JPH0637081A - Drying method for wafer and wafer dryer therefor - Google Patents

Abstract

PURPOSE:To provide a centrifugal force dryer for a wafer without trouble such as a deformation, etc., of a carrier. CONSTITUTION:A wafer dryer has a rotary base 1 fixedly supported to a rotary shaft 8, an oblique bottom and a covered cylindrical body 6, and comprises a vessel placed on a turntable 1 to contain a waver carrier 3 thereby to fix a released part of the carrier 3 toward a centrifugal side to the base 1. Further, a stopper is provided at the released part side of the carrier 3 thereby to connect the wafer to prevent the wafer from jumping out even if a centrifugal force is applied to the wafer by the rotation of the base 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for drying a wafer stored in a carrier by centrifugal force.

[0002]

2. Description of the Related Art Conventionally, there is known a drying apparatus which utilizes a centrifugal force in a so-called batch system in which a plurality of wafers are stored in a carrier. FIG. 5 is a central longitudinal sectional view of this essential portion, and FIG. 6 is a sectional view taken along line VV in FIG.

As shown in the figure, this apparatus has a fixed cylindrical main body 6 in which a bottom plate 6a forms an inclined surface, a drainage port 7 is provided at the lowest portion, and a circular portion is formed at the center of the upper edge opening portion. A lid 5 having a cutout 5a is installed. And the main body 1
A rotary shaft 8 penetrating a hole provided in the center of the bottom plate 6a is provided, and a rotary base 1 is arranged inside the main body and is fixedly supported on the upper end of the rotary shaft 8.

A plurality of carriers 3 for the wafer 2 made of PFA or the like are integrated, and are housed in a box (hereinafter referred to as a cradle) fixed to the upper peripheral edge of the rotary table to accommodate the carriers. As shown in FIG. 7, the portions of the carrier 3 where the wafers are housed each have an approximately eight shape, and a sharp stepped portion 3a is formed in the reduced width portion. Further, the member has a groove 3b on the inner side surface, and the wafer 2 has an orientation flat portion of the wafer (hereinafter,
This groove 3b is inserted from the opposite side (called the flat part).
The peripheral portion is loosely fitted in and is sandwiched. (B) of FIG. 6 is (a)
This state is represented by a sectional view taken along line bb in the figure.

The wafer 2 thus accommodated in the cradle 4 together with the carrier 3 is arranged on the upper surface of the rotary table 1 with the narrowed portion of the carrier 3 on the centrifugal side, and is rotated by a drive source (not shown). It is rotated with the rotation of 8. The arcuate arrow on the shaft represents the direction of rotation of the shaft, and is 800 to 1200 r. p. It rotates at a high speed of m. Therefore, the wafer 2 in the carrier 3 accommodated in the cradle 4 on the rotary table 1 is dried by shaking off water droplets attached to the wafer by centrifugal force.

[0006]

The conventional wafer drying apparatus for drying by the centrifugal force as described above is used for the wafer 2
Is applied to the carrier 3 by the centrifugal force of 1, and a pressure that pushes open the stepped portion 3a of the carrier 3 is applied. Figure 7
Indicates this state. The thick arrow drawn on the wafer indicates the direction in which the centrifugal force acts, and the right-angled arrow indicates the direction in which the narrowed portion of the carrier 3 is pushed open. As a result of such pressurization, the carrier is gradually deformed into the shape shown by the imaginary line. Further, these pressures inevitably cause not only the carrier 3 but also the cradle 4 including the carrier 3 to direct the total centrifugal force of the wafer 2 and the carrier 3 to swell the inner wall portion 4a. FIG. 8A shows this state,
(B) shows that as a result of the carrier 3 being pushed open to the wafer, the center portion of the cradle 4 is also bulged and deformed in both directions.

As a result, in the conventional technique, the carrier 3
There is a problem in that the pitch of the wafer holding means becomes irregular, and when the wafer 2 is transferred by an automatic machine, the wafer 2 is cracked and the interlock causes the device to stop operating.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to apply a wafer drying method in which the carrier is not deformed and a wafer drying apparatus in this method.

[0009]

In order to solve the above-mentioned problems, the present invention places a carrier containing a plurality of wafers on a turntable and rotates the turntable to allow the wafers in the carrier to be rotated. The wafer drying device for drying is a carrier mounting member that is mounted so that the wafer storage front of the carrier for loading and unloading the wafer faces the outside of the turntable, and when the carrier is mounted on the carrier mounting member, A locking member that locks the wafer so that the wafer does not come out is provided on the wafer storage front side.

[0010]

According to the present invention, since the storage front of the carrier is placed toward the outside of the turntable and each wafer in the carrier is locked by the locking member to rotate, the centrifugal force due to the rotation is directly applied. Each member of the carrier can be prevented from receiving, and the deformation of the carrier can be prevented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wafer drying method and an embodiment of a wafer drying apparatus according to this method will be described below.

1 to 4 relate to the present invention,
FIG. 1 is a vertical cross-sectional view of the central portion of the main part of this example, and FIG.
II-II sectional view taken along line (b) in FIG.
It is a -b line sectional view. This example has a lot in common with the conventional example as shown in the figure. Therefore, by omitting the details of the common points and focusing on the differences from the conventional one, the characteristics of this example should become remarkable.

That is, the main body 6 of the present example, the rotary table 1 and the carrier 3 for the wafer 2 provided therein are no different from the conventional ones.
The different point is the orientation of the carrier 3 on the turntable 1 as shown in FIG. The orientation of the open portion of the carrier 3, that is, the wafer storage front side is conventionally the centripetal side, whereas in the case of this example, it is located on the centrifugal side. As a result, the carrier 3 never receives the centrifugal pressure of the wafer 2.

Therefore, the following measures are taken as a method of treating the centrifugal pressure of the wafer. 2 and 3 show the core member and its position. That is, the stopper 13 is a locking member newly added in this embodiment. As shown in both figures, the flat portion 2a of the wafer 2
Comes into contact with the stopper 13 located on the centrifugal side,
The stopper 13 intensively receives the centrifugal force of the wafer 2, the direction of which is indicated by the arrow in FIG. As a method capable of achieving this, the following storage means for the carrier 3 is provided.

FIG. 4 is a perspective view of the carrier accommodating means in this example. First, the wafer 2 is held in the groove 3b of the carrier 3 with the flat portion 2a being the open side of the carrier 3, and is stored in the container 11 as the first storing means with the open portion of the carrier 3 placed on the open side. . In the figure, the phantom line shows the wafer 2 and the carrier 3 in the housed state. A notch hole 11a is provided in the center of the bottom surface of the container 11, which serves as an important vent hole described later.

Pins 11b are provided on both side surfaces of the container 11, and the pins 11b are engaged with the grooves of guides 12c projecting from the cradle 11 described below.
As a result, the container 11 accommodating the wafer 2 and the like is easily accommodated in the cradle 12.

The cradle 12 is installed in advance so that its back surface is aligned with the circumference of the rotary table 1. Therefore, the opening faces the centripetal side, and the open portion of the carrier 3 and the flat portion 2a of the wafer 2 stored in this opening are both located on the centrifugal side. Similarly, the cradle 12 is also provided with a notch 12b in the center of the back surface, and abuts on the remaining edge portion 12a of the back surface, and a stopper 13 is fixed and installed vertically to the center. Therefore, the flat portion 2a of the wafer 2 stored in the container 11 inevitably comes into contact with the stopper 13 while the flange portion 3c at the open end of the carrier 3 is placed on the inner surface of the edge portion 12a of the cradle 12. Abut. With such a structure, the stopper 13 receives the centrifugal pressure of the wafer 2 and the rim portion 12a receives the centrifugal pressure of the carrier 3 and the container 11, respectively, so that the deformation factor of the carrier 3 can be avoided.

The wafer 2 set on the rotary table 1 is stored in the storage means while being kept in the range of 800 to 1200 r. p. m
It is spun at high speed and the attached water drops are shaken off to dry. However, in the device 6 which is rotating at high speed, centrifugal force is generated not only in the internal objects but also in all the objects. Therefore, even in the storing means for the wafer 2, a fast air flow is involved, which is the reason why the notches 11a and 12b are provided. Although the water droplets that have been shaken off are also discharged from this cutout portion, a part of them will also remain inside the storage means, so that the container 11 and the cradle 12 will also have innumerable small holes for the purpose of further improving the air circulation performance. The material is a punched metal plate.

[0019]

As described above, the wafer drying method and apparatus of the present invention have been described in detail. According to the present invention, the carrier is not deformed by the pressure due to the centrifugal force of the wafer, and the centrifugal force of the carrier is It concentrates on the flange part and receives it on the back of the cradle, so the cradle itself does not deform. Further, in the cradle whose lower part is fixed to the rotary table, the upper part is inclined in the centrifugal direction by the action of the centrifugal force during the rotation, so that the internal wafer is unevenly distributed upward in the groove of the carrier. Therefore, since the contact area with the carrier is reduced, it is possible to prevent insufficient drying, which is likely to occur at the contact portion, and stain-like stains.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of a wafer drying apparatus of the present invention,

2 (a) is a sectional view taken along line II-II in FIG. 1, (b).
Is a sectional view taken along line bb in FIG.

FIG. 3 is a direction of centrifugal force in the wafer drying apparatus of the present invention,

FIG. 4 is a perspective view of a carrier and a wafer storing means in the present invention,

FIG. 5 is a vertical cross-sectional view of a main part of a conventional wafer drying device,

6A is a sectional view taken along line VV in FIG. 5, FIG.
Is a sectional view taken along line bb in FIG.

FIG. 7: Direction of centrifugal force in a conventional wafer drying device,

8A is a front view of a deformed carrier, and FIG. 8B is a plan view of the same.

[Explanation of symbols] 1 turntable 2 wafer 3 carrier 4,12 cradle 5 lid 6 main body 7 drainage port 8 rotary shaft 11 container

Claims (2)

[Claims] 1. A wafer drying method in which a carrier containing a plurality of wafers is placed on a turntable, and the turntable is rotated to dry the wafers in the carrier. The wafer storage front to be carried is placed toward the outside of the turntable, and a locking member for locking the wafer so as not to jump out of the storage front when the turntable is rotated is arranged in the wafer front. When the wafer is rotated, each wafer in the carrier is rotated while being locked by the locking member. 2. A wafer drying apparatus for placing a carrier containing a plurality of wafers on a turntable, and rotating the turntable to dry the wafers in the carrier. A carrier mounting member for mounting the wafer storage front facing the outside of the turntable; and when the carrier is mounted on the carrier mounting member, the wafer is placed outside the wafer storage front. And a locking member that locks the wafer so that it does not come out. When the wafer rotates, each wafer in the carrier rotates while being locked by the locking member.