JPH0451544A - Wafer container - Google Patents

Abstract

PURPOSE:To prevent adherence of particles by providing a predetermined number of diffusing plates for distributing atmospheric air sucked by a blower uniformly to an atmospheric air region on the entire surface of an air filter at a predetermined air speed. CONSTITUTION:A wafer container 1 is composed of a containing region 1a, an atmospheric air region 1b and a sucking region 1c. The region 1a is opened at its bottom. The region 1b communicates with the opposed surface of the region 1a through an air filter 4. Two diffusing plates 5a, 5b are provided on the back surface in the region 1b. On the other hand, the region 1c is provided on the region 1b, and blowers 6a, 6b are provided at both opposed sides to suck the atmosphere. The fans 6a, 6b are driven by batteries 7a, 7b provided in the top of the region 1a. Here, the plates 5a, 5b are arranged to converge from above the back surface of the region 1b toward center. Thus, a laminar flow of the air is brought into contact within a carrier at a uniform air speed of a rated value or more to prevent adherence of particles to the wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wafer storage device used for storing and transporting wafers in the manufacturing process of semiconductor devices.

In recent years, as semiconductor devices have become highly integrated, particles adhering to wafers during the manufacturing process have become a major factor in reducing yield. Therefore, it is necessary to prevent particles from adhering even during storage and transportation.

[Conventional technology]

During the manufacturing process of semiconductor devices, a large number of wafers are held and transported by carriers. There are two types of transport: inter-process transport and intra-process transport. In inter-process transport, carriers are transported inside transport tunnels that have ensured sufficient air cleanliness, but in intra-process transport, the carriers are transported by workers themselves or by individual workers. Transported to manufacturing equipment. In this case, the wafer is exposed and particles may adhere to it during transportation and storage within the process.

Therefore, it is known to house a carrier holding a wafer in a clean box. FIG. 4 shows an external view of a conventional clean box (wafer storage container). In Figure 4, the clean box 5
0 is formed in the shape of a rectangular cylinder with an open bottom, and a hole 51 for passing the handle of the carrier is formed in the ceiling. On the back side, there is an air intake part 5 that communicates with an air filter 52.
3 is provided. The air intake part 53 is connected to the air filter chamber 5
3a, a battery chamber 53b, and an air suction chamber 53C, and the air suction chamber 53c is an air filter chamber 53a.
is communicated with through a ventilation hole 53d. Further, a fan 54 for drawing air from the ceiling surface is provided in the air drawing room, and a battery 55 for driving the fan 54 is arranged in the battery room 53b.

Then, while the carrier holding the wafer is housed in the clean box 50 and sealed, the fan 54 is rotated to draw in outside air, and the air is circulated inside the carrier while being filtered by the air filter 52. This allows the wafer to be stored in a clean atmosphere and prevents particles from adhering to it.

[Problem to be solved by the invention]

By the way, in order to prevent particles from adhering to the wafer, it is necessary to apply a laminar flow to the wafer uniformly over the entire area inside the carrier at a wind speed of 0.3 m/s or more.

However, when the diameter of the sea urchin harrow is relatively small, the blown area is also small and the rated wind speed can be obtained, but if the blown area increases due to the enlargement of the carrier as the diameter of the wafer increases, the rated wind speed cannot be obtained. Therefore, one way to increase the amount of outside air drawn in is to use multiple fans, but even if it is possible to obtain a large amount of air, the entire area of the air filter surface
Furthermore, there is a problem in that it is difficult to obtain a uniform wind speed over the entire area within the carrier.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a wafer storage device that can obtain a uniform air velocity exceeding the rated value over the entire air filter surface and prevent particles from adhering to large-diameter wafers. purpose.

[Means to solve the problem]

The above problem is solved by storing a carrier that holds a plurality of wafers in parallel in a storage area, drawing outside air using a plurality of blowers into an outside air area that communicates with the storage area through an air filter, and In the wafer storage device that blows air filtered by the air filter to the wafers in the air filter, a predetermined number of diffusers are provided to uniformly distribute the outside air drawn in by the blower to the outside air area at a predetermined wind speed over the entire surface of the air filter. This problem can be solved by providing a board.

[Effect]

As described above, the outside air drawn in by the plurality of blowers is distributed uniformly over the entire surface of the air filter at a predetermined wind speed by a predetermined number of diffusion plates provided in the outside air area. That is, filtered air that passes uniformly over the entire surface of the air filter at a predetermined speed is blown onto the wafers within the storage area.

As a result, even if the storage area is expanded as a result of increasing the diameter of the wafer, a laminar flow with a wind speed higher than the rated value can be obtained uniformly throughout the storage area, thereby preventing particles from adhering to the wafer. It becomes possible.

〔Example〕

FIG. 1 shows a configuration diagram of an embodiment of the present invention. In FIG. 1, the wafer storage device 1 has a storage area portion 1a.

It is composed of an outside air area portion 1b and a drawing area portion 1c.

The storage area portion 1a has an open bottom surface.

Further, holes 2a and 2b are formed in the ceiling surface, and the holes 2a,
Although not shown, the space between 2b is formed into a double structure. A hole is formed in the lower plate portion of the ceiling surface of this double structure to pass through a handle of a carrier (see FIG. 3), which will be described later. and,
Electrodes 3 for voltage supply and charging are provided on the side surface of the storage area 1a.

The outside air area 1b is communicated with the opposing surface of the storage area 1a via the air filter 4. Here, the air 7 and router 4 are, for example, HEPA (High Effci
ency Particulate Air-filt
er) filters and ULPA (Ultra low
Pexetration Air-filter) filter, etc. are used. Furthermore, two diffusion plates 5a and 5b (described later) are provided on the back surface in the outside air area 1b.

On the other hand, the drawing-in area 1c is provided on the outside air area 1b, and blowers (fans) 6 are provided on both opposing sides.
a and 6b are provided to draw outside air. This fan 6a,
6b is a battery 7 installed inside the upper part of the storage area 1a.
a, 7b, and the batteries 7a, 7b are connected to the electrodes 3
connected to.

Here, FIG. 2 shows a configuration diagram of the diffusion plates 5a and 5b. In FIGS. 2(A) and 2(B), the diffusion plates 5a and 5b are
From the upper part of the back of the outside air area 1b to the center, there is an inverted "ha" shape
It is set up in the shape of a square. In addition, the thickness of the outside air area 1
b is set to 1/2 to 1/3 of the depth of the remaining area where the air filter 4 is located.

By the way, when the volume of the storage area 1a increases as the size of the wafer increases (e.g. 8 inches, 10 inches), and the outside air is drawn in from the sides by the two blowers 6a and 6b, when the diffusion plates 5a and 5b are not provided, , the wind speed at the center of the surface of the air filter 4 is extremely reduced. Therefore, as described above, the diffusion plate 5a is used.

By providing 5b in an inverted "V" shape, the wind speed at the center is prevented from decreasing and the wind speed is made uniform over the entire surface of the air filter 4.

Therefore, for example, when the inlets of the fans 6a and 6b are provided on the upper surface of the drawing area 1c, the outside air area 1b
When the laminar flow inside changes, the diffuser plate 5a changes accordingly.
, 5b can be installed by appropriately setting the angle, position, number, shape, etc.

The carriers stored in such a wafer storage container 1 are
As shown in the figure. In FIG. 3, the carrier 10 is box-shaped with openings on two opposing sides, and the opening 10a through which the wafer is taken in and out is formed with locking parts 11a and l1b, and the opposing opening lOb is formed with locking parts 11a and l1b. Extending portions 12a and 12b are formed. Furthermore, a handle 13 for transportation is provided on the ceiling surface of the carrier IO. On the other hand, a large number of support grooves 14 are formed on the opposing inner surfaces of the carrier 10.
A large number of wafers (for example, 8 inches) are supported in parallel. Note that the bottom portion is opened downward.

A carrier 10 holding a large number of wafers is stored from the bottom of the wafer storage container 1. That is, the carrier lO
The handle 13 passes through a hole formed in the lower plate part of the ceiling surface of the double structure as described above between the holes 2a and 2b.
By having both the carrier 10 and wafer storage,
Both of Conclusion 1 are transportable. Also, the carrier
The locking portion 11b of the opening 10a of O is a stopper during storage, and is used to position the above-mentioned air filter 4 between the extending portions 12a and 12b of the opening 10b.

In this case, by driving the fans 6a and 6b and uniformly distributing air at a predetermined speed over the entire surface of the air filter 4, the air filtered by the air filter 4 is evenly blown to the wafer in the carrier 10 at a rate higher than the rated value. This makes it possible to prevent particles from adhering to the wafer. Therefore, when the wafer storage container 1 increases in size, there is no need to greatly change the shape of the outside air region 1b in order to obtain uniform air blowing.

For example, if a ULPA filter is used as the air filter 4, particles will be 99,999% in a 0.1 m square area.
It is possible to cut the wafer, and a wind speed exceeding the rated value of 0.35 m/s can be obtained on the wafer.

〔Effect of the invention〕

As described above, according to the present invention, by providing a predetermined number of diffusion plates in the outside air area, the air is uniformly distributed over the entire surface of the air filter at a predetermined speed, and a laminar flow is created uniformly within the carrier at a wind speed higher than the rated value. This can prevent particles from adhering to the wafer and can improve product yield.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a block diagram showing a diffusion plate of the present invention, Fig. 3 is a perspective view of a carrier stored in a wafer storage container, and Fig. 4 is a conventional FIG. 2 is an external view of a wafer storage device. In the figure, l is a wafer storage container, 1a is a storage area, 1b is an outside air area, 1c is a drawing area, 2a and 2b are holes, 3 is an electrode, 4 is an air filter, 5a and 5b are diffusion plates, and 6a , 6b is a blower (fan), and 7a and 7b are batteries.

Claims (1)

[Claims] A carrier holding a plurality of wafers in parallel is stored in a storage area (1a), and an outside air area (1b) is communicated with the storage area (1a) via an air filter (4). ), in a wafer storage device that draws outside air using a plurality of blowers (6a, 6b) and blows air filtered by the air filter (4) to the wafers in the storage area, the outside air area (1a) having: The blower (6a, 6b)
a predetermined number of diffusion plates (5a, 5b) that distribute the outside air drawn in uniformly over the entire surface of the air filter (4) at a predetermined wind speed;
A wafer storage device characterized by being provided with.