TWI819160B - Equipment front-end module (EFEM) - Google Patents

Abstract

[Problem] To improve the safety of workers at the EFEM introduction site, it is proposed to suppress the decrease in oxygen concentration in the isolation portion between the nitrogen supply space and the atmosphere. [Solution] EFEM1 is set so that the purge nozzle (9) is connected to the first adjustment part in contact with the port (40), the boundary part of the base (21) including the load port (2) and the load port door (22), or with The second adjustment position of at least one of the boundary parts of the FOUP door (43), the transfer chamber (3) and the boundary part of the base (21) of the loading port (2), that is, the third adjustment position, is in the transfer chamber (3) The outer side is used to store a part of the door driving mechanism (27) of the loading port (2) and forms a downward airflow of inert gas in the inner space around the driving system storage box (28), that is, the fourth adjustment position. Nozzle ports (x1), (x2), and (x3) for ejecting air are provided near at least one of the adjustment positions.

Description

Equipment front-end module (EFEM)

The present invention relates to an Equipment Front End Module (EFEM) used for automatic transportation of wafers.

In the semiconductor manufacturing process, wafers are processed in clean rooms in order to improve yield or quality. In recent years, the "mini-environment method" has been adopted to further improve the cleanliness of only the local space around the wafer, and other processing methods such as transportation of the wafer have been adopted. In the micro-environment method, the interior of the casing forms part of the wall of a substantially closed wafer transfer chamber (hereinafter referred to as the "transfer chamber"), and a container containing wafers is placed in a high-clean internal space. That is, the FOUP (Front-Opening Unified Pod), and the load port (Load Port) that has the function of opening and closing the FOUP door in a state of close contact with the FOUP door (hereinafter referred to as the "FOUP door") is installed adjacent to the transfer room. .

The load port is a device for entering and exiting wafers from the transfer chamber, and functions as an interface between the transfer chamber and the FOUP. When the load port door (hereinafter referred to as the "load port door") that can engage with the FOUP door and open and close the FOUP door is opened, the transfer robot (wafer transfer device) installed in the transfer chamber can The wafers in the FOUP are taken into the transfer chamber, or the wafers are stored in the FOUP from the transfer chamber.

In the semiconductor manufacturing process, in order to properly maintain the atmosphere around the wafer, the above-mentioned storage container called FOUP is used to store and manage the wafer inside the FOUP. Especially in recent years, with the advancement of high integration of components or miniaturization of circuits, it is required to maintain high cleanliness around the wafer without causing dust or moisture to adhere to the surface of the wafer. Here, in order not to change the surface properties of the wafer surface due to oxidation, etc., the inside of the FOUP is filled with nitrogen gas, and the periphery of the wafer is made into an inert gas, that is, nitrogen atmosphere, and is placed in a vacuum state ( Purification treatment) is also carried out.

Furthermore, an EFEM composed of a transfer chamber filled with inert gas, that is, nitrogen, has also been proposed and put into practical use (for example, Patent Document 1). Specifically, this EFEM is provided with: a circulation channel including a transfer chamber that circulates nitrogen within the transfer chamber; a gas supply means for supplying nitrogen to the circulation channel; and a gas discharge means for discharging nitrogen from the circulation channel. Nitrogen is appropriately supplied and discharged in response to changes in oxygen concentration and the like in the circulation flow path. This makes it possible to suppress an increase in the supply amount of nitrogen and maintain a nitrogen atmosphere in the transfer chamber compared with a configuration in which nitrogen is constantly supplied and discharged. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2017-212322

[Problem to be solved by the invention]

However, the oxygen concentration in the vicinity of the portion that isolates the nitrogen supply space from the atmospheric space (for example, within 1 mm from the isolated portion) needs to be maintained at a safe concentration (for example, 19.5% or more) for the operator. This is to avoid the risk of workers falling into a hypoxic state and fainting when entering a space with extremely low oxygen concentration.

The present invention was made in view of such a problem, and its main purpose is to provide an EFEM that can suppress the supply of inert gas such as nitrogen between the space and the atmosphere in order to improve the safety of workers at the EFEM introduction site. The oxygen concentration in the isolated part is reduced. In addition, the present invention is a technology that can cope with wafer storage containers other than FOUP. [Means to solve the problem]

That is, the EFEM of the present invention is characterized by having: a transfer chamber in which a loading port and a processing device are connected to an opening provided in the wall surface to form a substantially closed wafer transfer space; and a wafer transfer device. , which is disposed in the wafer transfer space, and transfers wafers between the wafer storage container placed in the loading port and the processing device; the EFEM is configured to generate a downward airflow in the wafer transfer space and simultaneously generate nitrogen. The inert gas circulates in the wafer transfer space. In the EFEM of the present invention, the following can be used as the loading port: a base that forms part of the front wall of the transfer chamber and has a plate shape with an opening opening to the inner space of the transfer chamber; and the opening of the base is A loading port door that opens and closes; a mounting table installed on the base in a substantially horizontal position; and a bottom purification device that brings a nozzle provided on the mounting table into contact with a port disposed on the bottom of a wafer container placed on the mounting table In this state, the gas atmosphere in the wafer storage container can be replaced with a purification gas composed of an inert gas such as nitrogen from the bottom side of the wafer storage container; and a door driving mechanism that drives the load port door; the nozzle system An ejection port or a gas suction port for ejecting air is provided near at least one of the plurality of adjustment parts. The plurality of adjustment parts are the first adjustment part that contacts the port, including the base and the loading port. The second adjustment position is at least one of the boundary part of the door or the door of the wafer storage container, that is, the container door, and the third adjustment position, the boundary part of the transfer chamber and the base, is used outside the transfer chamber. The fourth adjustment position is located around the drive system storage box that stores a part of the door drive mechanism in the loading port and forms a downflow of inert gas in the internal space.

The inventors of the present invention have focused on the main cause of the reduced oxygen concentration that is dangerous for operators at the EFEM introduction site, originating from the port provided on the bottom surface of the wafer storage container and the bottom purification nozzle provided in the loading port. Inert gases such as nitrogen used in the bottom purification process may leak slightly but may leak, or inert gases such as nitrogen originating from the wafer container between the wafer container body and the wafer container door. Although it is small, there is still a leak. In the EFEM, which is constructed by filling the transfer chamber with inert gas such as nitrogen, it may come from between the transfer chamber and the load port, or from the drive system storage box that houses the mechanism that drives the load port door. The EFEM of the present invention was developed and completed in order to prevent and suppress the local decrease in oxygen concentration in the vicinity of the leakage portion, even though there is a small leakage of inert gas in the transfer chamber of the loading port door.

According to the EFEM of the present invention, air is supplied from an ejection port to a portion (isolation portion) that isolates a space for supplying inert gas such as nitrogen from the atmosphere, or the gas in the isolation portion (high temperature) is supplied through a gas suction port. By absorbing an inert gas with a certain concentration, the decrease in oxygen concentration in the vicinity of the isolated part can be suppressed, thereby improving the safety of the operator.

In particular, the EFEM of the present invention is equipped with an adjustment means by which the supply amount of the inert gas to the wafer transfer space, the supply amount of the purification gas by the bottom purification device, or the direction of the inert gas in each adjustment part is adjusted. The amount of leakage on the atmospheric pressure side can be adjusted based on either the amount of air ejected from the ejection port or the suction force of the gas suction port. Therefore, the area around the isolated part can be suppressed by an appropriate air supply amount or suction force. The decrease in oxygen concentration in the [Effects of the invention]

According to the present invention, at an EFEM introduction site that performs appropriate processing on wafers, it is possible to suppress the decrease in oxygen concentration in a portion isolated from the atmosphere by supplying an inert gas such as nitrogen, thereby improving operator safety. EFEM.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

The EFEM (Equipment Front End Module) 1 of this embodiment is equipped with a load port 2 and a transfer chamber 3 arranged in a clean room in the semiconductor manufacturing process as shown in FIG. 1 . Figure 1 schematically shows the relative positional relationship between EFEM1 and its peripheral devices. The figure shows that FOUP4 is used simultaneously with EFEM1.

A transfer robot 31 capable of transferring the wafer W between the FOUP 4 and the processing apparatus M is provided in the wafer transfer space 3S, which is an internal space of the transfer chamber 3 . By driving the fan filter unit 32 installed in the transfer chamber 3, a downward airflow is generated in the wafer transfer space 3S of the transfer chamber 3, so that high-purity gas, that is, inert gas (ambient gas) such as nitrogen, can pass through the wafer. 3S circulation of transportation space. In the transfer chamber 3 , a processing device M (semiconductor processing device) is provided adjacent to the rear wall surface 3B facing the front wall surface 3A on which the load port 2 is arranged. That is, the loading port 2 is connected to the opening on the front wall 3A of the transfer chamber 3 , and the processing device M is connected to the opening on the rear wall 3B, thereby forming a substantially closed wafer inside the transfer chamber 3 Transport space 3S.

In the clean room, the internal space MS of the processing device M, the wafer transfer space 3S of the transfer chamber 3, and the internal space 4S of the FOUP 4 placed on the load port 2 are maintained at high purity.

In the present embodiment, as shown in FIG. 1 , the loading port 2 , the transfer chamber 3 , and the processing device M are arranged in close contact with each other in order in the front and rear direction D of the EFEM 1 . In addition, the operation of EFEM1 is controlled by the controller of the load port 2 (control unit 2C shown in FIG. 3) or the controller of the entire EFEM1 (control unit 3C shown in FIG. 1), and the operation of the processing device M is controlled by the processing device. M's controller (control unit MC shown in Figure 1) performs control. Here, the control unit MC, which is the entire controller of the processing device M, or the control unit 3C, which is the entire controller of the EFEM 1 , is an upper-level controller of the control unit 2C of the load port 2 . Each of the control units 2C, 3C, and MC is composed of a common microprocessor equipped with a CPU, a memory, and an interface. Programs necessary for processing are stored in the memory in advance, and the CPU sequentially retrieves and executes the necessary programs. , and work together with peripheral hardware resources to achieve the desired function.

As shown in FIGS. 1 and 2 , the FOUP 4 is provided with a FOUP body 42 that can be opened to the internal space 4S through a carry-out entrance 41 , which is an opening, and a FOUP door 43 that can open and close the carry-out entrance 41 . It is known that a plurality of wafers W are stored in a plurality of stages in the vertical direction H, and the wafers W can be moved in and out through the unloading entrance 41 .

The FOUP body 42 is provided with a rack (wafer mounting rack) capable of mounting the wafer W at a plurality of predetermined pitches in the internal space 4S. The bottom wall of the FOUP body 42 is provided with ports 40 at predetermined locations as shown in FIG. 2 and others. For example, the main system of the port 40 is formed by a hollow cylindrical grommet seal that can be inserted into a through-hole for port installation formed in the bottom wall of the FOUP body 42, and is configured to be opened and closed by a check valve. A flange portion held by a container transport device (for example, OHT: Over Head Transport) or the like is provided at the upper center portion of the upper wall of the FOUP body 42 .

The FOUP door 43 faces the load port door 22 of the load port 2 in a state of being placed on the mounting table 23 described later on the load port 2, and is formed in a rough plate shape. The FOUP door 43 is provided with a lock key (not shown) that can lock the FOUP door 43 to the FOUP body 42 . In the FOUP door 43, a gasket (not shown) is provided at a predetermined portion that is in contact with or close to the FOUP body 42 in a state where the carry-out entrance 41 is locked by the FOUP door 43. The gasket is brought into contact with the FOUP body 42. The elastic deformation can seal the internal space 4S of FOUP4.

The load port 2 of this embodiment, as shown in FIGS. 2 to 5 , etc., has an opening 21 a forming a part of the front wall 3A of the transfer chamber 3 and forming the wafer transfer space 3S of the transfer chamber 3 . A plate-shaped base 21; a loading port door 22 that opens and closes the opening 21a of the base 21; and a mounting base 23 installed in a substantially horizontal position on the base 21.

A foot portion 24 having casters and set legs is provided at the lower end of the base 21, and a window unit 214 is provided at a position facing the FOUP door 43 (see Fig. 6). The opening 215 provided in the window unit 214 is an opening that allows the wafer W to pass. In this embodiment, as shown in this figure, a loading port 2 having a sealing portion 5 surrounding the opening 21a of the base 21 is used. As shown in Fig. 2 , a seal is provided at a position where the base 21 is held along the thickness direction. Parts 5 and 6.

The mounting base 23 is provided on an upper portion of a horizontal base 25 (support base) arranged in a substantially horizontal attitude at a position slightly above the center in the height direction of the base 21 . This mounting base 23 is capable of placing the FOUP 4 in a state where the FOUP door 43 and the loading port door 22, which can open and close the internal space 4S of the FOUP body 42, are facing each other. Furthermore, the mounting table 23 is configured such that the FOUP door 43 is at a predetermined docking position (refer to FIG. 7 ) close to the opening 21 a of the base 21 with respect to the base 21 , and the FOUP door 43 is further away from the base 21 by a predetermined distance than the docking position. It can move forward and backward between the positions (see Figure 2). The mounting platform 23, as shown in FIG. 3, has a plurality of protrusions (pins) 231 protruding upward. By engaging these protrusions 231 with holes (not shown) formed in the bottom surface of the FOUP 4, the mounting platform 23 is mounted. Positioning of FOUP4 on stage 23. Furthermore, a lock claw 232 is provided for fixing the FOUP 4 to the mounting base 23 . By hooking the locking pawl 232 on a locked portion (not shown) provided on the bottom surface of the FOUP 4 and setting it in a fixed locking state, it cooperates with the positioning protrusion 231 to guide one side of the FOUP 4 to the carrier. Fix it while placing it in an appropriate position on the platform 23. In addition, by releasing the locked state of the locked portion provided on the bottom surface of the FOUP 4 by the locking pawl 232, the FOUP 4 can be brought into a state in which it can be separated from the mounting base 23.

The loading port door 22 is provided with a linking mechanism 221, which allows the FOUP door 43 to be connected to the cover in a state where the FOUP door 43 can be detached from the FOUP body 42, and to a state in which the FOUP door 43 is unlinked and the FOUP door 43 is detachable. The door 43 is switched between the disconnected state of the cover attached to the FOUP body 42 (see FIG. 5 ), and the FOUP door 43 is held in an integrated state by the connection mechanism 221 and moves along a predetermined path. Mover. The load port 2 of this embodiment is configured so that the load port door 22 can move at least between the following fully closed position (C) and the open position (O). The fully closed position (C) is the position shown in FIG. 7, That is, the internal space 4S of the FOUP body 42 is sealed by the FOUP door 43 held by the load port door 22. The open position (O) is the position shown in FIG. 8, that is, the load port door 22 The held FOUP door 43 is separated from the FOUP body 42 and opens the internal space 4S of the FOUP body 42 into the transfer chamber 3 . The load port 2 of this embodiment is movable to the open position (O) shown in FIG. 8 while maintaining the upright posture of the load port door 22 positioned at the fully closed position (C), and is configured to maintain the upright position. In the posture state, it can move in the downward direction from the open position (O) shown in FIG. 8 to the fully open position (not shown). Such movement of the load port door 22 is realized by the door driving mechanism 27 provided in the load port 2 .

The door driving mechanism 27, as shown in FIG. 2 and others, includes: a support frame 271 that supports the loading port door 22; a movable block 273 that supports the support frame 271 through a sliding support portion 272 so as to be movable in the front-rear direction D; The movable block 273 supports a slide rail 274 that can move in the up and down direction H; and a driving source (for example, not shown) that moves in the front and rear direction D along the horizontal path of the loading port door 22 and moves in the up and down direction H along the vertical path. actuator shown). By supplying a drive command to the actuator from the control unit 2C, the load port door 22 is moved in the front-rear direction D and the up-down direction. Alternatively, the actuator may be provided with an actuator for forward and backward movement and the actuator for up and down movement, or a common actuator may be used as a driving source to perform forward and backward movement and up and down movement.

The support frame 271 supports the lower rear portion of the load port door 22 . After extending downward, the support frame 271 passes through the slit-shaped insertion hole 21b formed in the base 21 and takes a substantially crank shape protruding toward the outside of the transfer chamber 3 (toward the mounting table 23 side). The sliding support part 272, the movable block 273, and the slide rail 274 that support the support frame 271 are also arranged closer to the mounting table 23 side than the base 21, that is, closer to the outside of the transfer chamber 3. The sliding support part 272, the movable block 273, and the slide rail 274 become the sliding parts when the loading port door 22 moves. In this embodiment, by arranging them outside the transfer chamber 3, even if fine dust is generated when the loading port door 22 is moved, the insertion hole 21b is set in a minute slit shape. It is possible to prevent and suppress the entry of fine dust into the transfer chamber 3 state. In addition, the loading port 2 of this embodiment is provided with members or parts of the door driving mechanism 27 arranged outside the transfer chamber 3, specifically a part of the support frame 271, the sliding support part 272, the movable block 273 and the sliding block 272. The drive system storage box 28 is covered with rails 274 . Thereby, it is set so that the inert gas (ambient gas) in the transfer chamber 3 will not flow out of the EFEM1 through the insertion hole 21b formed in the base 21. Furthermore, a downward airflow of inert gas is formed in the internal space of the drive system storage box 28 .

Furthermore, the load port 2 of this embodiment is provided with a movement restriction part L that restricts the movement of the FOUP 4 positioned on the mounting base 23 at the docking position in the direction away from the base 21 . In this embodiment, the movement restriction part L is unitized as a window unit 214 (see FIG. 6 ).

The loading port 2 of this embodiment is equipped with a purification device P that injects a purification gas made of an inert gas such as nitrogen into the internal space 4S of the FOUP 4 and can replace the gas atmosphere in the internal space 4S of the FOUP 4 with the purification gas (see Figure 3). The purification device P is provided with a plurality of purification nozzles 9 (gas supply and discharge devices) arranged at a predetermined position in a state where the upper end can be exposed from the mounting table 23 . The plurality of purification nozzles 9 are installed at appropriate positions on the mounting table 23 corresponding to the position of the port 40 provided on the bottom surface of the FOUP 4, and can be connected while in contact with the port 40. The bottom purification process using such a purification device P causes a predetermined number (except all) of the plurality of ports 40 provided at the bottom of the FOUP 4 to function as "supply ports" by connecting to the supply ports. The purge nozzle 9 injects an appropriately selected purification gas such as nitrogen gas, inert gas, or dry air into the FOUP 4, and at the same time, the remaining port 40 functions as an "exhaust port", and the remaining port 40 is connected to the exhaust port through the exhaust port. The purge nozzle 9 discharges the gas atmosphere in the FOUP 4, thereby filling the FOUP 4 with purification gas. The loading port 2 is equipped with a pressure sensor (not shown) for detecting the gas pressure (exhaust pressure) of the purge nozzle 9 connected to the port 40 functioning as an exhaust port during the bottom purification process.

The load port 2 of this embodiment is equipped with a mapping part (mapping) m that can detect the presence or storage posture of the wafer W in the FOUP 4 as shown in FIG. 9 . The mapping unit m has mapping sensors (transmitter m1 and receiver m2) that can detect the presence or absence of wafers W housed in multiple segments in the height direction H in the FOUP 4, and a sensor frame that supports the mapping sensors m1 and m2. m3. The mapping unit m may be in a posture between a mapping retraction posture in which the entirety of the mapping unit m is disposed in the transport space within the transport chamber 3 and a mapping posture in which at least the mapping sensors m1 and m2 are positioned in the FOUP 4 through the opening 21 a of the base 21 . The mapping unit m is configured to be movable in the height direction H while maintaining the mapping retraction posture or the mapping posture. As shown in FIG. 9 , by attaching a part of the sensor frame m3 to a part of the door driving mechanism 27 , the lifting movement of the mapping part m and the lifting movement of the load port door 22 are performed integrally. In addition, the mapping part m is omitted in each figure except FIG. 9 .

The mapping sensor is composed of a transmitter m1 (light-emitting sensor) that emits a signal, that is, a light beam (light), and a receiver m2 (light-receiving sensor) that receives the signal emitted from the transmitter m1. In addition, the mapping sensor may be composed of a transmitter and a reflection part that reflects light emitted by the transmitter toward the transmitter. In this case, the transmitter also functions as a receiver.

Next, the operation flow of EFEM1 will be explained.

First, the FOUP 4 is transported above the loading port 2 by a container transport device such as an OHT, and placed on the mounting table 23 . At this time, for example, the positioning protrusion 231 provided on the mounting base 23 is fitted into the positioning recess of the FOUP 4, and the locking pawl 232 on the mounting base 23 is set to the locked state (locking process). In this embodiment, three FOUPs 4 can be placed on the mounting bases 23 of the load ports 2 arranged in parallel in the width direction of the transfer chamber 3 . Alternatively, the seat sensor (not shown) that detects whether the FOUP 4 is placed at a predetermined position on the placement base 23 may be configured to detect that the FOUP 4 is placed in a regular position on the placement base 23 .

The loading port 2 of this embodiment detects when the FOUP 4 is placed in a regular position on the mounting table 23, such as a pressure sensor provided on the mounting table 23, and the pressed part passes through the bottom surface of the FOUP 4. Pressure. Taking this as an opportunity, the purge nozzles 9 (all the purge nozzles 9) installed on the mounting table 23 are moved in and out upward from the upper surface of the mounting table 23 and connected to each port 40 of the FOUP 4, and each port 40 is switched from the locked state. is open. Next, in the loading port 2 of this embodiment, the purification device P supplies nitrogen gas to the internal space 4S of the purified FOUP 4 to perform a process of replacing the internal space 4S of the FOUP 4 with nitrogen gas (bottom purification process). During the bottom purification process, the gas atmosphere in the FOUP 4 is discharged out of the FOUP 4 from the purge nozzle 9 connected to the port 40 that functions as an exhaust port. Through such bottom purification processing, the moisture concentration and oxygen concentration in FOUP 4 are respectively reduced to below predetermined values, and the surrounding environment of wafer W in FOUP 4 is set to a low-humidity environment and a low-oxygen environment.

In the load port 2 of this embodiment, after the locking process, the mounting base 23 located in the position shown in FIG. 2 is moved to the docking position shown in FIG. 7 (docking process), and at least both sides of the FOUP 4 are held using the movement restriction part L. Then, the fixing process (clamping process) is performed, the connection mechanism 221 is switched to the cover connection state (cover connection process), the FOUP door 43 and the load port door 22 are moved simultaneously, and the opening 21 a of the base 21 and the carry-out entrance of the FOUP 4 are opened. 41. Execute the process of releasing the sealed state in FOUP4 (sealed release process). The load port 2 of this embodiment implements mapping processing by the mapping unit m in the process of moving the load port door 22 from the open position (O) to the fully open position. The mapping process is such that the mapping unit m, which was in the mapping retraction posture just before the seal release process is executed, switches to the mapping posture after the load port door 22 moves from the fully closed position (C) to the open position (O), so that the load port The door 22 moves downward toward the fully open position, whereby the mapping unit m also moves downward while maintaining the mapping posture, and the presence or absence or storage posture of the wafer W stored in the FOUP 4 is measured using the mapping sensors m1 and m2. Detection processing. That is, a signal path is formed between the transmitter m1 and the receiver m2 by sending a signal from the transmitter m1 to the receiver m2. If the wafer W is present, the signal is blocked, and if the wafer W is not present, the signal path is not blocked. is intercepted and reaches the receiver m2. In this way, the presence or storage posture of the wafers W stored side by side in the height direction H in the FOUP 4 can be detected sequentially.

By performing the sealing release process, the internal space 4S of the FOUP body 42 and the wafer transfer space 3S of the transfer chamber 3 are brought into a connected state, and based on the information (wafer position) detected by the mapping process, the wafer transfer space 4S installed in the transfer chamber 3 is implemented. The transfer robot 31 in the round transfer space 3S takes out the wafer W from a predetermined wafer mount or stores the wafer W in a predetermined wafer mount (transfer process).

In the load port 2 of this embodiment, after the processing process of all the wafers W in the FOUP 4 by the processing device M is completed, the door drive mechanism 27 moves the load port door 22 to the fully closed position (C), and the base 21 is The opening 21a and the carry-out entrance 41 of the FOUP 4 are closed, the internal space 4S of the FOUP 4 is sealed (sealing process), and then the linking mechanism 221 is switched from the cover connection state to the cover release state (cover release process). . Through this process, the FOUP door 43 can be attached to the FOUP body 42, and the opening 21a of the base 21 and the carry-out entrance 41 of the FOUP 4 are locked by the loading port door 22 and the FOUP door 43 respectively, and the internal space 4S of the FOUP 4 is sealed.

Next, the load port 2 of this embodiment performs a clamping release process to release the fixed state (clamped state) of the FOUP 4 by the movement restricting portion L, and then moves the mounting table 23 in a direction away from the base 21 After the process (the docking release process), the locking state of the FOUP 4 with the lock claw 232 on the mounting table 23 is released (the lock release process). Thereby, the FOUP 4 containing the wafer W that has completed the predetermined processing is transferred from the mounting table 23 of each load port 2 to the container transport device, and is transported to the next process.

The key point of the EFEM 1 of this embodiment that has gone through such an operation flow is to prevent the decrease in oxygen concentration around the part that isolates the space for supplying inert gas such as nitrogen from the atmospheric space, and to avoid the operator from entering the oxygen concentration extreme. There is a risk of fainting due to hypoxia in a low space.

When the load port 2 that can perform bottom purification processing is applied as in this embodiment, there is a gap between the port 40 (eyelet) provided on the bottom surface of the FOUP 4 and the purge nozzle 9 provided on the mounting base 23 of the load port 2. There is a slight leakage of inert gases such as nitrogen used for bottom purification.

Here, in this embodiment, the part where the purification nozzle 9 constituting the bottom purification device P comes into contact with the port 40 (buttonhole) provided on the bottom surface of the FOUP 4 is set as the first adjustment part, and is applied to the mounting table 23 with a pair of The loading port 2 of the first ejection port x1 that ejects air near the first adjustment part.

Specifically, as shown in FIG. 3 , during the bottom purification process, the port 40 functioning as a supply port among the ports provided at the bottom of the FOUP 4 is in contact with the purge nozzle 9 near the third port that blows air upward. 1. The ejection port x1 is provided on the mounting base 23. This figure shows that among the total four purge nozzles 9 installed on the mounting table 23, the first discharge port x1 is provided near each of the three purge nozzles 9 connected to the port 40 that functions as a supply port. of manner.

In this embodiment, the purge nozzle 9 is configured to move up and down between a protruding position where the purge nozzle 9 can contact the port 40 of the FOUP 4 and a retreat position where the purge nozzle 9 cannot contact the port 40. The purge nozzle 9 can move up and down. , is realized by supplying and exhausting air to the internal space of a holding portion (not shown) that can protrude/retract to support the purge nozzle 9. Here, the piping for the upward and downward movement of the purification nozzle 9 is appropriately branched so that the air can be supplied to the first discharge port x1 from the same air supply source as the air used for the upward and downward movement of the purification nozzle 9 . FIG. 3 schematically shows the direction of the air ejected from each first ejection port x1 with an arrow.

Next, the air is ejected from the first ejection port x1 at the same time or approximately at the same time as the bottom purification process is started, and the first adjustment is made at the location where the purification nozzle 9 contacts the port 40 provided on the bottom surface of the FOUP 4 from the first ejection port x1 By ejecting air from the position, even if the inert gas such as nitrogen leaks slightly from the boundary part of the purge nozzle 9 and the port 40 into the atmospheric space, the amount of the inert gas in the first adjustment part can be relatively reduced. The concentration can maintain the oxygen concentration in the vicinity of the portion that isolates the internal space 4S of the FOUP 4 from the atmospheric space, where inert gas such as nitrogen is supplied, above a prescribed value that ensures the safety of the operator (for example, 19.5% above) concentration.

In addition, this embodiment is applied to the EFEM 1, and the boundary portion between the base 21 of the load port 2 and the load port door 22 is set as the second adjustment position, and is provided with a second ejection port x2 that ejects air near the second adjustment position. Load port 2.

Specifically, as shown in FIGS. 4(a) and 4(b) , a hollow top cover extending in the width direction is provided in the base 21 of the loading port 2 at a position above the opening. x21, the front end of the air supply pipe x22 is arranged inside the top cover x21, so that the air supplied from the air supply pipe x22 to the inside of the top cover x21 is directed from the second outlet x2 provided on the bottom of the top cover x21. It is formed by spraying out from below. Figure 4(b) is a schematic cross-sectional view along the z-z line of Figure 4(a). In Fig. 4(a), a predetermined pattern is added to the top cover x21. Moreover, inside the top cover x21, a filter x23 is provided near the second discharge port x2, and a sealing material x24 is provided at a corner close to the base 21. In FIG. 4 , an arrow schematically indicates the ejection direction of the air ejected from the second ejection port x2.

Next, in the EFEM 1 of this embodiment, at the same time or substantially at the same time as the bottom purification process is started, the second adjustment portion is adjusted from the second discharge port x2 to the portion of the base 21 of the load port 2 that is bounded by the load port door 22. Blow out air. The portion of the base 21 of the load port 2 that is bounded by the load port door 22, that is, the second adjustment portion is a docking process performed after the bottom purification process or during the bottom purification process (to make the load port located at the position shown in Figure 2 The end point of the process of moving the platform 23 to the docking position shown in FIG. 7 is the boundary between the base 21 of the loading port 2 and the FOUP door 43, or is very close to the boundary between the FOUP body 42 and the FOUP door 43. position (see Figure 7 and Figure 8). Therefore, by ejecting air from the second ejection port x2 toward the second adjustment portion, even a slight amount of inert gas such as nitrogen can escape from the boundary portion between the base 21 of the load port 2 and the load port door 22, or from the load port. 2, the boundary part between the base 21 and the FOUP door 43, even when the boundary part between the FOUP body 42 and the FOUP door 43 leaks into the atmospheric space, the concentration of the inert gas in the vicinity of the second adjustment part can be relatively reduced. The oxygen concentration in the vicinity of the portion where an inert gas such as nitrogen is supplied, that is, the inner space 3S of the transfer chamber 3 or the inner space 4S of the FOUP 4 is isolated from the atmospheric space, is maintained at a prescribed value that ensures the safety of the operator. concentration above. In addition, the entire top cover x21 including the second discharge port x2 is omitted in figures other than FIG. 2 , FIG. 4 , FIG. 7 and FIG. 8 .

In addition, this embodiment is applicable to EFEM1, as shown in Fig. 3 and Fig. As shown in FIG. 10 , the boundary between the wafer transfer chamber 3 and the base 21 of the load port 2 is set as the third adjustment position, and the load port 2 is provided with a third ejection port x3 for ejecting air near the third adjustment position.

Specifically, as shown in FIG. 3 , the base 21 of the loading port 2 is configured to include: a flat base body 211; and a surface ( The side frames 212 are provided on the left and right sides of the front surface); and the hollow tube frame 213 is provided in a posture closely contacting the outer surface of each side frame 212. Each hollow tube frame 213 is provided with a plurality of third ejection ports x3 having openings on its outward facing surface at predetermined intervals along the height direction, and is configured to eject air outward from each third ejection port x3. In FIG. 10 , the direction of the air ejected from each third ejection port x3 is schematically shown by an arrow. FIG. 10 omits the hollow tube frame 213 shown in the base 21 of the loading port 2 with a predetermined pattern added thereto. In addition, in figures other than FIG. 3 and FIG. 10 , the hollow pipe frame 213 including the third discharge port x3 is omitted.

Next, the EFEM1 of this embodiment is connected to the third ejection port x3 through appropriate piping and an air supply source (not shown). The EFEM1 is set according to the timing of supplying the inert gas to the transfer chamber 3, that is, according to the driving sequence. The fan filter unit 32 installed in the transfer chamber 3 generates a downward airflow in the wafer transfer space 3S of the transfer chamber 3 and circulates high-purity gas, that is, an inert gas (ambient gas) in the wafer transfer space 3S. At this time, the air is ejected from the third ejection port x3 toward the third adjustment position, which is the boundary between the transfer chamber 3 and the base 21. This allows the inert gas to leak even slightly from the boundary between the transfer chamber 3 and the base 21. In the case of atmospheric space, the concentration of the inert gas in the third adjustment part can be relatively reduced, and the oxygen concentration near the part that isolates the internal space of the transfer chamber 3 from the atmospheric space, which is the space for supplying the inert gas, can be increased. Maintain a safe concentration above the specified value.

Furthermore, the EFEM 1 of this embodiment is suitable for a drive system storage box 28 that houses a part of the door drive mechanism 27 in the load port 2 outside the transfer chamber 3 and forms a downflow of inert gas in the internal space. The loading port 2 has a fourth discharge port (not shown) that discharges air to the vicinity of the fourth adjustment site.

Next, the EFEM1 of this embodiment is connected to the fourth ejection port through an appropriate piping and an air supply source (not shown). The setting of the EFEM1 is in accordance with the timing of supplying the inert gas to the transfer chamber 3, that is, in accordance with The fan filter unit 32 installed in the transfer chamber 3 is driven to generate a downward airflow in the wafer transfer space 3S of the transfer chamber 3, and the high-purity gas, that is, the inert gas (ambient gas) starts to circulate in the wafer transfer space 3S. At this time, the air is ejected from the fourth ejection port toward the fourth adjustment position. By this, even if the inert gas from the surroundings of the drive system storage box 28 only slightly leaks into the atmospheric space, the fourth adjustment position can be relatively reduced. The concentration of the inert gas in the adjustment part can be maintained at a safe oxygen concentration in the vicinity of the space that isolates the inert gas supply space, that is, the internal space of the drive system storage box 28 and the atmospheric space (a range of 1 mm from the isolation portion).

In this way, the EFEM 1 of this embodiment is a portion (isolation) of the space and the atmosphere where an inert gas such as nitrogen is supplied from the first outlet x1, the second outlet x2, the third outlet x3, and the fourth outlet respectively. Parts), that is, the first adjustment part, the second adjustment part, the third adjustment part, and the fourth adjustment part eject air, thereby suppressing a local decrease in oxygen concentration near the isolation part and improving operator safety.

Furthermore, according to the EFEM 1 of this embodiment, by moving from the first ejection port x1, the second ejection port x2, the third ejection port x3, and the fourth ejection port toward the first adjustment position, the second adjustment position, and the third adjustment position respectively, The air is ejected from the position and the fourth adjustment part, and the dust attached to the front end of the air ejection can also be eliminated (such as dust attached to the lock key, registration pin or the surface of FOUP4, etc.).

In particular, the EFEM 1 of the present embodiment is provided with a discharge amount adjustment means. By means of the discharge amount adjustment means, the supply amount of the inert gas to the transfer chamber 3, the supply amount of the purification gas by the bottom purification device, or each adjustment can be made. The amount of air ejected from the first ejection port x1, the second ejection port x2, the third ejection port x3, and the fourth ejection port is adjusted accordingly to any amount of leakage of the inert gas in the location to the atmospheric pressure side. . According to such a structure, the portion (isolation portion) that isolates the space where inert gas such as nitrogen is supplied from the atmosphere, that is, the first adjustment portion, the second adjustment portion, the third adjustment portion, and the third adjustment portion can be suppressed with an appropriate air supply amount. 4. Adjusting the reduction of oxygen concentration in the site can prevent and inhibit excessive use of air.

The embodiments of the present invention have been described above. However, the present invention is not limited to the configuration of the above-mentioned embodiments. For example, in the above-described embodiment, the adjustment portions (first adjustment portion, second adjustment portion, third adjustment portion, fourth adjustment portion) are portions (isolation portions) that are isolated from the atmosphere for supplying inert gas such as nitrogen. An outlet for ejecting air is provided near the adjustment part), but a gas suction port may be provided near the adjustment part. In this case, it is arranged near the adjustment parts (the first adjustment part, the second adjustment part, the third adjustment part, and the fourth adjustment part), and it is possible to prevent a small amount of leakage from the space where the inert gas such as nitrogen is supplied to the atmospheric space. For example, a frame with a quasi-sealed structure in which inert gas flows into can be sucked into the frame through a gas suction port provided in the frame, thereby making it possible to isolate the inert gas supply space from the atmospheric space near the part (1mm from the isolation part) The oxygen concentration within the range) is maintained at a concentration that is safe for the operator. Moreover, it may be configured so that the inert gas sucked from the gas suction port is recovered into an appropriate recovery space (recovery container).

When a gas suction port is installed near the adjustment part, the EFEM has a suction force adjustment means, and the suction force adjustment means depends on the supply amount of inert gas to the transfer chamber and the purification effect of the bottom purification device. By adjusting the suction force based on the gas suction port in accordance with either the gas supply amount or the leakage amount of the inert gas in each adjustment part toward the atmospheric pressure side, isolation can be suppressed by a moderate suction force. The oxygen concentration in the first adjustment portion, the second adjustment portion, the third adjustment portion, and the fourth adjustment portion is reduced in the portion (isolation portion) between the supply space of the inert gas such as nitrogen and the atmosphere.

Moreover, instead of providing the ejection port or the gas suction port corresponding to all of the first adjustment portion, the second adjustment portion, the third adjustment portion, and the fourth adjustment portion, only one of the adjustment portions, or the gas suction port may be provided. A mode in which an ejection port or a gas suction port is provided at only two selected adjustment locations or only at three selected selection locations.

In the above embodiment, a FOUP is used as the wafer storage container. However, the present invention can also use wafer storage containers other than FOUP, for example, MAC (Multi Application Carrier), H-MAC (Horizontal-MAC), FOSB (Front Open Shipping Box), etc. can be used.

In the above embodiment, nitrogen gas is used as the inert gas used for the bottom purification process, etc., but the invention is not limited thereto, and any desired gas such as dry gas or argon gas may also be used.

In addition, the container door (FOUP door) may temporarily enter a tilted posture (accompanied by the movement of drawing a partially arc-shaped trajectory) in the process of moving from the fully closed position to the fully open position.

In addition, the specific configuration of each part is not limited to the above-described embodiment, and various modifications can be made within the scope that does not deviate from the gist of the present invention.

1:EFEM

2: Loading port

21:Base

22: Loading port door

23: Loading platform

27:Door drive mechanism

28: Drive system storage box

3:Transportation room

4: Wafer storage container (FOUP)

43: Container door (FOUP door)

9:Nozzle

P: Bottom purification device

W:wafer

5:Sealing part

24:Feet

25: Horizontal base (support platform)

211:Base body

212: Side frame

213:Hollow tube frame

214:Window unit

215:Opening part

231:Protrusion (pin)

232:Lock claw

x1: No. 1 ejection port

x3: 3rd spout

C: Fully closed position

L: Movement restriction department

2C:Control Department

21a: opening

3C: Control Department

[Fig. 1] A side view schematically showing the relative positional relationship between the EFEM and its peripheral devices according to the embodiment. [Fig. 2] Fig. 2 is a schematic side cross-sectional view of a load port in an embodiment in which the FOUP is separated from the base and the load port door is in a fully closed position. [Fig. 3] A perspective view showing a part of the load port in the embodiment with a portion omitted. [Fig. 4] An x-direction observation view of Fig. 3 and an enlarged schematic view of the z-z line section of Fig. 4(a). [Figure 5] y-direction observation view of Figure 3. [Fig. 6] An overall perspective view of the window unit in the embodiment. [Fig. 7] A diagram corresponding to Fig. 2 showing a state in which the FOUP is close to the base and the load port door is in a fully closed position. [Fig. 8] A diagram corresponding to Fig. 2 showing a state in which the load port door is in an open position. [Fig. 9] A diagram showing a mapping unit in the embodiment. [Fig. 10] A front view schematically showing the relative positional relationship between the EFEM and its peripheral devices in the embodiment.

2C:Control Department

5:Sealing part

9:Nozzle

21:Base

21a: opening

22: Loading port door

23: Loading platform

24:Feet

25: Horizontal base (support platform)

28: Drive system storage box

211:Base body

212: Side frame

213:Hollow tube frame

214:Window unit

215:Opening part

231:Protrusion (pin)

232:Lock claw

x1: No. 1 ejection port

x3: 3rd spout

C: Fully closed position

L: Movement restriction department

P: Bottom purification device

Claims (2)

An EFEM characterized by, It is provided with: a transfer chamber that forms a substantially closed wafer transfer space inside by connecting a loading port and a processing device to an opening provided in the wall; and A wafer transfer device disposed in the wafer transfer space and transporting wafers between a wafer container placed in the load port and the processing device; The EFEM is configured to generate a downward airflow in the wafer transfer space and circulate an inert gas in the wafer transfer space; The aforementioned load ports are those with the following: The base forms part of the front wall of the transfer chamber and is in the shape of a plate with an opening opening to the internal space of the transfer chamber; A loading port door that opens and closes the opening of the base; A mounting platform installed on the aforementioned base in a substantially horizontal position; A bottom purification device capable of cleaning the wafer from the bottom side of the wafer storage container in a state where the nozzle provided on the mounting table is in contact with a port disposed on the bottom surface of the wafer container placed on the mounting table. The gas atmosphere in the storage container is replaced with purification gas formed from inert gas; and a door drive mechanism for driving the aforementioned loading port door; The nozzle is provided with an ejection port or a gas suction port for ejecting air near at least one of the plurality of adjustment parts, Their plural adjustment positions are, Contact the first adjustment part of the aforementioned port, The second adjustment portion includes at least one of the boundary portion of the base and the loading port door or the door of the wafer storage container, that is, the container door, The boundary between the aforementioned transfer chamber and the aforementioned base is the third adjustment position. The fourth adjustment position is located around a drive system storage box outside the transfer chamber that accommodates a part of the door drive mechanism in the load port and forms a downflow of inert gas in the internal space. Such as the EFEM of request item 1, where It is provided with: an adjustment means corresponding to the supply amount of the inert gas to the wafer transfer space, the supply amount of the purification gas by the bottom purification device, or the leakage amount of the inert gas in each of the adjustment parts to the atmospheric pressure side. Either of these quantities is used to adjust the amount of air ejected from the ejection port or the suction force based on the gas suction port.

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