JPH1074816A - Wafer transporting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily place a wafer on the front end section of an arm by swinging one piece of an L-shaped member provided at the front end section of the arm, so that the piece can approach the center of the wafer when the wafer is placed on the front end section and energizing the piece, so that the piece can be swung outward in the radial direction, when the wafer is not placed on the front end section of the arm. SOLUTION: An L-shaped wafer-holding member 7 is inclined outward, when a semiconductor wafer 6 is not placed on the member 7. The outside piece 7a of the member 7 is inclined outward in the radial direction of the placed wafer 6, so as to form a slope which opens outward. The wafer 6 is delivered to the front end section 5 of an arm, when a delivering device 10 is lowered. Since the elasticity of a spring 9 is set at a value smaller than the gravity of the wafer 6, the spring 9 shrinks and the other piece 7b of the member 7 receives the weight of the wafer 6 and descends. Consequently, one piece 7a of the member 7 rises and the other piece 7b of the member 7 extends toward the center of the wafer 6 along the lower surface of the wafer 6. Therefore, the water 6 can be easily placed on the front end section 5 of the arm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer transfer device used for a semiconductor manufacturing apparatus and the like, and more particularly to a wafer transfer device suitable for transferring a wafer in a vacuum.

[0002]

2. Description of the Related Art In a wafer transfer apparatus, a vacuum chuck is often used as a means for holding a wafer being transferred. The wafer is attracted to the vacuum chuck by applying a negative pressure to the wafer in contact with the vacuum chuck.

[0003] In general, in the manufacture of semiconductor devices, a process of carrying a semiconductor wafer as an object to be processed into a vacuum processing chamber of a semiconductor manufacturing apparatus and performing various processes under a reduced-pressure atmosphere is often used. In this case, it is necessary to load the semiconductor wafer into the vacuum processing chamber under a reduced-pressure atmosphere, and to transport the processed semiconductor wafer from the vacuum processing chamber. In such a wafer transfer device, the vacuum suction mechanism cannot be used for holding the semiconductor wafer when the semiconductor wafer is placed on the tip of the arm. That is, the semiconductor wafer can be vacuum-sucked in the atmosphere outside the vacuum processing chamber, but cannot be vacuum-sucked in a reduced-pressure atmosphere because the differential pressure does not act on the semiconductor wafer.

Therefore, conventionally, a member having a large coefficient of friction between the arm and the semiconductor wafer is provided at the end of the arm, and the arm is transported so that the semiconductor wafer does not shift due to friction.

[0005] Further, a conical side wall portion corresponding to the outer shape of the semiconductor wafer is provided at an end portion of the arm, or approximately three projections are provided, so that an inscribed circle formed by the conical side wall portion and the projection is formed. In some cases, semiconductor wafers are placed and transported.

[0006]

In the above-mentioned prior art, those using friction or those provided with a conical side wall portion conforming to the outer shape of the semiconductor wafer cause a positional shift when the conveying speed is increased, so that the transfer speed is reduced. Unable to increase, throughput as semiconductor manufacturing equipment (productivity)
Can not be improved.

In the semiconductor wafer provided with a protrusion corresponding to the outer shape of the semiconductor wafer, if the inscribed circle formed by the protrusion and the outer shape of the semiconductor wafer are close to each other, the semiconductor is placed above the inscribed circle formed by the protrusion. It becomes difficult to accurately position and lower the wafer and place the semiconductor wafer on the tip of the arm. If the inscribed circle formed by the protrusion is made larger than the outer shape of the semiconductor wafer with a margin, the mounting of the semiconductor wafer on the tip of the arm becomes easy, but the gap between the peripheral edge of the semiconductor wafer and the protrusion also increases. During transport, the periphery of the semiconductor wafer collides with the projection due to positional displacement, and a highly brittle semiconductor wafer or the like may lose its end.

It is therefore an object of the present invention to provide a wafer transfer device which can perform high-speed transfer, can easily place a wafer on the tip of an arm, and does not have a risk of losing the wafer.

[0009]

A feature of the wafer transfer device of the present invention that achieves the above-mentioned problem is that a wafer transfer device that mounts and transfers a wafer at the tip of an arm is provided at the tip of the arm. At least three L-shaped members provided at positions along the outer shape of the wafer to be formed, wherein each L-shaped member has a pair of pieces and a coupling portion thereof, and the arm tip portion at the coupling portion At least three L-shaped members, each of which is swingably supported, one of which rises and the other of which extends toward the center position of the wafer on which the wafer is placed, and each of which is L-shaped when the wafer is placed thereon The other piece of the member receives the weight of the wafer and swings each L-shaped member so that one piece approaches the center of the wafer, and the one piece is placed when the wafer is not placed. Is the wafer center Km is to and means for urging the respective L-shaped member so as to swing in the direction of the radially outward.

In the wafer transport apparatus of the present invention, when the wafer is not mounted, one of the pieces is inclined radially outwardly of the wafer on which one of the pieces is mounted to form a guide surface similar to the conical side wall portion. The wafer is positioned above the inscribed circle defined by the tip of each piece. Even if the wafer is slightly displaced, the wafer is guided by the guide surface, and the wafer can be lowered and placed on the other pieces.

In a state where the wafer is placed on the other piece, the other piece receives the weight of the wafer and swings the L-shaped member so that one piece stands up. The size of the inscribed circle formed at the tip of one of the pieces is small, and the movement of the wafer is restrained and the displacement of the wafer is prevented in the same way as the one with a projection that matches the outer shape of the wafer I do.

The wafer can be prevented from being displaced.
The change in the size of the inscribed circle defined by the tip of each piece depends on the presence or absence of the wafer, and does not require a special control mechanism. Since the configuration of the arm tip can be made simple and lightweight, the wafer can be transferred at high speed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, a motor or the like is built in a drive unit 2 of a wafer transfer device 1 to rotate a first arm 3, a second arm 4, and an arm tip 5 around a drive shaft, respectively. Driving for turning or expanding and contracting the entire arm is performed. Since the drive mechanism may be a known one, the description is omitted.

The tip 5 of the arm of the wafer transfer device 1 is U-shaped.
A fork-shaped part 5a having a character-shaped notch 5b is provided.
The semiconductor wafer 6 is placed on the fork-shaped portion 5a, and the first arm 3, the second arm 4, and the arm tip 5 are moved to arbitrary positions by driving the built-in motor, and the semiconductor wafer 6 is moved to a desired destination. Move and transport. The transfer device on the semiconductor manufacturing apparatus side moves up and down in the U-shaped notch 5b of the arm tip 5 to transfer the semiconductor wafer 6. The arm tip 5 is provided with three L-shaped wafer holding members 7. Each wafer holding member has two pieces and a connecting part where these two pieces are connected, and the bearing is supported by the connecting part in a swingable manner. In FIG. 1, a semiconductor wafer 6 is placed inside a rising piece of a wafer holding member 7. The wafer holding member 7 is formed of a slippery material having a small coefficient of friction with the semiconductor wafer 6.

As shown in FIG. 2, the L-shaped wafer holding member 7 is arranged at a position along the outer shape of the semiconductor wafer to be mounted, with one piece 7a rising and the other piece 7b being mounted. The semiconductor wafer 6 extends toward the center along the radial direction of the semiconductor wafer 6 and is supported so as to be able to swing at a desired angle around the two-piece joint (bend) 7c. The support shaft 8 rotatably supports the coupling portion 7c of the L-shaped wafer holding member 7, and serves as a rotation center when swinging. A compression bar 9 is coupled to the lower surface of the inner piece 7b, and when the semiconductor wafer 6 is not mounted, the L-shaped wafer holding member 7 is inclined outward. However, the compression spring 9 has a spring constant that can be compressed by the load of the wafer. At this time, the outer piece 7a is inclined in a radially outward direction of the semiconductor wafer 6 to be mounted so as to form an inclined surface that is open upward.

The delivery device 10 on the semiconductor manufacturing device side includes:
It has a wafer mounting table 10a that can pass through the U-shaped notch 5b of the fork 5a. The wafer 6 is mounted on the wafer mounting table 10a.

When one of the pieces 7a of the wafer holding member 7 swings in a radially outward direction of the semiconductor wafer 6 on which it is mounted and is inclined, the inscribed circle defined by the tip of the one piece 7a is mounted. Is larger than the outer shape of the semiconductor wafer 6 by the dimension d. Therefore, even if the wafer 6 on the transfer device 10 is displaced within the range of the dimension d, the wafer 6 is within the inscribed circle. Accordingly, the transfer device 10 can easily transfer the semiconductor wafer 6 to the L-shaped wafer holding member 7 when the transfer device 10 is lowered.

FIG. 2B shows a situation where the semiconductor wafer 6 has been transferred to the arm tip 5 by the lowering of the transfer device 10. When the transfer device 10 is lowered, the lower surface of the semiconductor wafer 6 contacts the other piece 7b of the wafer holding member 7. If the peripheral edge of the wafer contacts the inclined surface of the one piece 7a before the lower surface of the wafer contacts the other piece 7b, the wafer descends while the peripheral edge of the wafer slides on the inclined surface of the one piece 7a. Eventually, the lower surface of the wafer contacts the other piece 7b.

Since the elasticity of the spring 9 is set smaller than the gravitational force of the semiconductor wafer 6, the spring 9 contracts and the other piece 7b
Falls under the weight of the semiconductor wafer 6. The L-shaped wafer holding member 7 swings around the support shaft 8 to raise one piece 7a and sink the other piece 7b along the lower surface of the semiconductor wafer 6 to be mounted. The other piece 7b extends along the lower surface of the wafer 6 toward the center thereof.

The size of the inscribed circle of the one piece 7a when it rises is selected to be slightly larger than the outer shape of the semiconductor wafer 6. Therefore, the degree of freedom of the position of the wafer 6 in the horizontal plane is small. Even when the arm tip 5 is moved at a high speed, the rising piece 7a prevents the semiconductor wafer 6 from shifting or jumping out. There is almost no displacement of the semiconductor wafer 6, and there is no possibility that the semiconductor wafer 6 is missing due to the displacement.

The semiconductor wafer 6 in the state shown in FIG.
2A, when the semiconductor wafer 6 is received as shown in FIG. 2 (a), the spring 9 pushes up the other piece 7b due to the absence of the semiconductor wafer 6, and the L-shaped wafer holding member 7 Tilt outward.

A recess is formed in the surface of the arm tip 5 and the other piece 7b of the L-shaped wafer holding member 7 is accommodated in the recess. The swing range of the L-shaped wafer holding member 7 can be easily changed by the concave shape of the arm tip 5, and the arm tip 5 can be reduced in weight.

In the embodiments shown in FIGS. 1 and 2, the semiconductor wafer 6 is mounted on the other piece 7b of the wafer holding member 7, so that the contact area is small and the chance of contamination is small.

FIG. 3 shows another embodiment. In FIG. 3, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals.

The embodiment of FIG. 3 differs from the embodiments of FIGS. 1 and 2 in that the spring 9 is changed from a compression spring to a tension spring. FIG. 3A shows a state where the wafer 6 is not in contact with the wafer holding member 7, and FIG. 3B shows a state where the wafer 6 is placed on the wafer holding member 7. When the tension spring 9 pulls the outer rising piece of the wafer holding member 7 outward, the wafer holding member 7 is tilted outward in a state where there is no wafer. When the wafer is placed, the tension spring 9 is extended, and (the rising piece of) the wafer holding member rises.

FIG. 4 shows still another embodiment.
In FIG. 4, the same components as those in the embodiments of FIGS. 1 and 2 are denoted by the same reference numerals.

The embodiment of FIG. 4 differs from the embodiments of FIGS. 1, 2 and 3 in that the center of gravity of the wafer holding member 7 is devised without using the compression spring 9 or the extension spring 9. Is to be. That is, the center of gravity G of the wafer holding member 7 is located within the one piece 7a, and is located outside the support shaft 8 in the wafer radial direction even when the wafer 6 is mounted. In the figure, the center of gravity is located at a position higher than the support shaft 8 and close to the outer surface of the piece 7a.

The center of gravity G always generates a torque in the direction in which the wafer holding member is provided outside. Therefore, if the semiconductor wafer 6 is not placed on the wafer holding member 7, the wafer holding member 7 shown in FIG.
As shown in FIG. 4A, when the semiconductor wafer 6 is swayed and tilted and placed, the one piece 7a stands up by the weight of the semiconductor wafer 6 as shown in FIG.

The relationship between the rotating shaft 8 and the position G of the center of gravity of the wafer holding member 7 is similar to the relationship between the point of action of buoyancy and the position of the center of gravity when the ship rolls over. The restoring force does not work, and the wafer holding member (ship) falls down. The semiconductor wafer 6 has the same function as a floating material protruding from the lateral edge of the canoe to prevent it from falling down.

The semiconductor wafer 6 is connected to the arm tip 5
A part of the weight may be hung on the fork-shaped portion 5a in contact with the fork-shaped portion 5a. In such a case, it is only necessary to correct the inclination of the wafer holding member 7, so that the support structure of the wafer holding member 7 at the arm tip 5 can be made extremely simple.

The same effects as those of the embodiment of FIGS. 1 and 2 can be obtained also in the embodiment of FIGS.

In the embodiment shown in FIGS. 1 and 2 and the embodiments shown in FIGS. 3 and 4, when one of the pieces 7a rises due to the weight of the semiconductor wafer 6, the one piece 7a is perpendicular to the arm tip 5. Alternatively, it may be inclined so as to cover over the semiconductor wafer 6. An improvement in the holding characteristics for the semiconductor wafer 6 can be expected. Conversely, even if one piece 7a rises,
The inner surface may form a taper that opens upward.

In the above embodiment, the semiconductor wafer has been described as an example, but the present invention can be applied to the transport of other wafers such as a compact disk.

The present invention has been described in connection with the preferred embodiments.
The present invention is not limited to these. For example,
It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

[0036]

As described above, according to the present invention, it is possible to obtain a wafer transfer device capable of high-speed transfer, easy mounting of a wafer on the end of an arm, and free from the possibility of losing the wafer. it can.

[Brief description of the drawings]

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

FIG. 2 is an enlarged cross-sectional view taken along the line AA of the arm tip of the wafer transfer device shown in FIG.

FIG. 3 is an enlarged sectional view of a tip end of an arm of a wafer transfer device according to another embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view of a tip end of an arm of a wafer transfer device according to still another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Wafer conveyance apparatus 2 ... Drive part 3 ... 1st arm part 4 ... 2nd arm 5 ... Arm tip part 5a ... Fork-shaped part 5b ... U-shaped notch part 6 ... Semiconductor wafer 7 ... L-shaped wafer holding Member 7a: One piece 7b: The other piece 7c: Bending portion 8: Support shaft 9: Spring 10: Delivery device on the semiconductor manufacturing device side

Claims (2)

[Claims] 1. A wafer transport device for mounting and transporting a wafer on a tip of an arm, wherein at least three L-shaped members provided at positions along the outer shape of the wafer to be loaded at the tip of the arm. Wherein each of the L-shaped members has a pair of pieces and a joint thereof, and the joint is swingably supported by the distal end of the arm, and one of the pieces rises up and the other piece is placed thereon. At least three L-shaped members extending toward the center of the wafer, and the other piece of each L-shaped member receives the weight of the wafer when the wafer is placed, and one piece is the center of the wafer. Each L-shaped member is swung so as to approach the center of the wafer, and when the wafer is not placed, the one L-shaped member moves away from the center of the wafer on which the one piece is placed and swings radially outward. Means for biasing Wafer transfer apparatus according to claim and. 2. The wafer conveying device according to claim 1, wherein the means for urging the L-shaped member is a spring or a L-shaped member disposed at a position on the outer surface side of one of the pieces with respect to a swing center. A wafer transport device having a center of gravity.