JP2021156345A - Flexible joint device - Google Patents

Abstract

To provide a flexible joint device which can prevent vibration from being transmitted to a vacuum chamber.SOLUTION: A flexible joint device includes: a first member 31 having a flange part 35; a second member 32 having a housing part 36 that encloses the flange part 35; a bellows 38 connected to the first member 31 or the second member 32; and a seal device 45 which seals a gap between the flange part 35 and the housing part 36. The flange part 35 and the housing part 36 can move relative to each other.SELECTED DRAWING: Figure 3

Description

The present invention relates to a flexible joint device for connecting two chambers, and particularly to a flexible joint device having a sealing function.

Vacuum chambers are used in a variety of applications. For example, a scanning electron microscope includes a vacuum chamber that houses workpieces such as wafers, masks, and glass substrates. The vacuum chamber is connected to the transfer chamber by a bellows. The workpiece is transferred from the transfer chamber to the stage in the vacuum chamber through the bellows by the transfer robot.

Japanese Unexamined Patent Publication No. 2001-210576

The bellows is configured to flexibly connect the vacuum chamber and the transfer chamber while maintaining the vacuum in the vacuum chamber and the transfer chamber. Since the bellows has a stretchable shape, it can absorb vibrations in the stretchable direction.

However, the bellows cannot absorb the vibration in the direction perpendicular to the expansion and contraction direction very much. In particular, the stage of the vacuum chamber needs to be within reach of the transfer robot's hand, so short bellows are usually used. As a result, the bellows has high rigidity in the direction perpendicular to the expansion / contraction direction, and most of the vibration of the transfer robot is transmitted to the vacuum chamber through the transfer chamber and the bellows.

Therefore, the present invention provides a flexible joint device capable of preventing vibration from being transmitted to the vacuum chamber.

In one aspect, a first member having a flange portion, a second member having a housing portion surrounding the flange portion, a bellows connected to the first member or the second member, and the flange portion and the housing portion. A flexible joint device is provided in which a sealing device for sealing a gap between the flange portion and the housing portion is provided, and the flange portion and the housing portion are relatively movable.

In one aspect, the flange portion has a first flange end face, the housing has a first housing surface facing the first flange end face, and at least a portion of the sealing device is the first flange. It is arranged between the end surface and the first housing surface.
In one aspect, it further comprises a fluid supply system that supplies fluid to the gap between the flange portion and the housing portion.
In one aspect, the fluid supply system has a fluid supply port and a fluid discharge port located outside the sealing device in the radial direction of the flange portion.
In one aspect, the fluid supply system is an air supply system.
In one aspect, the sealing device is a ferrofluidic sealing device.

According to the present invention, the flange portion and the housing portion are relatively movable. Therefore, the vibration in the expansion / contraction direction of the bellows is absorbed by the bellows, and the vibration in the direction perpendicular to the expansion / contraction direction of the bellows and the vibration in the circumferential direction of the bellows are absorbed by the relative movement of the flange portion and the housing portion. Therefore, the flexible fitting device can prevent vibrations in all directions from being transmitted to the vacuum chamber.

It is a schematic diagram which shows the chamber system which provided one Embodiment of a flexible joint device. It is a perspective view of the flexible joint device. It is sectional drawing of the upper half of a flexible joint device. It is sectional drawing of another embodiment of a flexible joint device. FIG. 5 is a cross-sectional view of still another embodiment of the flexible joint device. It is a schematic diagram which shows one Embodiment of the scanning electron microscope which includes the chamber system which incorporated the flexible joint device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing a chamber system including an embodiment of a flexible joint device. The chamber system 1 includes a vacuum chamber 3 in which a stage 2 on which the workpiece W is placed is arranged, a transfer chamber 7 in which a transfer robot 6 for transferring the workpiece W is arranged inside, and a vacuum chamber 3. A flexible joint device 10 that airtightly connects the transfer chamber 7, a load lock chamber 12 that is connected to the transfer chamber 7, a vacuum pump 15A that is connected to the load lock chamber 12, and a vacuum pump that is connected to the vacuum chamber 3. It is equipped with 15B.

A table 16 is arranged in the load lock chamber 12. The chamber system 1 includes a first gate 18 that closes the entrance of the load lock chamber 12 and a second gate 19 that separates the load lock chamber 12 and the transfer chamber 7. When the first gate 18 is opened, the inside of the load lock chamber 12 communicates with the outside. When the second gate 19 is opened, the load lock chamber 12 and the transfer chamber 7 communicate with each other.

One end of the flexible joint device 10 is connected to the transfer chamber 7, and the other end of the flexible joint device 10 is connected to the vacuum chamber 3. The flexible joint device 10 has a transport passage 22 through which the workpiece W can pass. As will be described later, the flexible joint device 10 is configured to be able to absorb vibrations in all directions of the transfer chamber 7 while airtightly connecting the transfer chamber 7 and the vacuum chamber 3.

The vacuum chamber 3 is a sample chamber that forms a part of a precision machine such as a scanning electron microscope. The vacuum chamber 3 and the transfer chamber 7 are supported by a gantry 26 installed on the floor 25. In order to prevent the vibration of the floor 25 from being transmitted to the vacuum chamber 3, the chamber system 1 includes a plurality of vibration isolators 27 arranged between the vacuum chamber 3 and the gantry 26. The vibration isolator 27 is composed of an air spring or the like. The vibration isolator 27 is supported by the gantry 26, and the vacuum chamber 3 is supported by the vibration isolator 27. The vibration isolator 27 can absorb the vibration of the floor 25. Since the inside of the vacuum chamber 3 and the transfer chamber 7 is a vacuum, the vacuum chamber 3 and the transfer chamber 7 are subjected to a force of being pressed against each other by the atmospheric pressure. The vibration isolator 27 also has a function of generating a force that antagonizes this force and maintaining an appropriate positional relationship between the vacuum chamber 3 and the transport chamber 7.

The operation of the chamber system 1 is as follows. The second gate 19 is normally closed, the vacuum pump 15B is always in operation, and the vacuum chamber 3 and the transfer chamber 7 are always kept in a vacuum state. When the inside of the load lock chamber 12 is in an atmospheric pressure state, the first gate 18 is opened, and the workpiece W is placed on the table 16 in the load lock chamber 12 by a transfer device (not shown). The first gate 18 is closed while the second gate 19 is closed. Then, the vacuum pump 15A is operated. When the pressure in the load lock chamber 12 drops to approximately equal the pressure in the transport chamber 7, the second gate 19 is opened. The transfer robot 6 takes out the workpiece W in the load lock chamber 12. After the hand of the transfer robot 6 moves out of the load lock chamber 12, the second gate 19 is closed. The transfer robot 6 has at least two arms, and exchanges the workpiece W already placed on the stage 2 with the newly carried workpiece W through the transfer chamber 7 and the bellows 10. After the hand of the transfer robot 6 moves out of the vacuum chamber 3, observation such as imaging of the workpiece W is performed. During the observation, the transfer robot 6 continues the operation in preparation for the next workpiece replacement.

When the transfer robot 6 is operating, the transfer chamber 7 in contact with the transfer robot 6 also vibrates slightly. The flexible joint device 10 is configured to absorb the vibration of the transfer chamber 7 so that the vibration is not transmitted to the vacuum chamber 3, and the observation of the workpiece W can be continued even while the transfer robot 6 is operating.

FIG. 2 is a perspective view of the flexible joint device 10, and FIG. 3 is a cross-sectional view of the upper half of the flexible joint device 10. As shown in FIGS. 2 and 3, the flexible joint device 10 is connected to a first member 31 having a flange portion 35, a second member 32 having a housing portion 36 surrounding the flange portion 35, and a first member 31. A flange 38 and a connecting member 40 to which the bellows 38 are connected are provided. In this embodiment, the connecting member 40 is connected to the vacuum chamber 3 and the second member 32 is connected to the transport chamber 7. In one embodiment, the connecting member 40 may be connected to the transfer chamber 7 and the second member 32 may be connected to the vacuum chamber 3.

The bellows 38 is made of metal or resin. The entire bellows 38 of the present embodiment has a cylindrical shape, but the shape of the bellows 38 is not particularly limited. In one embodiment, the bellows 38 may have a rectangular cross-sectional shape. The bellows 38 is configured to be stretchable along its central axis CL. The expansion / contraction direction of the bellows 38 substantially coincides with the extension direction of the central axis CL of the bellows 38. As shown in FIG. 3, a gap is formed between the flange portion 35 and the housing portion 36, and the flange portion 35 and the housing portion 36 are relatively movable.

The first member 31 and the second member 32 each have a first inner wall 41 and a second inner wall 42 forming a transport passage 22. The first inner wall 41 and the second inner wall 42 have a width larger than that of the workpiece W. Further, the connecting member 40 also has a third inner wall 43 forming the transport passage 22. The width of the third inner wall 43 and the inner diameter of the bellows 38 are larger than the workpiece W. Therefore, the workpiece W can pass through the transport passage 22 of the flexible joint device 10.

The flexible joint device 10 includes a sealing device 45 that seals a gap between the flange portion 35 and the housing portion 36. The sealing device 45 is a magnetic fluid seal. That is, the sealing device 45 includes a magnetic fluid 45A arranged in a gap between the flange portion 35 and the housing portion 36, and a magnetic field generating device 45B that applies a magnetic field to the magnetic fluid 45A. The sealing device 45 composed of such a magnetic fluid seal can seal the gap between the flange portion 35 and the housing portion 36 without hindering the relative movement of the flange portion 35 and the housing portion 36.

In one embodiment, the sealing device 45 may include a non-contact seal such as a labyrinth seal instead of the ferrofluidic seal. Further, in one embodiment, the sealing device 45 may be a contact type seal such as an O-ring as long as it does not hinder the relative movement of the flange portion 35 and the housing portion 36. When an O-ring is used, the exposed surface of the O-ring may be coated with a highly lubricious material such as polytetrafluoroethylene. Polytetrafluoroethylene is known as so-called Teflon®.

The flange portion 35 is a flange outer peripheral surface located between the first flange end surface 51, the second flange surface 52 on the side opposite to the first flange end surface 51, and the first flange end surface 51 and the second flange surface 52. Has 53. The housing portion 36 has a first housing surface 61 facing the first flange end surface 51, a second housing surface 62 facing the second flange surface 52, and a housing inner peripheral surface 63 facing the flange outer peripheral surface 53. ing. The flange portion 35 is arranged in the space formed by the first housing surface 61, the second housing surface 62, and the housing inner peripheral surface 63.

The first flange end surface 51, the second flange surface 52, the first housing surface 61, and the second housing surface 62 are perpendicular to the expansion / contraction direction of the bellows 38 (perpendicular to the central axis CL of the bellows 38), and the flange outer peripheral surface 53. The inner peripheral surface 63 of the housing is parallel to the expansion / contraction direction of the bellows 38 (parallel to the central axis CL of the bellows 38). The entire first member 31 is supported by the bellows 38. The bellows 38 can be expanded and contracted in the direction in which the central axis CL extends, but has high rigidity in the direction perpendicular to the central axis CL. Therefore, the bellows 38 can support the first member 31 so that the flange outer peripheral surface 53 does not come into contact with the housing inner peripheral surface 63.

A gap is formed between the first flange end surface 51 and the first housing surface 61, a gap is formed between the second flange surface 52 and the second housing surface 62, and the flange outer peripheral surface 53 and the housing inner circumference are formed. A gap is formed between the surface 63 and the surface 63. In one example, the gap between the first flange end surface 51 and the first housing surface 61 and the gap between the second flange surface 52 and the second housing surface 62 are within the range of several μm to 10 μm.

At least a part of the sealing device 45 is located between the first flange end surface 51 and the first housing surface 61, and the gap between the first flange end surface 51 and the first housing surface 61 is formed by the sealing device 45. It is sealed. The first flange end surface 51 and the first housing surface 61 are adjacent to the transfer passage 22, and the sealing device 45 is also adjacent to the transfer passage 22. Although the gap between the first flange end surface 51 and the first housing surface 61 is adjacent to the transfer passage 22, the sealing device 45 connects the transfer passage 22 to the first flange end surface 51 and the first housing surface 61. It is partitioned from the gap between them. Therefore, the vacuum in the transport passage 22 is held by the sealing device 45.

The flange portion 35 is not fixed to the housing portion 36, and the flange portion 35 and the housing portion 36 can move relatively in a direction perpendicular to the expansion / contraction direction of the bellows 38 (that is, the central axis CL of the bellows 38). be. Further, the flange portion 35 and the housing portion 36 are relatively movable in the circumferential direction of the bellows 38 (that is, the rotation direction about the central axis CL of the bellows 38). The vibration in the expansion and contraction direction of the bellows 38 is absorbed by the bellows 38, and the vibration in the direction perpendicular to the expansion and contraction direction of the bellows 38 and the vibration in the circumferential direction of the bellows 38 are absorbed by the relative movement of the flange portion 35 and the housing portion 36. NS. Therefore, the flexible joint device 10 can prevent the vibration of the transfer chamber 7 in all directions from being transmitted to the vacuum chamber 3.

In order to enable smooth relative movement between the flange portion 35 and the housing portion 36, the flexible joint device 10 of the present embodiment is a fluid supply system 70 that supplies fluid to the gap between the flange portion 35 and the housing portion 36. Is further equipped. In this embodiment, the fluid supply system 70 is an air supply system. That is, the fluid supply system 70 is configured to supply air to the gap between the flange portion 35 and the housing portion 36. In one embodiment, the fluid supply system 70 may be a gas supply system that supplies air, an inert gas, or other gas.

The fluid supply system 70 includes a first fluid supply flow path 71, a second fluid supply flow path 72, a first fluid discharge flow path 81, and a second fluid discharge flow path 82 provided in the second member 32. There is. Although only one set of the first fluid supply flow path 71, the second fluid supply flow path 72, the first fluid discharge flow path 81, and the second fluid discharge flow path 82 is drawn in FIG. 3, FIG. 2 shows. As shown, the fluid supply system 70 has a plurality of sets of the first fluid supply flow path 71, the second fluid supply flow path 72, the first fluid discharge flow path 81, and the second fluid discharge flow path 82. ..

The first fluid supply flow path 71 has a first fluid supply port 74 that opens at the first housing surface 61. The first fluid supply port 74 is located outside the sealing device 45 in the radial direction of the flange portion 35. The first fluid supply port 74 faces the first flange end face 51, and air is blown from the first fluid supply port 74 to the first flange end face 51.

The second fluid supply flow path 72 has a second fluid supply port 75 that opens at the second housing surface 62. The second fluid supply port 75 faces the second flange surface 52, and air is blown from the second fluid supply port 75 to the second flange surface 52.

The first fluid discharge flow path 81 has a first fluid discharge port 84 that opens at the first housing surface 61. The first fluid discharge port 84 is located outside the sealing device 45 in the radial direction of the flange portion 35. Further, the first fluid discharge port 84 is located inside the first fluid supply port 74 in the radial direction of the flange portion 35. That is, the first fluid discharge port 84 is located between the sealing device 45 and the first fluid supply port 74 in the radial direction of the flange portion 35.

The second fluid discharge flow path 82 has a second fluid discharge port 85 that opens at the inner peripheral surface 63 of the housing. The second fluid discharge port 85 is located between the first fluid supply port 74 and the second fluid supply port 75.

Although not shown, the plurality of first fluid supply ports 74, the plurality of second fluid supply ports 75, the plurality of first fluid discharge ports 84, and the second fluid discharge port 85 are arranged in the circumferential direction of the flange portion 35. There is.

The first fluid supply flow path 71 and the second fluid supply flow path 72 are connected to a fluid supply line (not shown). Air as a lubricating fluid flows through the first fluid supply flow path 71 and the second fluid supply flow path 72, and is between the flange portion 35 and the housing portion 36 from the first fluid supply port 74 and the second fluid supply port 75. It is supplied to the gap of. The air flows toward the first fluid discharge port 84 and the second fluid discharge port 85, and forms a film of air between the flange portion 35 and the housing portion 36. This film of air enables smooth relative movement of the flange portion 35 and the housing portion 36. Air flows into the first fluid discharge port 84 and the second fluid discharge port 85, and is discharged to the surroundings through the first fluid discharge flow path 81 and the second fluid discharge flow path 82.

According to the present embodiment, the flexible joint device 10 can quickly absorb the vibration in the direction perpendicular to the expansion / contraction direction of the bellows 38 and the vibration in the circumferential direction of the bellows 38.

FIG. 4 is a cross-sectional view showing another embodiment of the flexible joint device 10. Since the configuration and operation of the present embodiment not particularly described are the same as those of the embodiment described with reference to FIGS. 2 and 3, the duplicate description thereof will be omitted. As shown in FIG. 4, the flexible joint device 10 of the present embodiment does not include the fluid supply system 70. Instead, the outer surface of the flange portion 35 and the inner surface of the housing portion 36 are coated with a lubricant (not shown). More specifically, the first flange end surface 51 and the second flange surface 52 of the flange portion 35, and the first housing surface 61 and the second housing surface 62 of the housing portion 36 are covered with a lubricant. The flange outer peripheral surface 53 and the housing inner peripheral surface 63 may also be coated with a lubricant. The first flange end surface 51 and the first housing surface 61 may come into contact with each other. Similarly, the second flange surface 52 and the second housing surface 62 may come into contact with each other.

Examples of the lubricant include a solid lubricant such as polytetrafluoroethylene and a liquid lubricant such as oil and grease. The lubricant allows smooth relative movement of the flange portion 35 and the housing portion 36. Therefore, the flexible joint device 10 can quickly absorb the vibration in the direction perpendicular to the expansion / contraction direction of the bellows 38 and the vibration in the circumferential direction of the bellows 38.

FIG. 5 is a cross-sectional view showing another embodiment of the flexible joint device 10. Since the configuration and operation of the present embodiment not particularly described are the same as those of the embodiment described with reference to FIGS. 2 and 3, the duplicate description thereof will be omitted. As shown in FIG. 5, the flexible joint device 10 of the present embodiment does not include the fluid supply system 70. Instead, the flexible joint device 10 includes a first rolling bearing 91 and a second rolling bearing 92 arranged between the flange portion 35 and the housing portion 36.

The first rolling bearing 91 is arranged between the first flange end surface 51 and the first housing surface 61, and the second rolling bearing 92 is arranged between the second flange surface 52 and the second housing surface 62. There is. The first rolling bearing 91 includes at least three rolling elements (balls, rollers, etc.) arranged in the circumferential direction of the flange portion 35. Similarly, the second rolling bearing 92 includes at least three rolling elements (such as balls or rollers) arranged in the circumferential direction of the flange portion 35.

The first rolling bearing 91 and the second rolling bearing 92 enable smooth relative movement between the flange portion 35 and the housing portion 36. Therefore, the flexible joint device 10 can quickly absorb the vibration in the direction perpendicular to the expansion / contraction direction of the bellows 38 and the vibration in the circumferential direction of the bellows 38.

FIG. 6 is a schematic view showing an embodiment of a scanning electron microscope including a chamber system 1 in which a flexible joint device 10 according to any one of the above-described embodiments is incorporated. The scanning electron microscope includes an electron beam irradiation system 101, a chamber system 1, and a lens barrel 105 fixed to the chamber system 1.

The electron beam irradiation system 101 is arranged in the lens barrel 105, and the lens barrel 105 is fixed to the upper wall of the vacuum chamber 3 of the chamber system 1. The electron beam irradiation system 101 deflects the electron gun 111 that emits an electron beam 110 composed of primary electrons (charged particles), the focusing lens 112 that focuses the electron beam 110 emitted from the electron gun 111, and the electron beam 110 in the X direction. It has an X deflector 113, a Y deflector 114 that deflects the electron beam 110 in the Y direction, and an objective lens 115 that focuses the electron beam 110 on the workpiece W as a sample.

The scanning electron microscope further includes a secondary electron detector 130, a backscattered electron detector 131, and an image acquisition device 118. The secondary electron detector 130 and the backscattered electron detector 131 are connected to the image acquisition device 118. The image acquisition device 118 is configured to convert the output signals of the secondary electron detector 130 and the backscattered electron detector 131 into an image.

The operation of the scanning electron microscope is as follows. The electron beam 110 emitted from the electron gun 111 is focused by the focusing lens 112, then focused by the objective lens 115 while being deflected by the X deflector 113 and the Y deflector 114, and is irradiated on the surface of the workpiece W. When the workpiece W is irradiated with the primary electrons of the electron beam 110, secondary electrons and backscattered electrons are emitted from the workpiece W. Secondary electrons are detected by the secondary electron detector 130, and backscattered electrons are detected by the backscattered electron detector 131. The secondary electron detection signal and the backscattered electron detection signal are input to the image acquisition device 118 and converted into an image.

The embodiment shown in FIG. 6 shows an example in which a chamber system incorporating a flexible joint device is applied to a scanning electron microscope, but the present invention is not limited to this example. For example, the chamber system incorporating the flexible joint device can also be applied to a semiconductor exposure device used for patterning wafers.

The above-described embodiment is described for the purpose of enabling a person having ordinary knowledge in the technical field to which the present invention belongs to carry out the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is construed in the broadest range according to the technical idea defined by the claims.

1 Chamber system 2 Stage 3 Vacuum chamber 6 Transfer robot 7 Transfer chamber 10 Flexible bearing device 12 Load lock chamber 15A, 15B Vacuum pump 16 Table 18 1st gate 19 2nd gate 22 Transfer passage 25 Floor 26 Stand 27 Vibration isolation device 31 1 member 32 2nd member 35 Flange part 36 Housing part 38 Bellows 40 Connecting member 41 1st inner wall 42 2nd inner wall 43 3rd inner wall 45 Sealing device 45A Magnetic fluid 45B Magnetic field generator 51 1st flange end face 52 2nd flange surface 53 Flange outer peripheral surface 61 First housing surface 62 Second housing surface 63 Housing inner peripheral surface 70 Fluid supply system 71 First fluid supply flow path 72 Second fluid supply flow path 81 First fluid discharge flow path 82 Second fluid discharge flow path 74 1st fluid supply port 75 2nd fluid supply port 84 1st fluid discharge port 85 2nd fluid discharge port 91 1st rolling bearing 92 2nd rolling bearing CL center axis W workpiece

Claims (6)

The first member having a flange and
A second member having a housing portion surrounding the flange portion and
With the bellows connected to the first member or the second member,
A sealing device for sealing the gap between the flange portion and the housing portion is provided.
A flexible joint device in which the flange portion and the housing portion are relatively movable. The flange portion has a first flange end face and has a first flange end face.
The housing has a first housing surface facing the first flange end surface.
The flexible joint device according to claim 1, wherein at least a part of the sealing device is arranged between the first flange end surface and the first housing surface. The flexible joint device according to claim 1 or 2, further comprising a fluid supply system for supplying a fluid to a gap between the flange portion and the housing portion. The flexible joint device according to claim 3, wherein the fluid supply system has a fluid supply port and a fluid discharge port located outside the sealing device in the radial direction of the flange portion. The flexible joint device according to claim 3 or 4, wherein the fluid supply system is an air supply system. The flexible joint device according to any one of claims 1 to 5, wherein the sealing device is a magnetic fluid sealing device.

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