JPH0473947A - Wafer transfer method - Google Patents

Abstract

PURPOSE:To equalize the pitch between the surfaces of wafers and to ensure the uniformity in treatment by detecting the presence or absence of the wafers under the state wherein the wafer is engaged with each engaging groove of a push-up member, arranging the wafers with chucks so that there is no missing when there is the engaging groove wherein the wafer is not present, thereafter holding the wafer with the chucks, and transferring the wafer. CONSTITUTION:A plurality of wafers W are contained in a carrier. The lower end side of the wafer W is held with an engaging groove. The wafer is pushed up with a push-up member 62. The wafer W is held with a pair of chucks 48 which are arranged at the upper side of the carrier and transferred. At this time, the presence or absence of the wafer W is detected under the state the wafer W is engaged with each engaging groove of the push-up member 62. When there is the engaging groove wherein the wafer W is missing, the wafers W are arranged with a pair of the chucks 48 so that there is no missing of the wafer W under the state wherein the wafers W are pushed up with the push-up member 62. Thereafter, all wafers W which are pushed up with the push-up member 62 are held and transferred with the chucks 48. For example, an optical wafer detecting sensor is housed in each engaging groove of the push-up member 62, and the presence or absence of the wafers W is detected.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a wafer transfer method.

(Prior Art) In a semiconductor manufacturing process, for example, a batch-type film deposition heat treatment process, a plurality of wafers, for example, 25 wafers, which have been processed in the previous process, are transported by a carrier, and the wafers in the transported carrier undergo the above film deposition process. For example, 150 sheets are transferred to, for example, a heat-resistant quartz boat that can withstand the treatment process. The quartz boat is then carried into a heat treatment furnace, where various film deposition treatments are performed.

Transfer the wafer in the carrier mentioned above to a quartz boat,
Alternatively, the reverse process is described in, for example, Japanese Patent Publication No. 61-4186, Utility Model Publication No. 81-205141. It is disclosed in many publications such as Utility Model Application Publication No. 61-2244110.

(Problem to be solved by the invention) A carrier that can accommodate up to 25 wafers does not necessarily accommodate 25 wafers, and wafers may not be mounted in the grooves in the carrier, which is called hollowing. Sometimes it hasn't been done.

If the wafers are transferred to a quartz boat with hollow holes as shown in 2, the pitch between the surfaces of the wafers on the boat will be partially different, making it difficult to perform processes such as diffusion and CVD. So it's not desirable.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a wafer transfer method that is capable of detecting the hollow state of a wafer on a push-up member before transferring the wafer to a boat.

[Structure of the Invention] (Means for Solving the Problems) The present invention holds a plurality of wafers housed in a carrier in an engagement groove and pushes them up with a push-up member, thereby pushing up the carrier. When the wafer is held and transferred by a pair of chucks placed above, the presence or absence of the wafer is detected while the wafer is engaged with each engagement groove of the push-up member, and ■ the presence of the wafer is detected. If there is an engagement groove that does not fit, the wafer is pushed up by the steam push-up member, and the wafers are arranged using a pair of chucks so that no part of the wafer falls out. It is characterized in that everything is held and transferred by the pair of chucks.

(Function) In step (2), an engagement groove in which no wafer is present is detected. That is, a hollow engagement groove is detected. Next, in step 2, if there is an engagement groove in which there is no Ueno\, rearrange the sea urchin \ with a pair of chucks so that there is no hole while pushing it up, and then in Step 2,
After eliminating the hollow state of the wafers on the push-up member, all the wafers are transferred using a pair of chucks.

By transferring the wafer as it is using the chuck device,
The wafers can be transferred to a processing container such as a boat with the same surface pitch.

(Example) Hereinafter, an example in which the present invention is applied to a method for transferring semiconductor wafer will be specifically described with reference to the drawings.

As shown in FIG. 2, in the wafer transfer device of this embodiment, a carrier stage 22 on which a plurality of carriers (also referred to as cassettes) 20 are mounted and a boat stage 32 on which boats 30 are mounted are arranged mutually. A chuck device 4 is disposed adjacent and substantially parallel to each other along each of these stages 22.32.
A moving groove 42 in which 0 moves is provided.

Further, the inside of the device main body 100 is formed in a hollow shape, and as shown in FIG.
A pair of rails 50.degree. 50 are provided along the rails 2, along which a slider 52 is configured to move.

The sliding position of the slider 52 is controlled by rotationally driving a ball screw 54 using a motor (not shown). The chuck device 40 is fixedly disposed on the slider 52. This chuck device 4
A push-up device 60 capable of pushing up, for example, 25 semiconductor wafers housed in the carrier 20 at a time, is disposed adjacent to the carrier 20 and below the carrier 20. Similarly, this push-up device 60 also has a pair of rails 6
4.64, and this slider 66 moves along the ball screw 6 using a motor (not shown).
By rotationally driving 8, its sliding position is controlled. A push-up plate 62 is supported by the slider 66 so as to be movable up and down. Using both devices 40 and 60, a wafer is taken out from the carrier 20 and transferred to the boat 30, and the reverse process is performed.

The carrier 20 has parallel vertical grooves 20a formed on the inner surfaces of both walls thereof to accommodate and hold wafers at regular intervals.

In a semiconductor device, a group of wafers, for example, a maximum of 25 wafers, stored in this carrier 20 is handled as a unit of one chuck. For this reason, the storage groove 20a is, for example, 31
25 wafers are provided at 16-inch pitch intervals, and are formed so that a maximum of 25 wafers can be stored in the carrier 20 as one unit.

As shown in FIG. 5, on the surface of the push-up plate 62, there are two
Five wafer support grooves 62a are formed to support the wafer W at its lower end at constant pitch intervals. This wafer support groove 62a supports a wafer W having a thickness of, for example, 675±25 μm.
It consists of a slit groove 62b with a width of 800 μm and a tapered groove 62c opening at an angle of 60'' at the upper end thereof, so that the wafer W can be stably supported vertically on the push-up plate 62. By moving this push-up plate 62 upward, the plurality of wafers W stored in the cassette 20 are separated from the cassette 20 and transferred upward with their lower ends stably supported by the push-up plate 62. In this embodiment, each engagement groove 62 of the push-up plate 24
For example, an optical sensor (not shown) is built in a, and is configured to be able to detect whether or not a wafer W is present in each engagement groove 62a.

Then, at a position where the wafer W is transferred to a predetermined upper position from which the wafer W is completely removed from the carrier 20, the wafer W is clamped using the chuck device 40 that functions as a wafer clamping means, and the wafer W is transferred through a predetermined movement path. The vessel is transferred to boat 30.

As shown in FIG. 3, the chuck device 40 includes a head 44 that moves up and down in the vertical direction in the figure, a slide block 46 that is supported by the head 44 so as to be horizontally movable, and is attached to both ends of the slide block 46. Two pairs of chucks 4 are examples of chuck members that clamp the wafer W.
8.48. Grooves for chucking the wafer W are formed on the inner surfaces of the pair of chucks 48, 48, respectively, and are formed at a pitch of 3/16 inch, which is the same pitch as the grooves of the carrier 2o, for example.

Further, as shown in FIG. 6, the push-up device 60 is provided with two sets of push-up plates 62, 62 that can be raised and lowered independently, corresponding to the two sets of pair of chucks 48, 48. It is being By selectively using one set and the other set depending on the type of process, it is possible to prevent process cross contamination.

Next, an embodiment of the method of the present invention in the above embodiment apparatus will be described with reference to FIG.

(2) Process First, the push-up plate 62 is pushed up from below the carrier 20 with the pair of chucks 48 and 48 in an open state waiting above the carrier 20. Then, all the wafers W are removed from the carrier 20 and transferred above the carrier 20 with the lower ends of the wafers W being locked in the engagement grooves 62a shown in FIG. At this time, a wafer detection sensor (not shown) built in each engagement groove 62a of the push-up plate 62, for example, a light emitting side and a light receiving side are provided in the valley groove 62a, and when a wafer enters between the photocouplers, By photoelectrically detecting when the wafer W does not enter the engagement groove 62a, the presence or absence of the wafer W is detected with respect to each engagement groove 62a.

■ Process Next, the first wafer group Wl, which is located on the far left side of the engagement groove 62a where no wafer W is present, is placed in a pair of chucks 48.
．． The horizontal positions of the pair of chucks 48, 48 are set so that the grooves on the right end side of the wafers 48 can be used to chuck, and the first group W of wafers is chucked by driving the chucks 48, 48 to close.

■ Process Next, a pair of chucks 4 holding the first wafer group w1
8.48 and the remaining 2nd. Third wafer group 1iV 2
, driven upward against the push-up plate 62 supporting w3,
The first wafer group W is removed from the push-up plate 62.

■ A pair of chucks 48.4 holding the first wafer group w1 in the process
The pair of chucks 48 and 48 are moved to the right while maintaining the height position of 8, so that the rightmost wafer of the first wafer group w1 is moved to the left side of the second wafer group w2. It is set above the matching groove 62a.

■ A pair of chucks 48.4 holding the first wafer group w1 in the process
The pair of chucks 48, 48 are moved downward while maintaining the horizontal position of the chucks 48, 48.

Then, the first wafer group w in the engagement groove 62a of the push-up plate 62
, is supported, the pair of chucks 48° 48 are released. As a result, 1. A state in which there is no hollow space between the second wafer groups wl and w2 is realized.

■ Process Next, the first step. Second wafer group'W 1. Regarding W 2 L, the above-mentioned steps 1 to 2 are carried out. That is, by handling the first and second wafer groups W+ and W7 in the same manner as the first wafer group w1 in each of the above steps, the wafers are rearranged as shown in ■ in FIG. A right-justified arrangement state can be realized on the plate 62.

In this way, by making it possible to arbitrarily set the horizontal positions of the pair of chucks 48 and 48 independently of the horizontal position of the push-up plate 62, it is possible to rearrange the wafers W on the push-up plate 62 without hollow holes. realizable. Also when aligning the wafer W to the left,
It can be realized in the same way. The above-mentioned transfer of the wafers is carried out in a quartz boat for heat treatment, and has the effect that the heat treatment within the quartz tube can be made uniform for all wafers. That is, if there is an intermittent portion of the wafer, a change occurs in the processing gas flow at that portion.

In addition to this effect, there is also the effect of being able to process a large number of sheets at a time.

Note that the present invention is not limited to the above embodiments,
Various modifications are possible within the scope of the invention.

For example, the detection of whether or not there is a hollow wafer on the push-up member is not necessarily performed using a sensor built into the push-up member piece, but can also be detected by other means.

[Effects of the Invention] As explained above, according to the present invention, the wafers can be rearranged on the push-up member without any hollow holes, and then the wafers can be transferred directly to the heat treatment container.
Since the pitch between the surfaces of the wafers can be made equal, uniformity of processing can be ensured.

[Brief explanation of drawings]

1 is a process explanatory diagram for explaining one embodiment of the method of the present invention; FIG. 2 is a schematic perspective view of a wafer transfer device; FIG. 3 is a schematic perspective view of a pair of chuck devices; The figure is a side view for explaining the positional relationship of a pair of chucks, a carrier, and a push-up device, FIG. 5 is an enlarged view of the engagement groove of a push-up plate, and FIG. FIG. 2 is a schematic explanatory diagram showing the relationship between push-up plates of /Ii. W...Wafer, 20...Carrier, 48...Chuck 60...
Push-up device, 62... Push-up plate 62a... Engagement groove. Figure 5 Agent Patent attorney Inoue - (1 other person) Figure 6

Claims (1)

[Claims] (1) A plurality of wafers housed in a carrier are held at the lower ends of the wafers in the engagement grooves and pushed up by a push-up member, and the wafers are clamped by a pair of chucks arranged above the carrier. When transferring the wafer, the presence or absence of the wafer is detected with the wafer engaged in each engagement groove of the push-up member, and if there is an engagement groove in which no wafer is present, the push-up member pushes the wafer up. A wafer transfer method characterized in that the wafers are arranged using a pair of chucks so that no wafers fall out, and then all of the wafers pushed up by the push-up member are held and transferred by the chucks.