JP2020150091A - Efem - Google Patents

Abstract

To provide an EFEM capable of suppressing deterioration of an oxygen concentration in a separation part with a space to which nitrogen is supplied and an atmospheric air in order to increase safety of an operator at an introduction site of the EFEM.SOLUTION: A EFEM 1 provides: a first adjustment place in which a purge nozzle 9 contacts with a port 40; a second adjustment place containing at least one of a boundary part of a base 21 of a load port 2 and a load port door 22 and a boundary part of a FOUP door 43; a third adjustment place that is the boundary part of a transfer chamber 3 and the base 21 of the load port 2; a fourth adjustment place that is a circumference of a driving system housing box 28 in which a drop air flow of an inactive gas is formed in an inner space while housing a part of a door driving mechanism 27 of the load port 2 on an outside of the transfer chamber 3; and exhaust nozzles x1, x2, and x3 that exhaust an air in the vicinity of at least one adjustment place of the plurality of those adjustment places.SELECTED DRAWING: Figure 3

Description

The present invention relates to an EFEM (Equipment Front End Module) used for automatic wafer transfer.

In the semiconductor manufacturing process, wafers are processed in a clean room in order to improve yield and quality. In recent years, a "mini-environment method" that further improves the cleanliness of only the local space around the wafer has been adopted, and means for transporting the wafer and other processing have been adopted. In the mini-environment method, FOUP is a container in which a wafer is housed in a highly clean internal space while forming a part of the wall surface of a wafer transfer chamber (hereinafter referred to as "convey chamber") that is substantially closed inside the housing. (Front-Opening Unified Pod) is placed, and a load port (Load Port) having a function of opening and closing the FOUP door in close contact with the FOUP door (hereinafter referred to as "FOUP door") is provided adjacent to the transport chamber. Has been done.

The load port is a device for loading and unloading wafers from and to the transport chamber, and functions as an interface unit between the transport chamber and the FOUP. Then, when the load port door (hereinafter referred to as “load port door”) that can be engaged with the FOUP door and opens and closes the FOUP door is opened, the transfer robot (wafer transfer device) arranged in the transfer chamber inside the FOUP. It is configured so that the wafer can be taken out into the transport chamber and the wafer can be stored in the FOUP from the transport chamber.

Then, in the semiconductor manufacturing process, in order to appropriately maintain the atmosphere around the wafer, the above-mentioned storage pod called FOUP is used, and the wafer is housed and managed inside the FOUP. Particularly in recent years, higher integration of elements and miniaturization of circuits have been promoted, and it is required to maintain a high degree of cleanliness around the wafer so that particles and moisture do not adhere to the surface of the wafer. Therefore, in order to prevent the surface properties from changing such as oxidation of the wafer surface, a process of filling the inside of the FOUP with nitrogen gas to create a nitrogen atmosphere, which is an inert gas, or to create a vacuum state around the wafer ( Purging process) is also performed.

Further, an EFEM configured to fill the transport chamber with nitrogen, which is an inert gas, has been devised and put into practical use (for example, Patent Document 1). Specifically, this EFEM includes a circulation channel including a transfer chamber for circulating nitrogen inside the transfer chamber, a gas supply means for supplying nitrogen to the circulation flow path, and a gas discharge means for discharging nitrogen from the circulation flow path. And. Nitrogen is appropriately supplied and discharged according to fluctuations in oxygen concentration and the like in the circulation flow path. This makes it possible to maintain a nitrogen atmosphere in the transport chamber while suppressing an increase in the amount of nitrogen supplied as compared with a configuration in which nitrogen is constantly supplied and discharged.

Japanese Unexamined Patent Publication No. 2017-21322

By the way, it is necessary to maintain the oxygen concentration in the vicinity of the portion that separates the space to which nitrogen is supplied and the atmospheric space (for example, in the range of 1 mm from the isolated portion) at a concentration that is safe for the operator (for example, 19.5% or more). There is. This is to avoid the risk of falling into an oxygen deficient state when the operator enters a space having an extremely low oxygen concentration.

The present invention has been made focusing on such a problem, and a main object thereof is a space and an atmosphere to which an inert gas such as nitrogen is supplied in order to enhance the safety of the operator at the introduction site of EFEM. The purpose of the present invention is to provide an EFEM capable of suppressing a decrease in oxygen concentration in a portion isolated from the above. The present invention is a technique that can be applied to a wafer storage container other than FOUP.

That is, the present invention is provided in a transfer chamber that internally constitutes a wafer transfer space that is substantially closed by connecting a load port and a processing device to an opening provided on the wall surface, and a load port that is arranged in the wafer transfer space. It is equipped with a wafer transfer device that transports wafers between the wafer storage container placed in the wafer and the processing device, creates a downdraft in the wafer transfer space, and circulates an inert gas such as nitrogen in the wafer transfer space. It relates to an EFEM configured to allow. The EFEM according to the present invention comprises a plate-shaped base as a load port, which constitutes a part of the front wall surface of the transport chamber and has an opening for opening the internal space of the transport chamber, and a base. The load port door that opens and closes the opening of the gas, the mounting table provided on the base in a substantially horizontal position, and the nozzle provided on the mounting table are brought into contact with the port arranged on the bottom surface of the wafer storage container mounted on the mounting table. It is equipped with a bottom purge device that can replace the gas atmosphere in the wafer storage container from the bottom side of the wafer storage container with a purging gas made of an inert gas such as nitrogen, and a door drive mechanism that drives the load port door. The first adjustment point where the nozzle contacts the port, the second adjustment point including at least one of the boundary part of the base with the load port door or the boundary part with the container door which is the door of the wafer storage container. A drive in which a part of the door drive mechanism of the load port, which is the third adjustment point at the boundary between the transport chamber and the base, is accommodated outside the transport chamber and a downdraft of inert gas is formed in the internal space. It is characterized in that a spout or a gas suction port for ejecting air is provided in the vicinity of a fourth adjusting point, which is the circumference of the system storage box, and at least one of the plurality of adjusting points.

The present inventor performs a bottom purge process between the port provided on the bottom surface of the wafer storage container and the bottom purge nozzle provided on the load port as a factor that causes the operator to have a dangerous decrease in oxygen concentration at the introduction site of EFEM. The small amount of the inert gas such as nitrogen used in the wafer leaks, and the small amount of the inert gas such as nitrogen in the wafer storage container leaks from between the wafer storage container body and the door of the wafer storage container. Further, if the EFEM is configured to fill the transport chamber with an inert gas such as nitrogen, the drive system storage box or load port that houses the mechanism for driving the load port door or between the transport chamber and the load port. Focusing on the fact that the inert gas in the transport chamber leaks from the door even though it is minute, the EFEM according to the present invention was devised in order to prevent or suppress the situation where the oxygen concentration in the vicinity of these leaked portions is locally reduced. I came to do it.

In the case of EFEM according to the present invention, air is supplied from a spout to a portion (isolated portion) that separates the atmosphere from the space to which an inert gas such as nitrogen is supplied, or the gas in the isolated portion. By sucking (high-concentration inert gas) with the gas suction port, it is possible to suppress a decrease in oxygen concentration in the vicinity of the isolated portion and improve the safety of the operator.

In particular, the EFEM according to the present invention supplies either the inert gas to the wafer transfer space, the purging gas supplied by the bottom purging device, or the amount of the inert gas leaking to the atmospheric pressure side at each adjustment point. If the gas is equipped with an adjusting means for adjusting the amount of air ejected from the ejection port or the suction force of the gas suction port according to the amount of gas, the oxygen concentration in the vicinity of the isolated portion is adjusted by an appropriate amount of air supply or suction force. It can be reduced.

According to the present invention, at the introduction site of EFEM in which the wafer is appropriately treated, the decrease in oxygen concentration in the space where the inert gas such as nitrogen is supplied and the separated portion from the atmosphere is suppressed, and the operator's safety It is possible to provide an EFEM capable of enhancing the sex.

FIG. 6 is a side view schematically showing a relative positional relationship between EFEM and its peripheral device according to the same embodiment. FIG. 5 is a diagram schematically showing a side cross section of a load port according to the same embodiment in a state where the FOUP is separated from the base and the load port door is in a fully closed position. The perspective view which shows the load port in the same embodiment partially omitted. The x-direction arrow view of FIG. 3 and the enlarged schematic view of the zz-line cross section of FIG. 4 (a). The y-direction arrow view of FIG. The whole perspective view of the window unit in the same embodiment. The figure which shows the state which FOUP approaches a base and the load port door is in a fully closed position corresponding to FIG. The figure which shows the state which the load port door is in an open position corresponding to FIG. The figure which shows the mapping part in the same embodiment. The front view schematically showing the relative positional relationship between EFEM and its peripheral device in the same embodiment.

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

As shown in FIG. 1, the EFEM (Equipment Front End Module) 1 according to the present embodiment includes a load port 2 and a transport chamber 3 arranged in a clean room in the semiconductor manufacturing process. FIG. 1 schematically shows the relative positional relationship between EFEM1 and its peripheral devices. FOUP4 shown in the figure is used together with EFEM1.

In the wafer transfer space 3S, which is the internal space of the transfer chamber 3, a transfer robot 31 capable of transferring the wafer W between the FOUP 4 and the processing device M is provided. By driving the fan filter unit 32 provided in the transfer chamber 3, a downdraft is generated in the wafer transfer space 3S of the transfer chamber 3, and an inert gas (environmental gas) such as nitrogen, which is a highly clean gas, is released. It can be circulated in the wafer transfer space 3S. A processing device M (semiconductor processing device) is provided adjacent to the rear wall surface 3B of the transport chamber 3 facing the front wall surface 3A where the load port 2 is arranged. That is, the load port 2 is connected to the opening provided in the front wall surface 3A of the transport chamber 3, and the processing device M is connected to the opening provided in the rear wall surface 3B, so that the inside of the transport chamber 3 is substantially closed. The formed wafer transfer space 3S is formed.

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 mounted on the load port 2 are maintained with high cleanliness.

In the present embodiment, as shown in FIG. 1, the load port 2, the transport chamber 3, and the processing device M are arranged in close contact with each other in this order in the front-rear direction D of the EFEM1. The operation of the EFEM1 is controlled by the controller of the load port 2 (control unit 2C shown in FIG. 3) and 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. It is controlled by the controller (control unit MC shown in FIG. 1). Here, the control unit MC which is the controller of the entire processing device M and the control unit 3C which is the controller of the entire EFEM1 are higher-level controllers of the control unit 2C of the load port 2. Each of these control units 2C, 3C, and MC is composed of a CPU, a memory, a normal microprocessor equipped with an interface, and the like. The memory stores programs necessary for processing in advance, and the CPUs are sequentially required. Program is taken out and executed, and the desired function is realized in cooperation with peripheral hardware resources.

As shown in FIGS. 1 and 2, the FOUP 4 includes a FOUP main body 42 capable of opening the internal space 4S through the carry-out entrance 41 which is an opening, and a FOUP door 43 capable of opening and closing the carry-out entrance 41. It is a known one in which a number of wafers W are accommodated in a multi-stage shape in the vertical direction H, and these wafers W can be taken in and out through a carry-in / out port 41.

The FOUP main body 42 is provided with a shelf portion (wafer mounting shelf) capable of mounting wafers W in a plurality of stages at a predetermined pitch in the internal space 4S. As shown in FIG. 2 and the like, ports 40 are provided at predetermined positions on the bottom wall of the FOUP main body 42. The port 40 is mainly composed of a hollow tubular grommet seal fitted in a port mounting through hole formed in the bottom wall of the FOUP main body 42, and is configured to be openable and closable by a check valve. A flange portion that is gripped by a container transport device (for example, OHT: Over Head Transport) or the like is provided at the center of the upward surface of the upper wall of the FOUP main body 42.

The FOUP door 43 faces the load port door 22 of the load port 2 in a state of being mounted on the mounting table 23 described later of the load port 2, and has a substantially plate shape. The FOUP door 43 is provided with a latch key (not shown) that can lock the FOUP door 43 to the FOUP main body 42. A gasket (not shown) is provided in a predetermined portion of the FOUP door 43 in which the carry-in / out port 41 is closed by the FOUP door 43 and is in contact with or close to the FOUP main body 42, and the gasket is brought into contact with the FOUP main body 42 to be elastically deformed. It is configured so that the internal space 4S of the FOUP4 can be sealed.

As shown in FIGS. 2 to 5, the load port 2 according to the present embodiment constitutes a part of the front wall surface 3A of the transport chamber 3, and is an opening for opening the wafer transport space 3S of the transport chamber 3. It includes a plate-shaped base 21 on which the portion 21a is formed, a load port door 22 for opening and closing the opening 21a of the base 21, and a mounting table 23 provided on the base 21 in a substantially horizontal posture.

A leg portion 24 having casters and installation legs is provided at the lower end of the base 21, and a window unit 214 (see FIG. 6) is provided at a position facing the FOUP door 43. The opening 215 provided in the window unit 214 is an opening that allows the wafer W to pass through. In the present embodiment, as shown in FIG. 2, a load port 2 having a seal portion 5 that orbits the opening 21a of the base 21 is adopted, and as shown in FIG. 2, the base 21 is sealed at a position sandwiched in the thickness direction. Parts 5 and 6 are provided.

The mounting base 23 is provided on the upper portion of the horizontal base 25 (support base) which is arranged in a substantially horizontal posture at a position slightly above the center in the height direction of the base 21. The mounting table 23 is capable of mounting the FOUP 4 in a direction in which the FOUP door 43 that can open and close the internal space 4S of the FOUP main body 42 faces the load port door 22. Further, the mounting table 23 has a predetermined docking position (see FIG. 7) in which the FOUP door 43 approaches the opening 21a of the base 21 and a position in which the FOUP door 43 is separated from the docking position by a predetermined distance (FIG. 2). (See), it is configured to be able to move forward and backward with respect to the base 21. As shown in FIG. 3, the mounting table 23 has a plurality of protrusions (pins) 231 protruding upward, and these protrusions 231 are engaged with holes (not shown) formed on the bottom surface of the FOUP4. Therefore, the FOUP 4 is positioned on the mounting table 23. Further, a lock claw 232 for fixing the FOUP 4 to the mounting table 23 is provided. By hooking the lock claw 232 on the locked portion (not shown) provided on the bottom surface of the FOUP4 to make it in a locked state, the FOUP4 is placed at an appropriate position on the mounting table 23 in cooperation with the positioning protrusion 231. It can be fixed while guiding to. Further, the FOUP 4 can be separated from the mounting table 23 by releasing the locked state of the lock claw 232 with respect to the locked portion provided on the bottom surface of the FOUP 4.

The load port door 22 connects the FOUP door 43 to release the lid connected state in which the FOUP door 43 can be removed from the FOUP main body 42 and the connected state to the FOUP door 43, and attaches the FOUP door 43 to the FOUP main body 42. A connection mechanism 221 (see FIG. 5) that can be switched between the lid connection release state and the connection mechanism 221 that can move along a predetermined movement path while holding the FOUP door 43 in an integrated state. Is. The load port 2 of the present embodiment has the load port door 22 at the position shown in FIG. 7, that is, the fully closed position (C) in which the internal space 4S of the FOUP main body 42 is sealed by the FOUP door 43 held by the load port door 22. ) And the position shown in FIG. 8, that is, an open position in which the FOUP door 43 held by the load port door 22 is separated from the FOUP main body 42 and the internal space 4S of the FOUP main body 42 is opened toward the inside of the transport chamber 3. It is configured to be at least movable to and from (O). The load port 2 of the present embodiment can be moved to the open position (O) shown in FIG. 8 while maintaining the standing posture of the load port door 22 positioned at the fully closed position (C), and further, as shown in FIG. It is configured to be movable downward while maintaining the standing posture from the open position (O) shown to the fully open position (not shown). Such movement of the load port door 22 is realized by a door drive mechanism 27 provided in the load port 2.

As shown in FIG. 2 and the like, the door moving mechanism 27 includes a support frame 271 that supports the load port door 22 and a movable block 273 that movably supports the support frame 271 in the front-rear direction D via the slide support portion 272. , To move the slide rail 274 that movably supports the movable block 273 in the vertical direction H, the front-rear direction D along the horizontal path of the load port door 22, and the vertical direction H along the vertical path. It is equipped with a drive source (for example, an actuator (not shown)). By giving a drive command to this actuator from the control unit 2C, the load port door 22 is moved in the front-rear direction D and the up-down direction. The actuator for moving back and forth and the actuator for moving up and down may be provided separately, or the actuator may move back and forth and move up and down using a common actuator as a drive source.

The support frame 271 supports the lower rear portion of the load port door 22. The support frame 271 has a substantially crank shape that extends downward and then passes through a slit-shaped insertion hole 21b formed in the base 21 and projects to the outside of the transport chamber 3 (mounting table 23 side). are doing. The slide support portion 272, the movable block 273, and the slide rail 274 for supporting the support frame 271 are also arranged on the mounting base 23 side of the base 21, that is, outside the transport chamber 3. The slide support portion 272, the movable block 273, and the slide rail 274 serve as sliding points when the load port door 22 is moved. In the present embodiment, by arranging these outside the transport chamber 3, the insertion hole 21b is set in a minute slit shape even if particles are generated when the load port door 22 is moved. Therefore, it is possible to prevent / suppress the situation where particles enter the transport chamber 3. Further, the load port 2 of the present embodiment is a part or portion of the door moving mechanism 27 arranged outside the transport chamber 3, specifically, a part of the support frame 271, a slide support portion 272, and a movable block 273. And a drive train storage box 28 that covers the slide rail 274. As a result, the inert gas (environmental gas) in the transport chamber 3 is set so as not to flow out of the EFEM1 through the above-mentioned insertion hole 21b formed in the base 21. Further, a downdraft of the inert gas is formed in the internal space of the drive system storage box 28.

Further, the load port 2 of the present embodiment includes a movement control unit L that regulates the movement of the FOUP 4 on the mounting table 23 positioned at the docking position in a direction away from the base 21. In the present embodiment, the movement control unit L is unitized as the window unit 214 (see FIG. 6).

The load port 2 of the present embodiment is a purging device P capable of injecting a purging gas made of an inert gas such as nitrogen into the internal space 4S of the FOUP 4 and replacing the gas atmosphere of the internal space 4S of the FOUP 4 with the purging gas. It is equipped (see Fig. 3). The purge device P is provided with a plurality of purge nozzles 9 (gas supply / discharge devices) arranged at predetermined positions on the mounting table 23 so that the upper end portion can be exposed. These plurality of purge nozzles 9 are attached to appropriate positions on the mounting table 23 according to the position of the port 40 provided on the bottom surface of the FOUP 4, and can be connected in contact with the port 40. In the bottom purge process using such a purge device P, a predetermined number (excluding all) of the plurality of ports 40 provided at the bottom of the FOUP4 function as "supply ports" and are connected to the supply ports. An appropriately selected purging gas such as nitrogen gas, an inert gas, or dry air is injected into the FOUP 4 by the purge nozzle 9, and the remaining port 40 functions as an "exhaust port" through the purge nozzle 9 connected to the exhaust port. This is a process of filling the FOUP4 with a purging gas by discharging the gas atmosphere in the FOUP4. The load port 2 includes a pressure sensor (not shown) that detects the gas pressure (exhaust pressure) of the purge nozzle 9 connected to the port 40 that functions as an exhaust port during the bottom purge process.

As shown in FIG. 9, the load port 2 of the present embodiment includes a mapping unit m capable of detecting the presence / absence of the wafer W and the storage posture in the FOUP4. The mapping unit m is a mapping sensor (transmitter m1, receiver m2) capable of detecting the presence or absence of wafers W housed in multiple stages in the height direction H in FOUP4, and a sensor frame supporting the mapping sensors m1 and m2. It has m3. The mapping unit m can be positioned between a mapping retracted posture in which the entire mapping unit m is arranged in the transport space in the transport chamber 3 and a mapping posture in which at least the mapping sensors m1 and m2 are positioned in the FOUP4 through the opening 21a of the base 21. Is. The mapping unit m is configured to be movable in the height direction H while maintaining the mapping retracted posture and the mapping posture. As shown in FIG. 9, by attaching a part of the sensor frame m3 to a part of the door drive mechanism 27, the mapping unit m is configured to move up and down integrally with the load port door 22. ing. In each figure other than FIG. 9, the mapping unit m is omitted.

The mapping sensor is composed of a transmitter m1 (light emitting sensor) that emits a beam (line light) that is a signal, and a receiver m2 (light receiving sensor) that receives a signal emitted from the transmitter m1. It is also possible to configure the mapping sensor by a transmitter and a reflecting unit that reflects the line light emitted from the transmitter toward the transmitter. In this case, the transmitter also functions as a receiver.

Next, the operation flow of EFEM1 will be described.

First, the FOUP 4 is transported to the upper part of the load port 2 by a container transport device such as OHT, and is mounted on the mounting table 23. At this time, for example, the positioning protrusion 231 provided on the mounting table 23 fits into the positioning recess of the FOUP 4, and the lock claw 232 on the mounting table 23 is locked (locking process). In the present embodiment, the FOUP 4 can be mounted on the mounting bases 23 of the load ports 2 arranged side by side in the width direction of the transport chamber 3, respectively. In addition, a seating sensor (not shown) that detects whether or not the FOUP4 is mounted on the mounting table 23 at a predetermined position detects that the FOUP4 is mounted on the mounting table 23 at a normal position. It can also be configured.

In the load port 2 of the present embodiment, when the FOUP 4 is mounted at the normal position on the mounting table 23, the bottom surface portion of the FOUP 4 presses the pressed portion of the pressure sensor provided on the mounting table 23, for example. Is detected. With this as a trigger, the purge nozzles 9 (all purge nozzles 9) provided on the mounting table 23 advance above the upper surface of the mounting table 23 and are connected to each port 40 of the FOUP4, and each port 40 is in an open state from a closed state. Switch to. Then, the load port 2 of the present embodiment supplies nitrogen gas to the internal space 4S of the purge FOUP 4 by the purge device P, and performs a process (bottom purge process) of replacing the internal space 4S of the FOUP 4 with nitrogen gas. During the bottom purge process, the gas atmosphere in the FOUP 4 is discharged to the outside of the FOUP 4 from the purge nozzle 9 connected to the port 40 that functions as an exhaust port. By such a bottom purge treatment, the water concentration and the oxygen concentration in the FOUP4 are each lowered to a predetermined value or less, and the ambient environment of the wafer W in the FOUP4 is made into a low humidity environment and a low oxygen environment.

After the lock process, the load port 2 of the present embodiment moves the mounting table 23 at the position shown in FIG. 2 to the docking position shown in FIG. 7 (docking process), and uses the movement restricting unit L to move at least both of the FOUP4. The side is held and fixed (clamping), the connecting mechanism 221 is switched to the lid connecting state (lid connecting processing), the FOUP door 43 is moved together with the load port door 22, and the opening 21a of the base 21 and The carry-in / out port 41 of the FOUP4 is opened, and a process of releasing the sealed state in the FOUP4 (sealing release process) is executed. The load port 2 of the present embodiment performs a mapping process by the mapping unit m during the process of moving the load port door 22 from the open position (O) to the fully open position. In the mapping process, the mapping unit m, which is in the mapping retracted position until just before the sealing release process is executed, is switched to the mapping position after the load port door 22 is moved from the fully closed position (C) to the open position (O), and loaded. By moving the port door 22 downward toward the fully open position, the mapping unit m is also moved downward while maintaining the mapping posture, and the presence or absence of the wafer W housed in the FOUP 4 is used by using the mapping sensors m1 and m2. It is a process to detect the storage posture. That is, the signal path formed between the transmitter m1 and the receiver m2 by emitting a signal from the transmitter m1 to the receiver m2 is blocked where the wafer W exists, and the wafer W is blocked. Reach the receiver m2 unobstructed where there is no. As a result, it is possible to sequentially detect the presence / absence of wafers W stored side by side in the height direction H and the storage posture in the FOUP4.

By executing the sealing release process, the internal space 4S of the FOUP main body 42 and the wafer transfer space 3S of the transfer chamber 3 are in a state of communication, and the transfer chamber 3 is based on the information (wafer position) detected in the mapping process. The transfer robot 31 provided in the wafer transfer space 3S of the above performs a process (convey process) of taking out the wafer W from the specific wafer mounting shelf and storing the wafer W in the specific wafer mounting shelf.

In the load port 2 according to the present embodiment, when all the wafers W in the FOUP 4 have completed the processing process by the processing device M, the load port door 22 is moved to the fully closed position (C) by the door drive mechanism 27. , The opening 21a of the base 21 and the carry-in / out port 41 of the FOUP4 are closed to seal the internal space 4S of the FOUP4 (sealing process), and then the connecting mechanism 221 is changed from the lid connection state to the lid connection release state. Execute the switching process (lid connection release process). By this process, the FOUP door 43 can be attached to the FOUP main body 42, the opening 21a of the base 21 and the carry-in / out port 41 of the FOUP 4 are closed by the load port door 22 and the FOUP door 43, respectively, and the internal space 4S of the FOUP 4 is closed. It becomes a sealed state.

Subsequently, the load port 2 according to the present embodiment is subjected to a clamp release process for releasing the fixed state (clamp state) of the FOUP 4 by the movement restricting unit L, and then the mounting table 23 is moved in a direction away from the base 21. After executing the process (docking release process), the state in which the FOUP4 is locked by the lock claw 232 on the mounting table 23 is released (unlock process). As a result, the FOUP 4 storing the wafer W that has completed the predetermined processing is delivered to the container transport device from the mounting table 23 of each load port 2 and carried out to the next process.

The EFEM1 according to the present embodiment that undergoes such an operation flow prevents a decrease in oxygen concentration around a portion that separates the space to which an inert gas such as nitrogen is supplied from the atmospheric space, and the operator can perform the operation. It is important to avoid the risk of falling into an oxygen-deficient state when entering a space with extremely low oxygen concentration.

When the load port 2 capable of performing the bottom purge process is applied as in the present embodiment, the bottom purge is performed from between the port 40 (grommet) 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. The slightly inert gas such as nitrogen used for the treatment leaks.

Therefore, in the present embodiment, a portion where the purge nozzle 9 constituting the bottom purge device P contacts the port 40 (grommet) provided on the bottom surface of the FOUP4 is set as the first adjustment portion, and air is ejected in the vicinity of the first adjustment portion. The load port 2 provided with the first spout x1 on the mounting table 23 is applied.

Specifically, as shown in FIG. 3, among the ports provided at the bottom of the FOUP 4 during the bottom purge process, air is ejected upward in the vicinity of the purge nozzle 9 that contacts the port 40 that functions as the supply port. One spout x1 is provided on the mounting table 23. The figure illustrates an embodiment in which a first ejection port x1 is provided in each vicinity of each of the three purge nozzles 9 connected to the port 40 that functions as a supply port, out of a total of four purge nozzles 9 provided on the mounting table 23. are doing.

In the present embodiment, the purge nozzle 9 is configured to be movable up and down between a protruding position where the purge nozzle 9 can contact the port 40 of the FOUP 4 and a retracted position where the purge nozzle 9 cannot contact the port 40. The ascending / descending movement of 9 is realized by supplying / exhausting air to the internal space of a holder (not shown) that supports the purge nozzle 9 so as to be retractable. Therefore, the piping for moving the purge nozzle 9 up and down is appropriately branched so that air can be supplied to the first ejection port x1 from the same air supply source as the air used for moving the purge nozzle 9 up and down. In FIG. 3, the ejection direction of the air ejected from each first ejection port x1 is schematically shown by an arrow.

Then, at the same time as or substantially at the same time as the start of the bottom purge process, air is ejected from the first ejection port x1 and the first adjustment portion is directed toward the first adjustment portion where the purge nozzle 9 contacts the port 40 provided on the bottom surface of the FOUP4. By ejecting air from the ejection port x1, even if an inert gas such as nitrogen leaks into the atmospheric space from the boundary portion between the purge nozzle 9 and the port 40, it is not possible at the first adjustment point. The operator's safety is to determine the oxygen concentration in the vicinity of the part that separates the internal space 4S of FOUP4, which is a space to which an inert gas such as nitrogen is supplied, from the atmospheric space by relatively reducing the concentration of the active gas. Can be maintained at a concentration of a predetermined value or more (for example, 19.5% or more) that can be secured.

Further, in the EFEM 1 according to the present embodiment, the boundary portion of the base 21 of the load port 2 with the load port door 22 is set as the second adjustment portion, and the second ejection port x2 for ejecting air in the vicinity of the second adjustment portion. The load port 2 provided with is applied.

Specifically, as shown in FIGS. 4A and 4B, a hollow upper cover x21 extending in the width direction to a position above the opening of the base 21 of the load port 2 is provided. The tip of the air supply pipe x22 is arranged inside the upper cover x21, and the air supplied from the air supply pipe x22 to the inside of the upper cover x21 is provided on the downward surface of the upper cover x21. It is configured to eject downward from x2. FIG. 4B is a schematic cross-sectional view taken along the line zz of FIG. 4A. In FIG. 4A, a predetermined pattern is attached to the upper cover x21. Inside the upper cover x21, a filter x23 is provided in the vicinity of the second ejection port x2, and a sealing material x24 is provided in a corner portion close to the base 21. In FIG. 4, the ejection direction of the air ejected from the second ejection port x2 is schematically shown by an arrow.

Then, in the EFEM1 according to the present embodiment, at the same time as or substantially at the same time as the start of the bottom purge process, air is aired from the second ejection port x2 at the second adjustment point which is the boundary portion between the base 21 of the load port 2 and the load port door 22. Squirt. The second adjustment point, which is the boundary portion of the base 21 of the load port 2 with the load port door 22, is a docking process (the mounting table 23 at the position shown in FIG. 2 is shown in FIG. 7) to be performed after the bottom purge process or during the bottom purge process. At the end of the process of moving to the docking position shown in (1), the position becomes extremely close to the boundary portion between the base 21 of the load port 2 and the FOUP door 43, and the boundary portion between the FOUP main body 42 and the FOUP door 43. (See FIGS. 7 and 8). Therefore, by injecting air from the second ejection port x2 toward the second adjustment point, the boundary portion between the base 21 of the load port 2 and the load port door 22 and the base 21 of the load port 2 and the FOUP door 43 Even if an inert gas such as nitrogen leaks into the atmospheric space from the boundary portion between the FOUP main body 42 and the FOUP door 43, the inert gas in the vicinity of the second adjustment point is not active. Oxygen in the vicinity of the portion that separates the internal space 3S of the transport chamber 3 and the internal space 4S of the FOUP 4, which is the space to which the inert gas such as nitrogen is supplied by relatively lowering the gas concentration, and the atmospheric space. The concentration can be maintained at a concentration equal to or higher than a predetermined value that can ensure the safety of the operator. In addition, in the drawings other than FIGS. 2, 4, 7, and 8, the entire upper cover x21 including the second ejection port x2 is omitted.

Further, in EFEM 1 according to the present embodiment, as shown in FIGS. 3 and 10, the boundary portion between the wafer transfer chamber 3 and the base 21 of the load port 2 is set at the third adjustment location, and is located near the third adjustment portion. A load port 2 provided with a third outlet x3 for ejecting air is applied.

Specifically, as shown in FIG. 3, the surface of the base 21 of the load port 2 facing the flat plate-shaped base main body 211 and the FOUP4 mounted on the mounting base 23 of the base main body 211 (forward facing surface). The configuration is provided with side frames 212 provided on both the left and right sides of the above, and a hollow pipe frame 213 provided in a posture of being in close contact with the surface of each side frame 212 facing outward. Each hollow pipe frame 213 is provided with a plurality of third spouts x3 that open to the outward facing surface at a predetermined pitch along the height direction, and air is ejected from each third spout x3 toward the outside. It is set as. In FIG. 10, the ejection direction of the air ejected from each third ejection port x3 is schematically shown by an arrow. In FIG. 10, the base 21 of the load port 2 except for the hollow pipe frame 213 shown with a predetermined pattern is omitted. Further, in the drawings other than FIGS. 3 and 10, the hollow pipe frame 213 including the third ejection port x3 is omitted.

Then, in the EFEM 1 according to the present embodiment, an air supply source (not shown) is connected to the third ejection port x3 by an appropriate pipe, and the timing of supplying the inert gas into the transport chamber 3 at the time of setting up the EFEM 1, that is, the transport. The fan filter unit 32 provided in the chamber 3 is driven to generate a downdraft in the wafer transport space 3S of the transport chamber 3, and an inert gas (environmental gas), which is a highly clean gas, is generated in the wafer transport space 3S. At the timing when circulation starts, air is ejected from the third ejection port x3 toward the third adjustment point, which is the boundary portion between the transfer chamber 3 and the base 21, so that the boundary portion between the transfer chamber 3 and the base 21 is not present. Even if the active gas leaks into the atmospheric space, the concentration of the inert gas at the third adjustment point is relatively reduced, and the transport chamber 3 is a space to which the inert gas is supplied. The oxygen concentration in the vicinity of the portion that separates the internal space and the atmospheric space can be maintained at a safe concentration of a predetermined value or higher.

Further, in the EFEM 1 according to the present embodiment, a drive system storage box in which a part of the door drive mechanism 27 of the load port 2 is housed outside the transport chamber 3 and a downdraft of an inert gas is formed in the internal space. The circumference of 28 is set as the fourth adjustment point, and the load port 2 provided with the fourth ejection port (not shown) for ejecting air in the vicinity of the fourth adjustment point is applied.

Then, in the EFEM 1 according to the present embodiment, an air supply source (not shown) and a fourth ejection port are connected by an appropriate pipe, and the timing of supplying the inert gas into the transport chamber 3 at the time of setting up the EFEM 1, that is, the transport chamber. The fan filter unit 32 provided in 3 is driven to generate a downdraft in the wafer transfer space 3S of the transfer chamber 3, and an inert gas (environmental gas), which is a highly clean gas, circulates in the wafer transfer space 3S. This is a case where the inert gas leaks into the atmospheric space from the circumference of the drive system storage box 28 by injecting air from the fourth ejection port toward the fourth adjustment point at the timing when the operation starts. Also, the concentration of the inert gas at the 4th adjustment point is relatively lowered, and the vicinity of the portion that separates the internal space of the drive system storage box 28, which is the space to which the inert gas is supplied, from the atmospheric space ( A safe oxygen concentration can be maintained in the range of 1 mm from the isolated portion).

As described above, the EFEM1 according to the present embodiment has the first adjustment point, the second adjustment point, and the third adjustment point, which are the parts (isolation part) that separate the space to which the inert gas such as nitrogen is supplied from the atmosphere. Local oxygen concentration in the vicinity of the isolated portion by ejecting air from the first spout x1, the second spout x2, the third spout x3, and the fourth spout for the location and the fourth adjustment location, respectively. The reduction can be suppressed and the safety of the operator can be improved.

In addition, according to EFEM1 according to the present embodiment, for the first adjustment point, the second adjustment point, the third adjustment point, and the fourth adjustment point, the first spout x1, the second spout x2, and the second spout, respectively. By ejecting air from the 3 ejection ports x 3 and the 4th ejection port, it is possible to eliminate particles adhering to the air blowing destination (for example, particles adhering to the latch key, registration pin, surface of FOUP4, etc.). it can.

In particular, the EFEM 1 according to the present embodiment includes the supply amount of the inert gas to the transport chamber 3, the supply amount of the purging gas by the bottom purge device, or the leakage amount of the inert gas to the atmospheric pressure side at each adjustment point. An ejection amount adjusting means for adjusting 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 provided according to any amount. According to such a configuration, the first adjustment point, the second adjustment point, the third adjustment point, and the fourth adjustment point, which are the parts (isolation part) that separate the space to which the inert gas such as nitrogen is supplied from the atmosphere. The decrease in oxygen concentration at the adjustment point can be realized by an appropriate amount of air supply, and the excessive use of air can be prevented or suppressed.

Although the embodiment of the present invention has been described above, the present invention is not limited to the configuration of the above embodiment. For example, in the above-described embodiment, the adjustment points (first adjustment point, second adjustment point, third adjustment point) which are the parts (isolation part) that separate the space to which the inert gas such as nitrogen is supplied from the atmosphere. , A mode in which an outlet for ejecting air is provided in the vicinity of the adjustment point) has been illustrated, but a mode in which a gas suction port is provided in the vicinity of the adjustment point may be adopted. In this case, the space where the inert gas such as nitrogen is supplied leaks to the atmospheric space in the vicinity of the adjustment points (first adjustment point, second adjustment point, third adjustment point, fourth adjustment point). For example, a frame having a semi-sealed structure through which the inert gas can flow is arranged, and the inside of the frame is sucked by the gas suction port provided in the frame to separate the space to which the inert gas is supplied from the atmospheric space. The oxygen concentration in the vicinity of the portion (range of 1 mm from the isolated portion) can be maintained at a concentration safe for the operator. The inert gas sucked from the gas suction port may be configured to be recovered in an appropriate recovery space (recovery container).

When adopting a configuration in which a gas suction port is provided near the adjustment point, the amount of inert gas supplied to the transport chamber, the amount of gas supplied for purging by the bottom purge device, or leakage of the inert gas to the atmospheric pressure side at each adjustment point. If the EFEM is equipped with a suction force adjusting means that adjusts the suction force by the gas suction port according to the amount and any of these amounts, the space to which the inert gas such as nitrogen is supplied and the atmosphere are separated. It is possible to realize a decrease in oxygen concentration at the first adjusting portion, the second adjusting portion, the third adjusting portion, and the fourth adjusting portion, which are the existing portions (isolated portions), by an appropriate suction force.

Further, instead of providing an outlet or a gas suction port in association with all of the first adjustment point, the second adjustment point, the third adjustment point, and the fourth adjustment point, only one of the adjustment points or only one of the adjustment points is provided. It is also possible to adopt an embodiment in which a spout or a gas suction port is provided only at the two selected adjustment points or only at the three selected selection points.

In the above-described embodiment, FOUP is adopted as the wafer storage container. However, in the present invention, it is also possible to use a wafer storage container other than FOUP, for example, MAC (Multi Application Carrier), H-MAC (Horizontal-MAC), FOSB (Front Open Shipping Box) and the like.

In the above-described embodiment, nitrogen gas is taken as an example of the inert gas used for the bottom purge treatment and the like, but the present invention is not limited to this, and a desired gas such as a dry gas or an argon gas can be used.

Further, the container door (FOUP door) may be temporarily in an inclined posture (with an operation of drawing a partial arcuate locus) 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 embodiment, and various modifications can be made without departing from the spirit of the present invention.

1 ... EFEM
2 ... Load port 21 ... Base 22 ... Load port door 23 ... Mounting stand 27 ... Door drive mechanism 28 ... Drive system storage box 3 ... Conveyance chamber 4 ... Wafer storage container (FOUP)
43 ... Container door (FOUP door)
9 ... Nozzle P ... Bottom purging device W ... Wafer

Claims (2)

A transfer chamber that internally constitutes a wafer transfer space that is substantially closed by connecting a load port and a processing device to an opening provided on the wall surface.
A wafer transfer device arranged in the wafer transfer space and mounted on the load port and a wafer transfer device for transferring a wafer between the processing device and the wafer storage container is provided.
An EFEM configured to generate a downdraft in the wafer transfer space and circulate an inert gas in the wafer transfer space.
The load port
A plate-shaped base that forms a part of the front wall surface of the transport chamber and has an opening for opening the internal space of the transport chamber.
A load port door that opens and closes the opening of the base,
A mounting table provided on the base in a substantially horizontal position,
With the nozzle provided on the above-mentioned pedestal in contact with the port arranged on the bottom surface of the wafer storage container placed on the above-mentioned pedestal, the gas atmosphere in the wafer storage container is displayed from the bottom surface side of the wafer storage container. A bottom purge device that can be replaced with a purging gas consisting of an inert gas,
It is provided with a door drive mechanism for driving the load port door.
A first adjustment point where the nozzle contacts the port,
A second adjustment portion of the base, including at least one of the boundary portion with the load port door or the boundary portion with the container door which is the door of the wafer storage container.
A third adjustment point, which is a boundary between the transport chamber and the base,
A fourth adjustment point, which is the circumference of the drive system storage box in which a part of the door drive mechanism of the load port is housed outside the transport chamber and a downdraft of inert gas is formed in the internal space.
An EFEM comprising an outlet or a gas suction port for ejecting air in the vicinity of at least one of the plurality of adjustment points. Depending on the amount of the inert gas supplied to the wafer transfer space, the amount of the purging gas supplied by the bottom purging device, or the amount of the inert gas leaking to the atmospheric pressure side at each of the adjustment points, any of these amounts. The EFEM according to claim 1, further comprising an adjusting means for adjusting the amount of air ejected from the spout or the suction force of the gas suction port.

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