JPS6239821B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for stacking semiconductor wafers.

Semiconductor wafers (hereinafter simply referred to as "wafers") are generally held on a holder by arranging the wafers at intervals of several millimeters from each other. In order to downsize and save storage space, wafers are often stored one on top of the other with their main surfaces in contact with each other.

Furthermore, when thermally diffusing impurities into wafers, it is common to arrange the wafers on a boat at intervals of several millimeters, but when diffusing aluminum Al, gallium Ga, etc., it is possible to place the wafers closely stacked on top of each other. In the case of other impurity diffusion, diffusion can also be carried out while the wafers are overlapped by spreading an appropriate separation agent such as quartz powder or silicon carbide (SiC) powder between the wafers. There is. If impurity diffusion can be performed with the wafers stacked one on top of the other in this way, the diffusion processing capacity will be increased to about three times that of the usual one, and the manufacturing cost will be reduced accordingly.

1A to 1C are perspective views for explaining a conventional wafer handling method, and 1 shown in FIG. 1A is a wafer holder, and both side plates 1 facing each other are
A large number of parallel wafer holding grooves 1b are provided in the shape of a comb (hereinafter also referred to as comb-shaped grooves), so that the wafer 2 can be held in parallel. This wafer holder 1 also has an engaging pin 1 on the upper end surface.
It has one pair of engagement holes 1d and one pair of engagement holes 1d, and has a structure that facilitates engagement with other wafer holders having the same configuration when their openings 10 are overlapped. 3 shown in Figure 1C is a diffusion boat, and Figure 1B
As shown in the figure, the wafers 2 are placed one by one from the wafer holder 1 into the diffusion port 3 using tweezers 4 to form a wafer stack 2a, and blocks 3a and 3b are placed at each end of the wafer stack 2a to hold the stack. It's summery. Note that 3c is a hook hole for loading and unloading the diffusion boat 3 into and out of the diffusion furnace.

Conventionally, as shown in FIGS. 1A to 1C, wafers 2 are placed in a wafer holder 1 and pretreated for diffusion, and then placed on a diffusion boat 3 one by one using tweezers 4. was. Normally, the soaking zone of a diffusion furnace is 500 to 600 mm, so the amount of wafers 2 stored to fill this soaking zone is approximately 2,000, assuming the thickness of the wafers 2 is 200 μm, and the wafers must be handled one by one. It can be said that the effort is extremely large.

This invention was made in view of the above points, and an object of the present invention is to provide a semiconductor wafer stacking device that can stack wafers in bulk and transfer them to a diffusion boat efficiently. There is.

FIG. 2A is a perspective view showing a wafer stacking tool of a semiconductor wafer stacking apparatus according to an embodiment of the present invention, and FIG. 2B is a sectional view taken along the plane B--B. Wafer stacking tool 5 of this embodiment
The left and right side plates 5a and 5b, which do not have wedge-shaped grooves, and the front and rear end plates 5c and 5d form a frame shape, and the upper part has an opening 50 into which the wafer 2 can be freely inserted, and the lower part has the left and right side plates 5a and 5b. Wafer holding convex portions 51a and 51b are formed to protrude toward the inner surface to prevent the stored wafer 2 from falling off. Further, engagement pins 5e and engagement holes 5f are provided at the four corners of the upper opening 50, so that the upper opening 50 can be engaged with the wafer holder 1 shown in FIG. Furthermore, an opening 5 is provided in at least one of the front and rear end plates 5c and 5d [5c in this example].
A slit 5g is provided from the 0 side so that a large tweezers can be passed through it.

FIG. 3 is a partially cutaway side view showing the process of stacking the wafers 2 at once using this embodiment. That is, the wafers 2 are separated one by one and held in parallel in the wafer holder 1 in advance, and are subjected to a pre-diffusion treatment. Next, the opening 50 of the wafer stacking tool 5 of this embodiment and the wafer holder 1 will be described.
The openings 10 of the wafer 2 are aligned by engaging the respective engagement pins and the engagement holes, and the wafer 2 is inverted so that it becomes horizontal. Thereafter, when all the wafers 2 are pushed from the bottom of the wafer holder 1 toward the wafer stacking tool 5 in the direction of the arrow shown in the figure using the pusher 6, the wafers 2 are stacked on the wafer stacking tool 5 all at once.

In this case, it is convenient for the wafer stacking tool 5 to be made of a relatively soft synthetic resin such as Teflon to reduce the impact between the wafers 2.
In addition, the smaller the arrangement pitch of the wafers 2 in the wafer holder 1 and the larger the storage capacity, the smaller the impact force, which is preferable. Actually, there is almost no problem if the parallel arrangement pitch of the wafers 2 is 3/16 inch (approximately 5 mm) or less. Preferably, the arrangement pitch of the wafers 2 is 3/32 inch (approximately 2.5 mm) or less, and the storage capacity of the wafers 2 is preferably 25 or more and about 50 wafers. In addition, as another usage form of this embodiment, the wafer stacking tool 5 is placed upside down on the wafer holder 1, and the wafer holder 1 is pushed up from below with the pusher 6 to stack the wafers 2. Matching tool 5
The wafers 2 may be moved to the side, and then the wafer stacking tool 5 may be repositioned so that the wafers 2 are horizontal.

4A and 4B are perspective views showing the procedure for transferring the wafers from the wafer stacking tool 5 to the diffusion boat in this embodiment, in which the wafer stacks stacked in the wafer stacking tool 5 are stacked in the wafer stacking tool 5 in the manner described with reference to FIG. 2a is held between large tweezers 7 through a slit 5g as shown in FIG. 4A. At this time, it is important to hold the center of the wafer stack 2a with the large tweezers 7, and if the center is held, the wafer stack 2a will not collapse. Continuing,
As shown in FIG. 4B, the desired transfer operation is completed by placing the wafer stack 2a on the diffusion boat 3 as it is.

As described above, in the semiconductor wafer stacking apparatus according to the present invention, the wafers are stacked by transferring the wafers from the holder having the wafer holding groove to the stacking tool having no grooves, so that the wafers are stacked. Once engaged, the wafers can be pushed out in batches from the bottom of the wafer holder and transferred to the wafer stacking tool, making it easy to stack wafers for mass transportation, bulk processing, etc. This makes it possible to make the wafer simple, robust, and inexpensive, thereby reducing wafer handling costs.

[Brief explanation of the drawing]

1A to 1C are perspective views for explaining a conventional wafer handling method, FIG. 2A is a perspective view showing an embodiment of the present invention, and FIG.
3 is a partially cutaway side view showing the process of stacking wafers at once using this embodiment, and Figures 4 A and B are diffusion from the wafer stacking tool of this embodiment. FIG. 3 is a perspective view showing a procedure for transferring to a boat. In the figure, 1 is a wafer (wafer holding groove) holder, 1a is a first left and right side plate, 1b is a comb-shaped groove, 1c is a first engagement pin, 1d is a first engagement hole, 2 is a wafer, 10 is an opening, 5 is a wafer stacking tool, 5a is a second left side plate, 5b is a second right side plate, 5c is a second front end plate, 5d is a second rear end plate, and 5e is a second engagement plate. Dowel pin, 5f is second engagement hole, 5g is slit 50 is opening, 51a, 51b
is a convex portion for holding a wafer. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. Consisting of a frame-shaped body constituted by opposite front and rear end plates and opposite left and right side plates having wafer holding grooves at a predetermined pitch on the inner surfaces, and an opening in the upper surface for inserting a wafer. A frame consisting of a wafer holder having a lower opening smaller than the upper opening for pushing out the wafer with a pusher, opposing front and rear end plates, and opposing left and right side plates having no wafer holding grooves. having an opening in the same shape as the top opening of the wafer holder on the upper surface, a wafer holding convex portion on the inner surfaces of the left and right side plates near the lower surface, and at least one of the front and rear end plates. A semiconductor wafer stacking device comprising: a wafer stacking tool having a slit for inserting tweezers; and a wafer stacking tool having a slit for inserting a tweezers, and wafers can be transferred and stacked from the wafer holder to the wafer stacking tool. .