 30 using the transfer robot 34. After that, the valve 50 is closed, and the discharge of gas using the gas discharge pipe 52 can be stopped.

[0048] As Figure 1 、 Figure 3 、 Figure 4 illustrated, the substrate holding structure 120 can hold the substrate S in such a manner that at least a part of the side surface (outer peripheral surface) of the substrate S faces the inner surface of the load lock chamber 110. Here, this at least a part of the side surface (outer peripheral surface) of the substrate S held by the substrate holding structure 120 can hold the substrate S in a manner facing the inner surface of the load lock chamber 110 in a direction parallel to the surface of the substrate S.

[0049] AsFigures 1 - 5 As illustrated, the substrate holding structure 120 can be disposed at a plurality of positions in the internal space of the load lock chamber 110. As Figure 1 illustrated, the plurality of positions can include positions where a part of the side surface of the substrate S held by the substrate holding structure 120 faces the gas dispersion portion 162. Here, this part of the side surface (outer peripheral surface) of the substrate S held by the substrate holding structure 120 can face the gas dispersion portion 162 in a direction parallel to the surface of the substrate S.

[0050] As Figure 13A illustrated, the substrate holding structure 120 can also be configured such that the dimension DH of the facing surface OS of the substrate holding structure 120 in the surface direction (direction parallel to the XY plane) along the surface of the substrate S is smaller than the dimension DS of the substrate S in this surface direction. As Figure 13A , Figure 13B illustrated, the part PP of the substrate holding mechanism 120 can be located at a position inside the outer edge EE of the facing surface OS in a predetermined direction (Y direction) in the horizontal plane (XY plane). The cross-section of the facing surface OS cut at each of a plurality of planes (a plurality of planes parallel to the YZ plane) perpendicular to the horizontal plane (XY plane) and parallel to the predetermined direction (Y direction) can have the same shape as each other.

[0051] As Figure 14A shown, the substrate S held by the substrate holding structure 120 can have a rectangular shape. Alternatively, as Figure 14B illustrated, the substrate S held by the substrate holding structure 120 can have a circular shape with a notch portion NT indicating a reference orientation. However, the substrate S held by the substrate holding structure 120 can also have other shapes.

[0052] Figure 6 Schematically shows the structure of a processing apparatus including the load lock device 100 according to the second embodiment of the present invention. Matters not mentioned in the second embodiment can follow the first embodiment. In the load lock device 100 of the second embodiment, the top of the load lock chamber 110 includes a portion 601 facing the inner region of the outer edge of the substrate S and a portion 602 facing the outer edge of the substrate S, and the distance between the portion 601 and the substrate S is greater than the distance between the portion 602 and the substrate S.

[0053] Figure 7Schematically shows the structure of a processing apparatus including a load lock device 100 according to a third embodiment of the present invention. Matters not mentioned in the third embodiment can follow the first embodiment. In the load lock device 100 of the third embodiment, the top of the load lock chamber 110 includes a portion 601 facing the inner region of the outer edge of the substrate S and a portion 602 facing the outer edge of the substrate S, and the distance between the portion 601 and the substrate S is greater than the distance between the portion 602 and the substrate S. In the third embodiment, the portion 601 is formed of a smooth curved surface.

[0054] Figure 8 Schematically shows the structure of a processing apparatus including a load lock device 100 according to a fourth embodiment of the present invention. Matters not mentioned in the fourth embodiment can follow the first embodiment. In the fourth embodiment, the first member 125 has a corrugated vane shape. The corrugated vane shape is, for example, advantageous in suppressing large eddy currents such as those throughout the space between the opposing surface OS and the substrate S.

[0055] Figure 9 Schematically shows a top view of the first member 125 in the load lock device 100 according to a fifth embodiment of the present invention. In Figure 10 which, a side view of the first member 125 in the load lock device 100 according to a fifth embodiment of the present invention is schematically shown. Matters not mentioned in the fifth embodiment can follow the first embodiment. In the fifth embodiment, in a state where the substrate S is held by the substrate holding structure 120, a portion PP located inside the outer edge EE of the opposing surface OS is located inside the outer edge EE of the opposing surface OS in a predetermined direction DIR, and the first member 125 is divided into a plurality of portions 125a, 125b in a direction orthogonal to the predetermined direction DIR.

[0056] The present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, claims are added to disclose the scope of the invention.

[0057] Description of Reference Numerals

[0058] 100: Load lock device, 110: Load lock chamber, 111: First transfer port, 112: Second transfer port, 120: Substrate holding structure, 140: Extension chamber, 142: Opening, 144: Bottom surface, 150: Pump, 160: Gas introduction portion, 162: Gas dispersion portion, PP: Portion, EE: Outer edge, OS: Opposing surface.

Claims

1. A load lock device, the load lock device having a load lock chamber and a substrate holding structure for holding a substrate in the load lock chamber, characterized in that, the substrate holding structure includes a contact portion that contacts the substrate in a manner of supporting the substrate and a first member having an opposing surface that faces the substrate without contacting the substrate, and the substrate holding structure is configured to allow gas to flow in a space between the substrate and the opposing surface, in a state where the substrate is held by the substrate holding structure, a portion located inside the outer edge of the opposing surface is at a greater distance from the substrate than the distance between the outer edge of the opposing surface and the substrate, the outer edge of the opposing surface is defined by an exposed side surface on the outside of the first member.

2. The load lock device according to claim 1, characterized in that, the substrate holding structure includes a first member having the opposing surface and a second member having an upper surface that faces the lower surface of the first member.

3. The load lock device according to claim 2, characterized in that, the second member supports the first member and a plurality of the contact portions.

4. The load lock device according to claim 3, characterized in that, the upper surface of the second member has a shape along the lower surface of the first member.

5. The load lock device according to claim 3, characterized in that, the first member has a corrugated vane shape.

6. The load lock device according to claim 3, characterized in that, the portion is located inside the outer edge of the opposing surface in a predetermined direction, the first member is divided into a plurality of portions in a direction orthogonal to the predetermined direction.

7. The load lock device according to any one of claims 1 to 6, characterized in that, the load lock chamber has a first transfer port connected to a transfer chamber and a second transfer port connected to a loading chamber, the transfer chamber being connected to a decompression processing device, the load lock device further includes: a gas introduction portion disposed above a path between the substrate holding structure and the transfer chamber in a state where the substrate is transferred to the transfer chamber through the first transfer port; and a gas discharge portion configured to discharge gas through a space below the substrate holding structure.

8. The load lock device according to claim 7, characterized in that, the height of the first transfer port is lower than the height of the second transfer port.

9. The load lock device according to claim 7, characterized in that, the gas introduction portion includes a gas dispersion portion for dispersing gas, the gas dispersion portion is disposed at a position facing the second transfer port.

10. The load lock device according to claim 9, characterized in that, the gas dispersion portion has a columnar portion, and an inner side surface of the load lock chamber includes a curved surface separated from the columnar portion and along the columnar portion.

11. The load lock device according to claim 10, characterized in that, The column-shaped portion has a cylindrical shape, and the curved surface forms a part of a cylindrical surface.

12. The load lock device according to claim 9, characterized in that the gas introduction portion and the gas discharge portion are controlled to perform an operation of reducing the pressure in the load lock chamber in a state where the substrate held by the substrate holding structure is disposed at a position higher than the central axis of the gas dispersion portion, and an operation of reducing the pressure in the load lock chamber in a state where the substrate held by the substrate holding structure is disposed at a position lower than the central axis of the gas dispersion portion.

13. The load lock device according to claim 7, characterized in that the load lock device further includes a gas discharge pipe line configured to discharge gas from a space near the second transfer port.

14. The load lock device according to claim 1, characterized in that the substrate holding structure holds the substrate in such a manner that at least a part of the side surface of the substrate faces the inner surface of the load lock chamber.

15. The load lock device according to claim 1, characterized in that the load lock device further includes a gas dispersion portion that disperses gas in the internal space of the load lock chamber, the substrate holding structure holds the substrate in such a manner that at least a part of the side surface of the substrate faces the inner surface of the load lock chamber, the positions where the substrate holding structure can be disposed include positions where a part of the side surface of the substrate held by the substrate holding structure faces the gas dispersion portion.

16. The load lock device according to claim 1, characterized in that the size of the facing surface in the surface direction along the surface of the substrate is smaller than the size of the substrate in the surface direction.

17. The load lock device according to claim 1, characterized in that the portion is located inside the outer edge of the facing surface in a predetermined direction in the horizontal plane, and the cross-section of the facing surface cut at each of at least three planes perpendicular to the horizontal plane and parallel to the predetermined direction and separated from each other has the same shape.

18. The load lock device according to claim 1, characterized in that the substrate held by the substrate holding structure has a rectangular shape.

19. The load lock device according to claim 1, characterized in that the substrate held by the substrate holding structure has a circular shape with a notch portion indicating a reference orientation.

20. A load lock device, the load lock device including a load lock chamber and a substrate holding structure for holding a substrate in the load lock chamber, characterized in that the substrate holding structure has a facing surface facing the substrate and is configured to allow gas to flow in the space between the substrate and the facing surface, in a state where the substrate is held by the substrate holding structure, the distance between a portion located inside the outer edge of the facing surface and the substrate is greater than the distance between the outer edge of the facing surface and the substrate. The portion is located at a position inside the outer edge of the facing surface in a predetermined direction in the horizontal plane. The cross-section of the facing surface cut at each of at least three planes perpendicular to the horizontal plane and parallel to the predetermined direction and separated from each other has the same shape.

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