JPH11286332A - Wafer carrying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer carrying device which prevents minute particles from adhering to a wafer as much as possible, and can correct the attitude of a wafer. SOLUTION: This wafer carrying device is provided with an arm part 3 capable of being moved in the specified direction, and a wafer suction part 2 which is provided for the tip end of the arm part 3 to suck and hold the wafer. The plane view shape of the wafer suction part 2 is formed into a U- shape whose area in contact with the wafer is made as small as possible. A recessed groove 4 is formed at the tip end of the wafer suction part 2, and the recessed groove 4 is opened forward so as to be engaged with the orientation flat part of the wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for transferring a wafer serving as a substrate of an IC or LSI.

[0002]

2. Description of the Related Art A silicon wafer serving as a substrate of an IC or an LSI is obtained by slicing a silicon ingot. Many silicon wafers sliced from a silicon ingot are transferred by a wafer transfer device and temporarily stored in a wafer storage cassette or the like until circuit elements are formed on the surface. The wafer on which the circuit elements are already formed is also transferred by the wafer transfer device and stored in a wafer storage cassette or the like until its performance is inspected.

[0003] An example of use of a wafer transfer device will be described with reference to the drawings. FIG. 10 is a partial perspective view showing an example of the wafer transfer device, FIG. 11 is a perspective view showing a state immediately before the wafer transfer device holds the wafer, and FIG. 12 is a plan view of the wafer held by the wafer device. FIG. 13 is a partially enlarged front view of the wafer storage cassette.

[0006] As shown in FIG. 10, the wafer transfer device mainly includes a wafer suction section 11 and an arm section 12. An air suction hole 10 is provided in the wafer suction section 11 connected to the arm section 12, and FIG.
1. As shown in FIG. 12, the lower surface of the silicon wafer 1 is held by the wafer suction part 11 by suction of air. A robot (not shown) is connected to one end of the arm unit 12, and the robot drives the arm unit 12 so that the wafer 1 held by the wafer suction unit 11 is transferred to the cassette 131 and stored therein. .

As shown in FIG. 13, the cassette 131 has a box shape with an open front. Cassette 131
The inner wall of the side surface has convex portions 132, and these convex portions 132 are formed on the left and right side surfaces at regular intervals in the vertical direction. The silicon wafers 1a, 1b, 1c
The peripheral portion is supported in the cassette 131 by being supported between the convex portions 132 facing each other.
There is a space between the silicon wafers 1a, 1b, 1c that allows the wafer suction unit 11 to be inserted.

However, when the silicon wafer 1 is transferred by the above-described wafer transfer device, the following inconvenience may occur.

[0007]

The silicon wafers 1 (1a, 1b, 1c) stored in the cassette 131 are:
When the wafer is transferred by the wafer transfer device, the vicinity of the center of the lower surface is in contact with the wafer suction unit 11. As shown in FIG. 12, since the surface area of the wafer suction unit 11 is large, a large amount of fine particles such as dust existing on the wafer suction unit 11 adhere to the vicinity of the center of the lower surface of the silicon wafer 1. The fine particles hinder the work of forming circuit elements on the silicon wafer 1 and the work of inspecting the performance of the silicon wafer 1. For this reason, the operator had to cleanly remove the fine particles from the surface of the silicon wafer 1. Such an operation of removing fine particles is very troublesome for an operator.

Further, a slight play is provided between the inner wall surface of the cassette 131 and the peripheral edge of the silicon wafer 1 to make it easy to put the silicon wafer 1 in and out. For this reason, as shown in FIG.
There is a case where the attitude of the silicon wafer 1c housed in the wafer 1 is slightly shifted. In order to form circuit elements on the wafer 1 or to inspect the characteristics of the wafer 1c, if the silicon wafer 1c whose posture is displaced in the cassette 131 is taken out as it is, the posture of the silicon wafer 1c is changed by another apparatus. Must be corrected. Correcting the posture of the silicon wafer 1 by providing another device is
This is a factor that reduces work efficiency.

The present invention has been conceived under such circumstances, and it is an object of the present invention to provide a wafer transfer apparatus capable of correcting the attitude of a silicon wafer without adhering particles to the silicon wafer as much as possible. It is an issue.

[0010]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

That is, a wafer transfer device according to the present invention comprises an arm portion movable in a predetermined direction by a driving device, and a wafer suction portion provided at a tip of the arm portion and capable of sucking and holding a lower surface of a wafer. In the wafer transfer device, the wafer suction unit has a shape in plan view such that the area contacting with the lower surface of the wafer is reduced, and is provided at least in front of at least two places that can engage with the orientation flat portion of the wafer. It is characterized in that it has a concave groove that opens toward the tip.

The wafer suction portion in the wafer transfer device of the present invention is processed into a plan view shape such that the area in contact with the wafer is reduced. Fine particles such as dust adhere to the wafer suction part, and the fine particles adhere to the wafer when the wafer suction part contacts the wafer. However, when the wafer transfer device of the present invention is used, the contact area between the wafer suction portion and the wafer can be reduced, so that the amount of fine particles adhering to the wafer can be reduced as compared with the conventional case. Since the amount of fine particles that hinder the formation of circuit elements is reduced, the operation of removing the fine particles that have adhered to the wafer becomes easier than before. Since the operation of removing fine particles is facilitated, circuit elements can be efficiently formed on a wafer, and the production efficiency of a semiconductor wafer and a semiconductor chip in which the semiconductor wafer is divided for each circuit element is improved.

[0013] The wafer suction portion has at its front end at least two recessed grooves that can be engaged with the orientation flat portion of the wafer and that open forward. The concave groove is provided to correct the attitude of the wafer. When the attitude of the wafer is distorted, move the arm to move the wafer orientation flat
If the "orientation flat") portion is engaged with the concave groove and the arm portion is further moved in a predetermined direction, the concave groove pushes the orientation flat portion to move the wafer. Therefore, by adjusting the moving direction of the arm, the posture of the wafer can be correctly corrected. Since the posture of the wafer can be corrected by the wafer transfer device itself, and it is not necessary to correct the posture of the wafer by using another machine, the work efficiency is improved as compared with the related art.

As an embodiment of the present invention, the wafer suction portion has a U-shaped, V-shaped or katakana U-shaped plan view shape. By bringing the wafer suction unit having a U-shaped, V-shaped or katakana U-shape in plan view into contact with the lower surface of the wafer, the wafer can be stably held on the wafer suction unit. it can. If the shape of the wafer suction portion is a simple bar, the wafer is held in an unstable state by the wafer suction portion.

In a further preferred embodiment of the present invention,
The wafer suction section has an air suction hole at least on the upper surface of the base end. Since the air suction holes suck the wafer together with the outside air, even if the contact area between the wafer suction unit and the wafer is reduced, the wafer is held in a stable state by the wafer suction unit. For this reason, the wafer does not come off the wafer suction part when being transported.

As described above, the use of the wafer transfer device according to the present invention facilitates the operation of removing fine particles from the wafer, and makes it possible to form circuit elements on the wafer more efficiently than in the prior art. The production efficiency of wafers and semiconductor chips is improved. Further, since the posture of the wafer can be corrected by the wafer transfer device itself, it is not necessary to correct the posture of the wafer by using another machine when inspecting the performance of the wafer. Therefore, the inspection work can be performed efficiently.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall perspective view showing one embodiment of a wafer transfer device according to the present invention.
As shown in FIG. 1, the wafer transfer device A includes an arm 3 that is movable in a predetermined direction, and a wafer suction unit 2 that is provided at an end of the arm 3 and suctions and holds a wafer.
And

The arm section 3 is connected to a first arm section 3a connected to the wafer suction section 2, a rotating member 3b for rotating the first arm section 3a in the θ _X direction, and a rotating member 3b. A second arm portion 3c that can expand and contract in the X-axis direction. The arm 3 composed of the parts 3a, 3b, 3c is attached to a first rotating part 6, and the first rotating part 6 rotates in the θ _Y direction with respect to the second rotating part 7. Mounted as possible. The second rotating part 7 is rotatably mounted on the theta _Y direction with respect to the rotation stage 8, the rotation stage 8 is rotatably mounted in the theta _Z direction with respect to the base 9. Inside the base 9, a mechanism (not shown) for driving the rotating stage 8, the rotating units 6 and 7, and the arm unit 3 is built.

The wafer suction part 2 has a U-shaped plan view so as to reduce the area in contact with the wafer.
An air suction hole 5 for sucking a wafer is provided at the base end. Two concave grooves 4 are provided at the tip of the wafer suction unit 2. The concave groove 4 is opened forward, and can be engaged with an orientation flat (hereinafter abbreviated as “orientation flat”) portion 15 (see FIG. 3) of the wafer.

FIG. 2 is a sectional view taken along line AA of FIG. 1 and shows a sectional structure of the concave groove 4 in the wafer suction section 2. The orientation flat of the wafer is corrected by fitting the orientation flat 15 (see FIG. 3) of the wafer into the concave groove 4 and moving the arm 3 (see FIG. 1) connected to the wafer suction unit 2 in a predetermined direction.

An example of use of the wafer transfer device A according to the present invention will be described with reference to the drawings. FIG. 3 is a perspective view of a main part showing a state immediately before the silicon wafer is brought into contact with the wafer suction part, FIG. 4 is a plan view of the silicon wafer held by the wafer suction part, and FIG. It is a cross-sectional view of a main part showing a contact state with the suction unit,
FIG. 6 is a schematic diagram showing a state in which the attitude of the silicon wafer is corrected by the wafer transfer device, and FIG. 7 is a cross-sectional view taken along line AA of FIG.

When the silicon wafer 1 is transferred by the wafer transfer device A, the wafer suction part 2 is brought into contact with the silicon wafer 1 as shown in FIGS. Wafer suction unit 2
Has a small surface area, the amount of fine particles such as dust adhering to the silicon wafer 1 from the wafer suction part 2 is reduced. Since the shape of the wafer suction unit 2 is U-shaped (symmetric), the wafer suction unit 2 is brought into contact with the lower surface of the silicon wafer 1 and the air suction holes 5 are formed.
The outside air is sucked from the silicon wafer 1
Is held by the wafer suction unit 2 in a stable state.

When the attitude of the silicon wafer 1 is corrected by the wafer transfer device A, as shown in FIG.
Is driven to approach the silicon wafer 1 of the wafer suction unit 2. Since the groove 4 provided at the tip of the wafer suction unit 2 is engaged with the orientation flat 15 of the silicon wafer 1 (see FIG. 7), when the arm 3 is driven in a predetermined direction, the inner wall surface of the groove 4 is formed. The silicon wafer 1 is pushed, and the attitude of the silicon wafer 1 is corrected. The orientation flat 15 is
Since it is longer than the interval between the concave grooves 4 and 4 in the wafer suction part 2, it is easily held in the concave groove 4.

The wafer suction unit in the wafer transfer device of the present invention is not limited to the above embodiment. FIG.
FIG. 9 is a plan view of a principal part showing another embodiment of the wafer suction section, and FIG. 9 is a sectional view taken along line AA of FIG.

As shown in these figures, the wafer suction portion 82 has a U-shaped plan view shape, and has a U-shaped groove 90 on its upper surface. Since the air suction hole 85 is provided at the center of the U-shaped groove 90, the wafer suction unit 82 suctions the silicon wafer 1 not only from the air suction hole 85 but also from the entire U-shaped groove 90. Therefore, the silicon wafer 1 is held in a stable state by the wafer suction unit 82. The planar shape of the wafer suction unit 82 is U-shaped, like the wafer suction unit 2, and the structure of the concave groove 84 is the same as that of the concave groove 4 in the wafer suction unit 2. Therefore, the wafer suction unit 82 can reduce the amount of fine particles such as dust adhering to the silicon wafer 1, and furthermore,
The attitude of the silicon wafer 1 can be corrected by the groove 84.

The embodiments of the present invention have been described above. However, the present invention is not limited to these embodiments, and can be variously modified as described below.

In the above embodiment, the wafer suction units 2, 82
Has a U-shape in plan view, but the present invention is not limited to this. The planar shape of the wafer suction units 2 and 82 may be a V-shape or a U-shape of katakana. Any shape is possible as long as it has a small area in contact with the silicon wafer 1 and can hold the wafer stably.

In the above embodiment, the silicon wafer 1 is transferred, but the wafer transfer device A according to the present invention can be applied to transfer a wafer made of another material, for example, a germanium wafer or a gallium arsenide wafer. is there.

In the above embodiment, an example is described in which a silicon wafer is transported before circuit elements are formed. However, the present invention is applicable to a case where a semiconductor wafer on which circuit elements are already formed is transported. Can also be applied.

The present invention is not limited to the above, and various modifications may be made within the scope of the claims, including those in which each component is replaced with an equivalent. .

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a wafer transfer device according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a partial perspective view showing a state immediately before a silicon wafer is brought into contact with a wafer suction unit.

FIG. 4 is a plan view of a silicon wafer held by a wafer suction unit.

FIG. 5 is a sectional view of a main part showing a contact state between a silicon wafer and a wafer suction part.

FIG. 6 is a schematic diagram showing a state in which the posture of a silicon wafer is corrected by the wafer transfer device according to the present invention.

FIG. 7 is a sectional view taken along line AA of FIG. 6;

FIG. 8 is a main part plan view showing another embodiment of the wafer suction unit in the wafer transfer device according to the present invention.

FIG. 9 is a sectional view taken along line AA of FIG. 8;

FIG. 10 is a partial perspective view showing an example of a conventional wafer transfer device.

FIG. 11 is a partial perspective view showing a state immediately before a conventional wafer transfer device holds a silicon wafer.

FIG. 12 is a plan view of a silicon wafer held by a conventional wafer transfer device.

FIG. 13 is a partially enlarged front view of the wafer storage cassette.

FIG. 14 is a partial perspective view showing a posture of a silicon wafer stored in a cassette.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Silicon wafer 2,82 Wafer suction part 3,83 Arm part 4,84 Concave groove 5,85 Suction hole 15 Orientation flat 90 U-shaped groove 131 Cassette 132 Convex part A Wafer transfer device

Claims (3)

[Claims] 1. A wafer transfer device comprising: an arm portion movable in a predetermined direction by a driving device; and a wafer suction portion provided at a tip of the arm portion and capable of holding a lower surface of a wafer by suction. The wafer suction part has a shape in plan view such that the area in contact with the lower surface of the wafer is reduced, and has at least two recessed grooves that can be engaged with the orientation flat part of the wafer. A wafer transfer device, which is provided at a tip. 2. The wafer transfer device according to claim 1, wherein the wafer suction unit has a U-shaped, V-shaped, or katakana U-shaped plan view shape. 3. The wafer transfer device according to claim 1, wherein the wafer suction unit has an air suction hole at least on an upper surface of a base end portion.