JP7299474B2 - EFEM - Google Patents

Description

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

In a semiconductor manufacturing process, wafers are processed in a clean room in order to improve yield and quality. In recent years, a "mini-environment system" has been adopted to further improve the cleanliness of only the local space around the wafer, and a means of transporting the wafer and performing other processes has been adopted. In the mini-environment method, a FOUP, which is a container in which wafers are stored in a highly clean inner space, constitutes a part of the wall surface of the wafer transfer chamber (hereinafter referred to as the “transfer chamber”) that is almost closed inside the housing. (Front-Opening Unified Pod) is placed next to the transfer chamber and has the function of opening and closing the FOUP door (hereinafter referred to as "FOUP door") in close contact with the door. It is

The load port is a device for taking wafers in and out of the transfer chamber, and functions as an interface between the transfer chamber and the FOUPs. Then, when a 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, a transfer robot (wafer transfer device) arranged in the transfer chamber moves the inside of the FOUP. It is configured so that wafers can be taken out into the transfer chamber and wafers can be stored in the FOUP from the transfer chamber.

In the semiconductor manufacturing process, a storage pod called the above-mentioned FOUP is used in order to properly maintain the atmosphere around the wafer, and the wafer is stored and managed inside the FOUP. In particular, in recent years, the integration of devices and the miniaturization of circuits have progressed, and it is required to maintain a high degree of cleanliness around the wafer so that particles and moisture do not adhere to the wafer surface. Therefore, in order to prevent the wafer surface from being oxidized or otherwise changing the surface properties, the inside of the FOUP is filled with nitrogen gas, and the surroundings of the wafer are made into a nitrogen atmosphere, which is an inert gas, or in a vacuum state ( purge process) is also performed.

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

JP 2017-212322 A

By the way, it is necessary to maintain the oxygen concentration in the vicinity of the part separating the space to which nitrogen is supplied from the atmospheric space (for example, the range of 1 mm from the separated part) at a safe concentration for the operator (for example, 19.5% or more). There is This is to prevent the operator from falling into an oxygen-deficient state and fainting when entering a space with an extremely low oxygen concentration.

The present invention has been made with a focus on such problems, and the main purpose is to improve the safety of operators at the site where an EFEM is introduced. An object of the present invention is to provide an EFEM capable of suppressing a decrease in oxygen concentration in a portion isolated from. It should be noted that the present invention is a technique that can be applied to wafer storage containers other than FOUPs.

That is, the present invention includes a transfer chamber having a wafer transfer space which is substantially closed by connecting a load port and a processing apparatus to an opening provided in a wall surface, and a load port disposed in the wafer transfer space. A wafer transport device for transporting wafers between a wafer storage container placed on a wafer storage container and a processing device, generating a downward air current in the wafer transport space and circulating an inert gas such as nitrogen in the wafer transport space It relates to an EFEM configured to allow The EFEM according to the present invention includes a plate-shaped base serving as a load port and forming a part of the front wall surface of the transfer chamber and having an opening for opening the internal space of the transfer chamber; A load port door that opens and closes the opening of the wafer storage container, a mounting table provided in a substantially horizontal posture on the base, and a nozzle provided on the mounting table that is brought into contact with the port arranged on the bottom surface of the wafer storage container placed on the mounting table. a bottom purge device capable of replacing the gas atmosphere in the wafer storage container with a purge gas composed of an inert gas such as nitrogen from the bottom side of the wafer storage container in a state where the wafer storage container is closed; and a door driving mechanism for driving the load port door. A first adjustment point where the nozzle contacts the port, and a second adjustment point including at least one of the boundary portion of the base 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 portion between the transfer chamber and the base, and a drive in which a part of the door drive mechanism of the load port is housed outside the transfer chamber and a downward air current of inert gas is formed in the inner space. A fourth adjustment point around the system housing box is characterized in that an ejection port for ejecting air or a gas suction port is provided in the vicinity of at least one adjustment point among the plurality of adjustment points.

The present inventor has found that the bottom purge process from between the port provided on the bottom surface of the wafer storage container and the bottom purge nozzle provided on the load port is a factor that causes a dangerously low oxygen concentration state for the operator at the site of EFEM introduction. Inert gas such as nitrogen used in the wafer storage container leaks, albeit minutely, and inert gas such as nitrogen in the wafer storage container leaks, although minutely, from between the main body of the wafer storage container and the door of the wafer storage container, In the case of an EFEM configured to fill the transfer chamber with an inert gas such as nitrogen, a drive system storage box or a load port housing a mechanism for driving the load port door, or between the transfer chamber and the load port. Focusing on the fact that the inert gas in the transfer chamber leaks even from the door, albeit minutely, the EFEM according to the present invention was devised in order to prevent or suppress the situation where the oxygen concentration locally decreases in the vicinity of these leaks. came to.

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

In particular, the EFEM according to the present invention can measure any of the amount of inert gas supplied to the wafer transfer space, the amount of purge gas supplied by the bottom purge device, or the amount of inert gas leaked to the atmospheric pressure side at each adjustment point. Oxygen concentration in the vicinity of the isolated part can be adjusted by an appropriate amount of air supply or suction force, provided that it is equipped with an adjustment means for adjusting the amount of air ejected from the ejection port or the suction force by the gas suction port according to the amount. can be reduced.

According to the present invention, at an EFEM introduction site where appropriate processing is performed on wafers, it is possible to suppress the decrease in oxygen concentration in the space where an inert gas such as nitrogen is supplied and the space separated from the atmosphere, thereby ensuring the safety of the operator. It is possible to provide an EFEM capable of enhancing the properties.

FIG. 3 is a side view schematically showing the relative positional relationship between the EFEM and its peripheral devices according to the same embodiment; FIG. 4 is a diagram schematically showing a side cross section of the load port according to the embodiment with the FOUP separated from the base and the load port door in the fully closed position; FIG. 3 is a perspective view showing a partially omitted load port in the same embodiment; 3 and an enlarged schematic diagram of the zz line cross section of FIG. 4(a). The y-direction arrow directional view of FIG. The whole window unit perspective view in the same embodiment. FIG. 3 is a view corresponding to FIG. 2 and showing a state in which the FOUP is approaching the base and the load port door is in the fully closed position; FIG. 3 is a view corresponding to FIG. 2 and showing a state in which the load port door is in the open position; The figure which shows the mapping part in the same embodiment. FIG. 2 is a front view schematically showing the relative positional relationship between the EFEM and its peripheral devices in the same embodiment;

An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, an EFEM (Equipment Front End Module) 1 according to this embodiment includes a load port 2 and a transfer chamber 3 that are arranged in a clean room in a semiconductor manufacturing process. FIG. 1 schematically shows the relative positional relationship between the EFEM 1 and its peripheral devices. FOUP4 shown in the same figure is used 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 the internal space of the transfer chamber 3 . By driving the fan filter unit 32 provided in the transfer chamber 3, a downward air current 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 generated. It is possible to circulate in the wafer transfer space 3S. A processing apparatus M (semiconductor processing apparatus) is provided adjacent to a rear wall surface 3B of the transfer chamber 3 that faces a front wall surface 3A on which the load port 2 is arranged. That is, the load port 2 is connected to the opening provided on the front wall surface 3A of the transfer chamber 3, and the processing apparatus M is connected to the opening provided on the rear wall surface 3B of the transfer chamber 3, so that the inside of the transfer chamber 3 is substantially closed. A wafer transfer space 3S is formed.

In the clean room, the inner space MS of the processing apparatus M, the wafer transfer space 3S of the transfer chamber 3, and the inner space 4S of the FOUP 4 placed on the load port 2 are maintained at a high degree of cleanliness.

In this embodiment, as shown in FIG. 1, the load port 2, the transfer chamber 3, and the processing apparatus M are closely arranged in this order in the front-rear direction D of the EFEM 1. As shown in FIG. The operation of the EFEM 1 is controlled by the controller of the load port 2 (the controller 2C shown in FIG. 3) and the controller of the entire EFEM 1 (the controller 3C shown in FIG. 1). is controlled by the controller (control unit MC shown in FIG. 1). Here, the controller MC, which is the controller of the entire processing apparatus M, and the controller 3C, which is the controller of the entire EFEM 1, are upper controllers of the controller 2C of the load port 2. FIG. Each of these control units 2C, 3C, and MC is composed of a normal microprocessor or the like having a CPU, a memory, and an interface. It extracts and executes a specific program and cooperates with peripheral hardware resources to realize the desired function.

As shown in FIGS. 1 and 2, the FOUP 4 includes a FOUP body 42 capable of opening the internal space 4S through a loading/unloading port 41, which is an opening, and a FOUP door 43 capable of opening/closing the loading/unloading port 41. It is known to accommodate a plurality of wafers W in the vertical direction H in a multistage manner and to allow these wafers W to be taken in and out through a loading/unloading port 41 .

The FOUP main body 42 is provided with shelves (wafer mounting shelves) on which the wafers W can be mounted in a plurality of stages at a predetermined pitch in the internal space 4S. A port 40 is provided at a predetermined location on the bottom wall of the FOUP body 42, as shown in FIG. The port 40 is mainly composed of, for example, a hollow cylindrical grommet seal fitted in a port mounting through hole formed in the bottom wall of the FOUP main body 42, and can be opened and closed by a check valve. At the center of the upward surface of the upper wall of the FOUP main body 42, there is provided a flange portion that is gripped by a container transport device (for example, OHT: Over Head Transport).

The FOUP door 43 faces the load port door 22 of the load port 2 when mounted on a 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) capable of locking the FOUP door 43 to the FOUP body 42 . A gasket (not shown) is provided at a predetermined portion in contact with or close to the FOUP body 42 in a state in which the loading/unloading port 41 of the FOUP door 43 is closed by the FOUP door 43, and the gasket is brought into contact with the FOUP body 42 and elastically deformed. , so that the internal space 4S of the FOUP 4 can be sealed.

The load port 2 according to this embodiment, as shown in FIGS. A plate-shaped base 21 having a portion 21a formed thereon, 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 . An opening 215 provided in this window unit 214 is an opening through which the wafer W is allowed to pass. In this embodiment, as shown in FIG. 2, a load port 2 having a seal portion 5 surrounding an opening 21a of a base 21 is employed, and as shown in FIG. Sections 5 and 6 are provided.

The mounting table 23 is provided on top of a horizontal base 25 (support base) that is arranged in a substantially horizontal position at a position slightly above the center in the height direction of the base 21 . The mounting table 23 can mount the FOUP 4 in such a direction that the FOUP door 43 for opening and closing the internal space 4S of the FOUP main body 42 faces the load port door 22 . The mounting table 23 has a predetermined docking position (see FIG. 7) where the FOUP door 43 approaches the opening 21a of the base 21, and a position where the FOUP door 43 is separated from the base 21 by a predetermined distance from the docking position (see FIG. 2). ), and is configured to be movable 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. , the positioning of the FOUP 4 on the mounting table 23 is attempted. Further, lock claws 232 are provided for fixing the FOUP 4 to the mounting table 23 . By hooking the locking claws 232 to a locked portion (not shown) provided on the bottom surface of the FOUP 4 and fixing it in a locked state, the FOUP 4 can be positioned properly on the mounting table 23 in cooperation with the positioning projections 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 a lid connected state in which the FOUP door 43 can be removed from the FOUP body 42, releases the connection state to the FOUP door 43, and attaches the FOUP door 43 to the FOUP body 42. The FOUP door 43 can be moved along a predetermined moving path while holding the FOUP door 43 in an integrated state by the connecting mechanism 221 (see FIG. 5). is. In the load port 2 of this embodiment, the load port door 22 is placed in the position shown in FIG. 7, that is, the fully closed position (C ) and the position shown in FIG. 8, that is, the open position where 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 transfer chamber 3. (O) at least. The load port 2 of this embodiment can be moved to the open position (O) shown in FIG. It is constructed such that it can move downward from an open position (O) shown to a fully open position (not shown) while maintaining a standing posture. 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 supports the support frame 271 so as to be movable in the front-rear direction D via slide support portions 272. , slide rails 274 that support the movable block 273 so as to be movable in the vertical direction H, and movement of the load port door 22 in the front-rear direction D along the horizontal path and in the vertical direction H along the vertical path. and a drive source (for example, an actuator not shown). By giving a drive command from the controller 2C to this actuator, the load port door 22 is moved in the longitudinal direction D and the vertical direction. An actuator for front-rear movement and an actuator for vertical movement may be provided separately, or a common actuator may be used as a drive source for front-rear movement and vertical movement.

The support frame 271 supports the lower rear portion of the load port door 22 . The support frame 271 extends downward, passes through a slit-shaped insertion hole 21b formed in the base 21, and has a substantially crank-like shape projecting outside the transfer chamber 3 (toward the mounting table 23 side). are doing. A slide support portion 272 , a movable block 273 , and a slide rail 274 for supporting the support frame 271 are also arranged closer to the mounting table 23 than the base 21 , that is, outside the transfer chamber 3 . These slide support portion 272 , movable block 273 , and slide rail 274 serve as sliding portions when the load port door 22 is moved. In this embodiment, by arranging these outside the transfer chamber 3, even if particles are generated when the load port door 22 is moved, the insertion hole 21b is set in a minute slit shape. Therefore, it is possible to prevent or suppress the entry of particles into the transfer chamber 3 . Further, the load port 2 of the present embodiment includes parts and portions of the door moving mechanism 27 that are arranged outside the transfer chamber 3, specifically, a portion of the support frame 271, a slide support portion 272, and a movable block 273. and a drive system storage box 28 covering the slide rail 274 . As a result, the inert gas (environmental gas) in the transfer chamber 3 is prevented from flowing out of the EFEM 1 through the insertion hole 21 b formed in the base 21 . In addition, a descending air current of inert gas is formed in the internal space of the drive system storage box 28.

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

The load port 2 of this embodiment includes a purge device P capable of injecting a purge gas made of an inert gas such as nitrogen into the internal space 4S of the FOUP 4 and replacing the gas atmosphere in the internal space 4S of the FOUP 4 with the purge gas. (See Figure 3). The purge device P is provided with a plurality of purge nozzles 9 (gas supply/discharge device) arranged at predetermined positions on the mounting table 23 in such a manner that the upper end thereof can be exposed. The 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 while being 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 on the bottom of the FOUP 4 function as "supply ports" and are connected to the supply ports. An appropriately selected purge gas such as nitrogen gas, inert gas or dry air is injected into the FOUP 4 by the purge nozzle 9, and the remaining port 40 is made to function as an "exhaust port", and the purge nozzle 9 connected to the exhaust port This is a process of filling the FOUP 4 with the purge gas by discharging the gas atmosphere in the FOUP 4 . 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 bottom purge processing.

As shown in FIG. 9, the load port 2 of the present embodiment has a mapping section m capable of detecting the presence or absence of the wafer W in the FOUP 4 and the housing posture. The mapping unit m includes mapping sensors (transmitter m1, receiver m2) capable of detecting the presence or absence of wafers W stored in multiple stages in the height direction H within the FOUP 4, and a sensor frame supporting the mapping sensors m1 and m2. m3. The mapping unit m can be positioned between a mapping retraction posture in which the entirety is arranged in the transfer space within the transfer chamber 3 and a mapping posture in which at least the mapping sensors m1 and m2 are positioned inside the FOUP 4 through the openings 21a of the base 21. is. The mapping unit m is configured to be movable in the height direction H while maintaining the mapping evacuation 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 driving mechanism 27, the up-and-down movement of the mapping section m is performed integrally with the up-and-down movement of the load port door 22. ing. Note that the mapping unit m is omitted in each figure other than FIG.

The mapping sensor is composed of a transmitter m1 (light-emitting sensor) that emits a beam (line light) as a signal, and a receiver m2 (light-receiving sensor) that receives the signal emitted from the transmitter m1. It should be noted that the mapping sensor can also be configured by a transmitter and a reflector 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 conveyed above the load port 2 by a container conveying device such as an OHT and placed on the mounting table 23 . At this time, for example, the positioning projections 231 provided on the mounting table 23 are fitted into the positioning recesses of the FOUP 4, and the lock claws 232 on the mounting table 23 are locked (lock processing). In the present embodiment, the FOUPs 4 can be placed on each of the three FOUPs 23 of the load port 2 arranged side by side in the width direction of the transfer chamber 3 . Further, a seat sensor (not shown) for detecting whether or not the FOUP 4 is placed on the mounting table 23 at a predetermined position detects that the FOUP 4 is placed on the mounting table 23 at a proper position. Can also be configured.

In the load port 2 of the present embodiment, when the FOUP 4 is placed on the mounting table 23 at the normal position, the bottom surface of the FOUP 4 presses the pressed portion of the pressure sensor provided on the mounting table 23, for example. to detect Triggered by this, the purge nozzles 9 (all the purge nozzles 9) provided on the mounting table 23 advance upward from the upper surface of the mounting table 23 and are connected to the ports 40 of the FOUP 4, and the ports 40 change from the closed state to the open 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 to replace the internal space 4S of the FOUP 4 with nitrogen gas (bottom purge process). During the bottom purge process, the gas atmosphere inside the FOUP 4 is discharged out of the FOUP 4 through the purge nozzle 9 connected to the port 40 functioning as an exhaust port. By such a bottom purge process, the moisture concentration and the oxygen concentration in the FOUP 4 are lowered to a predetermined value or less, respectively, so that the surrounding environment of the wafer W in the FOUP 4 becomes a low-humidity environment and a low-oxygen environment.

After the locking process, the load port 2 of the present embodiment moves the mounting table 23 from the position shown in FIG. 2 to the docking position shown in FIG. The side is held and fixed (clamping process), the connection mechanism 221 is switched to the cover connection state (cover connection process), the FOUP door 43 is moved together with the load port door 22, and the opening 21a of the base 21 and the load port door 22 are moved. The loading/unloading port 41 of the FOUP 4 is opened to release the sealed state inside the FOUP 4 (unsealing process). The load port 2 of the present embodiment performs mapping processing by the mapping unit m during the processing of moving the load port door 22 from the open position (O) to the fully open position. In the mapping process, the mapping part m, which was in the mapping evacuation posture until immediately before the sealing release process is executed, is switched to the mapping posture after the load port door 22 is moved from the fully closed position (C) to the open position (O). By moving the port door 22 downward toward the fully open position, the mapping unit m is also moved downward while maintaining the mapping attitude, and the presence or absence of the wafer W accommodated in the FOUP 4 is detected using the mapping sensors m1 and m2. This is the process of detecting the storage posture. That is, the signal path formed between the transmitter m1 and the receiver m2 is interrupted where the wafer W is present by transmitting a signal from the transmitter m1 to the receiver m2. reaches the receiver m2 unobstructed where there is no . As a result, it is possible to sequentially detect the presence or absence of the wafers W stored in the FOUP 4 in the height direction H and the stored attitude.

By executing the sealing release process, the inner space 4S of the FOUP body 42 and the wafer transfer space 3S of the transfer chamber 3 are brought into communication, and the transfer chamber 3 is opened based on the information (wafer position) detected by the mapping process. A transfer robot 31 provided in the wafer transfer space 3S carries out a process (transfer process) of taking out a wafer W from a specific wafer mounting shelf or storing the wafer W in a specific wafer mounting shelf.

In the load port 2 according to the present embodiment, the load port door 22 is moved to the fully closed position (C) by the door driving mechanism 27 when all the wafers W in the FOUP 4 have finished the processing process by the processing apparatus M. , the opening 21a of the base 21 and the loading/unloading port 41 of the FOUP 4 are closed to seal the internal space 4S of the FOUP 4 (sealing process). A switching process (cover disconnection process) is executed. 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 loading/unloading 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. becomes closed.

Subsequently, the load port 2 according to the present embodiment performs a clamp releasing process for releasing the fixed state (clamped state) of the FOUP 4 by the movement restricting portion L, and then moves the mounting table 23 away from the base 21. After executing the processing (docking release processing), the state in which the FOUP 4 is locked by the lock claw 232 on the mounting table 23 is released (unlock processing). As a result, the FOUP 4 storing the wafers W that have undergone the predetermined processing is handed over from the mounting table 23 of each load port 2 to the container transfer device and carried out to the next process.

The EFEM 1 according to the present embodiment, which undergoes such an operation flow, prevents the oxygen concentration from decreasing around the portion separating the atmospheric space from the space to which the inert gas such as nitrogen is supplied. It is important to avoid the possibility of falling into an oxygen-deficient state and fainting when entering a space with extremely low oxygen concentration.

When the load port 2 capable of bottom purge processing is applied as in this 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 table 23 of the load port 2. An inert gas such as nitrogen used for processing leaks, albeit minutely.

Therefore, in the present embodiment, the location where the purge nozzle 9 constituting the bottom purge device P contacts the port 40 (grommet) provided on the bottom surface of the FOUP 4 is set as the first adjustment location, and air is ejected near the first adjustment location. A load port 2 having a mounting table 23 provided with a first ejection port x1 is applied.

Specifically, as shown in FIG. 3, air is jetted upward near the purge nozzle 9 that contacts a port 40 that functions as a supply port among the ports provided on the bottom of the FOUP 4 during the bottom purge process. 1 ejection port x1 is provided in the mounting table 23 . In the figure, of the four purge nozzles 9 provided on the mounting table 23, three purge nozzles 9 connected to a port 40 functioning as a supply port are each provided with a first ejection port x1 in the vicinity thereof. are doing.

In this embodiment, the purge nozzle 9 is vertically movable between a projecting 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 vertical movement of the purge nozzle 9 is realized by supplying and exhausting air to and from the inner space of a holder (not shown) that supports the purge nozzle 9 so as to be able to project and retract. Therefore, the piping for vertical movement of the purge nozzle 9 is appropriately branched so that air can be supplied from the same air supply source as the air used for vertical movement of the purge nozzle 9 to the first ejection port x1. In FIG. 3, arrows schematically indicate the direction of air jetting from each of the first jetting ports x1.

Simultaneously or substantially simultaneously with the start of the bottom purge process, air is ejected from the first ejection port x1, and the purge nozzle 9 is directed toward the first adjustment location where the port 40 provided on the bottom surface of the FOUP 4 is in contact with the first adjustment location. By ejecting air from the ejection port x1, even if an inert gas such as nitrogen leaks into the atmospheric space from the boundary between the purge nozzle 9 and the port 40, even if it is slightly By relatively reducing the concentration of the active gas, the oxygen concentration in the vicinity of the portion separating the inner space 4S of the FOUP 4, which is a space to which an inert gas such as nitrogen is supplied, and the atmospheric space is reduced for operator safety. can be maintained at a concentration equal to or higher than a predetermined value (for example, 19.5 percent or higher) that can ensure the

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 point, and the second ejection port x2 for ejecting air to the vicinity of the second adjustment point. is applied to the load port 2 with

Specifically, as shown in FIGS. 4A and 4B, a hollow upper cover x21 extending in the width direction is positioned above the opening of the base 21 of the load port 2. the tip of the air supply pipe x22 is arranged inside the upper cover x21, and the air supplied to the inside of the upper cover x21 from the air supply pipe x22 is supplied to the inside of the upper cover x21 as a second ejection port provided on the downward surface of the upper cover x21. It is configured to jet downward from x2. FIG. 4(b) is a schematic cross-sectional view taken along line zz of FIG. 4(a). 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 sealant x24 is provided at a corner adjacent to the base 21. As shown in FIG. In FIG. 4, arrows schematically indicate the ejection direction of the air ejected from the second ejection port x2.

At the same time or substantially at the same time as the start of the bottom purge process, the EFEM 1 according to the present embodiment supplies air from the second ejection port x2 to the second adjustment portion, which is the boundary portion between the load port door 22 and the base 21 of the load port 2. spout out. The second adjustment point, which is the boundary portion between the load port door 22 and the base 21 of the load port 2, is the docking process (the mounting table 23 at the position shown in FIG. 2), the boundary between the base 21 of the load port 2 and the FOUP door 43 and the boundary between the FOUP main body 42 and the FOUP door 43 are located extremely close to each other. (See FIGS. 7 and 8). Therefore, by ejecting air from the second ejection port x2 toward the second adjustment location, the boundary 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 can be adjusted. , and further, even if a small amount of inert gas such as nitrogen leaks into the atmospheric space from the boundary between the FOUP main body 42 and the FOUP door 43, the inert gas near the second adjustment point Oxygen in the vicinity of the portion separating the atmospheric space from the inner space 3S of the transfer chamber 3 or the inner space 4S of the FOUP 4, which is a space to which an inert gas such as nitrogen is supplied, by relatively reducing the concentration of the gas. The concentration can be maintained at a predetermined value or higher that can ensure the safety of the operator. 2, 4, 7 and 8, the entire top cover x21 including the second ejection port x2 is omitted.

Further, in the 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 as the third adjustment point, and near the third adjustment point. A load port 2 having a third ejection port x3 for ejecting air is applied.

Specifically, as shown in FIG. 3, the base 21 of the load port 2 is composed of a flat plate-like base body 211 and a surface of the base body 211 facing the FOUP 4 placed on the mounting table 23 (front surface). and a hollow pipe frame 213 provided in such a manner as to be 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 ejection ports x3 that are open on the surface facing the outside at a predetermined pitch along the height direction, and air is ejected outward from each of the third ejection ports x3. is set to In FIG. 10, arrows schematically indicate the direction of air jetting from each of the third jetting ports x3. FIG. 10 omits parts of the base 21 of the load port 2 other than the hollow pipe frame 213 shown with a predetermined pattern. Further, in figures other than FIGS. 3 and 10, the hollow pipe frame 213 including the third ejection port x3 is omitted.

The EFEM 1 according to the present embodiment connects the air supply source (not shown) and the third ejection port x3 with an appropriate pipe, and the timing of supplying the inert gas into the transfer chamber 3 at the time of setting up the EFEM 1, that is, the transfer A fan filter unit 32 provided in the chamber 3 is driven to generate a downward air current in the wafer transfer space 3S of the transfer chamber 3, and an inert gas (environmental gas), which is a highly clean gas, flows in the wafer transfer space 3S. At the timing when the 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, thereby removing the air from the boundary portion between the transfer chamber 3 and the base 21. Even if the active gas is slightly leaking into the atmospheric space, the concentration of the inert gas at the third adjustment point is relatively lowered, and the inert gas is supplied to the transfer chamber 3. It is possible to maintain the oxygen concentration in the vicinity of the portion separating the internal space and the atmospheric space at a safe concentration equal to or higher than a predetermined value.

Further, in the EFEM 1 according to the present embodiment, the drive system storage box accommodates a portion of the door drive mechanism 27 of the load port 2 outside the transfer chamber 3 and has a downward airflow of inert gas formed in the interior space. The circumference of 28 is set as a fourth adjustment point, and a load port 2 having a fourth ejection port (not shown) for ejecting air in the vicinity of the fourth adjustment point is applied.

The EFEM 1 according to the present embodiment connects an air supply source (not shown) and a fourth ejection port with an appropriate pipe, and the timing of supplying the inert gas into the transfer chamber 3 at the time of setting up the EFEM 1, that is, the transfer chamber A fan filter unit 32 provided in the chamber 3 is driven to generate a downward air current 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. When the inert gas is leaking into the atmospheric space from the periphery of the drive system storage box 28 by jetting air from the fourth jet port toward the fourth adjustment point at the timing of starting to Also, the concentration of the inert gas at the fourth adjustment point is relatively lowered, and the vicinity of the portion separating the inner 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 at a distance of 1 mm from the isolation part).

As described above, the EFEM 1 according to the present embodiment includes the first adjustment point, the second adjustment point, and the third adjustment point, which are portions (isolation portions) that separate the atmosphere from the space to which an inert gas such as nitrogen is supplied. By ejecting air from the first ejection port x1, the second ejection port x2, the third ejection port x3, and the fourth ejection port to the location and the fourth adjustment location, respectively, the local oxygen concentration in the vicinity of the isolated portion It is possible to suppress the deterioration and improve the safety of the operator.

In addition, according to the EFEM 1 according to the present embodiment, the first ejection port x1, the second ejection port x2, the second By ejecting air from the 3 ejection ports x3 and the 4th ejection port, it is also possible to remove particles adhering to the air blowing destination (for example, particles adhering to the surface of the latch key, registration pin, and FOUP 4). can.

In particular, the EFEM 1 according to the present embodiment can measure the amount of inert gas supplied to the transfer chamber 3, the amount of purge gas supplied by the bottom purge device, or the amount of inert gas leaked to the atmospheric pressure side at each adjustment point. There is provided 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 according to any amount. According to such a configuration, the first adjustment location, the second adjustment location, the third adjustment location, the fourth adjustment location, which are the portions (separation portions) that isolate the space to which the inert gas such as nitrogen is supplied from the atmosphere (separation portions). It is possible to reduce the oxygen concentration at the adjustment location by supplying an appropriate amount of air, thereby preventing or suppressing excessive use of air.

Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations of the above embodiments. For example, in the above-described embodiment, the adjustment points (the first adjustment point, the second adjustment point, the third adjustment point), which are the portions (separated portions) that separate the space to which the inert gas such as nitrogen is supplied from the atmosphere, , fourth adjustment point), a mode in which a gas suction port is provided in the vicinity of the adjustment point may be adopted. In this case, in the vicinity of the adjustment points (first adjustment point, second adjustment point, third adjustment point, fourth adjustment point), there is a slight leak from the space where the inert gas such as nitrogen is supplied to the atmospheric space. A space to which the inert gas is supplied is isolated from the atmospheric space by arranging, for example, a semi-sealed frame into which the inert gas can flow, and sucking the inside of the frame with a gas suction port provided in the frame. The oxygen concentration in the vicinity of the part (within 1 mm from the isolated part) can be maintained at a safe concentration for the operator. The inert gas sucked from the gas suction port may 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 transfer chamber, the amount of purge gas supplied by the bottom purge device, or inert gas leakage to the atmospheric pressure side at each adjustment point If the EFEM is provided with a suction force adjusting means for adjusting the suction force of the gas suction port according to any of these amounts, the space to which the inert gas such as nitrogen is supplied is isolated from the atmosphere. It is possible to reduce the oxygen concentration at the first, second, third, and fourth adjustment points, which are the portions (separate portions) where the air is present, with an appropriate suction force.

In addition, instead of the aspect in which the ejection port or the gas suction port is provided in association with all of the first adjustment point, the second adjustment point, the third adjustment point, and the fourth adjustment point, only any one adjustment point, or It is also possible to employ a mode in which only two selected adjustment points or only three selected points are provided with ejection ports or gas suction ports.

In the above-described embodiments, FOUPs are used as wafer storage containers. However, in the present invention, wafer storage containers other than FOUP, such as MAC (Multi Application Carrier), H-MAC (Horizontal-MAC), FOSB (Front Open Shipping Box), etc., can also be used.

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

In addition, the container door (FOUP door) may temporarily assume an inclined posture (accompanied by an operation that draws a partial arc-shaped trajectory) in the process of moving from the fully closed position to the fully opened position.

In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications are possible without departing from the scope of the present invention.

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

Claims (2)

a transfer chamber inside of which a closed wafer transfer space is formed by connecting a load port and a processing apparatus to an opening provided in a wall surface;
a wafer transfer device disposed in the wafer transfer space and configured to transfer wafers between the wafer storage container placed on the load port and the processing device;
An EFEM configured to generate a downward air current in the wafer transfer space and to circulate an inert gas in the wafer transfer space,
The load port is
a plate-shaped base forming a part of the front wall surface of the transfer chamber and having an opening for opening the internal space of the transfer chamber;
a load port door that opens and closes the opening of the base;
a mounting table provided in a substantially horizontal posture on the base;
A gas atmosphere in the wafer storage container is introduced from the bottom surface side of the wafer storage container while the nozzle provided on the mounting table is in contact with the port arranged on the bottom surface of the wafer storage container placed on the mounting table. a bottom purge device that can be replaced with the purge gas composed of the inert gas;
a door drive mechanism for driving the load port door,
a first adjustment point where the nozzle contacts the port;
a second adjustment point including at least one of a boundary portion of the base with the load port door or a boundary portion with the container door that is the door of the wafer storage container;
a third adjustment point that is a boundary portion between the transfer chamber and the base;
a fourth adjustment point around a drive system storage box that accommodates a portion of the door drive mechanism of the load port outside the transfer chamber and that has a downward airflow of inert gas formed in the interior space;
A jet port for jetting air or a gas suction port is provided in the vicinity of at least one adjustment point among a plurality of adjustment points in
any of the amount of inert gas supplied to the wafer transfer space, the amount of purge gas supplied by the bottom purge device, or the amount of leakage of the inert gas to the atmospheric pressure side at each of the adjustment points An EFEM characterized by comprising 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 need . a transfer chamber inside of which a closed wafer transfer space is formed by connecting a load port and a processing apparatus to an opening provided in a wall surface;
a wafer transfer device disposed in the wafer transfer space and configured to transfer wafers between the wafer storage container placed on the load port and the processing device;
An EFEM configured to generate a downward air current in the wafer transfer space and to circulate an inert gas in the wafer transfer space,
The load port is
a plate-shaped base forming a part of the front wall surface of the transfer chamber and having an opening for opening the internal space of the transfer chamber;
a load port door that opens and closes the opening of the base;
a mounting table provided in a substantially horizontal posture on the base;
A gas atmosphere in the wafer storage container is introduced from the bottom surface side of the wafer storage container while the nozzle provided on the mounting table is in contact with the port arranged on the bottom surface of the wafer storage container placed on the mounting table. a bottom purge device that can be replaced with the purge gas composed of the inert gas;
a door drive mechanism for driving the load port door,
An ejection port for ejecting air is provided in the base in the vicinity of a second adjustment location including at least one of a boundary portion with the load port door or a boundary portion with the container door, which is the door of the wafer storage container, in the base. An EFEM characterized in that it is provided at a position above an opening, and configured to blow air downward from the jet port.

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