JP7077593B2 - Temporary stocker - Google Patents

Description

The present invention relates to a temporary storage stocker for a wafer transfer container, which is attached to an OHT traveling rail.

In semiconductor factories, a transfer system for automatically transporting wafers to be processed is used for each processing device, and OHT (Overhead Hoist Transfer, automated guided vehicle) is used as one of them. The system is mentioned. In a transfer system using OHT, a large number of OHTs travel on a traveling rail provided on the ceiling of a semiconductor factory to process a wafer transfer container containing wafers from a stocker to a processing device and from a processing device to a processing device. It can be moved from the device to the stocker or from the stocker to the stocker.

In a transfer system using OHT, in order to quickly move a specific wafer transfer container to a processing device or a stocker, a transfer system having a temporary storage stocker attached to a traveling rail of OHT has been proposed. In such a temporary storage stocker, the predetermined wafer transfer container can be temporarily removed from the traveling rail so as not to interfere with the movement of the other wafer transfer containers, so that the transfer efficiency of the wafer transfer container can be improved. can. Further, by temporarily arranging the wafer transfer container in the temporary storage stocker, the wafer transfer container that has been processed by the predetermined processing device is transferred to the next processing device without moving to the stocker, which is the accumulation position. be able to.

In addition, in a transfer system equipped with a temporary storage stocker, a technique for supplying cleaning gas into the wafer transfer container during temporary storage is used for the purpose of preventing oxidation of the wafer in the wafer transfer container placed in the temporary storage container. Proposed.

International Publication No. 2016/047260

However, when the cleaning gas is supplied into the wafer transport container of the temporary storage stocker, the supplied cleaning gas or the gas in the stocker may leak to the vicinity of the wafer transport container, and local oxygen in the factory may occur. May cause a decrease in concentration. Further, in the conventional device, it is necessary to suppress the inflow rate of the cleaning gas in order to suppress the leakage of the cleaning gas, which hinders the rapid cleaning of the wafer transport container in the temporary storage stocker.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a temporary storage stocker capable of preventing problems such as a local decrease in oxygen concentration due to gas outflow from the temporarily placed wafer transfer container. Is.

In order to achieve the above object, the temporary storage stocker according to the present invention is
It is a temporary storage stocker for the wafer transfer container attached to the running rail of the OHT that transfers the wafer transfer container in the semiconductor factory.
A mounting shelf on which the wafer transport container is placed, and
A gas supply unit that is connected to the inside of the wafer transfer container placed on the above-mentioned shelf and allows the cleaning gas to flow in, and a gas supply unit.
It has a collector for recovering gas in the space around the wafer transfer container placed on the above-mentioned storage rack.

Since the temporary storage stocker according to the present invention has a collector that collects gas in the space around the wafer transfer container placed on the mounting shelf, it is provided from the inside of the temporarily placed wafer transfer container or the connection portion of the gas supply unit. It is possible to prevent a local decrease in oxygen concentration due to gas leakage. In addition, even if the gas flows out from the temporary storage stocker, it can be recovered by the collector, so the inflow rate of the cleaning gas into the wafer transfer container by the gas supply unit is increased, and efficient cleaning is achieved. It is possible to do.

Further, for example, the collector has an inflow opening through which gas in the surrounding space flows.
The inflow opening may be provided adjacent to the main opening of the wafer transfer container which is placed on the above-mentioned shelf and is closed by a lid.

By providing the inflow opening of the collector adjacent to the main opening of the wafer transfer container, the gas leaking from the main opening closed by the lid can be efficiently recovered by the collector.

Further, for example, the collector has an inflow opening through which gas in the surrounding space flows.
The collector may be provided below the wafer transfer container placed on the above-mentioned storage rack.

Further, for example, the collector has an inflow opening through which gas in the surrounding space flows.
The inflow opening may be open upward.

Such collectors prevent the flow of cleaning gas such as nitrogen and gas leaked from the wafer transfer container from the temporary stocker near the ceiling to near the floor where people may pass in the semiconductor factory. Can be effectively prevented.

Further, for example, the collector has an inflow opening through which gas in the surrounding space flows.
The inflow opening may be opened so as to face the lid of the wafer transfer container.

By opening the inflow opening of the collector so as to face the lid of the wafer transfer container, the gas leaked from the main opening closed by the lid can be efficiently recovered by the collector.

Further, for example, the above-mentioned storage rack can mount a plurality of the wafer transport containers.
The collector may recover the gas in the peripheral space of the plurality of wafer transfer containers placed on the above-mentioned storage rack.

When a plurality of wafer transport containers are temporarily placed on the mounting shelf, the amount of gas leakage tends to increase. However, the temporary stocker having a collector as described above is used in the temporarily placed wafer transport container or gas. It is possible to prevent a local decrease in oxygen concentration due to gas leakage from the connection portion of the supply unit.

Further, for example, the temporary storage stocker according to the present invention may have a control unit for starting and stopping the recovery of gas in the surrounding space by the collector.

The temporary storage stocker having such a control unit is provided by the collector, for example, when the wafer transfer container is not placed on the mounting shelf or when the cleaning gas is not supplied from the gas supply unit. It is possible to stop the collection of gas in the surrounding space.

Further, for example, the temporary storage stocker according to the present invention may have a gas discharging unit that is connected to the inside of the wafer transport container placed on the above-mentioned shelf and allows gas to flow out from the wafer transport container. good.

By having the gas discharge unit, it is possible to suppress the amount of gas leaking from the wafer transfer container and efficiently introduce the cleaning gas from the gas supply unit into the wafer transfer container.

FIG. 1 is a conceptual diagram of a semiconductor factory provided with a temporary storage stocker according to an embodiment of the present invention. FIG. 2 is a conceptual diagram of a temporary stocker according to an embodiment of the present invention as viewed from above. FIG. 3 is a conceptual diagram showing one state regarding the operation of placing the wafer transfer container on the temporary storage container shown in FIG. 1. FIG. 4 is a conceptual diagram showing another state regarding the operation of placing the wafer transfer container on the temporary storage container shown in FIG. 1. FIG. 5 is an enlarged perspective view of a collector included in the temporary stocker shown in FIG.

FIG. 1 is a conceptual diagram of a semiconductor factory 100 including a temporary storage stocker 20 according to an embodiment of the present invention. As shown in FIG. 1, in the semiconductor factory 100, the wafer to be processed is conveyed in a state of being housed in a wafer transfer container such as a hoop (FOUP) 80, except for the inside of the processing device 96 and the like. The semiconductor factory 100 is provided with a stocker 94 for storing the hoop 80 and a processing device 96 for processing the wafer.

In FIG. 1, only one stocker 94 and one processing device 96 are displayed, but the semiconductor factory 100 is usually provided with more processing devices 96 and stocker 94, and the hoop 80 is a hoop 80. Wafers are transported between the processing device 96 and the stocker 94 by a transport system 90 for automatically transporting wafers.

As shown in FIG. 1, the transport system 90 has a traveling rail 92 and an OHT 93 moving on the traveling rail 92. The traveling rail 92 is provided near the ceiling of the semiconductor factory 100, and the OHT 93 moves in the semiconductor factory 100 along the traveling rail 92. For example, the OHT 93 is stored in the stocker 94 and transports the hoop 80 containing the wafer before processing from the stocker 94 to the load port device 98 provided in the processing device 96. Further, the OHT 93 conveys the hoop 80 containing the processed wafer from the load port device 98 of the processing device 96 to the stocker 94.

In addition to moving along the traveling rail 92, the OHT 93 includes an elevating device (not shown) that moves the hoop 80 up and down, and a lateral feed device that moves the hoop 80 to the side of the traveling rail 92 (in a direction orthogonal to the traveling direction). (See FIGS. 2 and 3). The OHT 93 moves the hoop 80 containing the wafer 84 (see FIG. 4) from a predetermined position in the semiconductor factory 100 by using an elevating device or a lateral feed device while moving along the traveling rail 92. Can be moved to the position of. In FIG. 1, only one OHT93 is displayed, but in the semiconductor factory 100, a plurality of OHT93s are usually used.

As shown in FIG. 1, the semiconductor factory 100 is provided with a temporary storage stocker 20. The temporary storage stocker 20 is attached to the traveling rail 92 of the OHT 93 that transfers the hoop 80 in the semiconductor factory 100. The temporary storage stocker 20 is attached to the traveling rail 92 around the processing device 96, and the mounting shelf 22 of the temporary storage stocker 20 is provided near the ceiling 100a of the semiconductor factory 100.

The mounting shelf 22 of the temporary storage stocker 20 is closer to the traveling rail 92 than the mounting table of the load port device 98 that accesses the processing device 96 (or EFEM attached thereto), and is located higher than the mounting table of the load port device 98. Therefore, it is preferable that the hoop 80 is provided at a position that does not interfere with the transfer of the hoop 80 to the processing device 96. The mounting shelf 22 is preferably installed so as to be suspended from the ceiling 100a (see FIG. 3) of the semiconductor factory 100, but if the temporary storage stocker 20 can be supported, the mounting shelf 22 is installed. The embodiment is not particularly limited.

The temporary storage stocker 20 efficiently transfers the hoop 80 in the semiconductor factory 100 by temporarily storing the hoop 80 accommodating the wafer 84 before and after processing in the processing apparatus 96 at a position close to the stocker 94. Can be done. Further, as will be described later, since the temporary storage stocker 20 has a gas supply unit 24 for inflowing the cleaning gas into the hoop 80, the inside of the hoop 80 accommodating the wafer 84 before and after the processing in the processing device 96. Can be cleaned. By cleaning the inside of the hoop 80 in the temporary storage stocker 20, it is possible to prevent the problem that the wafer 84 housed in the hoop 80 is oxidized while being placed on the temporary storage stocker 20, and the load port device. By substituting the temporary storage stocker 20 for the cleaning process of the hoop 80 performed by the 98 or the like, the processing time by the load port device 98 can be shortened.

Only one hoop 80 may be placed on the mounting shelf 22 of the temporary storage stocker 20, but as shown in FIG. 1, the hoop 80 can be placed as a plurality of wafer transfer containers. May be good. The temporary storage stocker 20 does not have a housing (cover) for covering the hoop 80 mounted on the mounting shelf 22. Therefore, unlike the hoop 80 stored in the stocker 94, the hoop 80 placed on the mounting shelf 22 of the temporary stocker 20 is exposed to the environment in the semiconductor factory 100. However, the temporary storage stocker 20 may have a cover that covers the hoop 80 to be placed.

FIG. 2 is a conceptual diagram of the temporary storage stocker 20 shown in FIG. 1 as viewed from above (ceiling side). In the example shown in FIG. 2, two temporary storage stockers 20 are continuously arranged on the left side of the traveling rail 92 of the OHT 93. As shown in FIG. 1, the temporary storage stockers 20 may be provided on both sides of the traveling rail 92, and as shown in FIG. 2, a plurality of temporary storage stockers 20 are provided on one side of the traveling rail 92. They may be arranged side by side.

As shown in FIG. 2, the temporary storage stocker 20 has a mounting shelf 22 on which the hoop 80 is placed, and a collector 30 for recovering gas in the space around the hoop 80 mounted on the mounting shelf 22. Further, the temporary storage stocker 20 is connected to the inside of the hoop 80 mounted on the mounting shelf 22, and is mounted on the mounting shelf 22 and the gas supply unit 24 for allowing the cleaning gas to flow into the inside of the hoop 80. It has a gas discharge unit 26 that is connected to the inside of the hoop 80 and allows gas to flow out from the inside of the hoop 80.

As shown in FIG. 2, each of the mounting shelves 22 has a first mounting portion 22a, a second mounting portion 22b, and a third mounting portion 22c on which one hoop 80 can be placed. A maximum of three hoops 80 can be placed on the mounting shelf 22 of the temporary storage stocker 20. As shown in the second mounting portion 22b at the bottom of FIG. 2, the hoop 80 transferred by the OHT 93 is mounted on the mounting shelf 22 attached to the traveling rail 92 from directly below the traveling rail 92 by the lateral feed device 93a of the OHT 93. Handed over to.

The first mounting section 22a to the third mounting section 22c of the mounting shelf 22 have a gas supply nozzle that is a part of the gas supply section 24 and a discharge nozzle that is a part of the gas discharge section 26, respectively. Two are provided. The gas supply nozzle of the gas supply unit 24 is connected to an introduction hole (not shown) formed at the bottom of the hoop 80 mounted on the mounting shelf 22. Since the cleaning gas such as nitrogen is supplied to the gas supply nozzle, the cleaning gas can be introduced into the hoop 80 mounted on the mounting shelf 22 through the introduction hole of the hoop 80. ..

On the other hand, the gas discharge nozzle of the gas discharge unit 26 is connected to a discharge hole (not shown) formed at the bottom of the hoop 80 mounted on the mounting shelf 22. The discharge nozzle is connected to a discharge flow path having a lower pressure than the inside of the hoop 80, and the gas discharge unit 26 can discharge gas from the inside of the hoop 80 mounted on the mounting shelf 22. Further, the temporary storage stocker introduces the cleaning gas into the hoop 80 from the gas supply unit 24 to the hoop 80 placed on the mounting shelf 22, and also introduces the gas in the hoop 80 from the gas discharge unit 26. By discharging the gas, the inside of the hoop 80 can be efficiently cleaned.

As shown in FIG. 2, the collector 30 included in the temporary storage stocker 20 has an inflow opening 32 into which gas in the surrounding space flows. The collector 30 of the temporary storage stocker 20 has three inflow openings 32, and each inflow opening 32 corresponds to each of the first to third mounting portions 22a to 22c of the mounting shelf 22. It is provided. The collector 30 recovers the gas in the surrounding space of the plurality of hoops 80 mounted on the mounting shelf 22.

FIG. 5 is an enlarged display of the inflow opening 32 shown in FIG. The inflow opening 32 of the collector 30 has a hollow substantially rectangular shape whose upper surface is an opening surface 32a, and the inflow opening 32 opens upward. A discharge path 36 connected to a discharge duct (not shown) having a lower pressure than the inside of the semiconductor factory 100 is connected to the lower surface of the inflow opening 32, and the collector 30 passes the air of the semiconductor factory 100 through the inflow opening 32. Can be inhaled.

FIG. 3 is a conceptual diagram of the temporarily placed stocker 20 shown in FIG. 2 observed from a direction along the traveling rail 92. FIG. 3 shows a state in which the OHT 93 is stopped laterally of the temporary stocker 20 in order to deliver the hoop 80 held by the OHT 93 to the temporary stocker 20 (OHT93 shown in the upper part of FIG. 2). See). As shown in FIG. 3, in the mounting shelf 22 of the temporary storage stocker 20, the upper surface of the mounting shelf 22 is substantially the same as the bottom surface of the hoop 80 held by the OHT 93 traveling on the traveling rail 92 in the height direction. Arranged to be at a height.

FIG. 4 is a conceptual diagram of the temporarily placed stocker 20 observed from the direction along the traveling rail 92, as in FIG. FIG. 4 shows a state in which the OHT93 stopped on the side of the temporary storage stocker 20 delivers the hoop 80 to be held to the temporary storage stocker 20 (see OHT93 shown at the bottom of FIG. 2). As shown in FIG. 4, the OHT 93 uses the lateral feed device 93a to move the hoop 80 to be held in a direction orthogonal to the extending direction of the traveling rail, and puts the hoop 80 on the shelf of the temporary storage stocker attached to the traveling rail 92. , Place the hoop 80.

As shown in FIG. 4, the OHT 93 mounts the hoop 80 on the mounting shelf 22 so that the main opening 80a of the hoop 80 closed by the lid 82 faces the side opposite to the traveling rail 92. Further, the hoop 80 mounted on the mounting shelf 22 is mounted so that the end portion on the main opening 80a side protrudes horizontally with respect to the mounting shelf 22.

As shown in FIG. 4, the inflow opening 32 of the collector 30 is provided adjacent to the main opening 80a of the hoop 80 mounted on the mounting shelf 22 and closed by the lid 82. Further, the inflow opening 32 of the collector 30 is arranged so that the opening surface 32a is substantially the same height as the upper surface of the mounting shelf 22, and a part of the hoop 80 protruding from the mounting shelf 22 is formed. It is located directly above the opening surface 32a.

As shown in FIG. 4, the inflow opening 32 of the collector 30 is connected to the exhaust duct via the discharge path 36, and the discharge path 36 is provided with a valve 34 that can be switched between opening and closing by the control unit 60. .. The structure of the exhaust path 36 may be a straight pipe connected by a hand, a bellows pipe, and is not particularly limited as long as it can be installed on the ceiling 100a of the semiconductor factory 100.

The control unit 60 can start and stop the gas recovery in the space around the hoop 80 by the collector 30 by switching the opening and closing of the valve 34 of the discharge path 36. The discharge path 36 and the valve 34 are provided for each inflow opening 32 of the collector 30, and the control unit 60 can control the start and stop of gas recovery for each inflow opening 32.

The control unit 60 may continue to collect gas by the collector 30 while the semiconductor factory 100 is in operation, but the control unit 60 may start and stop gas recovery by the collector 30 according to the state of the temporary storage stocker 20 and the exhaust duct. You may control it. For example, the control unit 60 has an inflow opening corresponding to the mounting unit 22c on which the hoop 80 is mounted, as in the third mounting unit 22c (see FIG. 4) of the temporary storage stocker 20 shown above in FIG. Gas recovery in the surrounding space can be performed from the section 32, and gas recovery can be stopped at the mounting section on which the hoop 80 is not mounted.

Further, the control unit 60 may control the start and stop of gas recovery by the collector 30 in synchronization with the introduction of the purified gas into the hoop 80 by the gas supply unit 24 shown in FIG. For example, the control unit 60 recovers the gas in the surrounding space by the collector 30 while the cleaning gas is introduced into the hoop 80 from the gas supply unit 24, and the cleaning gas is discharged from the gas supply unit 24 into the hoop 80. If it has not been introduced, the collection of gas by the collector 30 can be stopped. This is because the internal pressure in the hoop 80 tends to increase while the cleaning gas is being supplied to the hoop 80, and the gas leaks from the hoop 80 tends to increase.

Further, the control unit 60 may be able to change the flow rate of cleaning gas introduced into the hoop 80 by the gas supply unit 24, and in this case, the control unit 60 may change the flow rate of cleaning gas introduced into the hoop 80. Accordingly, the start and stop of gas recovery by the collector 30 may be controlled. For example, when the gas flow rate into the hoop 80 by the gas supply unit 24 is equal to or higher than a predetermined value, the control unit 60 recovers the gas in the surrounding space by the collector 30, and the gas flow rate into the hoop 80 is less than the predetermined value. If this is the case, the gas recovery by the collector 30 is stopped. This is because when the flow rate of the gas introduced into the hoop 80 is large, the leakage of gas from the hoop 80 tends to increase.

Further, the control unit 60 may limit the amount of gas recovered by the collector 30 in the factory in a unit time to a predetermined range so as not to affect the formation of downflow in the semiconductor factory 100. In such a case, the control unit 60 of all the temporary storage stockers 20 in the semiconductor factory 100 communicates the data regarding the gas recovery state by the collector 30 to the HOST computer of the semiconductor factory 100, and further, the HOST. The gas recovery operation by the collector 30 can be controlled based on the command received from the computer.

As shown in the above-described embodiment, the temporary storage stocker 20 shown in FIGS. 1 to 5 has a collector 30 for recovering gas in the space around the hoop 80 mounted on the mounting shelf 22, and thus is temporarily placed. It is possible to prevent a local decrease in oxygen concentration due to gas leakage from the hoop 80 or the connection portion of the gas supply unit 24. Further, even if the gas flows out from the inside of the hoop 80 placed on the temporary storage stocker 20, the gas leaked by the collector 30 can be recovered, so that the temporary storage stocker 20 is a gas supply unit. It is possible to increase the inflow rate of the cleaning gas into the hoop 80 by 24, and it is possible to efficiently clean the hoop 80.

The inflow opening 32 of the collector 30 may be provided near the main opening 80a where the gas in the hoop 80 may leak when the cleaning gas is introduced into the hoop 80 by the gas supply unit 24. It is preferable from the viewpoint of efficiently recovering the gas leaked from the hoop 80. Further, the opening direction of the inflow opening 32 may be arranged so as to face the main opening 80a of the hoop 80 or the lid 82 for the same reason. Further, by arranging the inflow opening 32 below the mounting shelf 22 and pointing the opening direction of the inflow opening 32 upward, there is a problem that the gas leaked from the hoop 80 flows to the floor 100b side of the semiconductor factory 100. , Can be effectively prevented.

As described above, the temporary storage stocker 20 has been described with reference to the embodiments, but the temporary storage stocker according to the present invention is not limited to the above-described embodiment and includes many other modified examples. Needless to say. For example, the shape of the opening surface 32a of the inflow opening 32 shown in FIG. 5 is not limited to a quadrangle, and may be a circular shape, an elliptical shape, a slit shape, a porous shape, or any other shape.

Further, as shown in FIGS. 3 and 4, the state in which the inflow opening 32 opens upward includes not only a mode in which the opening surface 32a faces directly upward but also a mode in which the opening surface 32a faces diagonally upward. .. Further, the inflow opening 32 may be opened in the horizontal direction.

Further, as shown in FIG. 2, the collector 30 may have an inflow opening 32 corresponding to each of the mounting portions 22a to 22c, but in the temporary storage stocker according to the modified example, the inflow opening is continuous. The collector may have a common flow path opening with respect to the mounting portions 22a to 22c included in the temporary storage stocker 20. Further, as shown in FIG. 2, the collector 30 may collect the leaked gas of the plurality of hoops 80 mounted on the mounting shelves 22, but the collector itself may collect the leaked gas for each of the mounting portions 22a to 22c. It may be provided one by one.

20 ... Temporary storage stocker 22 ... Mounting shelf 24 ... Gas supply unit 26 ... Gas discharge unit 30 ... Collector 32 ... Inflow opening 32a ... Opening surface 34 ... Valve 36 ... Exhaust flow path 60 ... Control unit 80 ... Hoop 80a ... Main Aperture 82 ... Cover 84 ... Wafer 90 ... Conveyance system 92 ... Travel rail 93 ... OHT
93a ... Horizontal feed device 94 ... Stocker 96 ... Processing device 98 ... Load port device 100 ... Semiconductor factory 100a ... Ceiling 100b ... Floor

Claims (5)

It is a temporary storage stocker for the wafer transfer container attached to the running rail of the OHT that transfers the wafer transfer container in the semiconductor factory.
A mounting shelf on which the wafer transport container is placed, and
A gas supply unit that is connected to the inside of the wafer transfer container placed on the above-mentioned shelf and allows the cleaning gas to flow in, and a gas supply unit.
A collector that collects gas in the space around the wafer transfer container placed on the above-mentioned storage rack, and
Have,
The collector is provided below the wafer transfer container placed on the above-mentioned storage shelf, and has an inflow opening through which gas in the peripheral space flows.
The inflow opening is open upward and
The inflow opening is provided adjacent to the main opening of the wafer transfer container which is placed on the above-mentioned shelf and is closed by a lid.
The opening surface of the inflow opening is arranged so as to be substantially the same height as the upper surface of the above-mentioned storage rack.
The opening surface of the inflow opening is arranged so that a part of the wafer transport container protruding from the above-mentioned shelf is located directly above the opening surface.
Temporary stocker. The collector has an inflow opening through which gas in the surrounding space flows.
The temporary storage stocker according to claim 1 , wherein the inflow opening is opened so as to face the lid of the wafer transport container. The above-mentioned storage rack can mount a plurality of the wafer transport containers.
The temporary storage stocker according to claim 1 or 2 , wherein the collector recovers gas in the peripheral space of the plurality of wafer transfer containers placed on the above-mentioned storage rack. The temporary storage stocker according to any one of claims 1 to 3 , further comprising a control unit for starting and stopping gas recovery in the surrounding space by the collector. The temporary placement according to any one of claims 1 to 4 , which is connected to the inside of the wafer transfer container placed on the above-mentioned storage shelf and has a gas discharge unit for discharging gas from the wafer transfer container. Stocker.

Images