JP2000188320A - Local clean system - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide a local green system for improving the yield of semiconductor production. SOLUTION: A wafer transfer system 2 for a semiconductor manufacturing apparatus.
In FIG. 2, a punching hole 8 for suction is provided in the area of 100 mm near the opening of the wafer carrier connecting portion 6 of the wafer transfer section 4, and an exhaust fan 7 is provided below the punching hole. Further, the clean air passage is divided from the clean air outlet 11A of the air purifying filter unit 9 installed on the upper surface, and the divided clean air outlet 11B is connected to the wafer carrier connecting portion 6 at a distance of 100 mm in the vicinity of the opening. It extends into the area. In this way, it is possible to prevent dust contamination of the wafer or entry of the dust into the semiconductor manufacturing process or the wafer carrier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a local clean system, and more particularly to a structure of a local clean system in a wafer transfer system for a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art A conventional wafer transfer system for a semiconductor manufacturing apparatus will be described with reference to FIG. FIG. 7 is an explanatory diagram of a conventional wafer transfer system for a semiconductor manufacturing apparatus. As shown, the wafer transfer system for semiconductor manufacturing equipment
A wafer transfer device 2 for transferring the wafer 14 into the semiconductor manufacturing apparatus 1 from a previous process; and a transfer mechanism unit (not shown) provided in the semiconductor manufacturing apparatus 1 and being continuous from the wafer transfer machine 2. ).

Further, the wafer transfer device 2 includes a carrier loading section 3 for loading the wafer 14 for transporting the wafer 14 and a wafer transport section 4 for transporting the wafer. The wafer 14 is stored in a container having an opening door called a wafer carrier.
Is mounted on the carrier loading section 3.

The opening door 6b of the wafer carrier 5 is brought into contact with the opening door 6c of the wafer carrier connection port 6 provided on the outer shell of the wafer transfer section 4, and both doors are slid up and down in conjunction with each other. The opening of the wafer carrier 5 and the wafer carrier connection port 6 are continuously formed with a communication hole. The details of the interlocking portion and the upper and lower sliding portions of the two doors are not shown. The wafer 14 is transferred from the wafer carrier 5 into the semiconductor manufacturing apparatus 1 through the communication hole via a wafer transfer means (not shown) of the wafer transfer unit, and a semiconductor is manufactured from the wafer.

In the wafer transfer system for a semiconductor manufacturing apparatus as described above, the removal of dust inside the system is strictly controlled. For example, in the inside of the wafer transfer section 4 accommodating the wafer transfer means, a clean filter unit 9 is provided on the upper surface of the outer shell, and clean air is blown out from the lower air blowout opening 11A of the clean filter unit 9 to blow out. The clean air is blown in the transfer space 10 of the wafer transfer unit 4 to remove dust on the wafer 14. However, the function of removing dust near the connection between the wafer carrier 5 and the wafer carrier connection 6 has been neglected, and there is no system provided with dust removal means.

[0006]

In the current wafer transfer system for a semiconductor manufacturing apparatus, a wafer stored in the wafer carrier 5 is generated by dust generated from an opening / closing portion of a wafer loading / unloading door of the wafer carrier 5. There is a drawback that it can lead to dust contamination to

[0007] In order to cope with the above drawbacks, various improved techniques have been proposed. For example, a box body connected to the carry-in / out entrance of the semiconductor manufacturing apparatus is provided with an opening / closing door for taking in / out a wafer into / out of the carry-in / out room, and a blower and a chemical filter are provided in the box body at the top of the carry-in / out room. There is a technique in which a box body is provided with an exhaust system for exhausting clean air in the carry-in / out room to the floor below. Related to this is a technique described in Japanese Patent Application Laid-Open No. 08-088155.

Further, for example, a carrier having a side door is hermetically sealed by the side door, and when the carrier is mounted on a tool, a gap is formed between the carrier and the tool. The side door is moved downward without passing through the transport path of the semiconductor substrate housed in the carrier. Related to this is a technique described in Japanese Patent Application Laid-Open No. H10-84034.

[0009] Of the above-mentioned improved techniques, the former is intended to prevent the molecular contamination from the circulating air in the clean room to the manufacturing apparatus by flowing clean air into the wafer loading / unloading chamber by a blower and a chemical filter, and to store the processing material. Was able to prevent molecular contamination. The latter, in an apparatus of the type that lowers the side doors and wafers, prevents contamination caused by the outside of the side doors, which had been placed in a relatively dirty manufacturing environment, falling through tools that maintain stringent clean room standards. It was something that could be done.

In both of the above techniques, when a wafer carrier is mounted on a carrier loading portion and is attached and detached to connect the wafer carrier to a wafer carrier connection portion of a wafer transfer portion, the wafer carrier is located near an opening of the connection portion of the wafer carrier. Although some measures have been taken against the possibility that the attached dust diffuses and enters the semiconductor manufacturing apparatus 1, there is a problem that it is insufficient. Further, both technologies have a problem that the protection against the intrusion of dust into the wafer carrier is not perfect, and that the wafer carrier has no consideration for the function of removing dust remaining inside. These problems have caused another problem that is directly linked to a reduction in semiconductor production failure of the semiconductor manufacturing apparatus.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art, and has made it possible to sufficiently prevent dust from being generated from an opening / closing portion of a wafer loading / unloading door of a wafer carrier.
It is another object of the present invention to provide a so-called local clean system in which prevention of dust intrusion at the time of attaching and detaching a wafer carrier and removal of dust remaining inside the wafer carrier container are considered.

[0012]

According to the present invention, in order to achieve the above object, a semiconductor carrier is connected to a former stage of a process, a wafer carrier loading portion for loading a wafer carrier, and a semiconductor manufacturing apparatus is connected to a latter stage of the process. A wafer transfer unit having an outer shell accommodating the wafer transfer means, which constitutes a semiconductor manufacturing transfer system, and a filter unit for an air cleaning device disposed on an upper surface of the outer shell; An opening for suctioning clean air from the air purifier filter unit in the vicinity of the wafer carrier connection opening provided on the outer shell side surface of the unit, for example, in an area within 100 mm from the connection opening. The clean air flow path supplied by the air purifying filter unit is divided into two clean air flow paths by a partition plate, and the outlet of one of the divided clean air flow paths is connected to the wafer cap of the outer shell. A near the opening of the connecting portion of the wafer carrier provided on a side surface of the loading unit, such as those provided in the region within 100 mm.

[0013] The wafer carrier may be provided with clean air provided from an air cleaning filter unit provided on the upper surface of the outer shell and provided on the upper surface of the wafer carrier near the opening of the wafer carrier connecting portion. It is configured to be supplied from the suction port and flow to the surface of the wafer stored in the wafer carrier.

Further, when attaching / detaching the wafer carrier to / from the wafer carrier connection portion provided on the outer shell side surface of the wafer transfer portion, for example, a wind speed sensor provided downstream of one of the divided clean air flow paths is provided. A change in wind speed due to the presence or absence of the wafer carrier is sensed, and the upper surface of the outer shell is adjusted so as to increase the suction air volume in the vicinity of the opening of the wafer carrier connection portion, for example, in the suction opening provided in an area within 100 mm. The rotation of a fan provided in the air cleaning filter unit is controlled so as to increase the amount of air blown out of the air cleaning filter unit provided in the above.

When the wafer transfer unit is in a halt state for a certain period of time, a stop signal of the wafer transfer unit, for example, a signal from a sensor for detecting opening / closing of a door of a wafer carrier connection unit is not input for a certain period of time. To reduce the amount of air blown out of the air cleaning filter unit,
It is configured to control the rotation of a fan provided in the air cleaning filter unit. Further, an air cleaning filter unit for removing dust is provided in the wafer carrier, and the structure is such that the clean air flows to the surface of the stored wafer.

Further, since the suction opening is arranged in the vicinity of the opening of the wafer carrier connection portion, for example, in an area of 100 mm or less, dust generated from the opening / closing portion of the wafer loading / unloading door of the wafer carrier is reduced. Since the wafer is sucked and removed from the opening, dust contamination on the wafer in the wafer carrier can be prevented.

The local clean system having the above configuration will be functionally described. Further, the clean air flow path supplied by the air cleaning filter unit provided on the upper surface of the outer shell is divided by a partition plate, and the outlet of the divided clean air flow path is an outer shell for accommodating the wafer transfer unit. In the vicinity of the opening of the wafer carrier connecting portion provided in the above, for example, in a region of 100 mm, by blowing a clean air flow, to prevent dust adhesion to the vicinity of the wafer carrier connecting portion. It is composed.

The clean air provided from the air cleaning filter unit provided on the upper surface of the outer shell is taken in from the clean air inlet provided on the upper surface of the wafer carrier, and flows to the surface of the wafer stored in the wafer carrier. A control circuit for removing dust adhering to the wafer surface, comprising a sensor for detecting whether or not the wafer transfer system for a semiconductor manufacturing apparatus can be operated, and a fan controlled by a signal from the sensor. Accordingly, the amount of air blown out from the air cleaning filter unit can be reduced in the idle state of the wafer transfer means for a certain period, thereby contributing to energy saving of the wafer transfer system.

The control circuit includes the sensor, a control unit that inputs a signal from the sensor and outputs a control output, and a fan that is controlled by the control output and has a feedback function. The unit has a function of increasing the amount of air blown out of the air cleaning filter unit depending on the presence or absence of the wafer carrier when the wafer carrier is attached / detached. This can improve the reliability of preventing dust from entering the carrier.

In addition, an air cleaning filter unit is provided on one side surface of the wafer carrier, and the structure is such that the clean air supplied into the wafer carrier is recirculated so that the wafer can be stored in the wafer carrier for a long time. Even in this case, since the clean air can always flow through the wafer surface, dust generated from inside the wafer carrier does not accumulate on the wafer surface.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a local clean system according to the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view showing an entire configuration of a wafer transfer system for a semiconductor manufacturing apparatus using a local clean system according to the present invention. FIG. 2 is a configuration around a wafer carrier connecting portion in the local clean system of FIG. A perspective view showing
FIG. 3 is a sectional view taken along line AA ′ of the wafer transfer system for a semiconductor manufacturing apparatus in which the local clean system of FIG. 1 is used. FIG. 4 is a sectional view of a wafer carrier and a wafer transfer unit in the local clean system of FIG. FIG. 5 is a side sectional view showing the structure of another wafer carrier in the local clean system of FIG. 1 when connected to the opening of the wafer carrier connecting portion. FIG. 6 is a side sectional view when the wafer carrier of FIG. 5 is connected in a region near the wafer carrier connection part in the local clean system of FIG.

In FIGS. 1, 2, 3, 4, 5, and 6, 1
Is a semiconductor manufacturing apparatus, 2 is a wafer transfer machine including a carrier loading section and a wafer transfer section, 3 is a carrier loading section,
4 is a wafer carrier, 5 is a wafer carrier having an opening door for taking in and out of a wafer, and 6 is a wafer carrier connection which connects the wafer carrier provided on the outer shell of the wafer carrier with the wafer carrier. Unit, 6a is an opening of a wafer carrier connection unit, 7 is an exhaust fan provided below the air flow path of the carrier loading unit, 7a, 7b are wind speed sensors,
8 is a punching hole provided in the vicinity of the opening surface of the wafer carrier, 9 is an air cleaning filter unit provided on the upper surface of the outer shell of the wafer transfer unit, 9a is a fan, 10
Is a wafer transfer space of the wafer transfer section, 11A is a clean air outlet from the air purification filter unit on the outer shell upper surface of the wafer transfer section, and 11B is a divided flow path of the clean air from the air purification filter unit. Clean air outlet, 12
Is a partition plate for dividing a clean air flow path from the upper surface air cleaning filter unit, 12o is an opposing surface of the partition plate, 13 is a clean air flow path from a suction port in the wafer carrier, and 14 is The wafer stored in the wafer carrier, 15 is a wafer loading / unloading door of a communication hole with a wafer carrier connection part in the wafer carrier, 16 is a clean air partition plate in the wafer carrier, and 17 is a wafer carrier upper surface portion. The provided clean air suction port, 18 is an air cleaning filter unit in the wafer carrier, and 19 is a fan in the wafer carrier. The solid arrow in the figure indicates
It shows the flow direction of clean air.

Referring to FIG. 1, a description will be given of a wafer transfer system for a semiconductor manufacturing apparatus constituted by the above members.
A wafer transfer system for a semiconductor manufacturing apparatus includes a wafer transfer machine 2 connected to a pre-process unit in a semiconductor process.
And a semiconductor manufacturing apparatus 1 continuous with the wafer transfer machine 2
And a transfer mechanism (not shown).
Further, the wafer transfer machine 2 includes a carrier loading section 3 for loading wafers for transport, and a wafer transport section 4 for transporting wafers loaded on the carrier loading section 3 into the semiconductor manufacturing apparatus 1. .

Referring to FIG. 2, the vicinity of the connection portion of the wafer carrier 5 will be described in detail. A wafer carrier connection portion 6 is provided on an outer shell of the wafer transfer portion 4, and an opening 6a is provided in the wafer carrier connection portion 6. The size of the opening 6a is such that there is no gap between the opening 6a and the wafer carrier 5, and the opening 6a can be tightly inserted. The wafer carrier 5 is connected to the opening 6 of the wafer carrier connecting portion 6.
When the wafer carrier 5 is connected, the wafer carrier 5 is inserted to a position slightly protruding in the wafer transfer section 4. Near the connection part, for example, about 100 mm
A punching hole 8 serving as a clean air passage opening
Is provided.

As shown in FIG. 2, when the wafer carrier 5 is connected to the wafer carrier connecting portion 6, dust generated from the wafer carrier 5 is sucked through the punching holes 8. Further, dust generated from the wafer transfer unit 4 is also sucked through the punching holes 8 (see FIG. 3). As a result, the dust is prevented from entering the semiconductor manufacturing apparatus 1 via the wafer carrier 5 and the wafer transfer unit 4.

Further, with reference to FIG. 3, the vicinity of the connection portion between the carrier loading section 3 and the wafer transfer section 4 and the air flow path will be described in detail. An air purifying filter unit 9 having a blower fan 9a is mounted on the upper surface of the outer shell of the wafer transfer unit 4, and below the air purifying filter unit 9,
A clean air outlet 11A is provided.

The clean air from the clean air outlet 11A flows in the wafer transfer space 10 defined by the outer shell of the wafer transfer section 4 as a clean air flow path. The clean air outlet 11A in the wafer transfer space 10
A partition plate 12 for dividing the clean air flow path
Is arranged. The lower edge of the partition plate 12 also functions as the upper edge of the opening 6 a provided in the wafer carrier connection 6.

Further, the clean air outlet 1 is
One clean air obtained by dividing the clean air flow from 1A forms both surfaces by the partition plate 12 and the opposing surface 12o to be the partition plate 12, and both side plates are formed by the outer shell side plate of the wafer transfer unit 4. It flows through a clean air channel formed and configured. Further, the facing surface 12o is inclined downward toward the partition plate 12 side. The end of the facing surface 12o is connected to the opening 6a of the wafer carrier connecting portion 6 of the wafer transfer portion 4.
, For example, in a region near 100 mm or less. Further, as described above, the clean air outlet 11B is formed by inclining toward the partition plate 12 side.

The thus-formed clean air outlet 11
B from the opening 6 of the wafer carrier connection 6
a in the vicinity of the wafer carrier connecting portion 6
It is possible to prevent dust from adhering to the surface. The facing surface 12o forms a part of the outer shell of the wafer transfer unit 4.

The other clean air flow path divided by the partition plate 12 flows down in the wafer transfer space 10, a part of which passes through the punch hole 8, and has a carrier having an exhaust fan 7 and a wind speed sensor 7a. The air is discharged from the air flow path 20 into the loading section 3. The wind speed sensor 7a detects the wind speed due to the presence or absence of the wafer carrier 5, and the control circuit adjusts the rotation of the blow fan 9a and the exhaust fan 7 to increase the amount of air blown out from the cleaning air filter 9. Although not shown, the control circuit receives a detection output of the wind speed, compares the detected output with a set value, controls the drive unit of the blower fan 9a and / or the exhaust fan 7, and feeds back a control result. , It can be easily realized.

Further, a wind speed sensor 7b is provided at the clean air outlet 11B, and the output of the wind speed sensor 7b and the wind speed sensor 7a
By comparing with the output of the clean air outlet 11B, the wind speed of the clean air at the clean air outlet 11B can be made higher than the wind speed of the clean air flowing directly into the punch hole 8 from the clean air outlet 11A. More specifically, it is easily controlled by adjusting the rotation of the blower fan 9a and the exhaust fan 7 and expanding and contracting the facing surface 12o of the partition plate 12 to increase or decrease the air resistance of the clean air outlet 11B. be able to.

FIG. 4 shows the wafer carrier 5 provided with a clean air suction port 17 on the upper surface of the wafer carrier 5 and the opening 6 a of the wafer carrier connecting portion 6 provided in the wafer transfer section 4.
FIG. 2 is a side sectional view showing a partial structure of a wafer transfer system for a semiconductor manufacturing apparatus when connected to a semiconductor device.

When the wafer carrier 5 is connected to the wafer carrier connecting portion 6 provided in the wafer transfer section 4, clean air is taken in from a clean air inlet 17 provided on the upper surface of the wafer carrier 5, and the clean air is After passing through the clean air flow path 13 provided in the wafer carrier 5, the wafer carrier 5
The direction is changed on the side opposite to the side of the wafer carrier connecting portion 6 and flows into the surface of the wafer 14 arranged in a stepwise manner.

Since each of the wafers 14 is arranged stepwise, clean air flows uniformly over the surface of the wafer 14 and diffuses dust adhering to the surface of the wafer 14 in the wafer carrier 5. Instead, the wafer is sucked and removed by a punching hole 8 provided in the vicinity of the opening 6a of the wafer connection portion 6, for example, in a region within 100 mm.

The opening door of the wafer carrier 5 is brought into contact with the opening door of the connection port 6 of the wafer transfer section 4, and both doors are slid up and down in conjunction with each other, so that the opening of the wafer carrier 5 and the opening A communication hole is formed continuously with the wafer carrier connection port 6, and a wafer is carried in and out of the communication hole. Although not shown in detail, a switch operated by sliding up and down both doors is omitted. And a control circuit (not shown) determines the operation and stop of the wafer transfer unit 4 according to a signal from the switch, and the control circuit adjusts the rotation of the blower fan 9 a and the exhaust fan 7.

The above-described wafer carrier 5 is a typical example, and the present invention is not limited to this example. Many variations are possible. 5 and 6 illustrate a modification of the wafer carrier in the local clean system according to the present invention. FIG. 6 is a side sectional view showing a structure of a wafer carrier that is not connected to a wafer carrier connection unit 6 provided in the wafer transfer unit 4 in the local clean system according to the present invention as shown in FIG. 5. FIG. 6 shows a case where the wafer carrier 5 in the local clean system according to the present invention is placed near the wafer carrier connecting portion 6 provided in the wafer transfer portion 4, for example, 1.
It is a sectional side view which shows the structure at the time of connecting in the area | region near 00mm.

As shown in FIG. 5, the wafer carrier 5 comprises:
An air purifying filter unit is mounted on the inner side surface, and when the wafer loading / unloading door 15 is closed, clean air circulates through a circulating air flow path 13 provided in an upper portion of the wafer carrier 5, and the above-described filter is again turned on. It is configured to be returned to the unit 18. A straightening plate 16 provided with a slit hole is disposed in front of the clean air outlet of the filter unit 18 of the wafer carrier 5, and the clean air passes through the straightening plate 16 and uniformly flows on the surface of the wafer 14. Then, the dust adhering to the surface of the wafer 14 is removed, and collected by a filter in the air cleaning filter unit 18.

As shown in FIG. 6, the wafer carrier 5 is placed near the wafer carrier connecting portion 6, for example, 100 mm.
When connected to the opening 6 in the nearby area, the wafer transfer unit 4
The clean air that has passed through the wafer transfer space 10 of the wafer transfer unit 4 from the air cleaning filter unit 9 (not shown) on the upper surface of the outer shell of FIG. Flow into 5.

The clean air is turned at the back of the wafer carrier 5 by the fan 19 and flows into the built-in filter unit 18. The clean air flowing into the filter unit 18 uniformly flows on the surface of the wafer 14 stored in the wafer carrier 5 and further removes dust adhering to the surface of the wafer 14 in the vicinity of the wafer carrier connection portion 6, for example, The air is sucked together with the air flow by the punching holes 8 provided in a region near 100 mm. 5 and 6
The clean air suction port 17 provided in FIG. 4 is not provided on the upper surface of the wafer carrier 5 of FIG. The reason why the vicinity of the wafer carrier connection portion 6 is set to approximately 100 mm is that the cleaning effect becomes thinner when the distance is further increased.

[0040]

As described above in detail, according to the configuration of the local cleaning system of the present invention, the vicinity of the connection opening with the wafer carrier provided on the outer shell of the wafer transfer section,
For example, with a suction opening provided in a region of 100 mm, dust generated when a wafer carrier is connected to the connection opening can be quickly suctioned and removed, and dust generated from inside the wafer carrier can be suctioned and removed. . Further, a partition plate for dividing the blow channel of the clean air filter unit provided on the upper surface in the outer shell of the wafer transfer unit is provided in the transfer space of the wafer transfer unit, and one of the divided blow channels is provided. Is extended to a region in the vicinity of the opening of the wafer carrier connecting portion, and by flowing clean air through the opening of the wafer carrier connecting portion, it is possible to prevent dust from adhering to the wafer carrier connecting portion.
According to the configuration of the present invention, it is effective to prevent dust contamination on the wafer surface in the wafer carrier and to prevent dust from entering the semiconductor manufacturing process.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall configuration of a wafer transfer system for a semiconductor manufacturing apparatus using a local clean system according to the present invention.

FIG. 2 is a perspective view showing a configuration near a wafer carrier connection part in the local clean system of FIG. 1;

FIG. 3 is a sectional view taken along the line AA ′ of the wafer transfer system for a semiconductor manufacturing apparatus using the local clean system of FIG. 1;

FIG. 4 is a side cross-sectional view when the wafer carrier in the local clean system of FIG. 1 is connected to a wafer carrier connection opening of a wafer transfer unit.

FIG. 5 is a side sectional view showing the structure of another wafer carrier in the local clean system of FIG. 1;

6 is a side sectional view when the wafer carrier of FIG. 5 is connected in a region near a wafer carrier connection portion in the local clean system of FIG. 1;

FIG. 7 is an explanatory diagram of a conventional wafer transfer system for a semiconductor manufacturing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor manufacturing apparatus, 2 ... Wafer transfer machine, 3 ... Carrier loading part, 4 ... Wafer conveyance part, 5 ... Wafer carrier, 6 ...
Wafer carrier connection, 7: exhaust fan, 8: punching hole, 9: filter unit for air cleaning, 10: wafer transfer space, 11A: clean air outlet, 11B: clean air outlet, 12: partition plate, 13 … Clean air channel, 14 wafers, 15… wafer loading / unloading door, 16 rectifier plate, 17…
Clean air inlet

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuji Toyama 46-1, Tomioka, Nakajo-cho, Kitakanbara-gun, Niigata Prefecture Inside the Industrial Machinery Division, Hitachi, Ltd. No. 1 Hitachi Industrial Machinery Division 5F031 CA02 DA01 DA08 DA17 FA01 FA09 FA11 JA01 NA02 NA03 NA10 NA16 NA20

Claims (6)

[Claims] 1. A wafer transfer unit for a semiconductor manufacturing apparatus, comprising: a wafer carrier loading unit on which a wafer carrier for storing and transferring a wafer is loaded; and a wafer transport unit for transporting a wafer from the wafer carrier and having an outer shell. Configure the system,
An air cleaning filter unit on the upper surface of the wafer transfer unit, and the clean air flow path supplied by the air purification filter unit into the wafer transfer unit is divided into a first clean air flow path and a second clean air flow path. A partition plate to be divided, a connection opening between the wafer carrier and the wafer transfer unit in an outer shell of the wafer transfer unit, and suction of the divided first clean air flow in a region near the connection opening A local clean system characterized by having an opening for use. 2. The local clean system according to claim 1, wherein an outlet of the divided second clean air passage is disposed in a region near a wafer carrier connection opening provided in the outer shell. A local clean system characterized by the following. 3. The local clean system according to claim 2, wherein clean air from an outlet of the second clean air flow path is taken in through a clean air suction port provided on an upper surface of the wafer carrier.
A local clean system comprising a supply unit for supplying the clean air into the wafer carrier. 4. The local clean system according to claim 1, wherein when the wafer carrier is connected to a connection opening with a wafer transfer section, a clean air flow path is provided downstream of the connection opening. A wind speed sensor for detecting a change in wind speed of the air purifying filter unit is provided so that a suction air volume of a suction opening provided in a region near the wafer carrier connection opening is increased by a signal of the wind speed sensor. And a control means for reducing the amount of air blown out of the filter unit for clean air when the wafer transfer unit is in a halt state for a certain period of time. 5. The local clean system according to claim 1, wherein the area in the vicinity is within about 100 mm from the connection opening. 6. The local cleaning system according to claim 5, wherein the wafer carrier is provided with an air cleaning filter unit in the wafer carrier, and the air flowing on the wafer surface is cleaned by the air cleaning filter unit. Local clean system characterized by its structure.