JPH10178089A - Wafer box and table for placing the same and truck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a contaminant floating in a clean room from adhering to a wafer and the characteristics of the wafer from deteriorating due to a long-term storage by providing an opening for ventilation on the bottom surface of a wafer box. SOLUTION: Air flows from the entrance side of a lid toward a bottom part also in a wafer box 1 along the flow of air of the down flow of a clean room flowing from the upper part to the lower part in the state while the upper lid of the wafer box 1 is open in a down-flow type clean room. Then, since the bottom part is open in the wafer box 1, air passes through an opening and flows downward, thus reducing the possibility of contamination of a wafer 3 accommodated in the wafer box 1 due to a floating contaminant in the clean room due to air flow.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer box for effectively protecting semiconductor wafers and wafer carriers from contaminants floating in a clean room, and a table and a trolley for mounting the same.

[0002]

2. Description of the Related Art Normally, in a semiconductor device manufacturing process, a semiconductor wafer (hereinafter, referred to as a wafer) is housed in a wafer carrier, and at the time of transportation and storage, the wafer carrier is further housed in a wafer box and transported and stored. Have been. The wafer box is usually a closed box, and has an upper cover that is opened and closed, and a wafer carrier is taken in and out. The table (including a flat plate such as a shelf) on which the wafer carrier and the wafer box are mounted and the mounting surface of the cart have a single smooth plate shape. On the other hand, in the clean room where semiconductor devices are manufactured today, the downflow method is the mainstream, and the flow of air in this room is basically from the upper side to the lower side unless there is an obstacle to this flow. Is a unidirectional laminar flow.

[0003]

However, in reality, there is an obstacle such as a semiconductor manufacturing apparatus, and turbulence is generated everywhere, and dust is scattered on a product (wafer). In particular, in the current wafer box, when the lid is opened, not only the air flow is shut off at the bottom, but also floating contaminants (hereinafter, referred to as dust) in the clean room that have flowed into the box. Because of the accumulation, there is a sufficient possibility that the dust adheres to the wafer, and in some cases, the characteristics of the product are deteriorated. Therefore, this box structure is not suitable for a downflow type clean room.

In addition, when storing wafers in a wafer box for a long period of time, the current wafer box keeps a structurally sealed state for a long period of time, which means that the wafer box is exposed to a specific atmosphere for a long time. This means that the surface layer of the wafer may undergo a chemical change in some cases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a wafer box and a table having a structure in which contaminants floating in a clean room do not adhere to the wafer and the characteristics of the wafer do not deteriorate due to long-term storage. And to provide trolleys.

[0006]

In order to achieve the above object, the present invention provides a wafer box for accommodating a wafer carrier, which has an opening for ventilation on the bottom surface of the wafer box.

The bottom surface is, for example, entirely open except for the peripheral edge of the bottom surface, or has a plurality of slits or through holes.

Further, in order to increase the effect of the wafer box of the present invention, the mounting surface of a table or a trolley on which the wafer box is mounted has a plurality of slits or through holes.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view showing a wafer box according to an embodiment of the present invention.
FIG. 11 is a schematic plan view showing a shape of a bottom surface of a wafer box according to another embodiment of the present invention. FIG. 3 is a perspective view showing a table according to the embodiment of the present invention, and FIG. 4 is a perspective view showing a carriage according to the embodiment of the present invention.

In the wafer box 1 according to the embodiment, as shown in FIG. 1, the bottom is opened except for the peripheral edge thereof in order to allow the downflow air in the clean room to pass therethrough. This is a so-called bottomless state. When the wafer 3 is transported and stored, the wafer 3 is housed in the wafer carrier 2, and
Is transported and stored in the wafer box 1.

By the way, when the upper lid of the wafer box 1 is opened in the down flow type clean room, the lid of the lid is also placed in the wafer box 1 along the flow of the down flow air of the clean room flowing downward from above. Air flows from the entrance to the bottom. At the bottom, in the case of a conventional wafer box, the flow of air is blocked at the bottom, and the air either stays at the bottom or generates convection in the wafer box. In, since the bottom is opened, the air passes through the opening and flows downward. Accordingly, the contaminants in the clean room floating along with the flow of the air escape from the bottom without staying in the wafer box 1, so that the wafers 3 accommodated in the wafer box 1 cause floating contamination in the clean room. The potential for contamination by materials is extremely low.

Further, even when the wafers 3 are stored in the clean room for a long time in a state of being housed in the wafer box 1 of the present invention, the wafer box 1
Since the inside is not closed, the atmosphere in the wafer box 1 is kept almost the same as that in the clean room, and the characteristics of the wafer 3 do not change.

The shape of the wafer box of the present invention and the shape of the opening at the bottom thereof are not limited to those shown in FIG. 1, and especially the opening at the bottom is a ventilation hole through which air in the wafer box is discharged to the outside. The size of the opening is determined by the size and shape of the wafer carrier housed in the wafer box. The larger the opening, the better the air permeability. FIG. 2 shows an embodiment of another bottom shape.
(A) is a slit-shaped opening, and (b) is an arrangement of round holes, but is not limited to a round hole and may be a through hole.

The wafer box of the present invention has air permeability,
It is good at effectively protecting wafers from floating contaminants. Its use increases its effect. FIG. 3 shows a table according to an embodiment of the present invention, and FIG. 4 shows a truck according to an embodiment of the present invention. Each of the table and the carriage has a base on which the wafer box is placed has a plurality of slits. Although not shown,
A base having a plurality of through holes is also effective in place of the slit.

When the table or the dolly is used in a down-flow type clean room, the air flow of the down flow of the clean room flowing downward from above is not interrupted by the table or the dolly, and From above, flows downward through the slit of the base. Therefore, when the wafer box of the present invention is placed on this table or trolley, and the upper lid of the wafer box is opened, the air in the downflow type clean room penetrates through the inside of the wafer box from above the wafer box. Also, the table or the platform of the truck also penetrates and falls downward. That is, as compared with the case where a conventional table or cart is used, the flow of air flows more smoothly from above to below and does not stagnate. Therefore, the possibility that the wafer and the wafer carrier in the wafer box are contaminated by contaminants floating in the clean room is further reduced.

[0016]

As described above, according to the present invention,
In the down flow type clean room, the air in the wafer box flows smoothly without stagnation in the wafer box, and effectively protects the wafer from contaminants floating in the clean room.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a wafer box according to an embodiment of the present invention.

FIG. 2 is a schematic plan view showing a shape of a bottom surface of a wafer box according to another embodiment of the present invention.

FIG. 3 is a perspective view showing a table according to the embodiment of the present invention.

FIG. 4 is a perspective view showing a truck according to the embodiment of the present invention.

[Explanation of symbols]

1 wafer box, 2 wafer carrier, 3 wafer.

Claims (8)

[Claims] 1. A wafer box for accommodating a wafer carrier, wherein the wafer box has a ventilation opening on a bottom surface of the wafer box. 2. The wafer box according to claim 1, wherein the opening is provided on the entire surface except for a peripheral edge of the bottom surface. 3. The wafer box according to claim 1, wherein said opening comprises a plurality of slits. 4. The wafer box according to claim 1, wherein said opening comprises a plurality of through holes. 5. A table on which the wafer box according to claim 1 is mounted and used in a clean room, wherein the mounting surface of the wafer box has a plurality of slits. 6. A table on which the wafer box according to claim 1 is mounted and used in a clean room, wherein the mounting surface of the wafer box has a plurality of through holes. 7. A trolley on which the wafer box according to claim 1 is mounted and used in a clean room, wherein the mounting surface of the wafer box has a plurality of slits. 8. A trolley on which the wafer box according to claim 1 is mounted and used in a clean room, wherein the mounting surface of the wafer box has a plurality of through holes.