JPH11288998A - Wafer transferring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable wafer transferring operation to be accelerated so as to enhance a wafer treatment process in operation efficiency. SOLUTION: A wafer transferring device is equipped with a carrier table 2, where a carrier case that houses a prescribed number of wafers 6 is placed, a pusher 5 which is provided below the carrier table 2 and capable of pushing up a prescribed number of wafers 6 as high as prescribed from the carrier case 3, and a controller 10 which outputs drive signals to motors 11, 12, and 13 so as to enable the carrier table 2 to rotate about a vertical shaft by an angle of 180 deg. in a state in which the pusher 5 is made to be lifted up to push up to the prescribed height of a prescribed number of wafers 6 and then to make the pusher 5 descend.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer transfer apparatus used for processing a wafer in semiconductor manufacturing.

[0002]

2. Description of the Related Art In a series of semiconductor manufacturing processes, in particular, wafer processing, various processes such as lapping, heat treatment, thin film formation, doping, resist processing, and etching are performed on a wafer made of silicon (Si) or the like. A desired circuit pattern is formed on the surface of the wafer through these steps. In the wafer processing process, as shown in FIG. 8, wafers 51 to be processed are stored in one carrier case 52, for example, with 25 wafers as one lot, and are supplied to each process in that state in that order. You.

Usually, inside a carrier case 52, as shown in FIG.
That is, the wafer is stored with the pattern forming surface facing upward, and transferred to the wafer processing apparatus in each process. However, as shown in FIG. 9B, when the wafer processing apparatus is taken out of the carrier case 52,
1b, that is, the surface opposite to the pattern forming surface needs to be upward.

[0004] For example, before the wafer 51 is divided into chips, the back surface 5 is formed in order to make the wafer 51 a predetermined thickness.
In a so-called backside polishing apparatus (back grinder) or the like for polishing 1b with a grindstone, it is necessary to perform processing with the backside 51b of the wafer 51 facing upward. In this case, since the carrier case 52 is delivered in a state where the front surface 51a of the wafer 51 faces upward in the process of the previous process, when polishing the back surface, the wafer 51 is stored in the carrier case 52 as a stored state. An operation of inverting the back surface is required.

[0005] Therefore, a backside polishing apparatus or the like that performs processing with the back surface 51b of the wafer 51 facing upward is used for the wafer 5 stored in the carrier case 52 with the front surface 51a facing upward.
1 is provided with a device for transferring the device 1 to the carrier case 52 such that the back surface 51b faces upward.

FIG. 10 is a perspective view showing the structure of a conventional wafer transfer apparatus. In FIG. 10, two carrier stages 54a and 54b are provided on a gantry 53 of the apparatus. These carrier stages 54a, 5
4b is horizontally movable in the direction of the arrow in the figure. Further, a resin pusher 55 is provided below one carrier stage 54a so as to be able to move up and down. On the upper surface of the pusher 55, a predetermined number of grooves that can be engaged with the lower peripheral surface of the wafer 51 are formed. On the other hand, above the carrier stage 54a, an openable / closable chuck arm 5 is provided.
6 are provided. The chuck arm 56 has a pair of left and right chuck members 56a and 56b, and a predetermined number of chuck grooves are formed on opposing surfaces of the chuck members 56a and 56b.

In the above configuration, when transferring a wafer, first, a predetermined number (for example, 25) of wafers 5 are transferred.
1 is placed on one carrier stage 54a, and an empty carrier case 52b is placed on the other carrier stage 54b. At this time, the directions of the carrier cases 52a and 52b are opposite to each other, and the start switch of the apparatus is pressed in this state. Then, the pusher 55 moves upward to move a predetermined number of wafers 51 stored in the carrier case 52a as shown in FIG.
Push up like 1. At this time, the wafer 51 enters a state between the left and right chuck members 56a and 56b.

Next, the chuck arm 56 is shown in FIG.
By performing the "close" operation as described above, the wafer 51 is chucked (gripped) by the left and right chuck members 56a and 56b of the chuck arm 56 as shown in FIG. After that, the pusher 55 starts descending and the wafer 5
After being separated from 1, below the carrier stage 54a,
That is, the carrier stage 54a, 54b is retracted to the position of the starting origin which does not hinder the horizontal movement.

Subsequently, carrier stages 54a and 54b
Are horizontally moved in the same direction, so that the carrier case 52a from which the wafer has been taken out is positioned at a broken line in the figure, and the empty carrier case 52b is moved to the chuck arm 56 (wafer 5).
They are arranged directly below 1). Next, the pusher 55 moves up again to engage the lower peripheral surface of each wafer 51. Then, the chuck arm 56 “opens” to open the wafer 51, whereby the wafer 51 is transferred from the chuck arm 56 to the pusher 55.

Finally, the wafer 51 is stored in the carrier case 52b by the lowering operation of the pusher 55. At this time, with respect to the original carrier case 52a,
Since the carrier case 52b is reversed, the storage state of the wafer 51 in the carrier case 52b is turned upside down as compared with the storage state in the carrier case 52a. At this point, a series of wafer transfer operations is performed. Completed.

[0011]

However, in the prior art, there has been a problem that a series of operation of the apparatus is complicated, a long time is required to transfer the wafer 51, and the working efficiency is poor. Further, in addition to the pusher 55 for pushing up the wafer 51, a drive mechanism for horizontally moving the two carrier stages 54a and 54b, a drive mechanism for opening and closing the chuck arm 56, and the like are required, so that the configuration of the apparatus is complicated and large. There was also the problem of becoming. In particular, in the case of the conventional apparatus, the space for placing the two carrier cases 52a and 52b on the gantry 53 of the apparatus and the space for moving the carrier case 52a from which the wafer has been taken out, that is, the space for three carrier cases are required. It was necessary to secure. For this reason, the number of parts has inevitably increased, and at the same time, the dimensions of the entire apparatus have become considerably large.

Further, in the conventional apparatus, since the wafer 51 pushed up by the pusher 55 is chucked (gripped) by the chuck arm 56, as shown in FIG.
a, 56b) has a problem that the contact area becomes large and the wafer 51 is strongly affected by contamination (contamination). Incidentally, the contamination here is a reaction between an industrial material such as tetrafluoroethylene resin generally used for a contact part (the pusher 55, the chuck arm 56, etc.) with the wafer 51 and a chemical solution on the surface of the wafer. Means what is caused by In particular, in the course of the semiconductor manufacturing process, contamination occurs not only in the careless contact of the human body with the wafer 51 but also in the component transfer system and the sample table in the apparatus.

[0013]

In a wafer transfer apparatus according to the present invention, a rotary table on which a wafer storage container storing a predetermined number of wafers is mounted, and a rotary table provided below the rotary table and the rotary table is provided. A wafer lifting member capable of lifting a predetermined number of wafers from a wafer storage container mounted on a table to a predetermined height, and a state in which the wafer lifting member is raised to push a predetermined number of wafers to a predetermined height. Rotating table around vertical axis 1
A drive control means for lowering the wafer lifting member after rotating by 80 ° is adopted.

In the wafer transfer apparatus having the above structure, the rotating table is rotated by 180 ° about a vertical axis while the lifting member is raised to push up a predetermined number of wafers to a predetermined height. The direction of the wafer storage container is reversed with respect to the wafer. Further, by lowering the wafer push-up member from that state, a predetermined number of wafers are stored in the original wafer storage container in a state of being turned upside down.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a view for explaining an embodiment of a wafer transfer apparatus according to the present invention, in which (a) is a perspective view and (b) is a block diagram showing a control configuration thereof.

First, in FIG. 1A, a carrier table 2 having a circular shape in plan view is provided on a gantry 1 of a wafer transfer apparatus. The carrier table 2 is rotatably mounted on a gantry 1 of the apparatus via a bearing (not shown) or the like. Further, an opening is provided at the center of the carrier table 2 to allow a pusher described later to enter and exit. The carrier table 2 corresponds to a rotary table according to the present invention, and has a configuration that can be rotated in forward / reverse directions by a table drive system (not shown).

As a table driving system, for example, although not shown, a driven pulley is mounted on the lower surface of the carrier table 2 coaxially with the carrier table 2, and a timing belt is provided between the driven pulley and the driving pulley on the driving side. And a configuration in which the drive pulley is mounted on the output shaft of a motor for rotating the table (such as a stepping motor) may be adopted.

A guide frame 4 for positioning and mounting a carrier case 3 serving as a wafer storage container is provided on the carrier table 2, and the lower end of the carrier case 3 is fitted inside the guide frame 4. It has become.

On the other hand, a pusher 5 made of resin is provided below the carrier table 2. This pusher 5
Is equivalent to a wafer lifting member according to the present invention, and has on its upper surface a shape corresponding to a predetermined number (for example, 25) of wafers 6 accommodated in the carrier case 3.
As shown in FIG. 2A, a plurality of grooves 5a are formed at equal intervals. A support rod 7 is connected to the lower surface of the pusher 5 so that the pusher 5 moves up and down together with the support rod 7 by a lifting drive system (not shown).

As the lifting drive system, for example, although not shown, a support rod 7 is connected to a linear motion (raising / lowering) robot combining a ball screw and a slider engaged with the ball screw, and a lifting motor (stepping motor or the like) is used. What is necessary is just to employ | adopt the structure which rotates the said ball screw (forward rotation / reverse rotation).

On the other hand, a wafer guide 8 is disposed above the carrier table 2 at a predetermined distance. The wafer guide 8 is made of, for example, tetrafluoroethylene resin, and includes a pair of left and right guide members 8a and 8b. Each guide member 8a, 8b
The wafer guide 8 is connected to an elevating drive unit (not shown) incorporated in the support case 9 so as to be able to move up and down along the long holes 9a, 9a of the support case 9 as shown in FIG. I have. A plurality of guide grooves 8c, 8c are formed on opposing surfaces of both guide members 8a, 8b so as to correspond to a predetermined number of wafers 6 accommodated in the carrier case 3.
are formed at equal intervals.

On the other hand, as a control configuration, as shown in FIG. 1B, a rotary motor 11, a first lifting motor 12, a second lifting motor 1
3 and the setup sensor 14 are connected. The controller 10 controls the operation of the entire apparatus at the time of wafer transfer, and provides a drive signal to each of the motors 11, 12, and 13 according to, for example, a preset control program.

Among the motors to be controlled by the controller 10, the rotary motor 11 is a drive source for rotating the carrier table 2, the first elevating motor 12 is a drive source for raising and lowering the pusher 5, and the second elevating motor Motor 13
Is a drive source for moving the wafer guide 8 up and down.

Further, the setup sensor 14 detects the orientation of the carrier case 3 as a setup state of the carrier case 3 placed on the carrier table 2 and sends a detection signal to the controller 10. The set-up sensor 14 is composed of, for example, a reflection type optical sensor in which a light emitting element and a light receiving element are combined, and is arranged so as to face the carrier case 3 placed on the carrier table 2 as shown in FIG. You.

Next, an operation procedure of the wafer transfer apparatus based on the control processing of the controller 10 will be described with reference to the flowchart of FIG. First, when transferring wafers, the carrier case 3 containing a predetermined number of wafers 6 is set on the carrier table 2, and in this state, the start switch of the apparatus is pressed (turned on) (step S1).

At this time, when the direction of the carrier case 3 placed on the carrier table 2 is not the normal direction, for example, as shown in FIG. 1, the handle portion 3a of the carrier case 3 does not face the front side of the apparatus. , A detection signal to that effect is sent from the setup sensor 14 to the controller 10.

More specifically, on the carrier table 2, there is a slight deviation between the center P1 of the carrier case 3 and the rotation center P2 of the carrier table 2 (carrier case 3), as shown in FIG. . Therefore, the carrier case 3 is set in a direction in which the handle 3a is located on the opposite side to the setup sensor 14 as shown in the drawing, and the carrier case 3 is set in a direction in which the handle 3a is located on the side opposite to the setup sensor 14. When the case 3 is set, the distance between the setup sensor 14 and the carrier case 3 changes. This change in distance appears as a change in the output level of the setup sensor 14.

Therefore, the controller 10 checks the direction of the carrier case 3 based on the output level of the setup sensor 14 and proceeds to the next processing. At this time, if the carrier case 3 is not set in the proper orientation, error processing such as sounding a buzzer or blinking a lamp is performed to notify the operator of the fact.

After checking the setup state (orientation) of the carrier case 3 in this way, the controller 10
A drive signal is output to the second lifting motor 13 to lower the wafer guide 8 (step S2). As a result, the wafer guide 8 gradually approaches the carrier case 3 and stops when the distance H between the wafer case 8 and the carrier case 3 becomes, for example, about 10 mm as shown in FIG.

Subsequently, the controller 10 outputs a drive signal to the first elevating motor 12 to raise the pusher 5 (step S3). This allows the pusher 5
As shown in FIG. 5B, a predetermined number of wafers 6 are advanced into the carrier case 3 through the opening 2a of the carrier table 2 and stored in the carrier case 3.
Push up.

At this time, the peripheral edges on both sides of the wafer 5 pushed up by the pusher 5 are removed from the carrier case 3 when the guide grooves 8 of the left and right guide members 8a and 8b are formed.
c, 8c. Then, when the wafer guide 8 captures the center position X of the wafer 6 in the vertical direction (up and down direction), at that time, the controller 10 causes the second lifting motor 1 to move.
3 outputs a drive signal to the wafer guide 8 and pushes it to the pusher 5.
(Step S4).

Thereafter, the wafer 6 is stopped together with the pusher 5 at the operation limit position (elevation limit position) of the lifting drive system, and at the same time, the wafer guide 8 is also stopped. In this rising stop state, as shown in FIG. 6, the wafer 6 pushed up by the pusher 5 comes out of the carrier case 3 completely. In addition, the wafer 6 by the pusher 5
May be appropriately set within a range that does not hinder the rotation operation of the carrier table 2 described later.

At this time, the wafer 6 supported by the pusher 5 is fitted in the groove 5a on the upper surface of the pusher 5 as shown in FIG.
Since the thickness of the wafer 6 must be wider than the thickness dimension of the wafer 6, there is a concern that the wafer 6 may fall down by an angle θ corresponding to the dimension difference. However, in the present embodiment, when the wafer 6 comes out of the carrier case 3,
As shown in FIG. 7B, both peripheral edges of the wafer 6 are engaged with the guide grooves 8c, 8c of the left and right guide members 8a, 8b, whereby the upright posture of the wafer 6 is maintained. The wafer 6 even when pushed up by the pusher 5
Will not fall.

In this state, the controller 10
A drive signal is output to the rotation motor 11 to rotate the carrier table 2 by 180 ° (step S5). As a result, the carrier case 3 rotates 180 ° around the vertical axis together with the carrier table 2, so that the direction of the carrier case 3 is reversed with respect to the wafer 6 pushed up by the pusher 5.

Next, the controller 10 outputs a drive signal to the first elevating motor 12 to lower the pusher 5 and also outputs a driving signal to the second elevating motor 13 to move the wafer guide 8 to the pusher 5. The lowering operation is performed synchronously (step S6).

Thereafter, when the wafer guide 8 is lowered to the position shown in FIG. 5A, the controller 10 temporarily stops outputting the drive signal to the second elevating motor 13. The center position X of the wafer 6 in the vertical direction is
At this point, a drive signal is output to the second elevating motor 13 again, and the wafer guide 8 is raised to the height at the start of operation (origin position) (step S7). At this time, the upright posture of the wafer 6 on the pusher 5 is held by the wafer guide 8 until the lower peripheral portion of the wafer 6 is taken into the carrier case 3. Wafer 6 can be fitted smoothly.

During this time, the output of the drive signal from the controller 10 to the first elevating motor 12 is continued, so that the pusher 5 enters the carrier case 3 while supporting the wafer 6. Thus, the wafer 6 supported by the pusher 5 is stored in the carrier case 3. After that, the pusher 5 separates from the wafer 6 and stops when it is lowered below the carrier table 2 (starting origin position).

Then, the controller 10 outputs a drive signal to the rotary motor 11 to set the carrier table 2 to 1
Reverse by 80 ° (step S8). As a result, the orientation of the carrier case 3 on the carrier table 2 is
The state returns to the initial state shown in FIG. This completes a series of wafer transfer operations.

As described above, in the present embodiment, the carrier case 3 is rotated by 180 ° around the vertical axis by the rotating operation of the carrier table 2 from the state in which the wafer 6 is pushed up by the raising operation of the pusher 5, The wafer 6 is housed in the carrier case 3 by the lowering operation, so that the direction of the wafer 6 is reversed. This allows the pusher 5 to be moved up and down only once when transferring wafers.
In addition, there is no need to chuck and hold the wafer as in the related art. As a result, the operation time (operating time of the apparatus) required for transferring the wafer can be significantly reduced.

Further, only one carrier case 3 is set on the gantry 1 of the apparatus, and there is no need to move the carrier case horizontally as in the prior art. It is only necessary to secure the space for the individual. As a result, the number of parts can be reduced and the configuration of the apparatus can be simplified at the same time, and the size of the entire apparatus can be reduced to about 1/3 of the conventional apparatus. Also,
In transferring wafers, there is no need to prepare an empty carrier case or to set two carrier cases in different directions (opposite directions), so that the burden on the operator can be reduced and artificial setting can be performed. The occurrence of mistakes can be reduced.

Further, in the conventional apparatus, since the wafer pushed up by the pusher is chucked by the chuck arm, the contact area of the chuck arm with respect to the wafer is increased. In the apparatus of this embodiment, the wafer is pushed by the pusher 5. Since the direction of the carrier case 3 is changed together with the carrier table 2 while the wafer 6 is pushed up, there is no need to chuck the wafer 6. The wafer guide 8 has guide grooves 8 c, 8 c formed on both sides of the wafer 6 for the purpose of preventing the wafer 6 supported by the pusher 5 from falling down and protecting the wafer 6 pushed out of the carrier case 3. Because of the engagement, the contact area of the wafer guide 8 with the wafer 6 is considerably reduced. As a result, in a series of wafer transfer operations, the contact area of the device component parts with respect to the wafer becomes smaller than in the past, so that contamination of the wafer can be minimized.

[0042]

As described above, according to the wafer transfer apparatus of the present invention, in order to reverse the state of storing a wafer in the wafer storage container, the lifting operation of the wafer lifting member can be performed only once. In addition, since the rotation table is rotated by 180 ° about a vertical axis to reverse the direction of the wafer storage container, a series of wafer transfer operations can be speeded up to improve work efficiency in the wafer processing process. Can be improved. Also,
Since a method is employed in which a predetermined number of wafers pushed up by the wafer pushing-up member are returned to the wafer storage container of the storage source, the configuration of the entire apparatus becomes very compact. Further, since it is not necessary to chuck the wafer pushed up by the wafer pushing up member, the influence of the contamination can be minimized.

[Brief description of the drawings]

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

FIG. 2 is a detailed view of components of the wafer transfer apparatus according to the embodiment.

FIG. 3 is a plan view showing a positional relationship between a carrier table and a carrier case.

FIG. 4 is an operation flowchart of the wafer transfer device in the embodiment.

FIG. 5 is a diagram (part 1) for explaining the state of the apparatus during operation.

FIG. 6 is a diagram (part 2) illustrating the state of the apparatus during operation.

FIG. 7 is a diagram (part 3) for explaining the state of the apparatus during operation.

FIG. 8 is an explanatory diagram of a carrier case.

FIG. 9 is a diagram illustrating a difference in a wafer storage state in a carrier case.

FIG. 10 is a perspective view illustrating a conventional wafer transfer apparatus.

FIG. 11 is an operation explanatory view (part 1) of a conventional wafer transfer apparatus.

FIG. 12 is an operation explanatory view (part 2) of the conventional wafer transfer apparatus.

[Explanation of symbols]

2 Carrier table, 3 Carrier case, 5 Pusher, 6 Wafer, 8 Wafer guide, 10 Controller, 11 Rotary motor, 12 First lift motor, 1
3: Second lifting motor

Claims (1)

[Claims] A rotary table on which a wafer storage container storing a predetermined number of wafers is mounted; and a predetermined number of wafer storage containers provided below the rotary table and mounted on the rotary table. A wafer push-up member capable of pushing up a wafer to a predetermined height, and in a state in which the wafer push-up member is raised to push up the predetermined number of wafers to a predetermined height, the rotary table is rotated 180 ° around a vertical axis. And a drive control means for lowering the wafer push-up member.