JP2004079738A - Wafer carrier and transfer arm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer carrier where a transfer arm is not necessary to be inserted into a narrow gap between wafers. <P>SOLUTION: In the wafer carrier 10, thin drawer-type wafer carriers A12 storing each wafer 11 are combined with a rack-type wafer carrier B13 storing a plurality of the wafer carriers A12. When the wafer 11 is transferred, a side of the wafer carrier A12 is held by a pawl of the transfer arm and the wafer is moved. Since the wafer 11 is stored in the wafer carrier A12, the pawl of the transfer arm is not brought into direct contact with the wafer 11. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wafer carrier for storing semiconductor wafers.
[0002]
[Prior art]
FIG. 5 is a perspective view of a conventional wafer carrier 20, and FIG. 6 is a front view of the conventional wafer carrier 20 as viewed from the entrance of a wafer 21. In a conventional wafer carrier 20, grooves 22 for accommodating wafers 21 at equal intervals are provided inside the wall surface of a box-shaped container made of polyethylene or soft resin. When storing the wafer 21, the wafer 21 placed on the transfer arm 23 is inserted into the groove 22, the transfer arm 23 is lowered, the wafer 21 is placed in the groove 22, and the transfer arm 23 is pulled out while leaving the wafer 21. When taking out the wafer 21, the transfer arm 23 is inserted between the wafers 21, the wafer 21 is lifted and placed on the transfer arm 23, and the wafer 21 is pulled out together with the transfer arm 23.
[0003]
The actual wafer carrier 20 can store about 30 wafers 21, but in the drawing, the number of stored wafers 21 is reduced to make the structure easier to see. The clearance between the stored wafers 21 is about 5 mm, while the thickness of the transfer arm 23 is about 3 mm. Therefore, the clearance between the transfer arm 23 and the wafer 21 is only about 1 mm. Also, since the clearance between the wafer 21 and the groove 22 is large, the parallelism between the stored wafers 21 is not very good.
[0004]
[Problems to be solved by the invention]
In the conventional wafer carrier 20, when storing and removing the wafer 21, the transfer arm 23 must be inserted between the wafers 21. Originally, the clearance between the wafers 21 is narrow and the parallelism between the wafers 21 is not good, so that the transfer arm 23 can easily touch the wafer 21 during insertion.
[0005]
Therefore, dust attached to the transfer arm 23 may fall and adhere to the surface of the lower wafer 21. Further, when the transfer arm 23 comes into contact with the back surface of the wafer 21, dust may be rubbed, and the dust may fall and adhere to the surface of the lower wafer 21. These cause the pattern of the elements on the surface of the wafer 21 to be lost.
[0006]
In addition, dust attached to the transfer arm 23 may adhere to the back surface of the wafer 21. If the wafer 21 having dust on the back surface is attracted to a stage (not shown) of a CVD or sputtering apparatus, the wafer 21 may be broken due to dust. Further, when the wafer 21 with the dust on the back side is put into an exposure apparatus (not shown), the height of the wafer 21 is out of focus and the wafer 21 is out of focus. This causes pattern collapse.
[0007]
Although dust on the front surface of the wafer 21 has been a problem for a long time, dust on the rear surface of the wafer 21 has recently become a problem. Therefore, a step of cleaning only the rear surface of the wafer 21 is particularly necessary.
[0008]
Although the vertical position of the transfer arm 23 is set near the rear surface of the wafer 21, if the wafer 21 is warped or inclined, the transfer arm 23 may touch the surface of the wafer 21. The element touched by the transfer arm 23 is damaged and becomes defective.
[0009]
It is difficult to avoid the above-mentioned trouble as long as the transfer arm 23 is inserted into the narrow gap between the wafers 21 as in the related art.
[0010]
In order to solve the above problems, the present invention provides a wafer carrier which does not require a transfer arm to be inserted into a narrow gap between wafers.
[0011]
[Means for Solving the Problems]
The wafer carrier of the present invention comprises a combination of a thin drawer-shaped wafer carrier A for accommodating wafers one by one and a shelf-shaped wafer carrier B for accommodating a large number of wafer carriers A. When the wafer carrier A is stored in the wafer carrier B and when the wafer carrier A is pulled out from the wafer carrier B, the wafer carrier A is moved with the claw of the transfer arm sandwiching the side surface of the wafer carrier A. Since the wafer is contained in the wafer carrier A, the claws of the transfer arm do not directly touch the wafer. This structure solves all the conventional problems described above.
[0012]
Conventionally, a wafer taken out of a wafer carrier is once mounted on a stage for centering, then centered there, and then sent to a processing apparatus such as CVD. However, since the center position of the wafer stored in the wafer carrier A of the present invention is determined when the wafer is stored, it is not necessary to center the wafer again. Therefore, the step of mounting on the centering stage can be omitted. This is also an advantage of the wafer carrier of the present invention.
[0013]
The invention according to claim 1 comprises a combination of a thin drawer-shaped wafer carrier A having a recess for accommodating one semiconductor wafer and a shelf-shaped wafer carrier B for accommodating a plurality of wafer carriers A. Wafer carrier.
[0014]
According to a second aspect of the present invention, there is provided the wafer carrier according to the first aspect, wherein a side surface of the wafer carrier A has a groove or an unevenness suitable for a claw of a transfer arm to fit therein. .
[0015]
Thus, when the transfer arm moves the wafer carrier A, the wafer carrier A can be reliably held.
[0016]
According to a third aspect of the present invention, there is provided the wafer carrier according to the first aspect, wherein only the outer periphery of the wafer is held by the recess of the wafer carrier A.
[0017]
In this case, since the back surface is exposed at the center of the wafer, it is easy to transfer the wafer from the wafer carrier A to the stage.
[0018]
The invention according to claim 4 is the wafer carrier according to claim 3, wherein the center of the wafer and the center of the wafer carrier A coincide with each other.
[0019]
In this way, if the wafer is transferred with the center of the wafer carrier A aligned with the center of the stage, the center of the wafer automatically matches the center of the stage. Therefore, the trouble of centering the wafer can be omitted.
[0020]
According to a fifth aspect of the present invention, there is provided a transfer arm having a claw for holding a side surface of a thin drawer-shaped wafer carrier A for accommodating semiconductor wafers one by one.
[0021]
According to a sixth aspect of the present invention, there is provided the transfer arm according to the fifth aspect, wherein the claw has a shape that fits into a groove or unevenness on a side surface of the wafer carrier A.
[0022]
This makes it possible to reliably hold the wafer carrier A when the wafer carrier A is moved between the claws of the transfer arm.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a perspective view of a wafer carrier 10 of the present invention. The wafer carrier 10 of the present invention includes a thin drawer-shaped wafer carrier A12 for accommodating the wafers 11 one by one, and a shelf-shaped wafer carrier B13 for accommodating a large number of wafer carriers A12. The material of the wafer carrier A12 and the wafer carrier B13 is polyethylene or soft resin. Although the shelves of the wafer carrier B13 are drawn in a small number for easy viewing, the actual number of shelves is about 30 steps.
[0024]
Since the wafer 11 fits in the circular groove of the wafer carrier A12, the surface of the wafer 11 is lower than the upper surface of the wafer carrier A12. Therefore, there is little possibility that something touches the surface of the wafer 11. Further, since the wafer carrier A12 holds only the vicinity of the outer periphery of the wafer 11, it is easy to transfer the center of the wafer 11 placed on the wafer carrier A12 to a suction stage or the like (not shown).
[0025]
FIG. 2 is a perspective view showing a state in which three wafer carriers A12 are housed in the wafer carrier B13 and the fourth wafer half is housed in the wafer carrier 10 of the present invention. Thus, the wafer carrier A12 fits perfectly on the shelf of the wafer carrier B13.
[0026]
FIG. 3 is a cross-sectional view of the wafer carrier 10 of the present invention in a state where the wafer carrier A12 is stored in all the shelves of the wafer carrier B13, as seen from the entrance side of the shelf. The positional relationship between the wafer 11, the wafer carrier A12, and the wafer carrier B13 is as shown in FIG.
[0027]
FIG. 4 is a perspective view when the wafer carrier A12 of the present invention is set on the transfer arm 14 of the present invention. With the two claws 15 of the transfer arm 14 sandwiching the side surface of the wafer carrier A12, the wafer is moved into and out of the wafer carrier B13 and moved to a stage (not shown) of a processing apparatus such as CVD. The claw 15 of the transfer arm 14 fits into the V-groove on the side surface of the wafer carrier A12, and securely holds the wafer carrier A12.
[0028]
This holding mechanism is not limited to the V-groove, and a concave portion (or a convex portion) may be provided on the side surface of the wafer carrier A12, and a convex portion (or a concave portion) fitted to the claw 15 of the transfer arm 14 may be provided. Good.
[0029]
The claw 15 of the transfer arm 14 does not directly touch the wafer 11 being transferred. Further, the claws 15 of the transfer arm 14 do not touch other wafers stored in the wafer carrier B13. Therefore, dust does not occur when the claws 15 of the transfer arm 14 touch the wafer 11, and dust does not fall from the claws 15 of the transfer arm 14 and adhere to the front and back surfaces of the wafer 11.
[0030]
The wafer carrier 10 of the present invention can solve the conventional problems such as pattern breakage due to dust adhesion on the wafer surface, exposure defocus due to dust adhesion on the wafer back surface, and wafer cracking.
[0031]
Conventionally, the wafer 21 taken out of the wafer carrier 20 is once mounted on a stage (not shown) for centering, and then sent to a processing apparatus (not shown) such as CVD after centering. . However, since the center position of the wafer 11 stored in the wafer carrier A12 of the present invention is determined when the wafer 11 is stored, it is not necessary to center the wafer 11 again. For this reason, the step of mounting on a centering stage (not shown) can be omitted. This is another advantage of the wafer carrier 10 of the present invention.
[0032]
【The invention's effect】
In the wafer carrier of the present invention, a thin drawer-shaped wafer carrier A for accommodating wafers one by one and a shelf-shaped wafer carrier B for accommodating a large number of wafer carriers A are combined. When carrying the wafer, the wafer is moved with the claw of the carrying arm sandwiching the side surface of the wafer carrier A. Since the wafer is contained in the wafer carrier A, the claws of the transfer arm do not directly touch the wafer. With this configuration, the problems of the transfer arm touching the wafer and dust falling from the transfer arm onto the wafer have been solved.
[Brief description of the drawings]
1 is a perspective view of a wafer carrier 10 of the present invention. FIG. 2 is a perspective view of a wafer carrier 10 of the present invention. FIG. 3 is a cross-sectional view of the wafer carrier 10 of the present invention. FIG. 5 is a perspective view of a transfer arm 14 of the present invention. FIG. 5 is a perspective view of a conventional wafer carrier 20. FIG. 6 is a front view of a conventional wafer carrier 20.
10 Wafer carrier 11 Wafer 12 Wafer carrier A
13 Wafer carrier B
14 Transfer arm 15 Claw 20 Wafer carrier 21 Wafer 22 Groove 23 Transfer arm

Claims (6)

A wafer carrier comprising a combination of a thin drawer-shaped wafer carrier A having a recess for accommodating one semiconductor wafer and a shelf-shaped wafer carrier B accommodating a plurality of the wafer carriers A. 2. The wafer carrier according to claim 1, wherein the side surface of the wafer carrier A has a groove or an unevenness suitable for a claw of a transfer arm to fit therein. 2. The wafer carrier according to claim 1, wherein only the vicinity of the outer periphery of the wafer is held by the recess of the wafer carrier A. 4. The wafer carrier according to claim 3, wherein the center of the wafer and the center of the wafer carrier A coincide with each other. A transfer arm having a claw for holding a side surface of a thin drawer-shaped wafer carrier A having a recess for accommodating one semiconductor wafer. 6. The transfer arm according to claim 5, wherein the claw has a shape that fits into a groove or unevenness on a side surface of the wafer carrier A.

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