Door opening / closing system and load port equipped with the door opening / closing system

Abstract

A door opening / closing system and a load port equipped with the door opening / closing system are provided that prevent the atmosphere from entering the FOUP and the EFEM when the FOUP and the EFEM are in communication with each other. [Solution] The device comprises a base (41) that forms part of a wall that separates the transport space from the external space, an opening (92) provided in the base (41), a door (81) that can open and close the opening (92), a first sealing member (94) that seals between the base (41) and the container (7), a second sealing member (96) that seals between the base (41) and the door (81), an airtight space formed by the base (41), the first sealing member (94), the second sealing member (96), the lid (72), and the door (81) when the container (7) is in contact with the opening (92) via the first sealing member (94), a first gas injection section (87) that injects gas into the airtight space, and a second gas exhaust section (88) that exhausts the airtight space.

Description

[Technical Field]

[0001] The present invention relates to a door opening / closing system that can circulate gas within a wafer transfer chamber so that wafers are not exposed to the outside air during transfer, and a load port equipped with the door opening / closing system. [Background technology]

[0002] Traditionally, semiconductors have been manufactured by subjecting wafers to various processing steps. In recent years, with the increasing integration of elements and miniaturization of circuits, it has become necessary to maintain a high level of cleanliness around the wafer to prevent particles and moisture from adhering to the wafer surface. Furthermore, to prevent changes in the surface properties of the wafer, such as oxidation, the area around the wafer is often placed in an inert nitrogen atmosphere or in a vacuum.

[0003] To maintain an appropriate atmosphere around these wafers, wafers are stored in a sealed storage pod called a Front-Opening Unified Pod (FOUP), which is filled with nitrogen. Furthermore, an Equipment Front End Module (EFEM) is used to transfer wafers between the processing equipment and the FOUP. The EFEM forms a substantially enclosed wafer transfer chamber within a housing, and one of its opposing walls is equipped with a load port that functions as an interface with the FOUP. The other is connected to a load lock chamber, which is part of the processing equipment. A wafer transfer device is installed within the wafer transfer chamber to transfer wafers between the FOUP connected to the load port and the load lock chamber using this wafer transfer device. The wafer transfer chamber typically has a constant downflow of clean air from a fan filter unit located above the transfer chamber.

[0004] Furthermore, in recent years, in cutting-edge wafer processes, even the oxygen and moisture contained in the clean air used as the downflow can change the properties of the wafer. For this reason, there is a demand for the practical application of technology to circulate inert gas within the EFEM, as described in Patent Document 1. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-112631 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the opening and closing system described in Patent Document 1, air and particles still remain in the sealed space between the seal member, lid, and door. As a result, in an EFEM, which requires even lower oxygen concentrations and humidity, the remaining air and particles can get into the FOUP or wafer transfer chamber, potentially changing the properties of the wafers.

[0007] Therefore, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a door opening / closing system and a load port equipped with the door opening / closing system that prevent air from entering the FOUP and EFEM when the FOUP and EFEM are connected to each other. [Means for solving the problem]

[0008] The door opening and closing system according to the present invention comprises: a base constituting a part of a wall separating the transport space from an external space; an opening provided in the base; a door that can open and close the opening and can fix and release the lid body to and from the container that contains the contents; a first seal member that seals between the base and the container; a second seal member that seals between the base and the door; When the container is in contact with the opening via the first seal member, a sealed space formed by at least the first seal member, the second seal member, the lid body, and the door; a first gas injection unit that injects gas into the sealed space; a second gas exhaust section that exhausts the sealed space; Equipped with:

[0009] This door opening / closing system includes a first gas inlet unit that injects gas into the sealed space between the container and the door when the container is in contact with the opening via the first seal member, i.e., when the container is attached to the opening, and a first gas outlet unit that exhausts gas from the sealed space. This allows the air between the container and the door to be removed and filled with nitrogen gas (purged) while the container is attached to the opening. This prevents air containing oxygen, moisture, particles, and other contaminants that could oxidize wafers and otherwise alter wafer properties from entering the transfer space and the container when the door is opened. In other words, oxygen, moisture, and particles can be removed from the sealed space before the container lid is opened to open the sealed space. This prevents oxygen and other contaminants from leaking into the container or the transfer space when the lid is opened, maintaining the desired environmental conditions inside the container and the transfer space.

[0010] The door opening and closing system according to the present invention comprises: The first gas injection unit repeatedly performs a gas injection operation to inject gas between the container and the door, and the first gas exhaust unit repeatedly performs a gas exhaust operation to exhaust the gas between the container and the door.

[0011] In this door opening and closing system, the gas injection operation by the first gas injection unit and the gas discharge operation by the first gas discharge unit are repeated, so that the air present between the container and the door can be reliably removed and the gas can be filled.

[0012] The door opening and closing system according to the present invention comprises: a pressure adjusting means for adjusting the pressure P1 and the pressure P2, where P1 is the pressure inside the container and P2 is the pressure in the sealed space; The pressure adjusting means controls the pressure P1 so that the pressure P2 approaches the pressure P2.

[0013] In this door opening and closing system, when the lid is released from the container, the internal space of the container may become connected to the sealed space. In this case, if the pressure difference between P1 and P2 is large, the flow rate of gas moving between the container and the sealed space increases, which may stir up particles accumulated at the bottom of the container and contaminate the contents. Therefore, by controlling P1 and P2 to approach each other, the amount of gas moving between the container and the sealed space is reduced, suppressing particle scattering and preventing contamination of the contents.

[0014] The door opening and closing system according to the present invention comprises: a transfer chamber including the base that forms the transfer space, When the pressure in the transfer space is P3, The pressure adjusting means further adjusts the pressure P3, and controls it so that P1, P2 and P3 approach each other.

[0015] In this door opening and closing system, when the door opens, the space inside the container, the sealed space, and the transfer space are connected. If the pressure difference between the spaces is large, the flow rate of gas moving between the spaces increases, which could cause particles in the spaces to be stirred up. Therefore, by controlling the distances between P1, P2, and P3 to be closer to each other, the amount of gas moving between the container, the sealed space, and the transfer space is reduced, suppressing particle scattering and preventing contamination of each space.

[0016] The door opening and closing system according to the present invention comprises: a transfer chamber including the base that forms the transfer space, a pressure adjusting means for adjusting the pressure P1, the pressure P2, and the pressure P3, where P1 is the pressure inside the container, P2 is the pressure inside the sealed space, and P3 is the pressure inside the transfer space; The pressure adjusting means controls the pressures P1, P2, and P3 so that they increase in this order.

[0017] In this door opening / closing system, the pressures P1, P2, and P3 are controlled to increase in order, thereby reducing the pressure difference between adjacent spaces among the space inside the container, the sealed space, and the transfer space. This reduces the flow rate of gas moving between the spaces when the door opens and the spaces are connected, compared to when the pressure difference between adjacent spaces is large. This reduces the amount of gas moving between the container, the sealed space, and the transfer space, suppressing particle scattering and preventing contamination of each space.

[0018] The door load port according to the present invention comprises: The door opening and closing system is provided, The opening is opened and the lid is removed, and the opening is closed and the lid is attached simultaneously.

[0019] In this load port, the lid of the container is reliably removed when the opening is opened, and the lid is attached when the opening is closed, so each operation can be carried out quickly. [Effects of the Invention]

[0020] The present invention includes a first gas inlet and a first gas outlet that inject gas into the sealed space between the container and the door when the container is in contact with the opening via the first seal member, i.e., when the container is attached to the opening. This allows the air between the container and the door to be removed and filled with nitrogen gas (purged) while the container is attached to the opening. This prevents air containing oxygen, moisture, particles, and other contaminants that may oxidize wafers or otherwise alter wafer properties from entering the transfer space and the container when the door is opened. In other words, oxygen, moisture, and particles can be removed from the sealed space before the container lid is opened to open the sealed space. This prevents oxygen and other contaminants from leaking into the container or the transfer space when the lid is opened, maintaining the desired environmental conditions inside the container and the transfer space.

[0021] In the present invention, the gas injection operation by the first gas injection section and the gas discharge operation by the first gas discharge section are repeated, so that the air present between the container and the door can be reliably removed and the container can be filled with gas.

[0022] In the present invention, when the lid is released from the container, the internal space of the container may become connected to the sealed space. In this case, if the pressure difference between P1 and P2 is large, the flow rate of gas moving between the container and the sealed space increases, which may stir up particles deposited at the bottom of the container and contaminate the contents. Therefore, by controlling P1 and P2 to approach each other, the amount of gas moving between the container and the sealed space is reduced, suppressing particle scattering and preventing contamination of the contents.

[0023] In this invention, when the door opens, the space inside the container, the sealed space, and the transfer space are connected. If the pressure difference between the spaces is large, the flow rate of gas moving between the spaces increases, which may stir up particles present in the spaces. Therefore, by controlling P1, P2, and P3 to be closer to each other, the amount of gas moving between the container, the sealed space, and the transfer space is reduced, suppressing particle scattering and preventing contamination of each space.

[0024] In this invention, when the door opens, the space inside the container, the sealed space, and the transfer space are connected. If the pressure difference between the spaces is large, the flow rate of gas moving between the spaces increases, which may stir up particles present in the spaces. Therefore, by controlling P1, P2, and P3 to be closer to each other, the amount of gas moving between the container, the sealed space, and the transfer space is reduced, suppressing particle scattering and preventing contamination of each space.

[0025] In the present invention, the lid of the container is reliably removed when the opening is opened, and the lid is attached when the opening is closed, so each operation can be carried out quickly. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a plan view schematically showing the relationship between an EFEM and a processing apparatus according to an embodiment of the present invention. [Figure 2] A side view of the EFEM with the side wall removed. [Figure 3] FIG. 2 is a perspective view showing a part of the EFEM in section. [Figure 4] Schematic diagram showing gas flow in the circulation path of the EFEM. [Figure 5] FIG. 2 is a perspective view of the load port shown in FIG. [Figure 6] FIG. 2 is a front view of the load port shown in FIG. 1. [Figure 7] FIG. 2 is a rear view of the load port shown in FIG. 1. [Figure 8] FIG. 2 is a side cross-sectional view of the load port shown in FIG. [Figure 9] FIG. 4 is a partially enlarged cross-sectional view showing the relationship between the door portion and the first seal member. [Figure 10] FIG. 9 is a side cross-sectional view showing a state in which the FOUP has been moved toward the housing from the state shown in FIG. 8. [Figure 11] FIG. 4 is a partially enlarged cross-sectional view showing a sealed space sealed by a sealing member. [Figure 12]FIG. 10 is an enlarged partial cross-sectional view showing the state in which the FOUP is brought close to the door section by clamping. [Figure 13] 11 is a side cross-sectional view showing a state in which the door portion together with the lid of the FOUP has been moved away from the opening from the state shown in FIG. 10. [Figure 14] 14 is a side cross-sectional view showing a state in which the door portion has been moved downward together with the lid of the FOUP from the state shown in FIG. 13. [Figure 15] FIG. 2 is an enlarged perspective view of the main parts of the window unit and door portion that constitute the EFEM. [Figure 16] 16 is an enlarged cross-sectional view of a main part taken along the line AA in FIG. 15. [Figure 17] FIG. 4 is an enlarged front view of a main part showing a clamp provided on the window unit. [Figure 18] FIG. 3 is a block diagram showing the connection state between the control unit and each pressure gauge and each valve. [Figure 19] 1 is a flowchart showing the procedure for connecting and communicating a FOUP with an EFEM. [Figure 20] 10A is a cross-sectional view showing a modified example of the clamp unit, and FIG. 10B is a front view showing the clamped state of FIG. [Figure 21] 21(a) is a cross-sectional view showing the clamp in FIG. 20 in an released state, and FIG. 21(b) is an enlarged cross-sectional view showing the support piece in FIG. 21(a). [Figure 22] (a) is an enlarged plan view showing the clamp released state, (b) is an enlarged plan view showing the clamp in operation, and (c) is an enlarged plan view showing the clamped state. [Figure 23] 10A is a cross-sectional view showing a modified door portion having a recessed portion recessed toward the transfer space side, and FIG. 10B is a cross-sectional view showing a modified door portion having a curved surface recessed in an arch shape toward the transfer space side. [Figure 24] 10A is a cross-sectional view showing a further modified door portion having a recessed portion recessed toward the transport space side, and FIG. 10B is a cross-sectional view showing a further modified door portion having a curved surface recessed in an arch shape toward the transport space side. [Figure 25] FIG. 10 is a diagram showing a gas flow path according to a modified example when pressure P1 is higher than pressure P2. [Figure 26] FIG. 10 is a diagram showing a gas flow path according to a modified example when pressure P1 is lower than pressure P2. [Figure 27] FIG. 10 is a block diagram showing a modified example of the connection state between the control unit and each pressure gauge and each valve. [Figure 28] 12 is a partially enlarged cross-sectional view showing a modified example in which the door portion is advanced from the state shown in FIG. 11 toward the lid of the FOUP. [Figure 29] FIG. 10 is a cross-sectional view showing a modified example in which two O-rings are integrated. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0028] FIG. 1 is a plan view showing a schematic diagram of the relationship between an EFEM 1 according to an embodiment of the present invention and a processing device 6 connected thereto, with the interior of the EFEM 1 and the processing device 6 being visible by removing the top plate and other components thereof. FIG. 2 is a side view showing the interior of the EFEM 1, with the side walls of the EFEM 1 being removed. As shown in FIGS. 1 and 2, the EFEM 1 is composed of a wafer transport device 2 that transports wafers W between predetermined transfer positions, a box-shaped housing 3 that surrounds the wafer transport device 2, multiple load ports 4 (three in the figure) connected to the outside of the front wall (front wall 31) of the housing 3, and a control unit 5.

[0029] In this application, the direction toward the side of the housing 3 to which the load ports 4 are connected is defined as the front, the direction toward the rear wall 32 opposite the front wall 31 is defined as the rear, and further, the direction perpendicular to the front-rear direction and the vertical direction is defined as the side. In other words, the three load ports 4 are arranged side by side.

[0030] As shown in FIG. 1, the EFEM 1 is connected to a load-lock chamber 61, which constitutes part of the processing apparatus 6, adjacent to the outer side of the rear wall 32. By opening a door 1a provided between the EFEM 1 and the load-lock chamber 61, communication between the interior of the EFEM 1 and the load-lock chamber 61 can be established. While various types of processing apparatuses can be used, a typical processing apparatus 6 includes a transfer chamber 62 provided adjacent to the load-lock chamber 61, and multiple processing units 63-63 (three in the figure) that process wafers W are provided adjacent to the transfer chamber 62. Doors 62a and 63a-63a are provided between the transfer chamber 62 and the load-lock chamber 61 and between the processing units 63-63, respectively, and these doors can be opened to allow communication between the units. A transfer robot 64 provided in the transfer chamber 62 can be used to move wafers W between the load-lock chamber 61 and the processing units 63-63.

[0031] 2, the wafer transport device 2 is composed of an arm 2a equipped with a pick on which a wafer W is placed and transported, and a base 2b that supports the arm 2a from below and has a drive mechanism and an elevating mechanism for operating the arm. The base 2b is supported on the front wall 31 of the housing 3 via supports 21 and guide rails 22. The wafer transport device 2 is capable of moving along the guide rails 22 that extend in the width direction within the housing 3. The control means 5 controls the operation of the wafer transport device 2, thereby enabling the transport of wafers (contents) W contained in FOUPs (containers) 7 placed on each of the load ports 4 lined up to the side to the load lock chamber 61, and the transport of wafers W back into the FOUPs 7 after they have been processed in each of the processing units 63.

[0032] The housing 3 includes a front wall 31, a rear wall 32, and side walls 33 and 34 that surround the wafer transfer device 2 on all four sides, a ceiling wall 35, a bottom wall 36, and support columns 37a to 37d that support the housing walls 31 to 35. A load port 4 is attached to an opening 92 provided in the front wall 31. A load lock chamber 61 is connected to a rectangular opening 32a provided in the rear wall 32. The housing 3 includes a transfer space 9 and a gas return path 10 (described later), which form a substantially enclosed space CS (see FIG. 4) that encompasses these components. While the above-described components are precisely attached to prevent gaps between the components that allow internal gas to escape, sealing members may be provided between the components to further enhance the airtightness of the housing 3. The opening 32a provided in the rear wall 32 can be closed by a door 1a (see FIG. 3), commonly referred to as a gate valve, that has a drive mechanism 1b and moves up and down. Although not shown in the drawings or explained, openings are also provided in the side walls 33 and 34, one of which is connected to an aligner used to adjust the position of the wafer W, and the other is an opening for maintenance that is normally closed.

[0033] The load port 4 is equipped with a door 81, which connects to a lid 72 provided on the FOUP 7 and moves together to open the FOUP 7 to the substantially enclosed space CS. The FOUP 7 is provided with a number of placement sections arranged vertically, which enable it to accommodate a number of wafers W. The FOUP 7 is normally filled with nitrogen, and the atmosphere within the FOUP 7 can also be replaced with nitrogen via the load port 4 under the control of the control means 5.

[0034] The control means 5 is configured as a controller unit provided in the upper space US located above the ceiling wall 35 of the housing 3 and between the top plate 38. The control means 5 also performs drive control of the wafer transport device 2, nitrogen substitution control of the FOUP 7 using the load port 4, opening and closing control of the door 1a and door portion 81, and nitrogen circulation control within the housing 3. The control means 5 is configured with a normal microprocessor equipped with a CPU, memory, and interface, and the memory stores programs required for processing. The CPU sequentially retrieves and executes the required programs, working in cooperation with peripheral hardware resources to achieve the desired functions. Nitrogen circulation control will be described later.

[0035] As shown in FIG. 4 , the substantially closed space CS is partitioned by a partition member 8 into a transfer space 9, which is a space in which the wafer transfer device 2 is driven, and a gas return path 10. The transfer space 9 and the gas return path 10 are connected only through a gas outlet 11 provided at an upper portion of the transfer space 9 and extending in the width direction, and a gas suction port 12 provided at a lower portion of the transfer space 9 and extending in the width direction. The gas outlet 11 and the gas suction port 12 generate a downward air current in the transfer space 9 and an upward air current in the gas return path 10, thereby forming a circulation path Ci shown by arrows in FIG. 4 within the substantially closed space CS, through which gas circulates. Note that, in this embodiment, nitrogen, an inert gas, is circulated in the substantially closed space CS, but the circulated gas is not limited to nitrogen, and other gases can also be used.

[0036] Next, the configuration of the gas return path 10 will be described in detail. As shown in Fig. 4, the gas return path 10 is a space enclosed by a bottom wall 36, a back wall 32, a ceiling wall 35, and a partition member 8. The gas return path 10 is provided to return the gas sucked through a gas suction port 12 at the bottom of the transfer space 9 to a gas delivery port 11 at the top of the transfer space 9.

[0037] A gas supply means (third gas injector) 16 for introducing nitrogen into the substantially closed space CS is connected to the upper rear side of the return path 10. The gas supply means 16 can control the supply and stop of nitrogen based on commands from the control means 5. Therefore, if some of the nitrogen leaks out of the substantially closed space CS, the gas supply means 16 can supply the leaked nitrogen to maintain a constant nitrogen atmosphere in the substantially closed space CS. In addition, a gas exhaust means (third gas exhauster) 17 for exhausting gas from the substantially closed space CS is connected to the lower rear side. The gas exhaust means 17 operates based on commands from the control means 5 and can open a shutter (not shown) to connect the inside of the substantially closed space CS to a gas exhaust destination located outside. When used in combination with the supply of nitrogen by the gas supply means 16, the substantially closed space CS can be replaced with a nitrogen atmosphere. In this embodiment, the gas circulated through the circulation path Ci is nitrogen, so the gas supply means 16 supplies nitrogen, but if another gas is to be circulated, the gas supply means 16 supplies the gas to be circulated.

[0038] A fan filter unit 13 (FFU13) consisting of a fan 13a and a filter 13b as a first blowing means is provided at the gas delivery port 11. The fan filter unit 13 removes particles contained in the gas circulating in the substantially closed space CS, and generates a downward air current in the transfer space 9 by blowing air downward into the transfer space 9. The FFU 13 is supported by a support member 18 connected to the partition member 8 and extending horizontally.

[0039] Meanwhile, a chemical filter 14 is connected to the gas suction port 12, and the gas in the transfer space 9 flows into the gas return path 10 through the chemical filter 14. As described above, the wafer transport device 2 (see FIG. 2) is supported on the front wall 31 of the housing 3 via the support portion 21 and the guide rail 22. This allows the gas suction port 12 to be open wide and upward without interfering with the wafer transport device 2. As described above, the gas suction port 12 extends in the width direction. Therefore, even if particles are generated during operation of the wafer transport device 2, the guide rail 22, which also extends in the width direction, can effectively suck these particles. Furthermore, by providing the chemical filter 14 at the gas suction port 12, it is possible to remove molecular contaminants that are generated during processing in the processing device 6 (see FIG. 1) and that flow into the transfer space 9. Furthermore, a fan 15 as a second blowing means is provided across the width of the gas return path 10 on the rear side of the chemical filter 14 (see FIG. 4). The fan 15 blows air toward the downstream side of the gas return path 10, i.e., upward in FIG. 4, thereby generating a suction force for the gas at the gas suction port 12 and sending the gas that has passed through the chemical filter 14 upward, thereby generating an ascending air current within the gas return path 10.

[0040] The fan 13a and fan 15 of the FFU 13 described above cause the gas in the substantially closed space CS to circulate by descending within the transfer space 9 and ascending within the gas return path 10. Because the gas delivery port 11 opens downward, the gas is delivered downward by the FFU 13. Because the gas suction port 12 opens upward, the gas can be sucked downward without disturbing the downward airflow generated by the FFU 13, thereby creating a smooth gas flow. The downward airflow generated within the transfer space 9 removes particles adhering to the top of the wafer W and prevents particles from floating within the transfer space 9.

[0041] Next, the operation of nitrogen circulation control for circulating nitrogen in the EFEM 1 configured as above will be described with reference to FIG.

[0042] First, in the initial stage, the control means 5 causes the gas discharge means 17 to discharge gas while causing the gas supply means 16 to supply nitrogen into the substantially closed space CS, thereby purging the substantially closed space CS of the EFEM 1, which is in the atmospheric atmosphere, into a nitrogen atmosphere. After this stage, if nitrogen leaks to the outside in the circulation path Ci, the control means 5 causes the gas supply means 16 to supply nitrogen according to the amount of leakage.

[0043] Then, in the substantially closed space CS that has thus been filled with a nitrogen atmosphere, the control means 5 drives the fan 13a and fan 15 of the FFU 13 to cause gas to circulate in the circulation path Ci. At this time, the filter 13b and chemical filter 14 of the FFU 13 remove particles and molecular contaminants from the circulating gas, so that a downward current of clean nitrogen is constantly generated in the transfer space 9.

[0044] In the EFEM 1 in this state, the FOUP 7 placed on the load port 4 and purged with a nitrogen atmosphere is connected to the transfer space 9, and wafers W are loaded and unloaded. At this time, both the transfer space 9 and the FOUP 7 are in the same nitrogen atmosphere, and the nitrogen in the transfer space 9 is also kept clean. Therefore, there is no need to create a positive pressure in the FOUP 7 relative to the transfer space 9 to prevent particles and molecular contaminants from entering the FOUP 7, and the consumption of nitrogen purged into the FOUP 7 can be reduced.

[0045] 5, 6, and 7 respectively show a perspective view, a front view as seen from the front, and a rear view as seen from the rear of the load port 4. The configuration of the load port 4 will be explained below using these drawings. Note that these drawings show the state in which the external cover 42 (see FIG. 3) located below the mounting table 44 has been removed, exposing part of the internal structure.

[0046] The load port 4 has a base 41 that stands vertically behind legs 45 to which casters and installation legs are attached, and a horizontal base 43 is provided facing forward at a height position that is approximately 60% of the height of the base 41. Furthermore, a mounting table 44 is provided on top of the horizontal base 43 for placing a FOUP 7 (see FIG. 2) thereon.

[0047] As shown schematically in Fig. 8, the FOUP 7 is composed of a main body 71 having an internal space Sf for accommodating wafers W (see Fig. 2), and a lid 72 for opening and closing an opening 71a provided on one side of the main body 71 to serve as an entrance for loading and unloading the wafers W. When the FOUP 7 is properly placed on the mounting table 44, the lid 72 faces the base 41. A space Sc is formed inside the lid 72 (see Fig. 11) for accommodating a connecting means 82 (see Fig. 7) (described later) for opening and closing the lid 72.

[0048] 5 to 7, the mounting table 44 is provided with positioning pins 44a for positioning the FOUP 7, and with locking claws 44b for fixing the FOUP 7 to the mounting table 44. By performing a locking operation, the locking claws 44b can cooperate with the positioning pins 44a to guide and fix the FOUP 7 to an appropriate position, and by performing an unlocking operation, the FOUP 7 can be made removable from the mounting table 44. Note that the mounting table 44 can be moved back and forth by a mounting table drive unit (not shown) with the FOUP 7 placed on it.

[0049] Furthermore, the mounting table 44 is provided with two second gas injection nozzles (second gas injection sections) 44c that supply gas into the FOUP 7 and two second gas exhaust nozzles (second gas exhaust sections) 44d that exhaust gas from the FOUP 7. The second gas injection nozzles 44c and the second gas exhaust nozzles 44d are normally located below the upper surface of the mounting table 44, and when in use, they extend upward and connect to the gas supply valve 73 and the gas exhaust valve 74 (see FIG. 8) that the FOUP 7 has, respectively.

[0050] During use, one end of the second gas injection nozzle 44c is connected to the interior of the FOUP 7, and a second gas injection valve 44e is provided at the other end. Similarly, one end of the second gas exhaust nozzle 44d is connected to the interior of the FOUP 7, and a second gas exhaust valve 44f is provided at the other end. Gas purging is possible by supplying a gas, such as dry nitrogen gas, from the second gas injection nozzle 44c to the internal space Sf of the FOUP 7 via the gas supply valve 73 and then exhausting the gas from the internal space Sf from the second gas exhaust nozzle 44d via the gas exhaust valve 74. Furthermore, by increasing the gas supply rate relative to the gas exhaust rate, a positive pressure setting can be achieved in which the pressure in the internal space Sf is increased relative to the pressure outside and the internal space Se of the housing 3 (see FIG. 2). By increasing the pressure inside the FOUP 7 (internal space Sf), the surface of the lid 72 bulges outward toward the door portion 81 relative to the contact surface 71b, as shown in FIG. 11.

[0051] The base 41 of the load port 4 constitutes a part of the front wall 31 that separates the transfer space 9 from the external space. As shown in FIG. 5, the base 41 is composed of support columns 41a, 41a standing on both sides, a base body 41b supported by these columns, and a window unit 90 attached to a window portion 41c that opens into a substantially rectangular shape on the base body 41b. Here, the term "substantially rectangular" as used herein refers to a shape in which the four corners are smoothly connected by arcs, with a rectangular frame-shaped elastic gasket 47 (see FIG. 7) provided near the outer periphery of the rear surface of the base body 41b. The gasket 47 is made of a rubber material that is less permeable to gases.

[0052] The window unit 90 is provided at a position facing the lid 72 (see FIG. 8) of the above-mentioned FOUP 7. As will be described in detail later, the window unit 90 is provided with a substantially rectangular opening 92 (see FIG. 15), and the internal space Se of the housing 3 can be opened through this opening 92. The load port 4 is provided with an opening / closing mechanism 80 for opening and closing the window unit 90 configured to be able to mount the FOUP 7.

[0053] As shown in Figure 6, the opening / closing mechanism 80 includes a door portion 81 for opening and closing the opening 92, a support frame 83 for supporting the door portion 81, a movable block 85 for supporting the support frame 83 so that it can move in the front-to-rear direction via a slide support means 84, and a slide rail 86 for supporting the movable block 85 so that it can move in the up-and-down direction relative to the base body 41b.

[0054] 8, the support frame 83 supports the lower rear portion of the door section 81 and has a generally clamp-like shape that extends downward and then passes through a slit-like insertion hole 41d provided in the base body 41b, protruding toward the front of the base body 41b. A slide support means 84, a movable block 85, and a slide rail 86 for supporting this support frame 83 are provided in front of the base body 41b. In other words, the drive points for moving the door section 81 are located outside the housing 3, and even if particles are generated in these areas, the slit-like shape of the insertion hole 41d makes it possible to prevent the particles from entering the housing 3.

[0055] The door section 81 of the opening / closing mechanism 80 will now be described in detail. As shown in Fig. 8, the door section 81 is provided with a first gas injection nozzle (first gas injection section) 87 that injects gas between the FOUP 7 and the door section 81 when the FOUP 7 is attached to the window unit 90, and a first gas exhaust nozzle (first gas exhaust section) 88 that exhausts gas from between the FOUP 7 and the door section 81. One end of the first gas injection nozzle 87 extends to the outer surface of the door section 81, and a first gas injection valve 87a is provided at the other end. Similarly, one end of the first gas exhaust nozzle 88 extends to the outer surface of the door section 81, and a first gas exhaust valve 88a is provided at the other end. As a result, as will be described later, with the door portion 81 and the lid body 72 integrated by clamping, the first gas injection nozzle 87 communicates with the sealed space Sd (see FIG. 11) to supply gas such as dry nitrogen gas, and the first gas exhaust nozzle 88 communicates with the sealed space Sd to exhaust gas, thereby enabling gas purging. The first gas exhaust nozzle 88 is branched midway and is provided with a pressure equalizing valve 89, and is also used as a pressure equalizing nozzle for equalizing the pressure between the sealed space Sd and the transfer space 9.

[0056] FIG. 9 is a partially enlarged cross-sectional view of FIG. 8 showing the relationship between the door portion 81 and the O-ring (first seal member) 94. As shown in FIG. 9, the FOUP 7-side end face 81c of the door portion 81 is located closer to the transfer space 9 than the FOUP 7-side end face of the O-ring 94 by a desired distance L2. In this manner, the entire FOUP 7-side end face 81c of the door portion 81 is located closer to the transfer space 9 than the FOUP 7-side end face of the O-ring 94. This reliably prevents contact between the lid 72 and the door portion 81, thereby maintaining the seal between the base 41 and the door portion 81 provided by the O-ring 96. In the drawing, the position of the FOUP 7-side end face of the O-ring 94 is indicated by an imaginary line L1. The distance L2 is, for example, 0.1 mm or more and 3 mm or less.

[0057] Furthermore, actuators (not shown) are provided for each direction to move the door section 81 in the forward / backward and vertical directions, and by giving these actuators drive commands from the control section Cp, the door section 81 can be moved in the forward / backward and vertical directions.

[0058] Furthermore, a cover 46 (see FIG. 8) is provided in front of base main body 41b, extending downward from directly below horizontal base 43. This cover 46 covers and seals support frame 83, slide support means 84, movable block 85, and slide rails 86. Therefore, although base main body 41b has insertion hole 41d, gas inside housing 3 (see FIG. 3) is prevented from leaking out through this portion. The lower end of first gas injection nozzle 87, first gas injection valve 87a, first gas exhaust nozzle 88, and first gas exhaust valve 88a are provided inside cover 46.

[0059] The door section 81 is equipped with a suction section 79 (see FIG. 6) that suctions the lid 72 of the FOUP 7, and a connecting means 82 (see FIG. 7) that performs a latch operation to open and close the lid 72 of the FOUP 7 and that holds the lid 72. The door section 81 can fasten and release the lid 72, allowing the lid 72 to be removed from and attached to the FOUP 7. The connecting means 82 can unlatch the lid 72 to place the lid 72 in an openable state, and can also connect the lid 72 to the door section 81 to form an integrated state. Conversely, the connection between the lid 72 and the door section 81 can be released, and the lid 72 can be attached to the main body 71 to place it in a closed state.

[0060] 15, the detailed configuration of the window unit 90 will be described. The window unit 90 is composed of a window frame 91, O-rings 94 and 96 as elastic members attached thereto, and a clamp unit 50 as a pulling means for tightly contacting the FOUP 7 with the window frame 91 via the O-ring 94.

[0061] The window frame 91 has a frame shape with a substantially rectangular opening 92 formed inside. The window frame 91 constitutes part of the base 41 (see FIG. 5) described above as a component of the window unit 90, and therefore the opening 92 can be said to open the front wall 31, which is a wall surface of the housing 3. An O-ring 94 is disposed on the front surface of the window frame 91 so as to go around the vicinity of the periphery of the opening 92. An O-ring 96 is disposed on the rear surface of the window frame 91 so as to go around the vicinity of the periphery of the opening 92.

[0062] The opening 92 is slightly larger than the outer periphery of the lid 72 of the FOUP 7 (see FIG. 8), and the lid 72 can move through this opening 92. When the FOUP 7 is placed on the mounting table 44, the front surface of the main body 71 that surrounds the lid 72 serves as abutment surface 71b and abuts against the front surface of the window frame 91 via the O-ring 94. As a result, when the FOUP 7 is attached to the window unit 90, the O-ring 94 seals the gap between the periphery of the opening 92 (base 41) and the FOUP 7 (see FIG. 16).

[0063] Additionally, the door portion 81 described above abuts against the rear surface of the window frame portion 91 via an O-ring (second seal member) 96. As a result, the O-ring 96 seals between the periphery of the opening 92 and the door portion 81. Specifically, a thin portion 81a provided in a flange-like shape on the outer periphery of the door portion 81 abuts against the window frame portion 91. At this time, a thick portion 81b formed inside the thin portion 81a is smaller than the opening 92, and therefore protrudes forward through the opening 92.

[0064] 15, the clamp units 50 are provided at four locations spaced apart in the vertical direction on both sides of the window frame 91. Each clamp unit 50 is generally composed of an engagement piece 51 and a cylinder 52 that operates the engagement piece, and presses the FOUP 7 toward the base 41 when the FOUP 7 is attached to the window unit 90.

[0065] Cylinder 52, which constitutes clamp unit 50, is attached to the rear of window frame 91 and has a shaft 53 that can advance and retreat forward through a hole formed in window frame 91. Base end 51a of engagement piece 51 is attached to the tip of shaft 53, and tip 51b extends from base end 51a toward the outer periphery of shaft 53. Also, guide groove 53a, twisted 90° along the axial direction, is formed on the outer periphery of shaft 53, and guide pin 54, fixed to the window frame 91 side, is inserted radially into guide groove 53a. Therefore, as cylinder 52 advances and retreats, guide groove 53a is guided by guide pin 54, and shaft 53 rotates 90° around its axis.

[0066] As shown in FIG. 17 , when the engaging piece 51 protrudes forward together with the shaft 53, the tip 51b faces upward. When the engaging piece 51 is retracted backward, the tip 51b faces the FOUP 7. By clamping, the tip 51b of the engaging piece 51 faces inward, allowing it to engage with the flange 71c that protrudes laterally from the FOUP 7. While maintaining this engaged state, the shaft 53 is further retracted by the cylinder 52. This allows the FOUP 7 contact surface 71b to be clamped even more tightly against the O-ring 94. The clamp unit 50 operates at four locations, uniforming the amount of deformation of the O-ring 94 and improving sealing performance. Even in the clamped state, the FOUP 7-side end surface 81c of the door portion 81 is positioned closer to the transfer space 9 than the FOUP 7-side end of the O-ring 94, which is pressed toward the base 41 by the contact surface 71b of the FOUP 7.

[0067] Furthermore, when the engaging piece 51 is moved forward, the tip 51b faces upward, so that it is positioned so as not to interfere with the flange 71c when viewed from the front. This allows the FOUP 7 to be moved together with the mounting table 44. Note that when the tip 51b is moved forward, it is only necessary to avoid interference with the flange 71c, and the tip 51b may be set not only upward but also downward or outward.

[0068] The load port 4 configured as described above is operated by the control unit Cp shown in Fig. 5, which issues drive commands to each unit. As shown in Fig. 18, the input side of the control unit Ct is connected to a pressure gauge that measures the pressure in the sealed space Sd, a pressure gauge that measures the pressure in the internal space Sf of the FOUP 7, and a pressure gauge that measures the pressure in the internal space Se of the housing 3. Similarly, the input side of the control unit Ct is connected to a hygrometer that measures the humidity in the sealed space Sd, a hygrometer that measures the humidity in the internal space Sf of the FOUP 7, and a hygrometer that measures the humidity in the internal space Se of the housing 3. To measure the oxygen concentration, the input side of the control unit Ct is connected to an oxygen (concentration) meter that measures the oxygen concentration in the sealed space Sd, an oxygen (concentration) meter that measures the oxygen concentration in the internal space Sf of the FOUP 7, and an oxygen (concentration) meter that measures the oxygen concentration in the internal space Se of the housing 3. Regarding flow rate, the input side of the control unit Ct is connected to a flow meter that measures the flow rate of the first gas injection nozzle 87, a flow meter that measures the flow rate of the second gas injection nozzle 44c, and a flow meter that measures the flow rate of the third gas injection unit 16.

[0069] The output side of the control unit Ct is connected to the first gas injection valve 87a, the first gas exhaust valve 88a, the second gas injection valve 44e, the second gas exhaust valve 44f, the third gas injection valve, the third gas exhaust valve, the gas supply means 16, the gas exhaust means 17, and the pressure equalizing valve 89 via the flow rate control unit Cf, and is connected to the clamp unit 50, the connecting means 82, and the adsorption unit 79 via the drive control unit Cd. The control unit Ct is installed in the EFEM1 and has various memories and a built-in controller that accepts operational inputs from the user. The flow rate control unit Cf and the drive control unit Cd are provided within the controller of the EFEM1.

[0070] An example of operation when the load port 4 of this embodiment is used will be described below with reference to Figures 8 to 12. Note that in the initial state, each valve is closed.

[0071] 8 shows a state in which the FOUP 7 is placed on the mounting table 44 and separated from the base 41. In this state, the door portion 81 abuts against the rear surface of the window frame portion 91 (see FIG. 15) that constitutes the window unit 90 via the O-ring 96, so no gap is created between the window frame portion 91 and the door portion 81, and high sealing performance can be achieved. Therefore, even if the internal space Se of the housing 3 is filled with nitrogen gas or the like, it is possible to prevent gas from leaking to the outside or gas from flowing from the outside into the internal space Se.

[0072] As shown in FIG. 19, in step S1, the FOUP 7 is locked in an appropriate position relative to the mounting table 44 by the locking action of the locking claws 44b (see FIG. 5) and the positioning action of the positioning pins 44a.

[0073] Then, the second gas injection nozzle 44c and the second gas exhaust nozzle 44d provided on the mounting table 44 protrude upward and are connected to the gas supply valve 73 and the gas exhaust valve 74 provided on the FOUP 7, respectively. Thereafter, in step S2, the second gas injection valve 44e is opened to supply fresh dry nitrogen gas from the second gas injection nozzle 44c through the gas supply valve 73. At the same time, the second gas exhaust valve 44f is opened to exhaust the gas that had remained in the internal space Sf from the second gas exhaust nozzle 44d through the gas exhaust valve 74. By performing gas purging in this manner, the internal space Sf is filled with nitrogen gas and the pressure therein is made higher than that of the internal space Se of the housing 3. The filling of the FOUP 7 with nitrogen gas continues until this flow is completed.

[0074] Next, in step S3, as shown in FIG. 10, the mounting table 44 is moved rearward to bring the contact surface 71b of the FOUP 7 into contact with the window frame 91. At this time, the end surface 81c of the door 81 is positioned toward the transfer space 9 by a predetermined distance L2 relative to the FOUP 7-side end of the O-ring 94. Therefore, even if the lid 72 of the FOUP 7 bulges toward the door 81, when the FOUP 7 is brought close to the window unit 90, the contact surface 71b of the FOUP 7 comes into contact with the O-ring 94, and the lid 72 does not come into contact with the end surface 81c of the door 81 (see FIG. 11). Therefore, a seal between the O-ring 96 and the door 81 is reliably maintained. In this way, the contact surface 71b comes into contact with the window frame 91 via the O-ring 94, and the door 81 comes into contact with the window frame 91 via the O-ring 96, forming a sealed space Sd. The door opening and closing system is constructed by adding an opening 92, a first gas injection nozzle 87, and a first gas exhaust nozzle 88 to the base 41, O-rings 94, 96, lid 72, and door portion 81 which form the sealed space Sd.

[0075] When moving the mounting table 44, the engaging piece 51 (see FIG. 15) is first protruded forward by the cylinder 52 that constitutes the clamp unit 50, so that the tip 51b faces upward and does not interfere with the FOUP 7.

[0076] Thereafter, in step S4, the FOUP 7 is clamped and fixed to the window unit 90. As a result, by moving the FOUP 7 toward the door portion 81 from a state in which the door portion 81 and the lid body 72 are spaced apart, the O-ring 94 is pressed and elastically deformed, improving the sealing performance between the FOUP 7 and the base 41 (see FIG. 12). Furthermore, it is preferable that the distance between the door portion 81 and the lid body 72 after the FOUP 7 has been moved toward the door portion 81 by the clamp unit 50 be set to a distance that allows the above-mentioned latching and unlatching operations to be performed.

[0077] Specifically, the cylinder 52 constituting the clamp unit 50 retracts the engagement piece 51 rearward, with the tip 51b facing inward and engaging with the flange 71c of the FOUP 7. Further retraction of the tip 51b brings the abutment surface 71b of the FOUP 7 into closer contact with the O-ring 94, enhancing the sealing performance. This series of operations is called a clamping operation. At this time, as shown in FIG. 11 , a space Sg is formed between the lid 72 and the door portion 81, and this space Sg communicates with the internal space Sc of the lid via the mounting hole 75, which mounts the connecting means 82. The space Sg and the space Sc form a sealed space Sd between the FOUP 7 and the door portion 81.

[0078] In step S5, the connecting means 82 (see Figure 7) provided on the door portion 81 is operated to unlatch the lid body 72, making it removable from the main body 71, and the door portion 81 holds the lid body 72 integrally via the suction portion 79.

[0079] In step S6, the first gas injection valve 87a is opened to supply nitrogen gas from the first gas injection nozzle 87 to the sealed space Sd. At the same time, the first gas exhaust valve 88a is opened to exhaust the gas (atmospheric air) that had been retained in the sealed space Sd from the first gas exhaust nozzle 88. After a predetermined time has elapsed, the first gas injection valve 87a and the first gas exhaust valve 88a are closed to complete the filling of the gas into the sealed space Sd. The gas injection operation of injecting gas into the sealed space Sd using the first gas injection nozzle 87 and the exhaust operation of exhausting gas into the sealed space Sd using the first gas exhaust nozzle 88 may be repeated. Here, the atmospheric air includes oxygen, moisture, particles, and the like that may change the properties of the wafers W, such as by oxidizing the wafers W. Discharging the gas (atmospheric air) retained in the sealed space Sd means that not only the atmosphere present between the FOUP 7 and the door 81 but also the atmosphere present inside the lid 72 is exhausted, allowing the sealed space Sd to be filled with gas.

[0080] In step S7, the pressure in the internal space Sf and the sealed space Sd of the FOUP 7 is equalized. Specifically, when the pressure in the internal space Sf after the clamping operation is P1 and the pressure in the sealed space Sd is P2, control is performed so that P1 and P2 approach each other.

[0081] This pressure adjustment is performed by adjusting the flow rates of the first gas injection nozzle 87 and the first gas exhaust nozzle 88 based on the pressure detected by the pressure gauges in the sealed space Sd and the FOUP 7. However, pressure adjustment may also be performed without using pressure gauges. Specifically, the pressure may be estimated from the flow rates of the first gas injection nozzle 87 and the first gas exhaust nozzle 88 and the flow rates of the second gas injection nozzle 44c and the second gas exhaust nozzle 44d, and pressure adjustment may be performed based on this estimated pressure. In this case, pressure adjustment can be performed without using a pressure gauge, thereby reducing costs. When estimating the pressure, the reached oxygen concentration measured by an oxygen concentration meter or the reached humidity measured by a hygrometer may also be taken into consideration.

[0082] Pressure can be adjusted in various ways. If the FOUP to be used is determined in advance, the volume of the internal space Sf of the FOUP 7 to be used and the volume of the lid of the FOUP 7 are determined, and therefore the volume of the sealed space Sd can be roughly estimated. Therefore, it is also possible to adjust the pressure P2 of the sealed space Sd to a predetermined pressure by filling the sealed space Sd with gas at a predetermined flow rate for a predetermined time. In this case, it is not necessary to use a pressure gauge, oxygen concentration meter, or hygrometer for pressure adjustment.

[0083] Here, we have described the method of adjusting pressure P2, but this can also be used to adjust pressures P1 and P3. Furthermore, pressure adjustment can be performed not only by adjusting the flow rate, but also by adjusting a pressure equalizing valve, or by combining the flow rate and a pressure equalizing valve. These mechanisms used for pressure adjustment are collectively called pressure adjustment means.

[0084] 13, the door portion 81 and the lid body 72 are moved rearward together with the support frame 83. This separates the lid body 72 of the FOUP 7 from the main body 71, opening the internal space Sf, and separates the door portion 81 from the opening 92, opening the housing 3 (internal space Se). At this time, the contact surface 71b of the FOUP 7 is in close contact with the window unit 90 via the O-ring 94, making it possible to prevent gas from flowing out or in between the housing 3 and the FOUP 7 and the outside.

[0085] Furthermore, since the pressure in the FOUP 7 is increased, a gas flow occurs from the internal space Sf of the FOUP 7 toward the inside of the housing 3. This makes it possible to prevent particles and the like from entering the FOUP 7 from the housing 3, thereby keeping the inside of the FOUP 7 clean. Note that continuously supplying a low flow rate of gas via the second gas injection nozzle 44c is also suitable for preventing particles from entering. After this, the pressure adjustment is completed.

[0086] 14, in step S9, the door portion 81 and the lid 72 are moved downward together with the support frame 83. This allows the rear of the opening 71a, which serves as the loading / unloading entrance for the FOUP 7, to be widely opened, making it possible to move wafers W between the FOUP 7 and the EFEM 1. As such, the mechanism for moving the door portion 81 is entirely covered by the cover 46, making it possible to prevent gas from leaking from inside the housing 3 to the outside.

[0087] As described above, the operations performed when opening the opening 71a of the FOUP 7 have been described, but the operations described above can be reversed when closing the opening 71a of the FOUP 7. However, in terms of the operation of the door opening / closing system, if the pressure, oxygen concentration, humidity concentration, and the like within the internal space Sf are at levels that do not pose a problem when closing the opening 71a of the FOUP 7, steps S6 and S7 can be omitted.

[0088] By repeating this operation, the O-rings 94, 96 are repeatedly brought into elastic contact with the lid 72 or the door part 81, which may generate new particles. These particles are carried downward by the downflow formed inside the housing 3 when the lid 72 or the door part 81 is opened. Therefore, the particles do not adhere to the surface of the wafer W, and the surface of the wafer W can be maintained in a clean state.

[0089] [Features of the load port of this embodiment] The load port 4 of this embodiment has the following features.

[0090] In the load port 4 of this embodiment, even if the lid 72 of the FOUP 7 expands toward the base 41, when the FOUP 7 is attached to the opening 92, the lid 72 and door 81 do not come into contact because the FOUP 7-side end face of the door section 81 is positioned closer to the transfer space 9 than the FOUP 7-side end of the first seal member 94. This prevents the lid 72 from coming into contact with the door section 81 and causing debris to fly off, keeping the space around the load port 4 clean. It also reduces the possibility of debris already attached to the door section 81 being blown up by the impact of contact, or of the FOUP 7 shaking due to the impact of contact, causing debris to fly off the bottom of the FOUP 7 or misalignment of the contents inside.

[0091] In the load port 4 of this embodiment, at least a portion of the FOUP 7-side end face of the door section 81 is positioned closer to the transfer space 9 than the FOUP 7-side end of the first seal member 94, which is clamped and pressed against the base 41. Therefore, contact between the lid 72 and the door section 81 can be reliably prevented when the FOUP 7 is attached to the opening.

[0092] In the load port 4 of this embodiment, even if the lid 72 of the FOUP 7 expands toward the base 41, contact between the lid 72 and the door portion 81 can be reliably prevented.

[0093] [Features of the door opening and closing system of this embodiment] The door opening and closing system of this embodiment has the following features.

[0094] The door opening / closing system or load port 4 of this embodiment includes a first gas injection nozzle 87 that injects gas into the sealed space Sd between the FOUP 7 and the door section 81 when the FOUP 7 is in contact with the opening 92 via the first seal member 94, i.e., when the FOUP 7 is attached to the opening 92, and a first gas exhaust nozzle 88 that exhausts gas from the sealed space Sd. This allows the air between the FOUP 7 and the door section 81 to be removed and filled with nitrogen gas (purged) while the FOUP 7 is attached to the opening 92. This prevents air containing oxygen, moisture, particles, and the like that may be present between the FOUP 7 and the door section 81 and cause changes in the properties of the wafers, such as oxidizing the wafers W, from flowing into the transfer space 9 and the FOUP 7 when the door section 81 is opened. In other words, the oxygen, moisture, and particles in the sealed space Sd can be removed before the lid 72 of the FOUP 7 is opened to open the sealed space Sd. This prevents oxygen and the like from leaking into the FOUP 7 or the transfer space 9 when the lid 72 is opened, thereby maintaining the cleanliness of the inside of the FOUP 7 and the transfer space Sd.

[0095] In the door opening and closing system of this embodiment, the gas injection operation using the first gas injection nozzle 87 and the gas exhaust operation using the first gas exhaust nozzle 88 are repeated, so that the atmosphere present between the FOUP 7 and the door portion 81 can be reliably removed and gas can be filled.

[0096] In the door opening and closing system of this embodiment, when the FOUP 7 is clamped to the base 41, the FOUP 7 is moved toward the door portion 81 from a state in which the door portion 81 and the lid body 72 are spaced apart. This improves the sealing performance between the FOUP 7 and the base 41 via the O-ring 94.

[0097] In the door opening and closing system of this embodiment, when the lid 72 is released from the FOUP 7, the internal space Sf of the FOUP 7 and the sealed space Sd may become connected. In this case, if the pressure difference between P1 and P2 is large, the flow rate of gas moving between the FOUP 7 and the sealed space Sd increases, which may stir up particles deposited on the bottom of the FOUP 7 and contaminate the wafers W. Therefore, by controlling P1 and P2 to approach each other, the amount of gas moving between the FOUP 7 and the sealed space Sd is reduced, and the scattering of particles is suppressed, thereby preventing contamination of the wafers W.

[0098] In the load port 4 equipped with the door opening / closing system of this embodiment, the lid 72 of the FOUP 7 is reliably removed when the opening 92 is opened, and the lid 72 is attached when the opening 92 is closed, so each operation can be performed quickly.

[0099] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configurations should not be considered to be limited to these embodiments. The scope of the present invention is defined not only by the description of the above embodiments but also by the claims, and further includes all modifications within the meaning and scope of the claims.

[0100] In the above embodiment, in step S6 of Fig. 19, the first gas injection nozzle 87 supplies nitrogen gas to the sealed space Sd, and the first gas exhaust nozzle 88 exhausts the gas from the sealed space Sd, thereby performing gas purging. However, this is not limited to this, and the first gas exhaust nozzle 88 may also perform negative pressure exhaust. Specifically, the first gas exhaust nozzle 88 sucks in the air present in the sealed space Sd to create a negative pressure, and then the first gas injection nozzle 87 supplies nitrogen gas. This allows the sealed space Sd to be filled with gas efficiently.

[0101] In the above embodiment, the control unit Ct, flow rate control unit Cf, and drive control unit Cd are installed in the EFEM 1. However, this is not limited to this, and some or all of the control unit Ct, flow rate control unit Cf, and drive control unit Cd may be installed in the load port 4. In this case, the load port 4 is provided with a receiving unit that receives signals from a higher-level computer such as the controller of the EFEM 1. When each control unit is installed in the load port 4, as shown in FIG. 27 , the input side of the control unit Ct is connected to the pressure gauge, hygrometer, and oxygen meter of the sealed space Sd and the internal space Sf of the FOUP 7, as well as to the flow meters of the first gas injection nozzle and second gas injection nozzle.

[0102] In the above embodiment, in step 7 of FIG. 19 , the pressure P1 in the internal space Sf and the pressure P2 in the sealed space Sd are made to approach each other. However, this is not limited to this. The pressure in the transfer space 9 may be designated as P3, and the pressures P1, P2, and P3 may be controlled to approach each other. Specifically, the pressures of the remaining two may be adjusted to match one of P1, P2, and P3. In this case, adjusting the pressures P2 and P3 to approach the pressure P1 in the housing internal space Se, which has the largest volume among the sealed space Sd, the FOUP internal space Sf, and the housing internal space Se, can shorten the pressure adjustment time. Alternatively, P1, P2, and P3 may be controlled to approach predetermined pressure values. When the door portion 81 opens the opening 92, the space Sf in the FOUP 7, the sealed space Sd, and the transfer space 9 are connected. If the pressure difference between the spaces is large, the flow rate of gas moving between the spaces increases, which may cause particles present in the spaces to become airborne. Therefore, by controlling P1, P2, and P3 to be closer to each other, the amount of gas moving between the FOUP 7, the sealed space Sd, and the transfer space 9 can be reduced, and by suppressing the scattering of particles, contamination of each space can be prevented.

[0103] Alternatively, in step S7, pressures P1, P2, and P3 may be controlled to increase in that order without bringing P1 and P2 closer together. By controlling pressures P1, P2, and P3 to increase in that order, the pressure difference between adjacent spaces among the space Sf in the FOUP 7, the sealed space Sd, and the transfer space 9 is reduced. This reduces the flow rate of gas moving between the spaces when the door section 81 opens the opening 92 and the spaces are connected, compared to when the pressure difference between the adjacent spaces is large. This reduces the amount of gas moving between the FOUP 7, the sealed space Sd, and the transfer space 9, suppressing particle scattering and preventing contamination of each space.

[0104] In the above embodiment, a FOUP7 used for wafer transport is used as the container. However, the wafer storage container is not limited to this, and a MAC (Multi-Application Carrier), H-MAC (Horizontal-MAC), FOSB (Front Open Shipping Box), etc. may also be used. Furthermore, the container is not limited to a wafer storage container, and the present invention can be applied to a sealed container that stores items such as electronic components that are transported while filled with inert gas.

[0105] In the above embodiment, the load port is attached to an EFEM, but the present invention can also be applied to a sorter equipped with a transfer chamber for sorting the contents of a container placed on the load port and exchanging the contents of a container placed on another load port, or to an apparatus in which the process equipment itself serves as the transfer chamber and the load port is attached to the process equipment itself.

[0106] Although the clamp unit 50 having the cylinder 52 is employed in the above embodiment, this is not limiting. As shown in FIG. 20(a), the clamp unit 100 installed in the window frame 91 includes a support piece 101, a rod-shaped rotor 103 rotatably supported by the support piece 101, and a motor 106 that drives the rotor 103. The support piece 101 extends forward from the window frame 91 and rotatably supports the rotor 103 in its hollow portion 102 (see FIG. 21(b)). The rotor 103 has a pressing piece 107 that protrudes from the upper end and the center in the axial direction (see FIG. 20(b)). A pressing protrusion 108 (see FIG. 22) is formed at the tip of the pressing piece 107, and the flange 71c of the FOUP 7 is clamped via the pressing protrusion 108. A motor 106 embedded in the horizontal base 43 is connected to the lower end of the rotor 103 and rotates the rotor 103 around its axis.

[0107] As shown in FIG. 21(a), in the released clamping state, the pressing piece 107 extends horizontally forward and perpendicular to the window frame portion 91 (see also FIG. 22(a)). From this state, the motor 106 drives the rotating body 103 to rotate, causing the pressing piece 107 to rotate around the axis of the rotating body 103, as shown in FIG. 22(b). Further rotation of the rotating body 103 causes the pressing piece 107 to press the flange portion 71c via the pressing protrusion 108, thereby clamping the FOUP 7 (see also FIG. 20(b)). Note that instead of the motor 106, an air-driven cam or the like may be used as the drive unit for rotating the rotating body 103.

[0108] By adopting the clamp unit 100 having the above configuration, the thickness of the clamp unit 100 in the front-to-rear direction can be reduced, and the clamp unit 100 can be positioned on the external space side, thereby preventing interference with the wafer transport device 2 operating within the transport space 9.

[0109] In the above embodiment, the entire FOUP 7 side end face 81c of the door part 81 is located closer to the transfer space 9 than the FOUP 7 side end face of the O-ring 94. However, it is sufficient if at least a part of the FOUP 7 side end face 81c of the door part 81 is located closer to the transfer space 9 than the FOUP 7 side end face of the O-ring 94.

[0110] As shown in FIG. 23( a), a recess 111 recessed toward the transfer space 9 is formed in an end face 110 of the door part 81 on the FOUP 7 side (front side). A bottom surface 112 of this recess 111 is located closer to the transfer space 9 than the imaginary line L1 indicating the position of the FOUP 7-side end of the O-ring 94. In other words, at least a portion (bottom surface 112) of the FOUP 7-side end face 110 of the door part 81 is located closer to the transfer space 9 than the FOUP 7-side end of the first seal member 94. This achieves the same effects as the above-described embodiment. "At least a portion of the end face 110" mainly refers to the vicinity of the center of the door part 81 or the area surrounding the center. The concept of the end face 110 does not include a latch mechanism that fastens and releases the lid 72 to the FOUP 7, a suction part 79 that fastens the lid 72 to the door part 81, or a registration pin (not shown) that positions the lid 72 on the door part 81. On the other hand, the outer peripheral surface 113 formed on the outer periphery of the end face 110 is located closer to the FOUP 7 than the imaginary line L1 due to the types of FOUP 7 and lid 72 and manufacturing precision errors. Note that the contact surface 71b of the FOUP 7 is located closer to the transfer space 9 than the lid 72, so the contact surface 71b can come into contact with the O-ring 94 to form the sealed space Sd.

[0111] As shown in FIG. 23(b), a curved surface 117 recessed toward the transfer space 9 is formed on an end surface 116 of the door portion 81 on the FOUP 7 side (front side). This curved surface 117 is located closer to the transfer space 9 than the imaginary line L1, which indicates the position of the FOUP 7-side end of the O-ring 94. In other words, most of the FOUP 7-side end surface 116 of the door portion 81 is located closer to the transfer space 9 than the FOUP 7-side end of the first seal member 94. This provides the same effects as the above-described embodiment. On the other hand, an outer peripheral surface 113 formed on the outer periphery of the end surface 116 is located closer to the FOUP 7 than the imaginary line L1 due to manufacturing precision errors. Note that a portion of the FOUP 7 (the lid 72) is curved toward the transfer space 9. Furthermore, because the contact surface 71b of the FOUP 7 is located closer to the transfer space 9 than the outer periphery of the lid 72, the contact surface 71b can contact the O-ring 94 to form a sealed space Sd. In this way, the shape of curved surface 117 corresponds to expansion surface 118 that expands due to an increase in the pressure inside FOUP 7, so that contact between FOUP 7 and door portion 81 can be reliably prevented even if FOUP 7 expands into various shapes.

[0112] 24(a), a configuration may be adopted in which a recess 111 is formed in an end face 110 of the door section 81, while the outer peripheral surface 113 is located closer to the transfer space 9 than the imaginary line L2. That is, in this modification, the entire end face 110 of the door section 81 is located closer to the transfer space 9 than the end of the first seal member 94 on the FOUP 7 side. This prevents interference between the lid body 72 and the door section 81, and allows the abutment surface 71b to abut against the seal member 94, even if the lid body 72 protrudes into the transfer space 9.

[0113] 24(b), a configuration may be adopted in which the door portion 81 has a curved surface 117, while the outer peripheral surface 113 is positioned closer to the transfer space 9 than the imaginary line L2. That is, in this modification, the entire end surface 110 of the door portion 81 is positioned closer to the transfer space 9 than the end of the first seal member 94 on the FOUP 7 side. This prevents interference between the cover body 72 and the door portion 81, even if the cover body 72 having the expansion surface 118 protrudes toward the transfer space 9, and allows the abutment surface 71b to abut against the seal member 94.

[0114] After the door portion 81 removes the expanded lid 72 from the FOUP 7, the lid 72 may return to its original expansion state. In this case, if the entire end surface 110 of the door portion 81 is positioned closer to the transfer space 9 than the first seal member 94, as shown in FIGS. 24(a) and 24(b), it may be impossible to properly secure the lid 72 to the FOUP 7 or attach the lid 72 to the FOUP 7, depending on the type of latch mechanism or suction unit. Therefore, the position where the above operations are performed may be a predetermined distance closer to the FOUP 7 than the position where the lid 72 is released from the FOUP 7 and removed from the FOUP 7. This predetermined distance is set appropriately depending on the expansion rate of the lid 72 and the type of latch mechanism or suction unit.

[0115] In the above embodiment, the pressure is adjusted using the independent first gas injection nozzle 87, second gas exhaust nozzle 88, second gas injection nozzle 44c, and second gas exhaust nozzle 44d, but the present invention is not limited to this.

[0116] 25 and 26, first supply nozzle 120 that supplies gas merges with second gas injection nozzle 44c. Second gas exhaust nozzle 44d and first gas injection nozzle 87 are connected via intermediate nozzle 121. Second gas injection nozzle 44c and second gas exhaust nozzle 88 are connected via connection nozzle 122. Intermediate nozzle 121 merges with second supply nozzle 123 midway.

[0117] 25, when pressure P1 is higher than pressure P2, first valve 125 and second valve 126 are opened, and third valve 127 through sixth valve 130 are closed. Therefore, gas supplied from first supply nozzle 120 flows into FOUP 7 via second gas injection nozzle 44c. Gas exhausted from FOUP 7 flows through intermediate nozzle 121 via second gas exhaust nozzle 44d and second valve 126. Then, gas supplied to sealed space Sd via first gas injection nozzle 87 is exhausted from second gas exhaust nozzle 88 and flows in this order through connection nozzle 122 and second gas injection nozzle 44c. At second gas injection nozzle 44c, the gas merges with gas newly supplied from first supply nozzle 120. As the gas flows through the above-mentioned flow path, pressure P1 within FOUP 7 and pressure P2 within sealed space Sd become closer to each other.

[0118] As shown in FIG. 26, when pressure P1 is lower than pressure P2, the fourth valve 128 and the fifth valve 129 are opened, and the first through third valves 125 through 127 and the sixth valve 130 are closed. Therefore, gas supplied from the second supply nozzle 123 via the fourth valve 128 flows into the sealed space Sd via the intermediate nozzle 121 and the first gas injection nozzle 87. Gas exhausted from the sealed space Sd flows sequentially through the second gas exhaust nozzle 88 and the connection nozzle 122 and then into the FOUP 7 via the second gas injection nozzle 44c. Gas exhausted from the FOUP 7 is discharged to the outside from the second gas exhaust nozzle 44d through the fifth valve 129. As the gas flows through the above-mentioned flow path, the pressure P1 inside the FOUP 7 and the pressure P2 inside the sealed space Sd become closer to each other. When adjusting the pressures P1 and P3, only the third valve 127 disposed in the transfer space 9 is opened. This allows the FOUP 7 and the transfer space 9 to communicate with each other via the second gas injection nozzle 44c and the connection nozzle 122, thereby making the pressure equal.

[0119] In the above embodiment, nitrogen is used as an example of an inert gas, but the present invention is not limited to this, and any desired gas such as dry gas or argon gas can be used.

[0120] In the above embodiment, O-rings are used as the first seal member 94 and the second seal member 96, but the present invention is not limited to these and any member that ensures sealing properties (hermetic sealing) may be used.

[0121] Furthermore, instead of an O-ring as a sealing member, a hollow sealing member that expands or contracts due to the introduction or discharge of fluid may be used. When this hollow sealing member is used as the first sealing member 94, the FOUP 7 can be brought into contact with the base 41 and then expanded to ensure close contact between the FOUP 7 and the base 41. Furthermore, to further enhance close contact, it is preferable to expand the hollow sealing member after clamping with the clamp unit 50. At this time, the hollow sealing member is crushed by the force applied by the clamp and the force applied by the expansion of the hollow sealing member, thereby improving sealing performance.

[0122] In step S4 of the above embodiment, when the FOUP 7 is clamped to the base 41, the FOUP 7 is moved toward the door portion 81. However, instead of this, after the sealed space Sd is formed, the door portion 81 may be advanced toward the lid body 72 from a state in which the door portion 81 and the lid body 72 are spaced apart (see FIG. 28 ). Note that this advancement is performed to bring the door portion 81 and the lid body 72 closer together and place the lid body 72 in an unlatched state. Therefore, the door portion 81 may be advanced to an extent that a gap is created between the door portion 81 and the lid body 72, or the door portion 81 may be advanced until it comes into contact with the lid body 72. When the door portion 81 is advanced toward the lid body 72, the O-ring 96 is pressed and elastically deformed, maintaining the sealed state of the sealed space Sd.

[0123] In the above embodiment, the sealed space Sd is formed by the base 41, the O-rings 94 and 95, the lid 72, and the door portion 81. However, by employing an O-ring 97 (see FIG. 29 ) in which two O-rings 94 and 95 are integrated, the sealed space Sd may be formed by the O-ring 97, the lid 72, and the door portion 81. [Explanation of symbols]

[0124] 3. Housing 7 FOUP (container) 9. Transport space 41 Base 50 Clamp unit (clamp) 72 Lid 81 Door section (door) 87 First gas injection nozzle (first gas injection part) 88 First gas discharge nozzle (first gas discharge part) 92 Opening 94 O-ring (first seal member) 96 O-ring (second seal member) Sd closed space

Claims

[Claim 1] a base that constitutes a part of a wall that separates the transport space from the outside space; an opening provided in the base; a door that can open and close the opening and that can remove and attach a lid to a container that contains an item; a seal member provided to seal between the container and the door; a sealed space formed by at least the seal member, the container, and the door while the container and the door are in contact with the seal member; a purge mechanism configured to be able to perform both of the following: injecting gas into the sealed space and discharging gas from the sealed space, and injecting gas into the container and discharging gas from the container.

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