JPH01230244A - Wafer conveying method - Google Patents

Abstract

PURPOSE:To simplify loading work, by preparing a plurality of slanted cassettes when many sheets of wafers are aligned and contained on a boat in a slanted attitude, inputting the specified number of the wafers in the cassettes, sequentially grasping the wafers with a chuck, moving the wafers, and dropping the wafers by opening the chuck when the chuck comes on the boat. CONSTITUTION:A cassette stage 12 and a boat stage 22 are provided on the same horizontal plane. Many sheets of wafers W are contained in a boat 20 provided on the stage 22 so that the wafers are uprightly supported with a supporting part provided at the edge part in a slanted attitude. A plurality of mounting parts 16 are provided on the neighboring stage 12 for accommodation. Cassettes 10 are arranged on the mounting parts so that the cassettes are inclined by 3-10 degrees. Thereafter, the specified sheets of the wafers W are contained. The wafer group W in the cassette 10 is sequentially grasped with a chuck 38, lifted and moved. When the chuck comes to a position over the boat 10, the wafer group W is lowered, and the chuck 38 is released. The wafer group W is dropped into the boat 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an improvement in a wafer transfer method for transferring a plurality of wafer groups stored in a storage jig to a boat.

(Prior Art) Generally, in semiconductor manufacturing equipment, diffusion processing is performed on a large number of wafers at once by carrying a group of wafers placed on a boat made of quartz or the like into a heat treatment furnace and taking them out. There is.

Therefore, when performing such thermal diffusion processing on wafers, a loading operation is performed in which a group of wafers is taken out from a storage jig, such as a cassette, in which a group of wafers is arranged and stored, and placed on a boat. Furthermore, after the diffusion process is completed, it is necessary to perform an unloading operation to store the group of evaporators placed on the boat back into the original cassette.

Semiconductor devices are equipped with a wafer transfer device that performs such loading and unloading operations. The material is transported to the desired location and transferred to a holding device called a chuck.
This chuck performs the loading operation by holding the transferred wafer group from both sides and transporting it to the boat. The processed wafers are aligned and placed along this groove at regular intervals.

This loading operation is repeated for multiple cassettes placed on the cassette floor.
As a result, groups of wafers housed in a plurality of cassettes are placed one after another in an array on the boat.

Note that the unloading operation for returning the wafer after the diffusion process to the cassette is performed in a completely reverse procedure to the above-described loading operation.

By the way, 3 to 10 wafers can be stored on such a boat.
Align by tilting in a certain direction with respect to the vertical direction, preferably 3 to 5 degrees. It is preferable to set the

This means that in order to diffuse the wafers and create a uniform coating on their surfaces, the wafers placed on the boat must be spaced at regular intervals, and when the processing gas is sent, there is a gap between each wafer. This is because it is known from experience that a good thermal diffusion process can be achieved by tilting wafers that are not inclined in the direction of inflow by a predetermined angle in the same direction to ensure uniform inflow.

Further, the storage groove provided in such a boat is usually oriented in the vertical direction, and its width is formed to be somewhat larger than the thickness of the wafer. For this reason, even if the wafers are simply transferred to the board, each wafer will be randomly tilted forward and backward little by little due to the play between the wafers and the grooves, causing the problem that the wafers will chip together. However, if the wafers are loaded obliquely in one direction from the beginning, such chipping between wafers can be prevented.

In particular, when a boat is made of a material such as quartz and used for a long period of time, the boat deforms to some extent and the pitch of the storage grooves becomes uneven. However, if the wafers are loaded while being tilted in one direction as described above, the influence of such deformation of the boat itself is reduced, and the wafers can be favorably subjected to thermal diffusion processing from this perspective as well.

By the way, as a technique for loading wafers onto a boat at a predetermined angle in a certain direction, a device has been proposed in which the boat itself is set up in advance at a predetermined angle and the wafers are loaded onto the boat. (Utility Model Publication No. 61-136543).

However, in this case, the boat itself must be returned to the horizontal position before being transported into the heat treatment furnace. This requires the provision of this angle adjustment mechanism and various accompanying mechanisms, and the entire equipment There was a problem that it became complicated.

In particular, considering the current situation where a large number of wafers, such as 100 or 200 wafers, are placed on a boat, the boat is transported into a heat treatment furnace and a large number of wafers are thermally diffused all at once. However, it is extremely problematic to move the boat itself on which the wafers are stored.

Therefore, the object of the present invention is to solve the above-mentioned conventional problems and to easily and reliably load and unload wafers onto a boat while tilting it at a predetermined angle to one side without tilting the boat itself. The purpose of the present invention is to provide a method for transferring wafers that is possible.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for storing wafers tilted at a predetermined angle from a first storage container in which a plurality of wafers are vertically arranged. When automatically transferring wafers to the second storage container in the groove row, the first storage container L2 is tilted at a predetermined angle and the wafers are transferred from the first storage container using the upward transfer means. The group of wafers is transferred upward to a predetermined position while being tilted, the transferred group of wafers is held while being tilted using a holding device, and the group of wafers is transferred to a second storage container. A group of wafers is placed thereon at a predetermined angle.

(Function) According to the present invention, the first storage container in which the wafer group is arranged and stored is placed on the floor at a predetermined angle θ, preferably 3 to 10 degrees.
More preferably, it is placed at an angle of 3 to 5 degrees.

Then, in this state, the plurality of wafer groups that are arranged and stored in the first storage container are transported to the second storage container while maintaining the tilt angle θ using the upward transfer means and the clamping means. There is.

Therefore, tilt at a predetermined angle θ on the floor! ! Such wafer transfer work is carried out for the plurality of first storage containers placed in the
That is, by repeating the loading operation, a plurality of wafer groups can be loaded from each first storage container into the second storage container in the same direction and at the same angle θ.

In particular, according to the present invention, it is possible to load a large wafer while tilting it in the same direction at a predetermined angle θ without tilting the second storage container itself, making the entire apparatus extremely simple. Moreover, the capacity of the second storage container containing the amount of wafers can be kept to the necessary minimum.

(Example) Next, preferred embodiments of the present invention will be described based on the drawings.

As shown in FIG. 2, the wafer transfer device of this embodiment includes a cassette stage 12 on which a plurality of cassettes 10 (first storage containers) are placed, and a boat 20 (second storage container). The boat stages 22 are arranged substantially linearly adjacent to each other, and a moving groove 32 is provided along which the chuck devices 7j-3Q move along each of these stages 12.22.

The inside of the device body 100 is formed into a hollow shape, and as shown in FIG.
0.40, and the slider 42 is configured to move along this rail 40 (along the movement 11132). The sliding position of the slider 42 is controlled by rotationally driving a ball screw 44 using a motor 46, as shown in FIG. The slider 42, F is equipped with the aforementioned chuck r! X! t
30 and a wafer pushing device 50 are arranged adjacent to each other.

Then, using both bags ff30.50, cassette 1
The wafer part is taken out from the boat 20 and transferred to the boat 20.

In this embodiment, the cassette stage 12 has a second
As shown in the figure, a plurality of table insertion holes 14 are provided at regular intervals.
In this embodiment, the wafer W is tilted at a predetermined angle θ in the same direction at the opening edge of this insertion hole 014, and a! The first feature is that a cassette mounting section 16 for mushrooms is provided.

Here, the inclination angle θ is t! of 3 degrees to 10 degrees, preferably 3 degrees to 5 degrees. is set within the

Usually, the cassette 10 placed on this placing section 16 is
As shown in FIG. 2, the bottom surface is formed with an opening, and the inner surfaces of both walls have vertical grooves 10 for storing and holding the wafer.
a are provided at regular intervals.

In semiconductor devices, a group of wafers stored in the cassette 10 is often taken out as one unit. Therefore, 25 storage containers are usually provided at regular intervals, and a maximum of 25 wafers can be taken out. 10 cassettes with wafers as one unit
It is designed so that it can be stored inside.

As described above, in this embodiment, the wafers W are vertically stored inside the cassette 10, and the cassette 10 is held in the g! Re is performed by tilting the mounting portion 16 by an angle θ. Therefore, on the cassette stage 12, the wafer W stored in the cassette 10 is tilted to the left by θ as shown in FIG.

The feature of the present invention is that the wafers W stored in the cassette 10 are taken out with their inclination θ and transferred to the boat 20, so that the wafers are tilted in the same direction and at the same angle θ to the boat 20, E. There is a problem with loading.

In this embodiment, such a loading operation is performed using the wafer push-up device 50 and the chuck device v30.

The wafer lifting device 50 is mounted on the slider 42 so that it can be positioned below the table insertion opening 14 of the cassette stage 12, and as shown in FIG. The upward direction of 12 is formed to be movable.

On the surface of this table 52, 25 wafers are supported according to the pitch interval of the storage m10a of the cassette 10. 1t 54 is formed. Therefore, by moving the table 52 upward through the insertion port 14 as shown in FIG. 3, the wafers W stored in the cassette 10 can be
It can be moved upward by supporting the lower end.

The second feature of this embodiment is that, as shown in FIG. 11, the wafer pushing device 50 is formed to move the table 528 downward by 1 along a locus inclined at an angle θ with respect to the vertical direction. Thereby, the table 52 can transport the wafer W stored in the cassette 10 upward while being tilted by a certain angle θ.

The wafer W that has been transferred to a predetermined upper position is clamped using a chuck device 30 that functions as a wafer clamping means, and is transferred to the port 1-20 through a predetermined movement trajectory.

In this embodiment, as shown in FIG. 5, the chuck device 30 is attached to the slider 421- with an angle θ tilted along the vertical direction, and the head 34 provided at the L portion of the slider 421- It is formed so that it can move in the F direction along a movement locus inclined by .

As shown in FIG. 3, a pair of chucks 38 and 38 are housed in this head 34 via an arm 36, and these chucks 38 and 38 are driven to open and close in the direction of the arrow shown in the same figure. It is designed to be

The third feature of the embodiment is that the pair of chucks 38.38
Groove 1 provided in the above-mentioned skein/sol l-10 on the inner surface of
The storage groove 38a formed at the same pitch as the eighth
As shown in the figure, it is provided at an angle θ with respect to the direction perpendicular to j9.

As shown in FIGS. 8 and 9, this storage groove 38a is provided with a pair of guide surfaces 26, 26 on both sides of its opening end,
Even if the transfer position of the wafer W is slightly shifted, this guide surface 26
The groove is formed so that the wafer W is accommodated in the groove.

Therefore, using the wafer lifting device 50 described above, the wafer W, which has been pushed up and transferred to a predetermined position above as shown in FIG. 6(a), is held between both sides as shown in FIG. 6(b). Therefore, the wafer W can be smoothly transferred from the wafer pusher W 50 to the chuck device 30.

At this time, as described above, the pair of chucks 38.3
Since the storage groove 38a provided in the chuck 8 is inclined at an angle θ with respect to the vertical direction, the chuck mounting rt! ,3
0 means that the wafer W is held at the same inclination θ as when the wafer W is stored in the cassette 10.

FIG. 1(b) shows the state at the time of this delivery, and after the completion of this delivery, for example, by moving the table 52 downward or moving the chuck 38 upward, chuck 38 in order from the wafer
The wafer W is caught in the storage groove 38a, and the surface connecting the E end surfaces of all the wafers W becomes horizontal.

After that, the ball screw 44 is rotationally driven, and the slider 42
moves to a predetermined position on the boat stage 22. At this time, the chuck device If 30 moves the wafer to a predetermined position above the boat 20 along a movement trajectory 200 shown in FIG. 1(C), and then lowers the head 34. Then, as shown in No. 7121, when the wafer W has descended to near the boat 20, the chamber 38.38 is opened in the direction of the arrow in the country, and the wafer W is moved to the left in FIG. 1 by a predetermined angle θ. and load to boat 20-1=.

In this embodiment, the boat 20 is formed to support the wafers W using four support rods 20a provided along the longitudinal direction of the boat 20. As shown in 21M, the inner surface of this rod 20a is provided with a plurality of wafer storage grooves 24 that match the pitch of the cassette 10, and this groove 26 is not shown in FIG.
Similarly, it is formed inclined at a predetermined angle θ with respect to the vertical direction. Therefore, the wafer W that is transferred while being tilted by the predetermined angle θ using the chuck device 30 described above can be stored in the boat 20 while maintaining the tilted state θ.

Further, as shown in FIG. 9, this storage groove 24 is provided with a pair of guide surfaces 26, 26, so that even if the transfer position of the wafer W is slightly shifted, the wafer W can be transferred into the groove via the guide surfaces 26. It is designed to accommodate.

In addition, in this embodiment, the groove 10a of the cassette 10,
The groove 38a provided in the chuck 38 is formed substantially in the same manner as the armature 24 shown in FIGS. 8 and 9.

The wafer transfer device of this embodiment is constructed as described above, and the wafer transfer operation performed using this device will now be described.

In this embodiment, the cassette containing the wafer W is
As shown in FIG. 1(a), the cassette stage 12-L
The cassette 81 is placed on the section 16 at an angle of a predetermined angle θ.

As a result, each wafer W stored in the cassette I/10
is 1;) tilted to the left in the figure by θ with respect to the plane.

In this state, the slider 42 is moved to control the position so that the table 52 of the chuck pushing device 50 is located below a predetermined table insertion opening 14 of the cassette stage 12.

Then, the wafer pushing device 50 moves the table 52 to the first position.
As shown in Figure (b), the group of double wafers stored in the cassette 10 is moved upward through the cassette insertion openings 1, 1, and is placed in an upper predetermined position while being tilted by an angle θ. Transport to.

When the wafer W is transferred to a predetermined position, the chuck 38, 38 is closed as shown in FIG. It is held while being tilted to the left by a predetermined angle θ. This completes the transfer of the wafer W from the table 52 to the chuck 38.

After such transfer is completed, the wafer push-up device 50 retreats the table 52 to the back side of the stage 12. As a result, the wafers move downward due to their own weight, and the wafers are chucked onto the chuck 38.3 so that the line connecting their upper ends is horizontal.
It will be held by 8.

In this way, when the wafer group is clamped by the chuck 38 and the table 52 is retreated to the lower side of the cassette stage 12, the apparatus of the embodiment operates as follows:
As shown in FIG.
8 is opened, whereby the wafer group stored in the cassette mounting table 16 is transferred to the boat 20 while maintaining the inclination θ with respect to the vertical direction, and is placed on the boat 20 in that state.

In particular, in this embodiment, the storage grooves 24 provided on both sides of the boat 20 are formed so as to be inclined by a predetermined angle θ in the vertical direction, as shown in FIG.

Therefore, as mentioned above, a group of wafers that have been transferred at an angle of θ can be reliably transferred while maintaining that tilted state.
-20f can be tlW.

In this embodiment, such boat transfer work is carried out for all cassettes 1 placed on the cassette stage 12.
0, so each of these cassettes 1
The wafer groups stored in 0 are placed on the boat 20 one after another.
It is loaded while being tilted by a predetermined angle θ to the left in the figure.

As described above, according to the present invention, a group of wafers can be loaded onto the boat 20 while being tilted at an angle θ in a certain direction without using any special equipment.

In particular, according to the present invention, after the loading of wafers W onto the boat 20'' is completed, there is no need to control the tilt of the boat 20 itself unlike the conventional device.
The movement of the boat loaded with four boats can be minimized, making it extremely suitable for manufacturing semiconductors.

Furthermore, in the present invention, once the diffusion process has been completed, the
The operation of loading the corresponding cassette 10 from the boat 20 can be carried out by completely reversing the procedure of the aforementioned loading operation.

Furthermore, the present invention is not limited to the above embodiments,
Modifications of each ball are possible within the scope of the invention.

For example, in the embodiment, the head 34 is used as the clamping means.
Although the present invention has been described using an example of using a chuck 38.38 that moves up and down along with the wafer, the present invention is not limited to this. good.

[Effects of the Invention] As explained above, according to the present invention, a first storage container, for example, a storage jig, in which a plurality of wafer groups are arranged and stored is placed on the floor at a predetermined angle, By transferring a group of wafers not stored in a first storage container to a second storage container, for example, onto a boat, using an upward transfer means and a clamping means while maintaining the inclination angle, the wafers are A group of wafers can be loaded while being tilted in the same direction at a predetermined angle, and this loading operation can be performed using a simple machine.

In particular, according to the present invention, after loading a group of wafers onto the second storage container, for example, a boat, the movement of the boat can be minimized, so a large number of wafers can be stored in one container.
There are no inconveniences caused by moving the 7ia boat itself, and this is an extremely suitable method for transferring wafers in semiconductor manufacturing equipment.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the operation of the wafer transfer method according to the present invention, and FIG. An explanatory diagram of the state in which the
b) Wafer press-1. An explanatory diagram of a state in which a group of wafers is taken out from a cassette using the device, FIG. Fig. 3 is an explanatory diagram of a state in which a wafer is taken out from a cassette using the wafer transfer device shown in Fig. 2, Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3, and Fig. 5 is an external perspective view of the apparatus. is an explanatory side view of FIG. 3, and FIG. 6 is an explanatory diagram of the operation of holding a wafer using a chuck.
b) is an explanatory diagram of the state in which the chuck is closed; Figure 7 is an explanatory diagram of the state in which transferred wafers are placed on the boat; Figure 8 is an explanatory diagram of the state in which the transferred wafers are placed on the boat; and Figure 8 is the storage provided on the side of the boat, chuck, and cassette. FIG. 9 is an explanatory side view of the groove, and is an explanatory cross-sectional view taken along line IX-IX of the side not shown in FIG. 10... Cassettes 10a, 24... Storage groove 20... Boat 30... Chuck device 38... Chuck 50... Wafer pusher, E device W... Wafer

Claims (1)

[Claims] When automatically transferring wafers from a first storage container in which a plurality of wafers are vertically arranged to a second storage container in a row of wafer storage grooves tilted at a predetermined angle, Place the first storage container tilted at the predetermined angle, and use the upward transfer means to transfer the group of wafers upward from the first storage container to a predetermined position while keeping the group tilted. A wafer transfer method comprising: placing a group of wafers on a second storage container at a predetermined angle by holding the wafers using a holding means and transferring the wafers toward the second storage container.