Wafer storage container processing equipment

Abstract

To efficiently replace gases within the storage space. [Solution] The wafer storage container processing apparatus according to the embodiment is a wafer storage container processing apparatus that processes a wafer storage container having a main body for storing semiconductor wafers and having a storage space communicating with an opening, and a door that is detachable from the opening, comprising: a mounting stand having a mounting surface on which the wafer storage container is placed; and a gas supply unit that supplies inert gas to the wafer storage container placed on the mounting stand, wherein the mounting stand is placed such that the door is placed on the mounting surface with the door and the main body attached, and the gas supply unit performs the process of supplying the inert gas through a gas supply port provided on an intersecting surface of the main body that intersects with the surface having the opening.

Description

Technical Field

[0001] Embodiments of the present invention relate to a wafer storage container processing apparatus.

Background Art

[0002] Conventionally, there is a wafer storage container processing apparatus that performs various processes such as cleaning and drying on a wafer storage container such as a FOUP (Front Opening Unified Pod) that houses semiconductor wafers.

[0003] Here, there is a technique for replacing the gas in the storage space by supplying an inert gas such as N2 to the storage space for storing the wafers of the FOUP while a door is attached to the main body of the FOUP (FOUP main body). For example, an input port through which an inert gas is input and an output port through which the gas in the storage space is output are provided at the bottom 20i of the FOUP main body 20a shown in FIG. 8.

[0004] Here, the accuracy of the FOUP varies depending on the manufacturer. For this reason, among a plurality of FOUPs, some FOUPs may have a slight gap 20j between the FOUP main body 20a and the door 20b as shown in FIG. 8. Also, due to factors such as aging deterioration, among a plurality of FOUPs, some FOUPs may have a slight gap 20j between the FOUP main body 20a and the door 20b. Therefore, when replacing the gas in the storage space, the inert gas input from the input port may leak through the gap 20j. In this case, the gas replacement in the storage space may not be efficiently performed. Such problems are not limited to FOUPs and similarly exist in other wafer storage containers such as FOSB (Front Opening Shipping Box).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] The present invention was made to solve the above-mentioned problems, and its objective is to provide a wafer storage container processing apparatus that can efficiently replace the gas inside the wafer storage container. [Means for solving the problem]

[0007] To solve the above-mentioned problems and achieve the objective, a wafer storage container processing apparatus according to one aspect of the present invention is a wafer storage container processing apparatus that processes a wafer storage container having a main body for storing semiconductor wafers and having a storage space communicating with an opening, and a door that is detachable from the opening, comprising: a mounting stand having a mounting surface on which the wafer storage container is placed; and a gas supply unit for supplying an inert gas to the wafer storage container placed on the mounting stand, wherein the mounting stand is placed such that the door is placed on the mounting surface with the door and the main body attached, and the gas supply unit performs the process of supplying the inert gas through a gas supply port provided on an intersecting surface of the main body that intersects with the surface having the opening. [Effects of the Invention]

[0008] According to one aspect of the present invention, a wafer storage container processing apparatus can be provided that can efficiently replace the gas in the storage space. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a plan view showing an example of a schematic configuration of a wafer storage container processing apparatus according to an embodiment. [Figure 2] Figure 2 is a perspective view of the buffer according to the embodiment. [Figure 3] Figure 3 is a perspective view of the buffer according to the embodiment. [Figure 4] Figure 4 is a side view of the buffer according to the embodiment. [Figure 5] Figure 5 is a diagram illustrating an example of the arrangement of slots according to the embodiment. [Figure 6] Figure 6 is a flowchart showing an example of the flow of a purging process performed by a wafer storage container processing apparatus according to the embodiment. [Figure 7] Figure 7 is a side view of a modified example of the embodiment of the buffer. [Figure 8] Figure 8 shows an example of the configuration of a wafer storage container. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the wafer storage container processing apparatus disclosed in this application will be described in detail with reference to the attached drawings. However, the wafer storage container processing apparatus disclosed in this application is not limited to the following embodiments. In the following embodiments, the wafer storage container to be subjected to various processes such as cleaning and drying is described as a FOUP, but the wafer storage container to be subjected to various processes is not limited to this. For example, the wafer storage container to be subjected to various processes may be an FOSB. The FOUP is provided with a flange 20c (see Figure 8), and the FOUP is transported by a robot or the like gripping this flange 20c.

[0011] (Embodiment) Figure 1 is a plan view showing an example of the schematic configuration of a wafer storage container processing apparatus 1 according to an embodiment. The wafer storage container processing apparatus 1 is installed, for example, in a factory that manufactures semiconductor wafers, and cleans and dries wafer storage containers.

[0012] As shown in Figure 1, the wafer storage container processing apparatus 1 includes a load port 2, a robot 3, a buffer (disassembly / connection stage) 4, a cleaning tank 5, a drying tank 6, an unload port 7, and a control unit 8.

[0013] The robot 3, buffer 4, washing tank 5, drying tank 6, and control unit 8 are located inside the casing 1a of the wafer storage container processing apparatus 1. On the other hand, the load port 2 and unload port 7 are located across both the inside and outside of the casing 1a of the wafer storage container processing apparatus 1.

[0014] The load port 2 loads the FOUP 20, which is to be cleaned and dried, into the interior of the casing 1a, where it is placed on the exterior of the casing 1a of the load port 2. The FOUP 20 comprises a FOUP body (shell) 20a and a door (lid) 20b. The FOUP body 20a has an opening (FOUP body opening) and a storage space for housing semiconductor wafers. The storage space is located inside the FOUP body opening and communicates with the FOUP body opening. The door 20b can be detached from and connected to the FOUP body 20a, and when connected to the FOUP body 20a, it is attached in a state that allows it to be opened and closed relative to the FOUP body opening. In other words, the door 20b is detachable relative to the FOUP body opening. The FOUP body 20a is an example of the body. The FOUP body 20a is provided with a flange 20c. The flange 20c is the part that is gripped (held) when the FOUP 20 is transported by an OHT (Overhead Hoist Transport) or robot 3, and is provided on the surface of the FOUP body 20a that intersects with the surface having the FOUP body opening.

[0015] For example, the FOUP 20, transported by the OHT, is placed on the external part of the casing 1a of the load port 2. For example, as shown in Figure 1, the FOUP 20 is placed so that its door 20b faces the shutter 2a provided at the opening 1b of the casing 1a. When the FOUP 20 is placed on the load port 2 in this way, the shutter 2a rises. This makes it possible to load the FOUP 20 into the casing 1a from the opening 1b. In other words, the FOUP 20 becomes ready to be loaded into the wafer storage container processing apparatus 1. Then, the FOUP 20 is slid in the direction of arrow 2b by the sliding device of the load port 2. This loads the FOUP 20 into the casing 1a.

[0016] The sliding by the slide device will be described. For example, the pin provided in the slide device is inserted into the hole provided in the bottom surface 20g of the FOUP 20 (see FIG. 3), so that the bottom surface 20g of the FOUP 20 is fixed to the slide device. In this state, when the slide device is slid in the direction of arrow 2b, the FOUP 20 is also slid along with the movement of the slide device. As a result, the FOUP 20 is placed on a predetermined portion inside the casing 1a of the load port 2. When the FOUP 20 is carried into the inside of the casing 1a in this way, the shutter 2a descends and the opening 1b of the casing 1a is closed. The slide device descends together with the pin to a position lower than the lower end of the shutter 2a (the bottom surface 20g of the FOUP 20) and returns to its original position outside the casing 1a.

[0017] The robot 3 conveys the FOUP 20 to each part while gripping the flange 20c of the FOUP 20. The robot 3 includes a robot arm 3a and a robot hand 3b (the gripping part of the robot 3). The robot 3 conveys the FOUP 20 to each part by expanding and contracting or rotating the robot arm 3a with the flange 20c gripped by the robot hand 3b. When the robot 3 conveys the door 20b alone separated (disassembled) from the FOUP main body 20a, it grips both sides of the door 20b and conveys it.

[0018] The buffer 4 is a mounting table on which the FOUP 20 is placed, and disassembles (separates) the FOUP 20 into the FOUP main body 20a and the door 20b, or connects the FOUP main body 20a and the door 20b. For example, the FOUP 20 carried into the inside of the casing 1a is conveyed by the robot 3 to the buffer 4. In this case, the buffer 4 disassembles the FOUP 20 into the FOUP main body 20a and the door 20b. Note that disassembling can be rephrased as unlocking, and connecting can be rephrased as locking.

[0019] The cleaning tank 5 is a tank for cleaning the FOUP 20. For example, in the cleaning tank 5, the FOUP main body 20a and the door 20b are separately conveyed by the robot 3. Then, the cleaning tank 5 performs a cleaning process on the FOUP 20 while holding the FOUP main body 20a and the door 20b separately. That is, the cleaning tank 5 cleans the storage space in a state where the FOUP main body 20a and the door 20b are separated. For example, the cleaning tank 5 holds the door 20b in the lid portion of the cleaning tank 5 and the FOUP main body 20a in the tank portion of the cleaning tank 5 (the cleaning tank main body of the cleaning tank 5), and rotates these by a rotation mechanism (not shown), and discharges a cleaning liquid (for example, pure water) from a cleaning liquid nozzle to each of the FOUP main body 20a and the door 20b, thereby cleaning the FOUP 20. In consideration of the dischargeability of the cleaning liquid, it is preferable that the FOUP opening of the FOUP main body 20a is arranged downward in the cleaning tank 5. The cleaning tank 5 is, for example, an example of a cleaning unit.

[0020] When the cleaning of the FOUP 20 in the cleaning tank 5 is completed, the FOUP main body 20a and the door 20b are continuously rotated in the cleaning tank 5, and dry air is blown onto them for drying. The drying in the cleaning tank 5 here is a process (temporary drying) for removing the cleaning liquid adhering to the FOUP 20. When the temporary drying of the FOUP 20 in the cleaning tank 5 is completed, the robot 3 separately conveys the FOUP main body 20a and the door 20b in the cleaning tank 5 to the drying tank 6.

[0021] The drying tank 6 is a device for vacuum-drying (main drying) the FOUP 20. When the vacuum drying of the FOUP 20 in the drying tank 6 is completed, the robot 3 separately conveys the FOUP main body 20a and the door 20b in the drying tank 6 onto the buffer 4. Then, the buffer 4 connects the FOUP main body 20a and the door 20b. In the present embodiment, after the main drying by the drying tank 6, an inert gas such as N2 is supplied to the storage space of the FOUP 20 in which the FOUP main body 20a and the door 20b are connected on the buffer 4, thereby replacing the gas in the storage space. Such a gas replacement process is also referred to as a purge process. The configuration of the buffer 4 and specific examples of the purge process executed by the buffer 4 will be described later.

[0022] The unload port 7 transports the cleaned, vacuum-dried, and purged FOUP 20, which has been placed inside the casing 1a of the unload port 7 by the robot 3, to the outside of the casing 1a.

[0023] For example, after purging, the FOUP 20 is transported by the robot 3 and placed inside the casing 1a of the unload port 7. When the FOUP 20 is placed in the unload port 7 in this way, the shutter 7a provided at the opening 1c of the casing 1a rises. This makes it possible to transport the FOUP 20 out of the casing 1a through the opening 1c. In other words, the FOUP 20 becomes ready to be transported out of the wafer storage container processing device 1. Then, the FOUP 20 is slid in the direction of arrow 7b by the sliding device of the unload port 7 (which has a mechanism similar to the sliding device of the load port 2), and the FOUP 20 is transported out of the casing 1a. Once the FOUP 20 has been transported out of the casing 1a in this way, the shutter 7a descends, and the opening 1c of the casing 1a is closed.

[0024] The control unit 8 controls the operation of the entire wafer storage container processing apparatus 1. For example, the control unit 8 controls the load port 2, robot 3, buffer 4, cleaning tank 5, drying tank 6, and unload port 7, thereby operating the load port 2, robot 3, buffer 4, cleaning tank 5, drying tank 6, and unload port 7 as described above. The control unit 8 also controls the gas supply nozzle 4c, valves 4e1, 4f1, 4j1, measuring unit 4h, etc., which will be described later.

[0025] For example, the control unit 8 includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), HDD (Hard Disk Drive), and a communication interface. These are connected via an internal bus.

[0026] The CPU executes various processes while using the RAM memory area as a temporary storage area for data used in various processes. The ROM and HDD store programs for executing the various processes described above, such as the purging process, as well as various databases and tables used when executing these processes. The communication interface communicates with the various parts of the wafer storage container processing device 1 described above, and also communicates with external devices connected to the wafer storage container processing device 1 via a network. For example, the communication interface is a network interface card.

[0027] Next, an example of the configuration of the buffer 4 according to this embodiment will be described. Figures 2, 3, and 4 are diagrams showing an example of the configuration of the buffer 4 according to this embodiment. Figures 2 and 3 are perspective views of the buffer 4 according to this embodiment. Figure 2 shows the buffer 4 without the FOUP 20 placed on it, and Figure 3 shows the buffer 4 with the FOUP 20 placed on it. Figure 4 is a side view of the buffer 4 according to this embodiment.

[0028] As shown in Figures 2, 3, and 4, the buffer 4 comprises two latch keys 4a, two frames 4b, a gas supply nozzle 4c, a gas discharge nozzle 4d, piping 4e, piping 4f, and a recovery box 4g.

[0029] The latch key 4a rotates while inserted into the keyhole formed in the door 20b of the FOUP 20, causing the FOUP 20 to separate into the FOUP body 20a and the door 20b, or to connect the FOUP body 20a and the door 20b. For example, if the keyhole of the door 20b is a rectangular recess, the latch key 4a has a so-called T-shape, with its head formed into a rectangular parallelepiped corresponding to the keyhole of the door 20b.

[0030] The two frames 4b have a shape that is a so-called U-shape facing each other in a plan view. The two frames 4b are provided with the open sides of the U-shape facing each other, and the roughly annular shape formed by the two frames 4b is sized to correspond to the outer shape of the door 20b. The door 20b is placed on top of the annular shape formed by the two frames 4b. The two frames 4b are provided at a predetermined distance apart. As a result, two gaps 4b1 are formed between the two frames 4b, and these gaps 4b1 are used as space for the robot arm 3a of the robot 3 to enter when the robot arm 3a places the door 20b on the frames 4b.

[0031] Note that the mounting surface of the door 20b is not limited to a shape such as two U-shaped frames 4b. For example, it may be a rectangular frame that does not have a gap 4b1 into which the robot arm 3a enters. When the FOUP 20 is mounted on two U-shaped frames 4b, if there is a gap 4b1 (a space into which the robot arm 3a enters) between the FOUP body 20a and the door 20b, gas will leak from there. However, if a rectangular frame is used in which no gap 4b1 is formed, gas leakage can be minimized. In this case, if only the door 20b is grasped by the robot hand 3b, it is desirable to provide a new mechanism to raise the door 20b and raise the door 20b accordingly.

[0032] In this embodiment, after the FOUP 20 is fully dried in the drying tank 6, the robot 3 first grasps the door 20b from the drying tank 6 and transports it to the frame 4b of the buffer 4, and then places the door 20b on the frame 4b. Next, the robot 3 grasps the FOUP body 20a and transports it to the frame 4b, and places the FOUP body 20a on the door 20b. At this time, the robot 3 places the FOUP body 20a on the door 20b while positioning it relative to the door 20b.

[0033] When the FOUP body 20a is placed on the door 20b, the latch key 4a connects the FOUP body 20a and the door 20b. As a result, the buffer 4 places the FOUP 20 so that the door 20b is placed on the mounting surface (the upper surface of the frame 4b) with the door 20b and the FOUP body 20a attached. The buffer 4 also has a detachment function that locks / unlocks the door 20b relative to the FOUP body 20a when the door 20b is placed on the mounting surface.

[0034] Here, a groove 4b2 is formed in the frame 4b. In this embodiment, when the FOUP body 20a and the door 20b are connected, a gap 20d is formed between the FOUP body 20a and the door 20b. In this embodiment, when the FOUP 20 is placed on the frame 4b, the groove 4b2 is formed in the frame 4b such that the space formed by the groove 4b2 communicates with the space of the gap 20d. As shown in Figure 2, the groove 4b2 is open only on the upper side of the frame 4b, and the end of the frame 4b on the gap 4b1 side is closed. In other words, when the FOUP 20 is placed on the upper surface of the frame 4b, the groove 4b2 is completely closed.

[0035] As shown in Figure 3, the bottom surface 20g of the FOUP body 20a, that is, the surface (intersecting surface) 20g that intersects with the surface having the opening, is provided with a gas supply port 20e and a gas discharge port 20f. With the FOUP 20 placed on the frame 4b, the gas supply nozzle 4c is coupled to the gas supply port 20e and the gas discharge nozzle 4d is inserted into the gas discharge port 20f. In other words, the gas supply nozzle 4c and the gas discharge nozzle 4d are positioned to correspond to the gas supply port 20e and the gas discharge port 20f when the FOUP 20 is placed on the frame 4b.

[0036] The gas supply nozzle 4c is connected to a gas tank containing an inert gas such as N2, and supplies the inert gas from the gas tank to the storage space of the FOUP body 20a via the gas supply port 20e. In this way, the gas supply nozzle 4c replaces the gas in the storage space of the FOUP 20 placed on the buffer 4 by supplying inert gas to it. The gas supply nozzle 4c and the gas tank are, for example, an example of a gas supply unit.

[0037] As described above, a gas supply port 20e for supplying gas is provided on the bottom surface 20g of the FOUP 20 (FOUP body 20a). When the FOUP 20 is placed so that the door 20b is placed on the upper surface of the frame 4b, which is the mounting surface, the bottom surface 20g of the FOUP 20 (FOUP body 20a) on which the gas supply port 20e is provided will be located on the left side of Figure 4. In this way, when the FOUP 20 is placed so that the door 20b is placed on the frame 4b, which is the mounting surface, the slots (shelves) 20h of the FOUP body 20a, which have a planar shape on which semiconductor wafers are placed, extend in a vertical direction, as shown in Figure 5. Therefore, if dust is attached to the slots 20h inside the FOUP body 20a, the force of the gas supply, in addition to gravity acting on the dust, makes it easier for the dust to move towards the door 20b below, thus suppressing the retention of dust in the slots 20h. Figure 5 is a diagram illustrating an example of the arrangement of the slots 20h according to the embodiment.

[0038] As shown in Figure 4, the gas present in the storage space of the FOUP body 20a is discharged through the gas discharge port 20f to the gas discharge nozzle 4d. A pipe 4e is connected to the gas discharge nozzle 4d, and a recovery box 4g is connected to the pipe 4e. Therefore, the gas discharged from the storage space of the FOUP body 20a flows into the recovery box 4g via the gas discharge port 20f, the gas discharge nozzle 4d, and the pipe 4e. In this way, the recovery box 4g recovers the gas discharged from the storage space. A valve 4e1 is also provided along the gas flow path of the pipe 4e, and the valve 4e1 adjusts the flow of gas into the recovery box 4g by opening and closing it.

[0039] Furthermore, a gas recovery pipe 4f, located on the opposite side from the frame 4b, is connected to the groove 4b2. That is, the space formed by the groove 4b2 is in communication with the space inside the pipe 4f. A recovery box 4g is connected to the pipe 4f. Gas present in the groove 4b2 flows into the recovery box 4g through the pipe 4f. Therefore, gas leaking from the gap 20d between the FOUP body 20a and the door 20b flows into the recovery box 4g via the groove 4b2 and the pipe 4f. In this way, the recovery box 4g recovers the gas leaking from the gap 20d. A valve 4f1 is also provided along the gas flow path of the pipe 4f, and the valve 4f1 adjusts the flow of gas into the recovery box 4g by opening and closing it. The valve 4f1 is located between the point where the two pipes 4f that recover gas from the groove 4b2 merge and the recovery box 4g.

[0040] Inert gas is discharged into groove 4b2 from the storage space of the FOUP body 20a through gap 20d. As a result, the space formed by groove 4b2 gradually becomes positively pressurized by the discharged gas. Pushed by this positive pressure, the gas in groove 4b2 is guided to the recovery box 4g. Alternatively, a suction source such as a pump may be installed at the end of the piping 4f to actively collect the gas in the recovery box 4g. By using a suction source in this way, the gas replacement efficiency can be improved.

[0041] As described above, there is a small gap 20d between the door 20b and the FOUP body 20a, so as the gas replacement in the storage space progresses, gas leaks out from the storage space through the gap 20d. The leaking gas, immediately after the gas supply is started, is air that contains oxygen and moisture similar to the air in the cleanroom where the wafer storage container processing device 1 is installed. However, as time passes after the supply is started, the inert gas supplied from the gas supply nozzle 4c gradually leaks out through the gap 20d.

[0042] The recovery box 4g recovers the gas and stores the recovered gas. For example, the recovery box 4g recovers the gas leaking from the gap 20d and the gas discharged from the gas discharge port 20f. That is, the recovery box 4g recovers a mixture of the gas leaking from the gap 20d and the gas discharged from the gas discharge port 20f (mixed gas). In this way, the recovery box 4g recovers the gas present in the storage space that is replaced by the supply of inert gas from the gas supply nozzle 4c, and the gas that leaks from the gap 20d between the FOUP body 20a and the door 20b. The recovery box 4g also recovers the gas present in the storage space that is replaced by the supply of inert gas from the gas supply nozzle 4c, and the gas discharged from the gas discharge port 20f. The recovery box 4g, gas discharge port 20f, piping 4e, 4f, and valves 4e1, 4f1 are, for example, an example of a gas recovery unit.

[0043] The recovery box 4g is equipped with a measuring unit 4h inside the recovery box 4g for measuring the oxygen concentration of the gas stored inside the recovery box 4g. The measuring unit 4h measures the oxygen concentration at predetermined time intervals and transmits the measured oxygen concentration to the control unit 8. The measuring unit 4h may be, for example, an oxygen concentration meter, which measures the oxygen concentration of the gas and transmits the measured oxygen concentration to the control unit 8. Alternatively, the measuring unit 4h may be, for example, a hygrometer. In this case, the hygrometer measures the humidity of the gas and transmits the measured humidity to the control unit 8.

[0044] Furthermore, a pipe 4j for exhausting the recovered gas is connected to the recovery box 4g. A valve 4j1 is also provided along the gas flow path in pipe 4j. When the recovered gas is to be exhausted, the valve 4j1 is open and the gas flows through pipe 4j. Here, a suction source such as a pump may be provided at the end of pipe 4j to actively exhaust the gas. By using a suction source in this way, the gas exhaust efficiency can be improved.

[0045] In this embodiment, the control unit 8 controls the supply of inert gas to the storage space based on the measured value transmitted from the measuring unit 4h. For example, the control unit 8 compares the measured value with a predetermined value, and if the measured value is greater than or equal to the predetermined value, it controls the gas supply nozzle 4c so that the supply of inert gas continues. On the other hand, if the measured value falls below the predetermined value, it is considered that the storage space of the FOUP body 20a is filled with inert gas, so the control unit 8 controls the gas supply nozzle 4c to stop the supply of inert gas from the gas supply nozzle 4c. To give a specific example, the control unit 8 compares the oxygen concentration with a first predetermined value, and if the oxygen concentration falls below the first predetermined value, it controls the gas supply nozzle 4c to stop the supply of inert gas. Also, the control unit 8 compares the humidity with a second predetermined value, and if the humidity falls below the second predetermined value, it controls the gas supply nozzle 4c to stop the supply of inert gas. The predetermined values ​​(the first predetermined value and the second predetermined value) are the oxygen concentration and humidity values ​​that create an environment where the components within the storage space can be kept from oxidizing. These oxygen concentration and humidity values ​​have been determined in advance through experiments, simulations, etc.

[0046] Next, an example of a purging process performed by the wafer storage container processing apparatus 1 according to this embodiment will be described. Figure 6 is a flowchart showing the flow of an example of a purging process performed by the wafer storage container processing apparatus 1 according to this embodiment. The purging process shown in Figure 6 is performed when the vacuum drying of the FOUP 20 is completed in the drying tank 6.

[0047] In step S101 of the purging process shown in Figure 6, the buffer installation step involves robot 3 transporting the FOUP body 20a and the door 20b separately onto the buffer 4 from within the drying tank 6. The buffer 4 then connects the FOUP body 20a and the door 20b.

[0048] Next, in the purge nozzle coupling step S102, with the FOUP 20 placed on the frame 4b, the gas supply nozzle 4c is coupled to the gas supply port 20e and the gas discharge nozzle 4d is inserted into the gas discharge port 20f.

[0049] Next, in the gas replacement step S103, the gas supply nozzle 4c starts supplying inert gas to the storage space of the FOUP body 20a, thereby starting the replacement of the gas in the storage space. In step S103, the control unit 8 opens valves 4e1 and 4f1 and closes valve 4j1. As a result, the recovery box 4g starts recovering the mixed gas described above.

[0050] Next, in the purge completion confirmation step S104, the control unit 8 controls the gas supply nozzle 4c so that the supply of inert gas continues if the measured value transmitted from the measuring unit 4h is equal to or greater than a predetermined value. On the other hand, if the measured value falls below the predetermined value, the control unit 8 controls the gas supply nozzle 4c to stop the supply of inert gas, as it is assumed that the storage space of the FOUP body 20a is filled with inert gas.

[0051] If the supply of inert gas is stopped, in the next step S105, the purge nozzle removal process, with the FOUP20 placed on the frame 4b, the gas supply nozzle 4c is removed from the gas supply port 20e and the gas discharge nozzle 4d is removed from the gas discharge port 20f.

[0052] Then, in the next step SS106, the buffer removal process, robot 3 removes FOUP20 from buffer 4 and transports the removed FOUP20 to unload port 7. FOUP20 is then discharged from wafer storage container processing device 1.

[0053] The wafer storage container processing apparatus 1 according to this embodiment has been described above.

[0054] Here, we will describe an example of a conventional wafer storage container processing device and a conventional FOUP. Conventionally, there is a technology to replace the gas inside the FOUP by supplying an inert gas. However, if there is a small gap between the FOUP body and the door, gas replacement may not be performed efficiently. Furthermore, since this gap differs from one FOUP to another, it is not possible to detect whether the gas replacement inside each FOUP has been sufficiently performed. It is also possible to set a predetermined time for when the gas replacement inside the FOUP will be completed, and to perform control so that the gas replacement inside the FOUP is determined to be complete when the predetermined time has elapsed from the start of inert gas supply. However, when performing such control, the predetermined time must be set to be long enough to ensure that the replacement is definitely completed, and as a result, the inert gas is supplied for longer than the time when the replacement is actually completed, resulting in wasted costs and processing time.

[0055] Furthermore, conventional FOUPs are equipped with both a gas supply port for supplying inert gases such as N2 gas and a gas discharge port for discharging gas. It is thought that measuring the gas discharged from the gas discharge port can detect whether the gas replacement is complete. However, both of these ports are located on the same surface of the FOUP (the bottom surface of the FOUP, the surface that intersects with the surface of the opening where the door is attached), and because these two ports are located in close proximity, a relatively large amount of inert gas may be discharged from the gas discharge port even if the gas replacement inside the FOUP is not complete.

[0056] Furthermore, with conventional FOUPs, a large amount of inert gas is released through the gap between the FOUP door and the FOUP body, and if only a small amount of gas is released from the gas discharge port, measurement may not be possible. Therefore, it is difficult to detect the gas displacement state inside the FOUP using this method as well.

[0057] On the other hand, in this embodiment, when the FOUP 20 is placed on the buffer 4 with the door 20b facing downwards during purging, the weight of the FOUP body 20a presses the door 20b against the frame 4b, causing the FOUP body 20a and the door 20b to be in close contact and reducing the size of the gap 20d. As a result, the amount of gas leaking out from the gap 20d can be reduced. Therefore, the gas inside the FOUP 20 can be replaced efficiently.

[0058] Furthermore, in the wafer storage container processing apparatus 1 according to the embodiment, the FOUP 20 is positioned such that the FOUP body 20a and the door 20b are connected and the door 20b is placed on the frame 4b. This allows for measurement of the oxygen concentration and humidity inside the storage space even when there is more gas coming out from the gap 20d between the door 20b and the FOUP body 20a than from the gas discharge port 20f.

[0059] Furthermore, as described above, by placing the FOUP 20 on the buffer 4 with the door 20b facing downwards and performing a purging process, the slot 20h of the FOUP body 20a will be positioned so that it extends vertically. As a result, in addition to the force of the gas supply, gravity acts on the debris, making it easier for the debris in the slot 20h to move towards the door 20b, thus suppressing the retention of debris in the slot 20h.

[0060] Furthermore, if the FOUP 20 were placed so that the gas supply port 20e and gas discharge port 20f were on the lower side, it would be necessary to provide a member to cover the entire door 20b in order to catch the gas leaking out from the gap 20d. However, according to this embodiment, the mounting surface of the buffer 4 also serves to cover the door 20b, so it is only necessary to provide an additional frame 4b to cover the gap 20d.

[0061] As described above, according to this embodiment, the gas inside the FOUP20 can be replaced efficiently.

[0062] Furthermore, compared to conventional systems that only measure the gas discharged from a single gas discharge port, this embodiment improves the reliability of the measurement because it also measures the gas leaking from the gap 20d in addition to the gas discharge port 20f.

[0063] Furthermore, since buffer 4 is equipped with a function to attach (connect) the door 20b and the FOUP body 20a of FOUP 20, gas replacement and the attachment of the door 10b and the FOUP body 20a can be performed simultaneously in the same location, enabling efficient purging.

[0064] (Modified examples of the embodiment) Next, a modified version of the embodiment will be described. In the following description of the modified version, we will mainly describe configurations that differ from the embodiment described above, and may omit descriptions of configurations that are the same as those in the embodiment described above.

[0065] Figure 7 is a side view of a modified example of the embodiment. The modified example of the buffer 4 shown in Figure 7 differs from the buffer 4 according to the embodiment shown in Figure 4 in that it further includes a flow meter 4e2 and a flow meter 4f2. Although not shown in Figure 7, the modified example of the buffer 4 also includes a flow meter (supply gas flow meter) installed on the gas flow path of the piping connecting the gas tank and the gas supply nozzle 4c.

[0066] The flow meter 4e2 is installed on the path through which the gas flows in the piping 4e, and measures the flow rate of the gas discharged from the gas discharge port 20f and flowing into the recovery box 4g at predetermined time intervals, and transmits the measured flow rate to the control unit 8.

[0067] The flow meter 4f2 is installed on the path through which gas flows in the piping 4f, and measures the flow rate of gas leaking out from the gap 20d and flowing into the recovery box 4g at predetermined time intervals, and transmits the measured flow rate to the control unit 8.

[0068] The supply gas flow meter measures the flow rate of gas supplied from the gas tank to the gas supply nozzle 4c at predetermined time intervals and transmits the measured flow rate to the control unit 8.

[0069] The modified control unit 8 performs various controls based on the flow rates transmitted from the flow meters 4e2, 4f2 and the supply gas flow meter. For example, each time the control unit 8 receives a flow rate transmitted by the flow meter 4f2, it controls the unit to output information indicating that gas is leaking according to the received flow rate.

[0070] To explain with a specific example, the control unit 8 compares the flow rate from the flow meter 4f2 with a predetermined threshold. If the flow rate from the flow meter 4f2 is greater than or equal to the predetermined threshold, it outputs information indicating that gas is leaking from the gap 20d by displaying it on a display connected to the control unit 8. An example of information indicating that gas is leaking from the gap 20d is a text message such as "Gas is leaking." Furthermore, if the flow rate from the flow meter 4f2 is greater than or equal to the predetermined threshold, the control unit 8 transmits the information indicating that gas is leaking, along with the flow rate from the flow meter 4f2, to an external server that centrally manages the FOUP 20, along with an ID (Identification) to identify the FOUP 20 placed in the buffer 4. As a result, this information and the flow rate from the flow meter 4f2 are output to the external server. The external server then stores the ID, the information indicating that gas is leaking, and the flow rate of the leaking gas in association. Furthermore, for FOUP20 units with the same ID, the history of gas leakage may be recorded, and information to discontinue the use of the FOUP20 unit may be stored in association with the ID if the leakage amount increases over time, if the rate of increase exceeds a predetermined rate, or if the leakage amount exceeds a predetermined threshold.

[0071] Furthermore, the control unit 8 compares the sum of the flow rates from flow meter 4f2 and flow rate from flow meter 4e2 with the flow rate from the supply gas flow meter. If the flow rate from the supply gas flow meter is greater than the sum of the two values, the control unit 8 determines that there may be a gas leak from a location other than the gas discharge port 20f. Therefore, if the flow rate from the supply gas flow meter is greater than the sum of the two values, the control unit 8 displays information on the display indicating that there may be a gas leak. For example, this information could be a text message such as, "There may be a gas leak from a location other than the discharge port." Also, if the flow rate from the supply gas flow meter is greater than the sum of the two values, the control unit 8 sends information indicating that there may be a gas leak, along with an ID to identify the FOUP 20 located in buffer 4, to an external server that centrally manages the FOUP 20. The external server then stores the ID and the information indicating that there may be a gas leak in association.

[0072] According to the modified version, the user of the wafer storage container processing device 1 can appropriately grasp the various gas leak conditions. This allows them to decide whether or not to continue using the FOUP 20 depending on the gas leak conditions. [Explanation of Symbols]

[0073] 1. Wafer storage container processing device 4 buffers 4a Latch key 4b frame 4b2 groove 4c Gas supply nozzle 4e, 4f, 4j piping 4e1, 4f1, 4j1 valves 20 FOUP 20a FOUP main unit 20b Door 20d gap

Claims

1. A wafer storage container processing apparatus having a main body for storing semiconductor wafers and having a storage space communicating with an opening, and a door that can be attached to and detached from the opening, A mounting platform having a mounting surface on which the wafer storage container is placed, The system includes a gas supply unit that supplies inert gas to the wafer storage container placed on the mounting platform, The mounting stand is used to place the wafer storage container such that the door is placed on the mounting surface described above, with the door and the main body attached. The wafer storage container processing apparatus includes a gas supply unit which supplies the inert gas via a gas supply port provided on an intersecting surface of the main body that intersects with the surface having the opening.

2. The wafer storage container processing apparatus according to claim 1, wherein the mounting platform has a detachment function for locking / unlocking the door relative to the main body when the door is mounted on the mounting surface described above.

3. The gas present in the storage space is replaced by the supply of the inert gas from the gas supply unit, and the gas that leaks out from the gap between the main body and the door is collected in a box by the gas recovery unit, A measuring unit for measuring at least one of the oxygen concentration and humidity of the gas inside the box, It has a control unit that controls the gas supply unit and the measuring unit, The wafer storage container processing apparatus according to claim 1, wherein the control unit controls the gas supply unit to stop supplying the inert gas from the gas supply unit when at least one of the oxygen concentration and humidity measured by the measuring unit falls below a predetermined value.

4. The unit has a cleaning section for cleaning the storage space while the main body and the door are separated, The wafer storage container processing apparatus according to claim 1, wherein the gas supply unit supplies the inert gas to the wafer storage container placed on the stand described above after cleaning by the cleaning unit.

5. The gas recovery unit further recovers the gas discharged from the gas discharge port provided on the intersecting surface. The wafer storage container processing apparatus according to claim 3, wherein the measuring unit measures at least one of the oxygen concentration and humidity of a mixed gas of the gas leaked from the gap and the gas discharged from the gas discharge port, which is recovered by the gas recovery unit.

6. A flow meter side section for measuring the flow rate of gas leaking from the aforementioned gap, A control unit that controls the output of information indicating that gas is leaking when the flow rate of the gas is above a predetermined threshold, A wafer storage container processing apparatus according to claim 3, comprising:

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