EFEM

Abstract

To provide a technology that can reduce particle contamination of a substrate in an EFEM that circulates gas.SOLUTION: In an EFEM 100 including a circulation path including a transfer chamber T2 forming a transfer space in which a substrate is transferred, and a return path T3 that returns gas that has flowed from one side of the transfer chamber T2 to the other side, the return path T3 and the transfer chamber T2 are provided across a partition, and in a state in which gas is circulated in the circulation path, a differential pressure is formed on both sides of the partition such that the return path T3 side is high pressure, and a capture portion 5 is provided that is provided in the return path T3 and electrically captures particles contained in the gas flowing therethrough.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an EFEM (Equipment Front End Module) capable of circulating gas. [Background technology]

[0002] A highly clean environment is required in semiconductor manufacturing processes and the like. In recent years, mini-environment systems have increasingly been adopted to create clean environments in semiconductor manufacturing plants and the like, replacing the downflow system. The mini-environment system creates a localized clean environment only around the substrate (e.g., wafer) that is the workpiece, and can create a highly clean environment at lower cost than the downflow system, which creates a clean environment throughout the entire plant.

[0003] In the mini-environment method, wafers are transported and stored in sealed containment containers called FOUPs (Front Opening Unified Pods), cassettes, pods, etc., which are kept at a higher level of cleanliness than the outside atmosphere. Wafers stored in the containment containers are transferred between the containment containers and processing equipment via EFEMs connected to the processing equipment without being exposed to the outside atmosphere.

[0004] Specifically, an EFEM includes a housing that defines a substantially closed transfer chamber inside, a load port that functions as an interface between the housing and a storage container, and other components. The load port is connected to one side of the housing, and a processing device is connected to the other side of the housing. A transfer device disposed in the transfer chamber transfers wafers between the storage container connected to the load port and the processing device.

[0005] Incidentally, in recent years, with the progress in the high integration of elements and the miniaturization of circuits, there is an increasing demand for the wafer to be surrounded by an atmosphere with a sufficiently low content of oxygen, moisture, etc., such as an inert gas atmosphere, so as to prevent changes in the surface properties of the wafer, such as oxidation.

[0006] To meet such demands, an EFEM has been proposed that circulates an inert gas or the like inside the housing. For example, in the EFEM described in Patent Documents 1 and 2, a fan filter unit provided above the transfer chamber creates a downflow of inert gas in the transfer chamber, and the inert gas that reaches the bottom of the transfer chamber is introduced into a return path, flows upward through this path, and is sent back to the transfer chamber through the fan filter unit.

[0007] In this way, with the EFEM configured to circulate the inert gas, the transfer chamber can be placed under an inert gas atmosphere while suppressing the amount of inert gas consumed. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2019-16116 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-5283 Summary of the Invention [Problem to be solved by the invention]

[0009] In an EFEM that circulates gas, when gas is circulating through the circulation path, a pressure difference may be formed on both sides of the partition wall that separates the return path from the transfer chamber, making the return path side higher pressure.

[0010] For example, the EFEM disclosed in Patent Document 1 has a return path provided in the hollow part of the pillar of the housing. A fan is provided to send the gas that has flowed through the transfer chamber into this return path, and by actively sending the gas into the return path with this fan, the gas is returned through the return path, which is narrower than the transfer chamber. The provision of such a fan increases the pressure in the return path, and a pressure difference is formed on both sides of the partition wall separating the return path from the transfer chamber (i.e., inside and outside the pillar) such that the pressure on the return path side is higher.

[0011] For example, in the EFEM disclosed in Patent Document 2, the inside of the housing is divided into a transfer chamber and a return path by a partition wall. Here, a supply pipe for supplying gas to the circulation path is connected to the middle of the return path, and gas is supplied from a position midway along the return path. When gas is supplied to the return path, the pressure in the return path increases, and a pressure difference is formed on both sides of the partition wall that separates the return path from the transfer chamber, making the return path side higher pressure.

[0012] However, when such a pressure difference is formed, there is a possibility that a small amount of gas may leak from the return path into the transfer chamber through a tiny gap in the partition wall separating the return path and the transfer chamber. If such a gas leak occurs, particles contained in the gas flowing through the return path, i.e., particles that would normally be removed by the fan filter unit, may flow into the transfer chamber along with the gas and adhere to the wafers inside the transfer chamber.

[0013] The present invention has been made to solve the above problems, and aims to provide a technique that can reduce particle contamination of a substrate in an EFEM that circulates gas. [Means for solving the problem]

[0014] In order to achieve the above object, the present invention takes the following measures.

[0015] That is, the present invention provides an EFEM having a circulation path including a transfer chamber that forms a transfer space in which a substrate is transferred and a return path that returns gas that has flowed from one side of the transfer chamber to the other, wherein the return path and the transfer chamber are provided on either side of a partition wall, and when gas is circulating through the circulation path, a pressure difference is formed on both sides of the partition wall such that the pressure on the return path side is higher, and the EFEM has a capture unit that is provided in the return path and electrically captures particles contained in the gas flowing therethrough. Basic configuration Let's say. The apparatus further includes a transfer device that transfers the substrate within the transfer chamber, and a fan filter unit that forms a downflow in the transfer chamber, and the capture unit is disposed upstream of the fan filter unit. It is characterized by:

[0016] With this configuration, particles contained in the gas flowing through the return path are electrically captured, so even if gas leaks from the return path toward the transfer chamber, which is at a lower pressure than the return path, the amount of particles in the transfer chamber is unlikely to increase. Therefore, adhesion of particles to the substrate in the transfer chamber can be sufficiently suppressed. Furthermore, if particles contained in the gas flowing through the return path were to be captured using, for example, a gas-permeable filter, the flow resistance of the return path would inevitably increase significantly. However, in this case, because the capture unit provided in the return path electrically captures particles, particles can be captured without significantly increasing the flow resistance of the return path. In addition to these basic effects, the system is further equipped with a transport device that transports substrates within the transport chamber and a fan filter unit that creates a downflow in the transport chamber, and by locating the capture section upstream of the fan filter unit, the amount of particles that accumulate in the fan filter unit is reduced compared to when no capture section is provided, resulting in an extended lifespan of the fan filter unit and a longer replacement cycle.

[0017] In the EFEM, the fan filter unit and the return path each include a fan; The capture part is The fan filter unit is disposed between the fan of the fan filter unit and the fan of the return path, and the fan is delivered to the return path from the fan of the return path. It is preferable that the particles contained in the gas are captured by adhering them to a charged surface by electrostatic force.

[0018] This configuration makes it possible to adequately capture particles contained in the gas flowing through the return path with a simple configuration, and maintenance is also easy. For example, if particles are captured with a filter, the filter must be replaced periodically, but if the particles are captured by adhering to a charged surface, the particles can be collected with a relatively simple procedure, such as releasing the charge on the charged surface and wiping it.

[0019] It is preferable that the EFEM comprises a housing including a plurality of panels and a support pillar supporting the plurality of panels, the support pillar being hollow, the return path being provided in the hollow portion of the support pillar, and the capture portion being provided on the inner wall surface of the support pillar.

[0020] According to this configuration, the return path is provided in the hollow portion of the support, so the footprint of the device can be kept small.

[0021] In an EFEM having the above basic configuration, it is preferable that the EFEM is provided with a housing including a plurality of panels and pillars supporting the plurality of panels, the pillars being hollow, the return path being provided in the hollow portion of the pillars, the capture portion being provided on the inner wall surface of the pillars, and the pillars being provided with an opening that allows access to the capture portion and a cover portion that can freely close and open the opening.

[0022] According to this configuration, In addition to the above-mentioned basic effects, since the return path is provided in the hollow part of the support, the footprint of the device can be kept small, and the capture part can be accessed through the opening when it is left open, which makes maintenance of the capture part easy.

[0023] The aforementioned Consists of the basic configuration In the EFEM, it is preferable that the circulation path includes an individual return path that returns gas that has flowed inside a specified device arranged in the transfer chamber, the individual return path and the transfer chamber are arranged on either side of a partition wall, and when gas is circulating through the circulation path, a differential pressure is formed on both sides of the partition wall such that the side of the individual return path is higher in pressure, and the capture section is provided in each of the return path and the individual return path.

[0024] According to this configuration, In addition to the above basic effects,Since the gas flowing inside the device disposed in the transfer chamber is returned through the individual return path, it is possible to sufficiently prevent the occurrence of a situation in which particles generated inside the device are released into the transfer chamber and adhere to the substrate inside the transfer chamber. Furthermore, since particles contained in the gas flowing through the individual return path are electrically captured, even if gas leaks from the individual return path toward the transfer chamber, which is at a lower pressure than the individual return path, the amount of particles in the transfer chamber is unlikely to increase.

[0025] The aforementioned Consists of the basic configuration In the EFEM, it is preferable that a connecting pipe for guiding gas that has flowed inside a predetermined device arranged in the transfer chamber is connected to a position in the middle of the return path and upstream of the capture section.

[0026] According to this configuration, In addition to the above basic effects, Since the gas flowing inside the device disposed in the transfer chamber is returned through the return path, it is possible to sufficiently prevent particles generated inside the device from being released into the transfer chamber and adhering to the substrate inside the transfer chamber. Furthermore, since the gas flowing inside the device is introduced into the return path at a position upstream of the capture unit, particles contained in the combined gas containing the gas flowing through the transfer chamber and the gas flowing inside the device are captured in the capture unit. Therefore, particles contained in both gases can be efficiently captured. [Effects of the Invention]

[0027] According to the present invention, particle contamination of a substrate can be reduced in an EFEM of the gas circulating type. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a perspective view schematically showing the appearance of an EFEM according to an embodiment. [Figure 2] FIG. 2 is a plan view schematically showing the EFEM. [Figure 3]FIG. 2 is a side view schematically showing the EFEM, showing the side including the return path. [Figure 4] FIG. 2 is a side view schematically showing the EFEM, showing a side including an individual return path connected to a transport device. [Figure 5] FIG. 2 is a side view schematically showing the EFEM, showing a side surface including an individual return path connected to an aligner. [Figure 6] A rear view of the panel that forms the front wall of the housing. [Figure 7] 7 is a diagram showing a state in which the fan filter unit, the chemical filter, and the cover part are removed from FIG. 6. FIG. [Figure 8] FIG. 2 is a diagram showing a corner support and a charging portion provided thereon. [Figure 9] FIG. 10 is a side view schematically showing an EFEM according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0030] <1. Overall structure of EFEM> The overall configuration of an EFEM (Equipment Front End Module) 100 according to an embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a perspective view schematically showing the appearance of the EFEM 100 according to an embodiment. FIG. 2 is a plan view schematically showing the main parts of the EFEM 100. FIG. 3 is a side view schematically showing the main parts of the EFEM 100.

[0031] EFEM 100 is a module that transfers wafers 9 between a processing device 900 that performs various processes on the wafers 9 and a storage container 90 that stores the wafers 9, and is used by being connected to the processing device 900 (typically, a load lock chamber of the processing device 900) as shown in Fig. 1. As shown in Fig. 3, the storage container (carrier) 90 is a sealed container that includes a main body 91 that stores wafers 9 in multiple stages in a horizontal position, and a lid 92 that closes an opening provided on one side wall of the main body 91, and is also called a FOUP (Front-Opening Unified Pod), cassette, etc.

[0032] As shown in Fig. 1, the EFEM 100 comprises multiple load ports 1 (three in the illustrated example), a main body 2, and a control unit 3. The load ports 1 are arranged at one end of the main body 2, and a processing device 900 is connected to the other end of the main body 2 (i.e., the end opposite to the end to which the load ports 1 are connected). For ease of explanation, the side of the main body 2 to which the load ports 1 are connected will be referred to as the "front" and the side to which the processing device 900 is connected will be referred to as the "rear" below. Furthermore, the horizontal direction perpendicular to the front-to-rear direction will be referred to as the "left-to-right direction."

[0033] (Loading port 1) The load port 1 is a module for connecting the containment vessel 90 to the EFEM 100, and includes a base plate 11, a mounting portion 12, a door portion 13, and the like.

[0034] The base plate 11 is a flat plate-like member arranged in an upright position. A support base 121 protruding in a horizontal position is provided on one main surface of the base plate 11, and the mounting portion 12 is provided thereon. The upper surface of the mounting portion 12 forms a mounting surface on which the storage container 90 is placed. The mounting portion 12 is provided with a mechanism (mounting portion driving mechanism) for moving the mounting portion 12 back and forth on the support base 121, and is driven by this mechanism to move the mounting portion 12 between a close position close to the base plate 11 and a distant position away from the base plate 11. The mounting portion 12 is also provided with a mechanism (gas replacement mechanism) for replacing the atmosphere inside the storage container 90 placed thereon with a predetermined gas (here, nitrogen gas).

[0035] Meanwhile, an opening 111 is formed in the base plate 11 at a position facing the lid portion 92 when the storage container 90 is placed on the placement portion 12. A door portion 13 is provided to close this opening 111. The door portion 13 is provided with a mechanism (lid holding mechanism) that removes (unlatches) the lid portion 92 disposed opposite it from the main body portion 91 and connects and integrates (docks) the lid portion 92 with the door portion 13. The door portion 13 is also provided with a mechanism (door portion drive mechanism) that moves the door portion 13, and is driven by this mechanism to move the door portion 13 between a closed position that blocks the opening 111 and an open position that retracts the door portion 13 below the opening 111 to open it.

[0036] The mounting section 12, the door section 13, and the case 14 in which various drive mechanisms are stored are supported by a base plate 11, and the base plate 11 supporting these sections 12, 13, and 14 is attached so as to cover an opening 2111 formed in the front wall of the housing 21 of the main body section 2.

[0037] The load port 1 operates as follows. First, a storage container 90 containing unprocessed wafers 9 is transported by an external robot such as an OHT, AMHS, or PGV, and placed on the top surface of the mounting part 12 with the lid part 92 facing the door part 13. At this time, the mounting part 12 is located at the separated position, and after the storage container 90 is placed on the mounting part 12, the mounting part drive mechanism moves the mounting part 12 from the separated position to the close position. As a result, the lid part 92 of the storage container 90 placed on the mounting part 12 is positioned close to and facing the door part 13.

[0038] In this state, the lid holding mechanism provided on the door part 13 removes the lid part 92 of the storage container 90 from the main body part 91 and connects it to the door part 13 to form an integrated unit. Next, the door part drive mechanism moves the door part 13 together with the lid part 92 integrated therewith from the closed position to the open position. As a result, the interior of the storage container 90 is brought into communication with the interior of the main body part 2 via the opening 111, and the unprocessed wafers 9 stored in the storage container 90 are removed by a transfer device 22 (described later) disposed inside the main body part 2.

[0039] (Main body 2) The main body 2 includes a housing 21, which is a rectangular parallelepiped frame, interposed between the multiple load ports 1 and the processing device 900. As shown in FIGS. 2 and 3, the housing 21 includes multiple panels 211, multiple corner supports 212, multiple intermediate supports 213, a support plate 214, and the like.

[0040] The panels 211 are generally rectangular, flat-plate-like members that form the peripheral wall surfaces of the housing 21. Here, six panels 211 are combined to form a rectangular parallelepiped. That is, four of the six panels 211 are arranged vertically and form the front, rear, left, or right wall of the housing 21. The remaining two panels 211 are arranged horizontally and form the ceiling or bottom plate of the housing 21. These six panels 211 are precisely attached so as to prevent gaps from forming that allow internal gas to escape, and the space surrounded by the six panels 211 is a generally airtight, closed space. Needless to say, a sealing member or the like may be provided between adjacent panels 211 to increase the airtightness of the internal space.

[0041] A panel 211 constituting the front wall of the housing 21 is provided with a plurality of openings 2111, and a load port 1 (specifically, a base plate 11) is attached so as to airtightly close each opening 2111 (FIG. 1). On the other hand, the panel 211 constituting the rear wall of the housing 21 is connected to, for example, a load lock chamber of the processing apparatus 900. An opening is formed in the panel 211 constituting the rear wall to connect the housing 21 with the load lock chamber, and the opening is configured to be able to be airtightly closed by a gate valve 2112 or the like.

[0042] The corner supports 212 are rod-shaped members for supporting the panel 211, and are provided at the four corners of the housing 21. That is, a corner support 212 is provided at each of the front left corner, front right corner, rear left corner, and rear right corner of the housing 21. Each corner support 212 is cylindrical, and has a hollow portion 2121 formed inside.

[0043] To avoid interference with the transport device 22 (described later) and the like, the front-to-rear width of each corner support 212 is preferably within 100 mm. On the other hand, as will be described later, the hollow portion 2121 of the corner support 212 constitutes the return path T3, and to reduce the flow path resistance, it is preferable to make the left-to-right width of each corner support 212 as large as possible. However, as the left-to-right width increases, the footprint of the device also increases. Taking these factors into consideration, the left-to-right width of each corner support 212 is set to, for example, approximately 200 mm.

[0044] The intermediate support columns 213 are rod-shaped members for supporting the panel 211 that constitutes the front wall, and are provided between adjacent openings 2111 in the panel 211. Here, three openings 2111 are provided corresponding to the three load ports 1, and an intermediate support column 213 is provided between the right opening 2111 and the middle opening 2111, and between the middle opening 2111 and the left opening 2111. Like the corner supports 212, each intermediate support column 213 is cylindrical, and has a hollow portion 2131 formed therein.

[0045] To avoid interference with the transport device 22 and the like, it is preferable that the front-to-rear width of each intermediate support 213 be within 100 mm. On the other hand, as will be described later, the hollow portion 2131 of the intermediate support 213 constitutes the individual return path T4, and to reduce the flow path resistance, it is preferable that the left-to-right width of each intermediate support 213 be as large as possible. However, as the left-to-right width increases, the distance between adjacent load ports 1 also increases. Taking these factors into consideration, the left-to-right width of each intermediate support 213 is set to, for example, approximately 80 mm.

[0046] The support plate 214 is a substantially rectangular, flat member for dividing the space surrounded by the six panels 211 into upper and lower sections, and is installed in a horizontal position near the panels 211 that form the ceiling. Of the space surrounded by the six panels 211, the space above the support plate 214 will be referred to as the "unit installation chamber T1" below. A fan filter unit 41 and the like are disposed in the unit installation chamber T1. Furthermore, of the space surrounded by the six panels 211, the space below the support plate 214 will be referred to as the "transfer chamber T2" below. The transfer chamber T2 forms a space (transfer space) in which wafers 9 are transferred between the storage container 90 placed on the load port 1 and the processing device 900.

[0047] The transfer chamber T2 is equipped with a transfer device 22, an aligner 23, and other components. The transfer device 22 is located approximately in the center of the transfer chamber T2. On the other hand, the aligner 23 is located to the right of the transfer device 22. Here, the panel 211 that forms the right wall of the housing 21 has a U-shaped cross section that includes portions that rise in the left-right direction from the front and rear edges, thereby forming a space within the transfer chamber T2 that protrudes further to the right than the right corner support 212. The aligner 23 is located in this protruding space.

[0048] The transport device 22 will be described with reference to Fig. 4. Fig. 4 is a side view that schematically shows the main part of the EFEM 100, and shows the side including the transport device 22 and an individual return path T4 (described later) connected thereto.

[0049] The transfer device 22 transfers the wafer 9 between the FOUP 90 placed on the load port 1 and the processing device 900, and includes a hand 221, an arm 222, a lifting column 223, a drive mechanism 224, a case 225, and the like.

[0050] The hand 221 is a member that grips the wafer 9 by an appropriate method such as a mechanical clamp method, a vacuum chuck method, or an electrostatic chuck method, and is connected to the tip of the arm 222. The number of hands 221 connected to the tip of the arm 222 may be one or more. The arm 222 has, for example, an articulated structure, and is driven by a drive mechanism 224 to freely rotate within a horizontal plane. The lifting column 223 is a rod-shaped member connected to the arm 222, and is raised and lowered by the drive of the drive mechanism 224. The drive mechanism 224 is a mechanism for driving the arm 222, the lifting column 223, etc., and is configured to include a motor, a ball screw mechanism, etc.

[0051] The case 225 is fixed inside the transfer chamber T2 and houses the drive mechanism 224 inside. An opening 2251 is provided in the top surface of the case 225, through which the lifting column 223 is inserted. The lifting column 223 is connected to the drive mechanism 224 at its lower end located inside the case 225, and is connected to the arm 222 at its upper end protruding above the case 225. The inner diameter of the opening 2251 is slightly larger than the outer diameter of the lifting column 223 so that the lifting and lowering of the lifting column 223 is not hindered, and a small gap is formed between the two.

[0052] A through hole 2252 is provided in the side wall of the case 225, and this through hole 2252 is connected to a closed duct 216, which will be described later, via a connecting pipe 226. A fan 227 is provided in the case 225 to send the gas inside the case 225 to the connecting pipe 226 via the through hole 2252. When the fan 227 is driven, the gas inside the case 225 is discharged to the connecting pipe 226 together with particles generated therein.

[0053] The transfer device 22 performs a predetermined transfer operation under the control of the control unit 3. That is, by combining operations such as raising and lowering the lifting column 223, turning the arm 222, and gripping and releasing the wafer 9 with the hand 221, the transfer device 22, for example, removes an unprocessed wafer 9 from the FOUP 90 placed on the load port 1 and carries it into the processing device 900, and also carries a processed wafer 9 from the processing device 900 and stores it in the FOUP 90 placed on the load port 1.

[0054] The aligner 23 will be described with reference to Fig. 5. Fig. 5 is a side view that schematically shows the main part of the EFEM 100, and shows the side surface including the aligner 23 and an individual return path T4 (described later) connected thereto.

[0055] The wafers 9 contained in the storage container 90 may be slightly misaligned during the time from when the storage container 90 is transported by an external robot to when it is placed on the placement unit 12 of the load port 1. The aligner 23 is a device that detects this misalignment and performs position correction (alignment) to correct the misalignment, and is configured to include a table 231, a rotating column 232, a drive mechanism 233, a detection unit 234, a case 235, and the like.

[0056] The table 231 is a member on which the wafer 9 to be aligned is placed. The rotating column 232 is a rod-shaped member connected to the center of the underside of the table 231, and rotates around its central axis when driven by a driving mechanism 233. The driving mechanism 233 is a mechanism for driving the rotating column 232 and other components, and is configured to include a motor, pulleys, and the like. The detection unit 234 detects how much the wafer 9 placed on the rotating table 231 is displaced from its intended position based on the peripheral position of the wafer 9 and other factors.

[0057] The case 235 is supported by a support table (not shown) provided in the transfer chamber T2, and houses the drive mechanism 233 inside. An opening 2351 is provided in the upper surface of the case 235, and the rotating pillar 232 is inserted through this opening. The rotating pillar 232 is connected to the drive mechanism 233 at its lower end located inside the case 235, and is connected to the table 231 at its upper end protruding above the case 235. The inner diameter of the opening 2351 is slightly larger than the outer diameter of the rotating pillar 232 so that the rotation of the rotating pillar 232 is not hindered, and a small gap is formed between them.

[0058] A through hole 2352 is provided in the side wall of the case 235, and this through hole 2352 is connected to a closed duct 216, which will be described later, via a connecting pipe 236. A fan 237 is provided in the case 235 to send gas inside the case 235 to the connecting pipe 236 via the through hole 2352. When the fan 237 is driven, the gas inside the case 235 is discharged to the connecting pipe 236 together with particles generated therein.

[0059] The aligner 23 performs a predetermined alignment operation under the control of the control unit 3. That is, when the transfer device 22 places the wafer 9 taken out of the storage container 90 on the table 231 of the aligner 23, the aligner 23 detects the peripheral position of the wafer 9 placed on the table 231 while rotating the table 231 using the detection unit 234, and determines how much the wafer 9 is deviated from its intended position. The determined amount of positional deviation is notified to the control unit 3. The control unit 3 corrects the receiving position of the hand 221 when the transfer device 22 transfers the wafer 9 placed on the table 231 in accordance with the amount of positional deviation. This ensures that the positional relationship between the wafer 9 and the hand 221 is as intended. That is, the wafer 9 is transferred from the aligner 23 in a properly aligned state after the positional deviation has been corrected, and is then transferred into the processing device 900.

[0060] (Control Unit 3) Referring again to Figure 1, the control unit 3 controls the operation of each unit included in the EFEM 100. Specifically, the control unit 3 performs various controls related to the operation of the load port 1, various controls related to the operation of the transfer device 22, various controls related to the operation of the aligner 23, various controls related to the nitrogen circulation (described later) in the housing 21, and the like.

[0061] The hardware configuration of the control unit 3 is similar to that of a general computer. That is, the control unit 3 includes a CPU that performs various arithmetic processing, a ROM that is a read-only memory that stores necessary programs, a RAM that is a read / write memory that stores various information, a magnetic disk that stores control software and data, and various interfaces. The CPU of the control unit 3 executes the programs stored in the memory, causing the EFEM 100 to perform predetermined operations.

[0062] <2. Circulation route> When the EFEM 100 is in operation, the internal space of the housing 21 is filled with a predetermined gas (nitrogen gas in this embodiment), and the predetermined gas is configured to circulate. The circulation path along which the gas circulates will be described with reference to FIGS. 6 and 7 in addition to FIGS. 2 to 5. FIG. 6 is a rear view of a panel 211 that constitutes the front wall of the housing 21. FIG. 7 is a view showing a state in which the fan filter unit 41, chemical filter 42, and cover part 202 have been removed from FIG. 6.

[0063] As shown in Figures 3 to 5, the circulation path is composed of a unit installation chamber T1 in which a fan filter unit 41 and the like are arranged, a transfer chamber T2 which forms a transfer space, a return path T3 (Figure 3) which returns nitrogen gas that has flowed from one side of the transfer chamber T2 to the other, and an individual return path T4 (Figures 4 and 5) which returns gas that has flowed inside each of the transfer device 22 and aligner 23 arranged in the transfer chamber T2.

[0064] (Unit installation room T1, transport room T2) As described above, the unit installation chamber T1 is the space above the support plate 214 among the spaces surrounded by the six panels 211. The transfer chamber T2 is the space below the support plate 214 among the spaces surrounded by the six panels 211. In other words, the unit installation chamber T1 and the transfer chamber T2 are separated by the support plate 214. An opening 2141 is provided in this support plate 214 (FIG. 7), and the unit installation chamber T1 and the transfer chamber T2 communicate with each other via this opening 2141.

[0065] A fan filter unit 41 and a chemical filter 42 are provided in the unit installation room T1.

[0066] The fan filter unit (FFU) 41 is a unit for forming a laminar flow flowing downward in the transfer chamber T2, and is supported by a support plate 214 and housed in the unit installation chamber T1. As shown in FIG. 3 and other figures, the fan filter unit 41 includes a fan 411 and a filter 412. The fan 411 draws in gas from above and sends it out downward. The filter 412 is formed of, for example, a ULPA filter, and captures and removes particles contained in the gas sent out by the fan 411.

[0067] When the fan 411 of the fan filter unit 41 is operated, the nitrogen gas in the unit installation chamber T1 is purified by the filter 412 and sent to the transfer chamber T2 through the opening 2141 provided in the support plate 214. This forms a laminar flow (downflow) flowing downward in the transfer chamber T2.

[0068] The chemical filter 42 is a filter that removes active gases, molecular contaminants, etc., and is disposed inside the unit installation chamber T1, upstream of the fan filter unit 41. Therefore, the nitrogen gas that flows into the unit installation chamber T1 has active gases, molecular contaminants, etc. removed as it passes through the chemical filter 42, and then flows into the fan filter unit 41.

[0069] (Return path T3) The return path T3 is provided in each hollow portion 2121 of two corner supports 212 arranged on the front side (that is, the corner supports arranged at the left front corner and the right front corner, hereinafter also referred to as "front corner supports").

[0070] As shown in FIG. 3, an opening 2122 communicating with the hollow portion 2121 is formed near the lower end of the rear surface of each front corner support 212, and an open duct 215 is provided to close this opening 2122. As shown in FIGS. 3 and 6, the open duct 215 extends downward along the front corner support 212 and reaches an open end 2151. The open end 2151 opens downward at a position below the opening 2122, connecting the interior of the open duct 215 to the transfer chamber T2. In other words, the return path T3 formed by the hollow portion 2121 of each front corner support 212 communicates with the transfer chamber T2 via the opening 2122 and the open duct 215.

[0071] 3, 7, and the like, each front corner support 212 is connected to a beam member 217 at its upper end. A hollow portion is formed inside the beam member 217, and the hollow portion 2121 of each front corner support 212 is connected to this hollow portion. The hollow portion of the beam member 217 is connected to the unit installation chamber T1 via an opening 2142 (FIG. 7) provided in the support plate 214. In other words, the return path T3 formed by the hollow portion 2121 of each front corner support 212 is connected to the unit installation chamber T1 via the hollow portion of the beam member 217 and the opening 2142 of the support plate 214.

[0072] A first fan 43 is disposed in the return path T3. As shown in FIG. 3, the first fan 43 is disposed inside the open duct 215, and draws in gas from below and sends it out upward, forming an airflow that flows upward through the return path T3. That is, when the first fan 43 is operated, nitrogen gas in the transfer chamber T2 (i.e., nitrogen gas that flows downward through the transfer chamber T2 and reaches the vicinity of the bottom of the transfer chamber T2) is drawn in through the open duct 215 and sent upward into the return path T3. The nitrogen gas that flows upward through the return path T3 flows into the unit installation chamber T1. That is, the nitrogen gas that flows downward through the transfer chamber T2 is returned to the unit installation chamber T1 through the return path T3. The nitrogen gas that has returned to the unit installation chamber T1 is purified by the filters 42, 412 and then sent out again to the transfer chamber T2.

[0073] (Individual return path T4) The individual return paths T4 are provided in the hollow portions 2131 of the two intermediate supports 213.

[0074] 4 and 5, an opening 2132 that communicates with the hollow portion 2313 is formed in a position near the lower end on the rear surface of each intermediate support 213, and a closed duct 216 is provided to close this opening 2132. As shown in Figures 4, 5, 6, etc., the closed duct 216 extends downward along the intermediate support 213 and reaches a closed end 2161 that is closed with respect to the transfer chamber T2.

[0075] 2 and 4, a connecting pipe 226 extending from a case 225 of the transport device 22 is connected to the closed duct 216 provided in the intermediate support 213 arranged on the left side. Also, as shown in FIGS. 2 and 5, a connecting pipe 236 extending from a case 235 of the aligner 23 is connected to the closed duct 216 provided in the intermediate support 213 arranged on the right side. In other words, the individual return path T4 formed by the hollow portion 2131 of each intermediate support 213 communicates with the cases 225 and 235 of the devices 22 and 23 arranged in the transport chamber T2 via the opening 2132, the closed duct 216, and the connecting pipes 226 and 236.

[0076] 4, 5, 7, etc., each intermediate support 213 is connected to a beam member 217 at its upper end. A hollow portion is formed inside the beam member 217, and the hollow portion 2131 of each intermediate support 213 is in communication with this hollow portion. As described above, the hollow portion of the beam member 217 is in communication with the unit installation chamber T1 via the opening 2142 (FIG. 7) provided in the support plate 214. In other words, the individual return path T4 formed by the hollow portion 2131 of each intermediate support 213 is in communication with the unit installation chamber T1 via the hollow portion of the beam member 217 and the opening 2142 of the support plate 214.

[0077] A second fan 44 is disposed in the individual return path T4. As shown in FIGS. 4 and 5 , the second fan 44 is disposed inside the closed duct 216 and draws in gas from below and sends it out upward, forming an airflow that flows upward through the individual return path T4. That is, when the second fan 44 is operated, nitrogen gas discharged from the cases 225, 235 of the devices 22, 23 disposed in the transfer chamber T2 is drawn into the closed duct 216 via the connecting pipes 226, 236 and then discharged upward through the individual return path T4. The nitrogen gas flowing upward through the individual return path T4 flows into the unit installation chamber T1. That is, the nitrogen gas that has flowed inside the devices 22, 23 is returned to the unit installation chamber T1 through the individual return path T4. The nitrogen gas returned to the unit installation chamber T1 is purified by the filters 42, 412 and then discharged again to the transfer chamber T2.

[0078] As described above, a circulation path including the unit installation chamber T1, the transfer chamber T2, the return path T3, and the individual return path T4 is formed inside the housing 21 of the EFEM 100. This circulation path is provided with a gas supply unit 45 that supplies nitrogen gas thereto, and a gas exhaust unit 46 that exhausts nitrogen gas from the circulation path.

[0079] 3, the gas supply unit 45 includes a supply pipe 451 and a supply valve 452 provided therein. One end of the supply pipe 451 is connected to the side wall of the unit installation chamber T1, and the other end is connected to a nitrogen gas supply source. The supply valve 452 includes, for example, a mass flow controller whose opening is freely adjustable, and changes the amount of nitrogen gas flowing through the supply pipe 451 (i.e., the supply amount of nitrogen gas) in response to an instruction from the control unit 3.

[0080] The control unit 3 monitors the oxygen concentration, moisture concentration, etc. of the nitrogen gas circulated through the circulation path, and controls the opening degree of the supply valve 452 so that the concentration is maintained at or below a predetermined value. Specifically, for example, when the oxygen concentration exceeds a predetermined value, the control unit 3 controls the supply valve 452 to increase the flow rate of the nitrogen gas supplied to the circulation path, thereby decreasing the oxygen concentration.

[0081] 3, the gas exhaust unit 46 includes an exhaust pipe 461 and an exhaust valve 462 provided therein. One end of the exhaust pipe 461 is connected to the vicinity of the lower end of the side wall of the transfer chamber T2, and the other end is connected to an exhaust line. The exhaust valve 462 includes, for example, a mass flow controller whose opening is freely adjustable, and changes the amount of nitrogen gas flowing through the exhaust pipe 461 (i.e., the amount of nitrogen gas exhausted) in response to an instruction from the control unit 3.

[0082] The control unit 3 monitors the pressure at at least one predetermined position in the circulation path and controls the aperture of the exhaust valve 462 and the like so that the pressure at each position is maintained within a predetermined appropriate range. Specifically, for example, if the pressure value exceeds the appropriate range, the aperture of the exhaust valve 462 is increased, and if the pressure value falls below the appropriate range, the aperture of the exhaust valve 462 is decreased. When the control unit 3 is performing appropriate control, the pressure in the transfer chamber T2 is slightly higher than the pressure in the external space of the housing 21. In other words, the appropriate range of the pressure value in the transfer chamber T2 is set to a value slightly higher than the pressure in the external space of the housing 21. This prevents nitrogen gas from leaking from the transfer chamber T2 to the external space of the housing 21 while preventing outside air from entering the transfer chamber T2 from the external space of the housing 21.

[0083] <3. Capture Section 5> As described above, a circulation path including the unit installation chamber T1, the transfer chamber T2, the return path T3, and the individual return path T4 is formed in the internal space of the housing 21 of the EFEM 100, and a circulation of nitrogen gas is formed, which is sent out from the unit installation chamber T1, flows downward through the transfer chamber T2, and is returned again to the unit installation chamber T1 via the return path T3. In addition, a circulation of nitrogen gas is formed, which flows inside the devices 22 and 23 arranged in the transfer chamber T2, and is returned again to the unit installation chamber T1 via the individual return path T4.

[0084] In this circulation path, the cross-sectional areas of the return path T3 and the individual return path T4 are smaller than the cross-sectional area of ​​the opening 2141 that connects the unit installation chamber T1 and the transfer chamber T2, and the flow resistance of the former is greater than the flow resistance of the latter. Therefore, the flow rate of nitrogen gas delivered through the opening 2141 is greater than the flow rate of nitrogen gas returned from the return path T3 and the individual return path T4, which may cause a decrease in pressure in the unit installation chamber T1. If the pressure in the unit installation chamber T1 becomes lower than the pressure in the external space of the housing 21, there is a risk of outside air entering the unit installation chamber T1 from the external space. However, in this EFEM 100, the first fan 43 and the second fan 44 actively deliver nitrogen gas to the return path T3 or the individual return path T4, thereby suppressing a decrease in pressure in the unit installation chamber T1 and preventing the intrusion of outside air.

[0085] On the other hand, when the first fan 43 sends nitrogen gas to the return path T3, the pressure in the return path T3 increases, and a pressure difference is formed on both sides of the partition wall separating the return path T3 from the transfer chamber T2 (i.e., inside and outside the front corner support 212) such that the return path T3 side is at a higher pressure. Similarly, when the second fan 44 sends nitrogen gas to the return path T3, the pressure in the individual return path T4 increases, and a pressure difference is formed on both sides of the partition wall separating the individual return path T4 from the transfer chamber T2 (i.e., inside and outside the middle support 213) such that the individual return path T4 side is at a higher pressure.

[0086] If a pressure difference is formed between the partition wall separating the return path T3 and the transfer chamber T2, such that the pressure on the return path T3 side is higher, a small amount of gas may leak from the return path T3 to the transfer chamber T2 through a small gap in the partition wall. The gas flowing through the return path T3 may contain particles. The downflow in the transfer chamber T2 also serves to sweep particles floating in the transfer chamber T2 downward, and the nitrogen gas returning through the return path T3 may contain particles that were floating in the transfer chamber T2. If gas containing such particles leaks into the transfer chamber T2, the cleanliness of the transfer chamber T2 may be reduced.

[0087] Similarly, if a pressure difference occurs between the partition wall separating the individual return path T4 and the transfer chamber T2, causing the individual return path T4 to be at a higher pressure, a small amount of gas may leak from the individual return path T4 into the transfer chamber T2 through a small gap in the partition wall. The gas flowing through the individual return path T4 may also contain particles. Specifically, when the transfer device 22 or the aligner 23 is driven, particles generated by the drive mechanisms 224, 233, etc. and floating within the cases 225, 235 are sent by the fans 227, 237 along with the nitrogen gas in the cases 225, 235 through the connecting pipes 226, 236 and flow into the individual return path T4 connected thereto. Therefore, the gas flowing through the individual return path T4 may contain particles generated by the drive mechanisms 224, 233, etc. of the devices 22, 23. If gas containing such particles leaks into the transfer chamber T2, the cleanliness of the transfer chamber T2 may be reduced.

[0088] Therefore, in this EFEM 100, a trapping unit 5 that traps particles is provided in each of the return path T3 and the individual return path T4. This trapping unit 5 will be described with reference to Fig. 8 in addition to Fig. 6 and Fig. 7. Fig. 8 is a diagram showing the front corner support 212 and the charging unit 51 provided thereon.

[0089] The trapping unit 5 electrically traps particles contained in the gas, and includes a charging unit 51, a voltage applying unit 52 that applies a voltage to the charging unit 51, and a conductor 53 that connects these.

[0090] Charging unit 51 is a thin member, one of whose main surfaces constitutes charging surface 511. When voltage application unit 52 applies a predetermined voltage to charging unit 51 through conductor 53, charging surface 511 of charging unit 51 becomes charged. When charging surface 511 becomes charged, particles around it are attracted by electrostatic force and adhere (adsorb) to charging surface 511, where they are captured.

[0091] As described above, each of the front corner pillars 212 and each of the intermediate pillars 213 is a cylindrical pillar with a rectangular cross section, and the hollow portions 2121, 2131 formed therein constitute the return path T3 or the individual return path T4. The charging portion 51 is provided on the inner wall surface of each of the front corner pillars 212 and each of the intermediate pillars 213.

[0092] Here, the configuration of each support (target support) 212, 213 to which the charging unit 51 is attached will be specifically described. The target support 212, 213 includes a main body 201 having a U-shaped cross section with an opening on the rear side, and a cover 202 attached to the main body 201 so as to airtightly close an opening 2011 on the rear side of the main body 201. When the cover 202 is removed from the main body 201, the opening 2011 on the rear side of the main body 201 is exposed, and the inner wall surfaces of the main body 201 (i.e., the front inner wall surface 201a and the left and right inner wall surfaces 201b) become accessible.

[0093] The charging unit 51 is provided on an inner wall surface that is accessible through the opening 2011 when the cover unit 202 is removed. Specifically, the charging unit 51 is attached to the front inner wall surface 201a with the charging surface 511 facing rearward. The charging unit 51 may be attached to the inner wall surface 201a in any manner. For example, a plurality of stud bolts 203 may be provided upright on the inner wall surface 201a, and the stud bolts 203 may be inserted into respective through-holes in the charging unit 51 and then nuts 204 may be fastened thereto, thereby attaching the charging unit 51 to the inner wall surface 201a.

[0094] The conducting wire 53 extending from the charging unit 51 passes through the open duct 215 (or the closed duct 216), is pulled out together with the wiring extending from the first fan 43 (or the second fan 44) housed therein, and is connected to the voltage application unit 52.

[0095] The charging portion 51 is preferably shaped and sized to cover substantially the entire inner wall surface 201a to which it is attached. That is, the left-to-right width of the charging portion 51 is preferably substantially the same as the left-to-right width of the inner wall surface 201a, and the up-to-down dimension of the charging portion 51 is preferably substantially the same as the up-to-down dimension of the inner wall surface 201a. Alternatively, substantially the entire inner wall surface 201a may be covered by arranging a plurality of charging portions 51 that are smaller than the inner wall surface 201a.

[0096] When the voltage application unit 52 applies a predetermined voltage to the charging unit 51 provided on the inner wall surface 201a of the target columns 212 and 213, the charged surface 511 is charged. Then, particles around the charged surface 511, i.e., particles contained in the nitrogen gas flowing through the return path T3 or the individual return path T4 formed by the hollow portions 2121 and 2131 of the target columns 212 and 213, are attracted by electrostatic force and adsorbed to and captured by the charged surface 511. This removes particles contained in the nitrogen gas flowing through the return path T3 or the individual return path T4. Therefore, even if gas leaks from the return path T3 or the individual return path T4 toward the transfer chamber T2, which is at a lower pressure than the return path T3 or the individual return path T4, the amount of particles in the transfer chamber T2 is unlikely to increase. In other words, the cleanliness of the transfer chamber T2 is unlikely to decrease.

[0097] The captured particles accumulate on the charged surface 511. Therefore, it is preferable to stop the application of voltage to the charged part 51 at an appropriate timing, such as during maintenance of the EFEM 100, and perform an operation (wet cleaning) to wipe off and collect the particles adhering to the charged surface 511. Here, the charged part 51 is provided in a position that is accessible through an opening 2011 that is exposed by removing the cover part 202. Therefore, an operator can remove the cover part 202 and wipe the charged surface 511 that appears at the back of the opening 2011 with a cloth or the like, thereby collecting the particles adhering to the charged surface 511.

[0098] <4. Effects> The EFEM 100 according to the embodiment described above includes a circulation path including a transfer chamber T2 that forms a transfer space in which a wafer 9 is transferred, and a return path T3 that returns gas that has flowed from one side of the transfer chamber T2 to the other. In this EFEM 100, the return path T3 and the transfer chamber T2 are disposed on either side of a partition wall, and when gas is circulating through the circulation path, a pressure difference is formed on both sides of the partition wall such that the pressure on the return path T3 side is higher. The EFEM 100 also includes a trapping unit 5 that is disposed in the return path T3 and electrically traps particles contained in the gas flowing therethrough.

[0099] With this configuration, particles contained in the gas flowing through the return path T3 are electrically captured, so even if gas leaks from the return path T3 toward the transfer chamber T2, which has a lower pressure than the return path T3, the amount of particles in the transfer chamber T2 is unlikely to increase, and therefore adhesion of particles to the wafer 9 in the transfer chamber T2 can be sufficiently suppressed.

[0100] Furthermore, if particles contained in the gas flowing through the return path T3 were to be captured using, for example, a gas-permeable filter (physical particle filter), a significant increase in the flow path resistance of the return path T3 would be unavoidable, and the fan (first fan) 43 that sends the gas to the return path T3 would have to be enlarged. Here, the capture unit 5 provided in the return path T3 captures particles electrically, so particles can be captured without significantly increasing the flow path resistance of the return path T3. This avoids the need to enlarge the first fan 43.

[0101] Furthermore, in the above configuration, since the trapping section 5 is provided in the return path T3, particles contained in the gas flowing through the circulation path are dispersed and captured by the filter 412 of the fan filter unit 41 and the trapping section 5. Therefore, the amount of particles accumulated on the filter 412 is reduced compared to when the trapping section 5 is not provided. This extends the life of the fan filter unit 41 and increases the replacement cycle.

[0102] In the EFEM 100 according to the above embodiment, the trapping unit 5 traps particles contained in the gas by causing them to adhere to the charged surface 511 by electrostatic force.

[0103] This configuration makes it possible to sufficiently capture particles contained in the gas flowing through return path T3 with a simple configuration, and maintenance is also easy. For example, if particles are captured with a filter, the filter must be replaced periodically, but if particles are captured by adhering them to charged surface 511, the particles can be collected by a relatively simple operation such as releasing the charge on charged surface 511 and wiping it.

[0104] Furthermore, the EFEM 100 according to the above embodiment includes a housing 21 including a plurality of panels 211 and pillars 212, 213 that support the plurality of panels 211, and the front corner pillar 212 is hollow, the return path T3 is provided in the hollow portion 2121 of the front corner pillar 212, and the capture portion 5 is provided on the inner wall surface 201a of the front corner pillar 212.

[0105] With this configuration, the return path T3 is provided in the hollow portion 2121 of the front corner support 212, thereby reducing the footprint of the device. On the other hand, since the return path T3 is limited to the narrow space of the hollow portion 2121 of the front corner support 212, it is inevitable that the flow path resistance of the return path T3 will be relatively large. However, in this case, the capture unit 5 provided in the return path T3 captures particles electrically, and therefore, as described above, the increase in flow path resistance due to the provision of the capture unit 5 is sufficiently small. Therefore, an increase in the size of the first fan 43, etc., can be avoided.

[0106] Furthermore, in the EFEM 100 according to the above embodiment, the front corner support 212 includes the opening 2011 that allows access to the capture part 5, and the cover part 202 that can freely close and open the opening 2011.

[0107] According to this configuration, when the opening 2011 is in an open state, the trapping part 5 can be accessed through the opening 2011. Therefore, maintenance of the trapping part 5 can be performed without difficulty.

[0108] Furthermore, in the EFEM 100 according to the above embodiment, the circulation path includes an individual return path T4 that returns gas that has flowed inside a specific device 22, 23 arranged in the transfer chamber T2, and the individual return path T4 and the transfer chamber T2 are arranged on either side of a partition wall, and when gas is circulating through the circulation path, a pressure difference is formed on both sides of the partition wall such that the side of the individual return path T4 is higher than the other, and a capture section 5 is provided in each of the return path T3 and the individual return path T4.

[0109] According to this configuration, the gas flowing inside the devices 22, 23 arranged in the transfer chamber T2 is returned through the individual return path T4, which sufficiently prevents particles generated inside the devices 22, 23 from being released into the transfer chamber T2 and adhering to the wafer 9 inside the transfer chamber T2. Furthermore, since particles contained in the gas flowing through the individual return path T4 are electrically captured, even if gas leaks from the individual return path T4 toward the transfer chamber T2, which is at a lower pressure than the individual return path T4, the amount of particles in the transfer chamber T2 is unlikely to increase.

[0110] <5. Other embodiments> In the above embodiment, the connecting pipes 226, 236 that guide the gas that has flowed inside the conveying device 22 or the aligner 23 are connected to the intermediate support 213. However, as in the EFEM 100a shown in FIG. 9, the connecting pipes 226, 236 may be connected to a position in the return path T3, upstream of the capture section 5 (specifically, for example, a position between the opening end 2151 of the open duct 215 provided in the front corner support 212 and the first fan 43).

[0111] According to this configuration, the gas flowing inside the transfer device 22 and the aligner 23 is introduced into the return path T3 at a position on the return path T3 that is upstream of the capture unit 5, and is returned through the return path T3. This effectively prevents particles generated inside the devices 22 and 23 from being released into the transfer chamber T2 and adhering to the wafer 9 inside the transfer chamber T2. Furthermore, since the gas flowing inside each device 22 and 23 is introduced into the return path T3 at a position upstream of the capture unit 5, particles contained in the collective gas that includes the gas that has flowed through the transfer chamber T2 and the gas that has flowed inside the devices 22 and 23 are captured in the capture unit 5. This allows particles contained in both gases to be efficiently captured.

[0112] In the example of Figure 9, both the connecting pipe 226 extending from the case 225 of the conveying device 22 and the connecting pipe 236 extending from the case 235 of the aligner 23 are connected to the same front corner support 212, but the connecting pipe 226 on the conveying device 22 side may be connected to, for example, the left front corner support 212, and the connecting pipe 236 on the aligner 23 side may be connected to, for example, the right front corner support 212.

[0113] In the above embodiment, the return path T3 is configured by the hollow portions 2121 of the front corner struts 212, but the configuration of the return path T3 is not limited to this. Also, the individual return path T4 is configured by the hollow portions 2131 of the middle struts 213, but the configuration of the individual return path T4 is not limited to this.

[0114] For example, the hollow portion 2121 of the corner support 212 arranged on the rear side or the hollow portion 2131 of the intermediate support 213 may form the return path T3. Alternatively, the hollow portion 2121 of the corner support 212 may form the individual return path T4.

[0115] For example, a partition panel may be provided near a panel 211 that forms a peripheral wall (front wall, rear wall, left wall, or right wall) of the housing 21, extending parallel to the panel 211 while leaving a gap between the panel 211 and the partition panel, and the space between the panel 211 and the partition panel may form a return path T3 or (and) an individual return path T4.

[0116] In the above embodiment, when gas is circulating through the circulation path, a pressure difference is formed on both sides of the partition wall separating the return path T3 (or the individual return path T4) from the transfer chamber T2, such that the pressure on the return path T3 (or the individual return path T4) side is higher. This pressure difference is preferably 10 (Pa) or more and 100 (Pa) or less, and particularly preferably 30 (Pa) or more and 50 (Pa) or less. That is, the present invention functions particularly effectively when such a pressure difference is formed between the return path T3 (or the individual return path T4) and the transfer chamber T2.

[0117] In the above embodiment, the individual return path T4 is not an essential component and may be omitted. For example, the connecting pipes 226, 236 extending from the cases 225, 235 of the transport device 22 and / or the aligner 23 may be connected to an exhaust line so that the gas inside the cases 225, 235 is exhausted without being circulated. If the individual return path T4 is not provided, the hollow portion 2131 of the intermediate support 213 may constitute the return path T3.

[0118] In the above embodiment, trapping unit 5 traps particles contained in the gas by adhering them to charged surface 511 using electrostatic force, but the configuration of trapping unit 5 is not limited to this. That is, trapping unit 5 may be any device that electrically traps particles contained in the gas. For example, trapping unit 5 may be a device that electrically traps particles by forming an electromagnetic field using electrodes disposed midway through the gas flow path. Alternatively, trapping unit 5 may be a device that electrically traps particles contained in the gas by generating plasma.

[0119] In the above embodiment, the charging portion 51 of the trapping portion 5 may be charged in any manner, for example, by bringing a terminal serving as a charge supply source into contact with the charging portion to supply and accumulate charge to the charging portion. Alternatively, the charging portion may be charged by a corona discharge method.

[0120] In the above embodiment, the first fan 43 and the second fan 44 are not essential components, and one or both of them may be omitted.

[0121] In the above embodiment, the supply pipe 451 of the gas supply unit 45 is connected to the unit installation chamber T1 to supply nitrogen gas to the unit installation chamber T1. However, the location of the nitrogen gas supply is not limited thereto, and nitrogen gas may be supplied from any location along the circulation path. For example, the supply pipe 451 of the gas supply unit 45 may be connected to the return path T3 to supply nitrogen gas to the return path T3. When nitrogen gas is supplied to the return path T3, the pressure in the return path T3 increases due to the supply of nitrogen gas. Therefore, even if the first fan filter unit 3 is not provided, a pressure difference may be formed on both sides of the partition wall separating the return path T3 and the transfer chamber T2 (i.e., inside and outside the front corner support 212) such that the pressure on the return path T3 side becomes higher when nitrogen gas circulates through the circulation path. This may ultimately result in gas leakage from the return path T3 to the transfer chamber T2. However, as described above, by providing the trapping unit 5 in the return path T3, even if such a gas leak occurs, the amount of particles in the transfer chamber T2 is unlikely to increase, that is, the cleanliness of the transfer chamber T2 is unlikely to decrease.

[0122] In the above embodiment, the exhaust pipe 461 of the gas exhaust section 46 is connected to the transfer chamber T2, and nitrogen gas is exhausted from the transfer chamber T2, but the position from which the nitrogen gas is exhausted is not limited to this, and the nitrogen gas may be exhausted from any position in the circulation path.

[0123] In the above embodiment, when the hand 221 grips the wafer 9 using a so-called mechanical clamping method in which the clamping member is driven by a driving mechanism to hold and release the wafer 9, a configuration may be provided in which particles generated when the clamping member is driven are sucked in and introduced into the connecting pipe 226.

[0124] In the above embodiment, a filter for capturing particles may be provided near the fan 227 provided in the case 225 of the transport device 22. Similarly, a filter for capturing particles may be provided near the fan 237 provided in the case 235 of the aligner 23.

[0125] In the above embodiment, the gas circulating through the circulation path is nitrogen gas, but the circulating gas is not limited to nitrogen gas and may be other gases (for example, various inert gases such as argon gas, dry air, etc.).

[0126] In the above embodiment, the object to be transferred is not limited to the wafer 9, but may be a glass substrate or the like.

[0127] In the above embodiment, the present invention is applied to the EFEM 100. However, the present invention is not limited to the EFEM 100. For example, the present invention can be applied to various devices that form a transfer space inside to which objects requiring a clean environment are transferred. Specifically, the present invention can be applied to a sorter device that replaces and rearranges objects stored in a storage container (e.g., wafers 9 stored in a storage container 90). Furthermore, the present invention can be applied to a transfer unit that forms a transfer space in which substrates are transferred between processing units in a substrate processing apparatus that includes multiple processing units. The present invention can also be applied to other devices (e.g., a storage device) that form a storage space inside to store objects requiring a clean environment, or devices (e.g., various substrate processing apparatuses) that form a processing space inside to process objects requiring a clean environment.

[0128] Other configurations can also be modified in various ways without departing from the spirit of the present invention. [Explanation of symbols]

[0129] 100 EFEM 1 Loading port 2 Main body 21. Cabinet Panel 211 212 Corner Support 213 Intermediate Support 201 Main body 202 Cover 22 Conveyor equipment 225 cases 226 Connecting Pipe 23 Alaina 235 cases 236 Connecting Pipe 3. Control Unit 41 Fan filter unit 42 Chemical Filter 43 First Fan 44 Second Fan 45 Gas supply section 46 Gas exhaust section 5. Capture Section 51 Charging section 511 Charged Surface 52 Voltage application section 53 Conductor T1 unit installation room T2 Transport Room T3 return path T4 Individual return path

Claims

1. a circulation path including a transfer chamber that forms a transfer space in which the substrate is transferred and a return path that returns a gas that has flowed from one side of the transfer chamber to the other side; the return path and the transfer chamber are provided on either side of a partition wall, and when gas is circulating through the circulation path, a pressure difference is generated between both sides of the partition wall such that a pressure on the return path side is higher, An EFEM including a trapping unit provided in the return path and configured to electrically trap particles contained in the gas flowing therethrough, a transfer device that transfers substrates within the transfer chamber; a fan filter unit that forms a downflow in the transfer chamber, The capture section is disposed upstream of the fan filter unit. EFEM, characterized in that

2. 2. The EFEM of claim 1, the fan filter unit and the return path each include a fan; The capture section is disposed between the fan of the fan filter unit and the fan of the return path, and captures particles contained in the gas sent from the fan of the return path to the return path by attaching them to a charged surface by electrostatic force. EFEM, characterized in that

3. 3. The EFEM according to claim 1 or 2, a housing including a plurality of panels and a support column supporting the plurality of panels; The support is hollow, the return path is provided in a hollow portion of the support, The capture portion is provided on the inner wall surface of the support. EFEM, characterized in that

4. a circulation path including a transfer chamber that forms a transfer space in which the substrate is transferred and a return path that returns a gas that has flowed from one side of the transfer chamber to the other side; the return path and the transfer chamber are provided on either side of a partition wall, and when gas is circulating through the circulation path, a pressure difference is generated between both sides of the partition wall such that a pressure on the return path side is higher, An EFEM including a trapping unit provided in the return path and configured to electrically trap particles contained in the gas flowing therethrough, a housing including a plurality of panels and a support column supporting the plurality of panels; The support is hollow, the return path is provided in a hollow portion of the support, The capture portion is provided on an inner wall surface of the support, The support pillar is an opening allowing access to the trap; a cover portion that can freely close and open the opening; An EFEM comprising:

5. a circulation path including a transfer chamber that forms a transfer space in which the substrate is transferred and a return path that returns a gas that has flowed from one side of the transfer chamber to the other side; the return path and the transfer chamber are provided on either side of a partition wall, and when gas is circulating through the circulation path, a pressure difference is generated between both sides of the partition wall such that a pressure on the return path side is higher, An EFEM including a trapping unit provided in the return path and configured to electrically trap particles contained in the gas flowing therethrough, the circulation path includes an individual return path that returns the gas that has flowed inside a predetermined device disposed in the transfer chamber, the individual return path and the transfer chamber are provided on either side of a partition wall, and when gas is circulating through the circulation path, a pressure difference is generated between both sides of the partition wall such that a pressure is higher on the side of the individual return path, The capture portion is provided in each of the return path and the individual return path. EFEM, characterized in that

6. a circulation path including a transfer chamber that forms a transfer space in which the substrate is transferred and a return path that returns a gas that has flowed from one side of the transfer chamber to the other side; the return path and the transfer chamber are provided on either side of a partition wall, and when gas is circulating through the circulation path, a pressure difference is generated between both sides of the partition wall such that a pressure on the return path side is higher, An EFEM including a trapping unit provided in the return path and configured to electrically trap particles contained in the gas flowing therethrough, a connecting pipe for guiding the gas that has flowed inside a predetermined device disposed in the transfer chamber is connected to a position in the return path upstream of the capture section; EFEM, characterized in that

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