JPS629220B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a conveyor belt device that is installed in a semiconductor manufacturing line and transfers the wafer to the next processing device after the wafer has been subjected to a certain type of processing by one processing device. It is something.

Various processes performed on a semiconductor wafer, such as resist coating and exposure in a photolithography process, are performed using different processing apparatuses, so the wafer after resist coating is placed on a conveyor belt and transferred to an exposure apparatus. Transferring wafers using this conveyor belt method is extremely useful because the movement of wafers can be automated. However, if there is a large difference in the processing capacity of the processing device installed at the front stage of the conveyor belt compared to the processing capacity of the processing device installed at the rear stage (both processing capacities per unit time), for example, there is a 2:1 relationship. However, there is a problem in that wafers that are loaded at a later stage are overloaded.

Therefore, an adjusting device as shown in FIG. 1 has conventionally been used in such places. That is, a schematic plan view of a conventional wafer transfer time adjustment device is shown in FIGS. In the figure, reference numeral 1 indicates a wafer, and reference numeral 2 indicates an in-line basket shown in a perspective view in FIG. Arrows indicate the flow of the wafer 1 in the transport direction.
First, FIG. 1 shows how the wafers 1 are stored one by one in an in-line basket 2 when they are transferred as indicated by the arrows. The inline basket 2 is moved upward by a predetermined pitch by an elevator mechanism (not shown). Conversely, when carrying out the wafer 1, it moves downward at a predetermined pitch.
In this example, there are many downstream processing devices (25 wafers/
When wafers (one lot) are processed one by one over a fixed period of time, and the semiconductor manufacturing equipment installed at the front of the basket 2 (on the left side in the figure) is a batch processing semiconductor manufacturing equipment. Because of the difference in processing time between the two, one wafer lot is first loaded into the basket 2 and then taken out after a certain period of time. This is also because basket 2 cannot carry in and out at the same time. Furthermore, even if two baskets 2a and 2b are installed in series as shown in FIG.
Although it is possible to load the next lot into basket 2a while the lot is being transferred from basket 2b, it is not allowed to transfer wafers into basket 2a while wafer 1 is being transferred from basket 2a to basket 2b. It is possible. For the above reasons, the conventional apparatus has a long waiting time and is unsuitable for processing a large number of wafers.

The present invention was made with the aim of solving the above-mentioned drawbacks all at once, and by adding a branching device to the conveyor belt, it corrects the unbalance of processing capacity between various processing devices, so that the processing power of each processing device is constantly The object of the present invention is to provide a wafer transfer device that can stably load or unload wafers commensurate with processing capacity. Hereinafter, some preferred embodiments of the present invention will be explained in detail with reference to the drawings.

3 is a schematic plan view of the first embodiment of the device of the present invention, FIG. 4 is a schematic plan view of the second embodiment of the device of the present invention, and FIG. 5 is a part of FIG. An enlarged perspective view is shown. Identical parts are denoted by the same reference numerals in each of these drawings. 10 is a wafer, 11 to 20 are conveyor belts (hereinafter sometimes simply referred to as belts), and 21 and 22 are inline baskets having the structure shown in FIG. 2, which are used in the second embodiment of the present invention. (hereinafter simply referred to as basket), 23 and 24
25 to 29 are sensors for detecting the arrival of a wafer, 30 to 33 are outer guides, and 34 and 35 are stoppers. Also, the third
The arrows in the figures and FIG. 4 indicate the direction in which the wafer 10 enters. The conveyor belts 11 to 20 are rotated in the forward or reverse direction individually or in conjunction with a certain portion of the belt, thereby transferring the wafer 1.
0 is mounted on this rubber belt and transported. And these are preferably all installed at approximately the same height. Furthermore, the inner guides 23 and 2
4 and outer guides 30, 31, 32, and 33 are guides for the wafer transfer path, so the transfer belt 11
The wall is formed to be higher than the height of ~20 mm plus the thickness of the wafer. Further, the forward rotation described in the present invention is assumed to be right rotation throughout the specification.

First, the first embodiment of the present invention will be explained in detail using FIG. 10 is detected, and a belt rotation control device (not shown) determines the rotation direction of the belt at the branching point to determine whether to supply it to either the subsequent device B or C. For example, when the processing apparatus B at the subsequent stage inputs the wafer 10, the belt rotation control device activated by the detection signal of the sensor 25 rotates the belts 12 and 13 in the forward direction and rotates the belt 17 in the reverse direction. Then, the wafer 10 moves from the belt 11 onto the belts 12 and 13, and is loaded (loaded) into the apparatus B. When the wafers 10 are continuously conveyed on the belt 11 at a certain interval, the sensor 25 detects the successively arriving wafers 10, and the sensor 26 sends an arrival signal of the wafer 10 to the belt rotation control device. Next wafer 10
In order to input the sample into the device C, the belts 17 and 18 are rotated in the forward direction and the belt 12 is rotated in the reverse direction. If the interval between the wafers 10 conveyed on the belt 11 is
If it has enough time to pass through the sensor 25 and be input to the subsequent processing device B or C, the sensor 2
6 and 28 are not necessarily necessary. In other words, the belts 12 and 17 may be rotated alternately from normal to reverse and vice versa based on the passing signal from sensor 25.
However, it must be noted that the conveyor belts 12 and 17 must always be rotated in an opposite relationship. That is, when transferring the wafer 10 from the belt 11 to the belt 12 or 17, the wafer 10 often stagnates at the branching point and is not transferred to the belt 12 or 17. The reason why either one of the belts 12 or 17 rotates in the opposite direction to the conveying direction is to prevent the belt from entering device C by rotating it in the opposite direction when carrying the belt to either device B or C in the subsequent stage, for example, device B. This is to feed the wafer 10 onto the conveyor belt 12 in order to convey it in the direction of the apparatus B.

In addition, in the apparatus according to the embodiment shown in FIG. The device of the present invention can be used in such cases as well, since stable supply can be ensured for the device A, which has a processing capacity equal to the total processing capacity of the devices. In this case, it goes without saying that belts 12 and 17 must be rotated in the same direction. The conveyance of the wafers 10 is controlled by the rotation of the belts 13 and 18 based on the signals detected by the sensors 27 and 29 so that the wafers 10 carried out from the apparatuses B and C do not collide with each other at the merging part (the branching part in the above example). It can be controlled by

Next, a second embodiment of the present invention will be described with reference to FIGS. 4 and 5. In this second embodiment of the apparatus, the processing capacity per unit time of the former apparatus A and the latter apparatus B is balanced, but apparatus A is a device that performs batch processing, and apparatus B is an apparatus that processes wafers one by one. Wafer 1 carried out from apparatus A in such a case
This is a suitable example when time adjustment is required so that 0 is not overloaded into device B. The in-line baskets 21 and 22 employed in the apparatus of this embodiment are shown in detail in FIG.
It is a pass-through type basket in which wafers 10 are temporarily stored (carried in) and then carried out. The baskets 21 and 22 have a large number of grooves 36 so that 25 wafers 10 can be arranged and stored therein, and a shutter 37 is fitted into the basket so that the wafers can be transported with the wafers stored in the baskets. It has a groove 38. The baskets 21 and 22 are arranged at the bottom of the baskets 21 and 22 by an elevator mechanism (not shown) so that each groove 36 receives one wafer 10 from the apparatus A installed in the previous stage. ) installed so that it can be moved upward or downward.

Next, the operation will be explained with reference to FIG. 6. As shown by the arrow in FIG. When the wafer 10 is transported by rotation, the wafer arrival detection sensor 25 (hereinafter simply referred to as a sensor) detects the arrival of the wafer 10, and a belt (not shown) is moved to store the wafer 10 into either the basket 21 or 22. A rotation control device determines the rotation of the belt and its direction. For example, since the basket 22 is empty, when a signal is issued from the conveyor belt rotation control device to store the maximum amount (for example, 25 sheets) of this basket 22, the belts 11, 12, and 13 rotate in the normal direction. On the other hand, the belt 17 rotates in the opposite direction, and the wafers 10 on the belt 11 are successively conveyed to the in-line basket 22 via the belts 12 and 13 and stored therein. By the way, the reason why the conveyor belt 17 is rotated in the opposite direction when storing the wafers 10 in the basket 22 has been described in the description of the first embodiment, and will therefore be omitted. Since the rotations of the conveyor belts 12 and 17 are always reversed and synchronous, it is also possible to install two drive sources, for example, two motors, and rotate them synchronously. As shown, a combination of one motor 39, a pulley 40, and a chain 41 may be used. Note that the arrow in FIG. 6 indicates the direction of rotation.

Now, the arrival of the wafers 10, which are sequentially transferred in the direction of the basket 22, is detected by the sensor 26 installed at the entrance of the basket 22, and the stopper pin 35 is protruded, a detection signal is emitted, and the wafers 10 are stored by the counter device. The number of wafers is managed. When all the wafers are stored in the basket 22, that is, when the counter device connected to the sensor 26 reaches a predetermined count, a termination signal is sent to the belt rotation control device, which controls the belts 11, 17, and 18. The belt 12 is controlled to rotate in the forward direction and the belt 12 to rotate in the reverse direction, and the wafer 10 is
is set so that it is conveyed in the direction of the basket 21. It should be noted that the belt 12 on the side of the basket 22 at the branching portion also rotates in the opposite direction at this time. In this way, while the wafers 10 pass through the sensor 25 and are stored in the basket 21 one after another, the wafers stored in the basket 22 are moved to the belts 14, 15, 1 by the control signal from the belt rotation control device.
By controlling the rotations 6 and 20 in the normal direction, the sheets can be taken out from the basket 22 one by one.

During this unloading, the sensor 27 detects the unloading of the wafer 10 and sends a wafer passage signal to the elevation control device, so that the elevator mechanism moves the wafers upward or downward one step at a time and unloads all the wafers from the basket 22. . Also, the sensor 2
If the number of wafers remaining in the basket 22 can be determined by counting the amount of wafers passed by using a counter device based on the passing signal from the wafer 7, the number of wafers in the basket 2
It is also possible to store as many wafers 10 as have been carried out. This means that wafer 10 is transferred to belt 1 in a short time.
This means that when a large number of items are transported on one basket, that is, when they cannot be stored in one basket alone, they can be stored alternately in baskets 21 and 22.

As described above, the apparatus of the present invention can be used in a wafer transfer apparatus using a transfer belt system that connects processing apparatuses that perform various processes on semiconductor wafers, when the wafer transfer path is divided into two. In addition to the first major effect of being able to transport smoothly without stagnation, there is also an imbalance in the processing capacity per unit time between the processing equipment installed at the front stage of this transport path and the processing equipment installed at the latter stage, or batch processing. When adopted in this type of system, it exhibits outstanding effects, such as being able to correct unevenness in conveyance amount due to (batch processing) and individual processing.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a time adjustment device of a conventional conveyor belt device, FIG. 2 is a perspective view of a passing type in-line basket adopted in the device of the present invention, and FIG. 3 is a plan view of the first embodiment of the device of the present invention. 4 is a schematic plan view of a second embodiment of the device of the present invention, FIG. 5 is a partially enlarged perspective view of FIG. 4, and FIG. 6 is an example of driving the conveyor belt of the device of the present invention. It is a diagram. 10...Wafer, 11-20...Transport belt,
21, 22...inline basket, 23,
24...Inner guide, 25-29...Sensor, 3
0 to 33...outer guide, 34, 35...stopper, 36...wafer storage groove, 37...shutter,
38... Shutter fitting groove, 39... Motor,
40...Pulley, 41...Chain.

Claims (1)

[Claims] 1. In a wafer transport device that transports a semiconductor wafer that has been subjected to a certain type of processing using a transport belt to perform the next processing, a plurality of transport belts that transport the wafer by placing the wafer on the belt. a guide that is installed on both sides of the conveyor belt and forms a conveyance path wall for the wafer placed on the conveyor belt and transferred; and a drive device that rotates the plurality of conveyor belts in a forward or reverse direction. The plurality of conveyor belts include first, second, and third conveyor belts, and these three conveyor belts constitute a substantially Y-shaped branch conveyor path, and the drive device One of the second and third conveyor belts is rotated in the same direction as the rotation direction of the first conveyor belt, the other is rotated in the opposite direction, and the second and third conveyor belts are synchronized. A wafer transfer device comprising a belt rotation control device for rotating a wafer.