JPH09298229A - Transportation device for semiconductor wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a scar on the surface of a semiconductor wafer while it is transported in liquid and to prevent the contamination of particles and metal and to easily turn over wafer in the middle transportation. SOLUTION: Holes 13 are formed below a chute-like channel 11 and pure water is jetted from the holes 13 so as to form a flow. A holder 14 opened to an upstream side is provided in the middle of the channel and the wafer 12 is stored and kept. The holder 14 can freely rotate with a horizontal shaft as a center and the holder is arranged so that a part is immersed on a tank 16. The inner face of the holder 14 is a tapered form and a central part becomes hollow. When the wafer is inserted, the central part holds the peripheral part. The insertion of the wafer is detected and the supply of pure water is stopped. The holder 14 turned over by 180 degrees by driving a motor and the wafer 12 is turned over. The supply of pure water is resumed and it is transported to a downstream side by turning a face 12A upward. The particles and metal are prevented from adhering to the face 12A which is immersed in pure water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer transfer device, and more particularly to a semiconductor wafer transfer device using liquid transfer means.

[0002]

2. Description of the Related Art The following methods have been known as conventional single-wafer transfer methods for semiconductor wafers. Wafer transfer in the dry state included belt transfer, robot transfer, gas floating transfer, and walking beam transfer. In addition, a method of suspending the wafer in a liquid and carrying the wafer in a wet state has been known. Further, as a technique of reversing the front and back surfaces of the wafer, there has been known a technique of vacuum suction or mechanically holding the peripheral portion of the wafer and reversing it by a robot.

[0003]

However, such a contact type conveying device has a drawback in that dust and particles adhere to the surface thereof. Also,
Metal contamination may occur on the surface. In addition, the surface may be scratched. Further, in the non-contact type conveyance, since the reversing device by mechanical contact is used when reversing the front and the back, there are similarly problems of dust adhesion, metal contamination, and scratches. Also, the structure of the device is complicated,
It was getting expensive.

[0004]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a semiconductor wafer transfer device which prevents dust and particles from adhering to the surface. Another object of the present invention is to provide a semiconductor wafer transfer device which can be inverted with a simple structure. Another object of the present invention is to provide a carrier device capable of inverting a semiconductor wafer without contacting the surface of the semiconductor wafer. further,
An object of the present invention is to provide a wafer transfer device having a wafer reversing mechanism that can be installed in a narrow space.

[0005]

According to a first aspect of the present invention, there is provided a transfer means for transferring a semiconductor wafer floating in a liquid, and a semiconductor wafer transferred and provided in the middle of a transfer path by the transfer means. Holding means capable of holding,
The semiconductor wafer transfer apparatus is provided with a reversing unit for reversing the semiconductor wafer held by the holding unit by rotating the semiconductor wafer by a predetermined angle about a straight line included in the surface as a central axis.

According to a second aspect of the invention, there is provided the semiconductor wafer transfer apparatus according to the first aspect, wherein the holding means contacts only the peripheral portions of the front and back surfaces of the semiconductor wafer to hold the semiconductor wafer.

According to a third aspect of the present invention, the holding means has a structure in which a gap having a predetermined interval is formed between the pair of flat plates, and the semiconductor wafer is inserted and held in the gap. 3. The semiconductor wafer transfer device according to claim 2, wherein a taper is formed on the facing surface so that the central portion is recessed.

[0008]

According to the first aspect of the invention, the semiconductor wafer is floated in the liquid and transferred by the transfer means. And
The semiconductor wafer transferred by the transfer means is held by the holding means. The semiconductor wafer held by the holding means is rotated by a predetermined angle about a straight line included in the surface of the semiconductor wafer as a central axis by the rotating means, and the semiconductor wafer is inverted. As a result, one surface of the semiconductor wafer can be transported to a desired position while being covered with pure water, for example, and it is possible to prevent generation of scratches and surface contamination (particles / metals) on the surface.
For example, it can be used for transporting a semiconductor wafer from the final polishing step to the storage in a cassette. Even when the semiconductor wafer is turned over, the semiconductor wafer is protected by the liquid and mechanical damage can be prevented.

According to a second aspect of the present invention, the holding means makes contact with a part of both front and back surfaces of the semiconductor wafer to hold it. Therefore, the contact portion of the semiconductor wafer on the holding means is reduced, and the adhesion of foreign matters such as dust and particles can be minimized.

According to a third aspect of the present invention, the holding means has a structure in which a gap having a predetermined interval is formed between the pair of flat plates, and the semiconductor wafer is inserted and held in the gap. A taper is formed on the facing surface so that the central portion is depressed. Therefore, even if the semiconductor wafer is transported by the liquid, it is smoothly held by the holding means, and the subsequent reversal can be easily performed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. 1 to 5 are views showing a semiconductor wafer transfer apparatus according to an embodiment of the present invention.

In these figures, reference numeral 11 denotes a flow path for forming a transfer path for a semiconductor wafer (for example, a mirror surface silicon wafer) 12, which is formed in a predetermined gutter shape. Pure water or other liquid is jetted out through the plurality of holes 13 on the lower surface of the gutter-shaped channel 11, and forms a flow toward the downstream side in the channel 11. That is, the plurality of pure water ejection holes 13 and the trough-shaped flow passage 11 constitute a transfer means for floating the semiconductor wafer 12 in pure water which is a liquid and transferring it from the polish to the cassette transfer step.

A holder 14 as a means for holding the semiconductor wafer 12 is provided in the middle of the flow path 11. The holder 14 has a structure capable of holding the transferred semiconductor wafer 12, and is formed in a box-like or sheath-like shape whose one surface is open toward the upstream side. That is, the upper plate 14A and the lower plate 14B, which are parallel to each other, are
Are provided to face each other at an insertable interval, and a plurality of bottom plate members 14D located on the opposite side of the opening 14C are inserted and the semiconductor wafer 12 is stopped and accommodated inside. A plurality of pure water supply holes 14E are formed in the upper plate 14A and the lower plate 14B.

Further, on both side plates of the holder 14, shafts 15A and 15B on the same axis are provided in a protruding manner. The shafts 15A and 15B project vertically from the side plate with respect to the flow path 11 and extend in the horizontal direction. Shaft 15A, 1
5B serves as a rotation center axis of the holder 14 when the semiconductor wafer 12 is inserted and held in the holder 14. That is, the holder 14 is configured to be rotatable around the horizontal shafts 15A and 15B around the axis. As a means for rotating, an output shaft such as a motor is used as shafts 15A and 15B
It can be used by connecting to. And the shaft 15A,
15B is positioned by, for example, a stopper so that the holder 14 can be stopped at a predetermined horizontal position. The holder 14 is rotatable about a horizontal axis 15A, 15B in a plane including a straight line showing the direction of the flow path 11 by 360 degrees, and part of the holder 14 is placed in a water tank 16 filled with pure water during rotation. Is rotatably supported on the water tank 16 so that The water tank 16 is arranged at a predetermined position in the middle of the gutter-shaped flow path 11. In addition,
Pure water is supplied to the water tank 16 from the water injection port 17 and overflows, so that the water tank 16 can be used as a cleaning tank for the semiconductor wafer 12. In addition, the supply / discharge / supply amount of these pure water
The flow velocity and the like are managed by a control device (not shown).

Further, the pair of upper plates 14 of the holder 14
The semiconductor wafer 12 is inserted into the gap between the A and the lower plate 14B. As shown in FIG. 5, a pair of upper plates 14A and 14B into which the semiconductor wafer 12 is inserted and one surface of which is in contact with each other.
The inner surfaces 14F and 14G facing each other are each tapered so that the central portion thereof is recessed. In other words, each of the inner surfaces 14F, 14G is formed as an inclined surface having the lowest central portion along the flow path direction and the higher side plate side farthest from the central portion.

In the semiconductor wafer transfer apparatus having the above structure, when the semiconductor wafer 12 is put into the flow path 11 in which pure water is supplied and a flow is formed, the semiconductor wafer 12 floats in pure water. Then, it is made to flow along this flow path 11 (FIG. 2). Then, the semiconductor wafer 12 is held in the holder 14
Is inserted into. The holder 14 detects that the semiconductor wafer 12 has been inserted by, for example, a sensor, stops the supply of pure water, and drives the motor to reverse the holder 14. That is, the shafts 15A and 15B are rotated 180 degrees. As a result, the semiconductor wafer 12 is also inverted. Then, by restarting the supply of pure water, the semiconductor wafer 12
The surface 12A, which had been immersed in the pure water, faces upward and is conveyed downstream (FIGS. 3 and 4). That is, no foreign matter such as particles or metal adheres to the surface 12A immersed in pure water during transportation. Therefore, if this holder 14 is disposed in the vicinity of the next process device, for example, the cassette transfer / storage device, pure water cleaning or rinsing and wafer transfer can be performed at the same time. Further, the contact of the semiconductor wafer 12 with the holder 14 is only a part (peripheral part) thereof,
Problems due to contact can be eliminated as much as possible.

Incidentally, other than pure water, other liquids can be used as the liquid serving as the transfer means. Further, in the above embodiment, it is necessary to return the opening 14C to the initial state in which the opening 14C is directed upstream after the holder 14 is reversed.
1, as shown in FIG. 6, both upper and lower plates 22 and 2 are freely retractable.
By arranging it in No. 3, it is not necessary to perform the initialization restoration. Therefore, it is possible to improve the transportation efficiency.

7 to 9 show still another embodiment of the wafer transfer apparatus according to the present invention. According to this embodiment, the holder 34 is made more compact. The size of the holder 34, which is the wafer reversing means, is about half that of the above-described embodiment, and the semiconductor wafer 12 can be reversed with a part (a little less than half) of the semiconductor wafer 12 protruding from the holder 34. That is, the length of the holder 34 in the direction orthogonal to the rotation axis is formed to be a little over half the length of the semiconductor wafer 12. According to this embodiment, the holder 34, which is the reversing means,
Can be further reduced in size.

[0019]

According to the present invention, during transportation with liquid,
There are no scratches on the surface of the semiconductor wafer, contamination of particles, metals, etc. can be prevented, and the wafer can be easily inverted during transportation. If pure water is used as the liquid, the washing process with pure water can be omitted.

[Brief description of drawings]

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

FIG. 2 is a longitudinal sectional view showing a semiconductor wafer transfer device according to an embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing the operation of the semiconductor wafer transfer apparatus according to the embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing the operation of the semiconductor wafer transfer apparatus according to the embodiment of the present invention.

FIG. 5 is a front view showing a holder which is a part of a semiconductor wafer transfer device according to an embodiment of the present invention.

FIG. 6 is a vertical sectional view showing a holder according to another embodiment of the present invention.

FIG. 7 is a longitudinal sectional view showing a semiconductor wafer transfer device according to still another embodiment of the present invention.

FIG. 8 is a vertical cross-sectional view showing the operation of a semiconductor wafer transfer apparatus according to still another embodiment of the present invention.

FIG. 9 is a vertical cross-sectional view showing the operation of a semiconductor wafer transfer apparatus according to still another embodiment of the present invention.

[Explanation of symbols]

 11 flow paths (transfer path), 12 semiconductor wafers, 13 pure water ejection holes (transfer means), 14 holders (holding means), 14A, 14B upper and lower plates, 14F, 14G taper inner surfaces (opposing surfaces of a pair of flat plates) ), 15A, 15B Central axis of rotation (reversing means).

Claims (3)

[Claims] 1. A transfer means for floating a semiconductor wafer to transfer a semiconductor wafer, a holding means provided in the middle of a transfer path by the transfer means, capable of holding the transferred semiconductor wafer, and held by the holding means. And a reversing means for reversing the semiconductor wafer by rotating the semiconductor wafer by a predetermined angle about a straight line included in its surface as a central axis. 2. The semiconductor wafer transfer apparatus according to claim 1, wherein the holding means is in contact with and holds only the peripheral portions of the front and back surfaces of the semiconductor wafer. 3. The holding means has a structure in which a gap having a predetermined interval is formed between a pair of flat plates, and a semiconductor wafer is inserted and held in the gap, and a central portion is provided on an opposing surface of the pair of flat plates. The semiconductor wafer transfer device according to claim 2, wherein the taper is formed so as to be recessed.