JP2002076108A - Wafer cassette and method for containing wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably store wafers in a horizontal position, preventing warping of the stored wafers, even the wafers are large in diameter or small in thickness. SOLUTION: A wafer cassette 1 has plural pairs of wafer receiving parts 2, which are arranged in rows in vertical direction for almost horizontally storing a wafer (a), at least on the opposing side planes of a box-shaped container that has an opening 3 for putting in and taking out the wafer (a). A wafer support 4 is provided to support the wafer from below with the pair of wafer receiving parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wafer cassette for storing wafers. Further, the present invention relates to a method for storing wafers in a wafer cassette, and further to an auxiliary member of the wafer cassette.

[0002]

2. Description of the Related Art Conventionally, as a wafer cassette used for storing semiconductor wafers, as shown in FIG.
A pair of shelf-shaped wafer receiving portions 2 for vertically storing the peripheral portion of the wafer a on the inner side surfaces of the opposite side plates of the wafer cassette body 1 of the box-shaped container are provided in a vertical direction. There is a known one having a structure arranged in a row. Then, in the semiconductor manufacturing apparatus, the wafer cassette is positioned in the loader section before the processing or the unloader section after the processing, and the wafer a is transferred by, for example, a hand section of a wafer transfer robot so that the wafer cassette can be moved in and out. The wafers are sequentially stored in the wafer receiving portion 2 from the opening 3.

In the above-mentioned wafer cassette, as shown in FIG. 3, the shelf-like surface on which the peripheral edge of the wafer a of the wafer receiving portion 2 is placed is generally inclined in a direction in which it goes inward. Only the outer end of the wafer a placed and stored in the receiving portion 2 was held in contact with the surface of the wafer receiving portion 2. In addition, since the planar shape of the wafer a is substantially circular, the wafer a is only held on the shelf-like surface of the wafer receiving portion 2 by point contact at one point on each of the right and left sides.

In recent years, semiconductor wafers have been increasing in diameter and thinning, and only by holding the wafer by point contact at one point on each of the left and right sides as in the above-described conventional wafer cassette, the wafer is kept in a horizontal state. It has become impossible to maintain stability. For example, if a wafer is stored in a bent and inclined state (see FIG. 3), when the wafer is transferred from the wafer cassette by the hand unit of the wafer transfer robot, the transfer may not be performed smoothly. As a result, a new problem arises in that a wafer transfer trouble occurs, which causes a stoppage of the apparatus in the manufacturing process, thereby lowering the manufacturing efficiency of semiconductor manufacturing and the like.

[0005] Further, since only the outer end of the wafer is held in contact with the surface of the wafer receiving portion, the intermediate portion of the wafer having a large diameter bends downward due to its own weight.
Further, in the case of a thinned wafer, the intermediate portion may bend downward due to a decrease in the rigidity of the wafer (see FIG. 3). As a result, the pitch between the wafers may change, which causes a new problem of causing a transfer trouble.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has been developed to reduce the deflection of a wafer in a housed state even when a large-diameter wafer or a thin wafer is stored. It is an object of the present invention to provide a wafer cassette and a method for storing a wafer which can suppress the wafer horizontally and stably hold the wafer.

[0007]

In order to achieve the above object, the present invention has the following arrangement.

That is, according to the present invention, a pair of wafer receiving portions capable of accommodating a wafer substantially horizontally is provided on at least the inner side surfaces of both opposing side plates of a box-shaped container having an opening portion for entering and exiting a wafer. The present invention relates to a wafer cassette (1), comprising a pair of wafer receiving portions and a wafer supporting portion for supporting a wafer from below. In the above-mentioned wafer cassette (1), it is preferable that the wafer supporting portion is provided so that the wafer can be moved in and out of the opening for entry and exit by the wafer transfer hand portion.

The present invention is also directed to a box-shaped container having a wafer inlet / outlet, and at least a pair of wafer receiving portions capable of storing a wafer substantially horizontally are provided on at least the inner side surfaces of the opposite side plates. The present invention relates to a wafer cassette (2) in which an auxiliary member capable of storing wafers substantially horizontally is provided in the pair of wafer receiving portions of the arrayed wafer cassettes.
In the above-mentioned wafer cassette (2), it is preferable that the shape of the auxiliary member is such that the wafer can be moved in and out of the entrance opening by the wafer transfer hand.

The present invention also provides a pair of wafer receiving portions capable of storing a wafer substantially horizontally in at least the inner side surfaces of both opposing side plates of a box-shaped container having a wafer inlet / outlet opening. A method for storing a wafer, comprising: mounting a pair of wafer receiving portions of a row of wafer cassettes with an auxiliary member capable of storing a wafer substantially horizontally; and storing the wafer on the auxiliary member. . In the above-described method for storing a wafer, it is preferable that the shape of the auxiliary member is a shape that allows the wafer to be moved in and out of the opening and exit opening by the wafer transfer hand unit.

Further, the present invention relates to an auxiliary member of a wafer cassette which is placed on a wafer receiving portion of a wafer cassette and can support a wafer from below at a portion other than the receiving portion. In the auxiliary member of the wafer cassette, it is preferable that the shape of the auxiliary member is such that the wafer can be moved in and out of the opening through the opening by the wafer transfer hand.

[Operation] The operation of the present invention is as follows.
Since the wafer cassette (1) of the present invention has a wafer supporting portion in addition to the pair of wafer receiving portions, the back surface of the stored wafer is supported by at least three contact portions. Thereby, the deflection of the wafer stored in the wafer cassette can be suppressed, and the wafer can be held horizontally and stably.

According to the wafer cassette (2) of the present invention, the auxiliary member also supports the back surface of the accommodated wafer by at least three contact portions, thereby suppressing the deflection of the wafer accommodated in the wafer cassette. As a result, the wafer can be held horizontally and stably. Similarly, the above-described wafer storage method can also suppress the deflection of the wafer stored in the wafer cassette, and can hold the wafer horizontally and stably.

Further, in the above-described wafer cassette and wafer storing method of the present invention, the setting of the installation position of the wafer support portion and the shape of the auxiliary member are appropriately determined in accordance with the wafer transfer hand portion, whereby the wafer transfer is performed. Can be performed well.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a wafer cassette and a method for storing a wafer according to the present invention will be described below with reference to the drawings.

FIG. 1 is a front view (A) and a central cross-sectional view (B) showing a state in which wafers are stored in a wafer cassette (1) of the present invention.

In the above-mentioned wafer cassette, a pair of wafer receiving portions 2 for mounting the peripheral portion of the wafer a on the inner side surfaces of the opposite side plates of the wafer cassette body 1 of the box-shaped container are vertically arranged in plural rows. Has been established. The pair of wafer receiving portions 2 are provided so as to be able to store the wafer a substantially horizontally. In FIG. 1, the wafer receiving portion 2 has a shelf shape inclined inward, but the shape of the wafer receiving portion 2 is not particularly limited.
The wafer receiving portion may extend, for example, to the inner surface of the back plate as long as the wafer receiving portion is at least on the inner surfaces of the opposing side plates. In addition, the front surface of the wafer cassette is a wafer input / output opening 3. From the entrance 3
The transfer of the wafer a is performed by the hand unit b of the wafer transfer robot.

The wafer cassette has a wafer support 4 in addition to the wafer receiving section 2. The wafer supporting portion 4 is provided at substantially the same height as the pair of wafer receiving portions 2 so that the wafer can be stored substantially horizontally together with the wafer receiving portion 2, and supports the wafer from below. Wafer support 4
Thereby, the deflection of the wafer a can be suppressed, and the wafer a can be held horizontally and stably. In FIG. 1A, for example, two wafers a are stored in a horizontal state from the top.

In FIG. 1, one wafer support portion 4 is provided for a pair of wafer receiving portions 2, but a plurality of wafer support portions 4 may be provided. Further, in FIG. 1, the wafer support portion 4 is attached to the back surface of the wafer cassette main body 1, but the attachment position is not particularly limited, and may be installed on a side surface or the like. The shape of the box-shaped container of the wafer cassette body 1 is not particularly limited as long as it can store the wafer a.

Further, as shown in FIG. 1 (B), the wafer supporting portion 4 is provided so that the wafer a can be moved in and out of the opening / inlet 3 in accordance with the shape of the wafer carrying hand b. . That is, in FIG. 1 (B), the wafer support portion 4 has a shape corresponding to a convex portion corresponding to the concave portion of the hand portion b with respect to the concave hand portion b.
Does not interfere. As a result, the hand portion b of the wafer transfer robot can be moved up and down below the wafer a for delivery of the wafer a, and the delivery of the wafer a can be performed smoothly. The number and shape of the wafer supporting portions 4 are appropriately determined according to the shape of the hand portion b.

FIG. 2 is a front view (A) and a central cross-sectional view (B) showing a state in which wafers are stored in the wafer cassette (2) of the present invention.

The wafer cassette (2) of the present invention is applied to a conventionally used wafer cassette, and is equipped with an auxiliary member 5 in a pair of wafer receiving portions 2 of the wafer cassette.
By storing the wafer on the auxiliary member, the deflection of the wafer a is suppressed, and the wafer a is held horizontally and stably.

In FIG. 2A, for example, five auxiliary members 5 are provided in the wafer receiving portion 2 of the wafer cassette from the upper stage. The wafer a is stored in a horizontal state on the upper two auxiliary members 5 from the upper stage.

Since the auxiliary member 5 is mounted on the wafer receiving portion 2, it has a shape supported by the wafer receiving portion 2,
There is no particular limitation as long as the portion other than the receiving portion 2 can support the wafer from below and can store the wafer a substantially horizontally.

Further, as shown in FIG.
Is provided so as to allow the wafer a to enter and exit through the entry / exit opening 3 in accordance with the shape of the wafer transfer hand section b. That is, in FIG. 2B, the auxiliary member 5 has a shape corresponding to a concave portion of the hand portion b so as to be a convex portion corresponding to the concave portion of the hand portion b. Has become. As a result, the hand portion b of the wafer transfer robot can be moved up and down below the wafer a for delivery of the wafer a, and the delivery of the wafer a can be performed smoothly. The number and shape of the auxiliary members 5 are appropriately determined according to the shape of the hand portion b.

The material of the wafer support portion 4 and the auxiliary member 5 is not particularly limited as long as it can suppress the deflection of the wafer a, and any material can be applied.

[0027]

As is apparent from the above description, the following effects can be obtained by the wafer cassette and the method for storing wafers according to the present invention.

When a wafer having a large diameter or a thin wafer is accommodated in a wafer cassette, the wafer can be prevented from sagging downward, and the wafer accommodated in the wafer cassette can be held horizontally and stably. Can be held. In particular, the wafer cassette and the method for storing a wafer according to the present invention are useful when the diameter of the wafer is increased to 200 mm or more and the thickness is reduced to 150 μm or less.

Thus, when the wafer is transferred by the hand unit of the wafer transfer robot, the transfer can be smoothly performed, and a decrease in the manufacturing efficiency due to a wafer transfer trouble can be prevented. Further, cracking and damage of the wafer due to the bending of the wafer can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view (A) and an example of a central cross-sectional view (B) showing a state where wafers are stored in a wafer cassette (1) of the present invention.

FIG. 2 is an example of a front view (A) and a central cross-sectional view (B) showing a state where wafers are stored in a wafer cassette (2) of the present invention.

FIG. 3 is a front view showing a conventional wafer cassette.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wafer cassette main body 2 Wafer receiving part 3 Wafer in / out opening part 4 Wafer support part 5 Auxiliary member a Wafer b Wafer transfer hand part

Claims (8)

[Claims] A pair of wafer receiving portions capable of storing a wafer substantially horizontally are provided in a plurality of rows on at least the inner side surfaces of both opposing side plates of a box-shaped container having a wafer input / output opening. A wafer cassette comprising: a pair of wafer receiving portions; and a wafer supporting portion for supporting a wafer from below. 2. The wafer cassette according to claim 1, wherein the wafer supporting portion is provided so that the wafer can be moved in and out of the opening and exit opening by the wafer transfer hand portion. 3. A pair of wafer receiving portions capable of storing a wafer substantially horizontally are provided in a plurality of rows in the vertical direction on at least the inner side surfaces of the opposite side plates of a box-shaped container having a wafer inlet / outlet opening. A wafer cassette provided with an auxiliary member capable of storing wafers substantially horizontally in the pair of wafer receiving portions of the wafer cassette. 4. The wafer cassette according to claim 3, wherein the shape of the auxiliary member is such that the wafer can be moved in and out of the opening and exit opening by the wafer transfer hand portion. 5. A pair of wafer receiving portions capable of storing wafers substantially horizontally are provided in a plurality of rows on the inner side surfaces of at least opposing side plates of a box-shaped container having a wafer input / output opening. A pair of wafer receiving portions of a wafer cassette provided with an auxiliary member capable of storing the wafer substantially horizontally, and storing the wafer on the auxiliary member. 6. The method for storing a wafer according to claim 5, wherein the shape of the auxiliary member is such that the wafer can be moved in and out of the opening and exit opening by the wafer transfer hand unit. 7. An auxiliary member for a wafer cassette, which is placed on a wafer receiving portion of a wafer cassette and has a shape capable of supporting a wafer from below at a portion other than the receiving portion. 8. The auxiliary member for a wafer cassette according to claim 7, wherein the auxiliary member has a shape that allows a wafer to be transferred into and out of the opening for input and output by a wafer transfer hand portion.