JPH02184044A - Wafer transfer method - Google Patents

Abstract

PURPOSE:To make it possible to insert wafers into grooves accurately regardless of the magnitudes of pitches and diameters by supporting the wafer train on a pushing-up member under the state wherein the wafers are coupled into the grooves of a second container and the position is corrected, opening chucks, and lowering the pushing-up member. CONSTITUTION:Wafers (w) in a boart 30 are pushed up with a pushing-up plate 62. Chucks 48 and 48 are closed and driven, and the specified number of the wafers (w) are chucked. The wafers are arranged at the upper part of a carrier 20 in a vacant state. The upper stopping position of the chucks 48 and 48 is the position where the lower part of each wafer (w) is aligned with grooves 20a of the carrier 20. Namely, the position of the input part of the wafer train is corrected. Thereafter, the pushing-up plate 62 is moved upward through the inside of the vacant carrier 20. The lifting movement is continued until the plate comes into contact with the lower end of the wafer (w). Thereafter, the chucks 48 and 48 are opened and driven, and the train of the wafers (w) is coupled and supported with the groove of the pushing-up plate 62. Then, the pushing-up plate 62 is lowered and moved.

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 are coated with the film described above. For example, 150 sheets are transferred to, for example, a heat-resistant quartz boat that can withstand the deposition 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, for example, equity 11r (61-4186
, Utility Model 61-205141, Utility Model 81-3344
3. Japanese Patent Publication No. 62-69634. Japanese Patent Publication No. 61-22443
It is specifically disclosed in numerous publications such as 0.

(Problems to be Solved by the Invention) Generally, a maximum of 25 wafers are stored in the carrier at a pitch of 3716 inches, and the wafers are normally transferred to a boat for heat treatment at this pitch.

However, depending on the content of the heat treatment of the wafer, the wafer may be mounted at a pitch different from the groove pitch of the carrier, such as e7te inch pitch, which is double the pitch. This is the case.

This pitch conversion technique is well known.

However, the following problems occurred.

In other words, since the lifting plate of the wafer lifting device simply supports the lower end of the wafer and moves it while standing vertically, the larger the wafer diameter becomes, the more the 8-inch wafer in particular tilts. In this case, when the push-up plate is lowered, the wafer is not inserted accurately into the groove of the carrier, resulting in problems such as inability to transfer or damage to the wafer.

Therefore, an object of the present invention is to provide a wafer transfer method that allows wafers to be accurately inserted into the grooves of a carrier regardless of the wafer system, no matter what pitch the wafers are transferred. It's about doing.

[Structure of the Invention (Means for Solving the Problems)] The present invention provides for pushing up a plurality of rows of wafers from a first storage container in which wafers are fitted and supported in several grooves, holding them by a chuck member, and moving the wafers to a second storage container. When transferring the row of wafers to the second storage container, the positions of the wafers are corrected by fitting some of the wafers into the grooves of the second storage container while holding the plurality of wafers between the chuck members, and in this corrected state. By supporting the wafer row on the push-up member, releasing the chuck state, and lowering the push-up member that supported the wafer row, the wafer is pushed up by m2.
It can be transferred to a storage container.

(Function) In order to transfer wafers from the first storage container to the second storage container, point the wafers at the chuck member that chucks and supports a plurality of wafers above the second storage container. This will cause the push-up member to rise. At this time, in the present invention, the wafer supported by the chuck member is in a state where a portion thereof is caught in the groove of the second storage container. In this state, the lower end of the wafer supported by the chuck member is supported by the push-up member, and then the chuck state of the chuck member is released. As a result, each wafer is supported vertically by the push-up member and the groove of the second storage container. After this, the push-up member is moved downward. Then, each wafer supported by the push-up member is carried into the second storage container using the groove of the second storage container as a guide.

Therefore, even if the distance between the surfaces of the wafers supported by the push-up member is large, the pitch of these wafers is maintained by the grooves of the second storage container, and therefore, these wafers cannot be moved downward along the grooves. It becomes possible to reliably transfer it into the second storage container.

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

As shown in FIG. 2, the wafer transfer device of this embodiment includes a cassette stage 22 on which a plurality of cassettes 20 are placed,
Boat stages 32 on which boats 30 are mounted are arranged adjacent to each other in a substantially straight line, and each of these stages 22
．． 32 along which the chuck device 40 moves.
is provided.

Further, the inside of the device main body 300 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 W40 and the wafer lifting device 60 are arranged adjacent to each other on the slider 52, and these two devices are used to take out the wafer from the carrier 20 and transfer it to the boat 30. Reverse process work is performed.

In the embodiment, the cassette stage 22 is provided with a plurality of table insertion holes 24 at regular intervals as shown in FIG. It is placed on the table 22 so as to be located above the mouth 24. Each carrier 20 placed in this manner has vertical grooves 20a formed in parallel on both inner surfaces of its walls to accommodate and hold wafers at regular intervals.

In a semiconductor device, a group of 25 wafers, for example, stored in the carrier 20 is handled as a unit of one chuck. For this reason, 25 storage grooves 20a are provided at 3/18 inch pitch intervals, and a maximum of 25 wafers can be stored at one time.
It is formed so that it can be stored in the carrier 20 as a unit.

Further, the wafer push-up device 60 includes a cassette stage 2
It is mounted on the slider 52 so that it can be positioned below the push-up plate insertion opening 24 of No. 2. And the third
As shown in the figure, a push-up plate 62, which is an example of a push-up member, is configured to be movable above the stage 22 through the insertion opening 24.

Twenty-five wafer support grooves are formed on the surface of the push-up plate 62 to match the pitch of the storage grooves 20a of the cassette 20, and support the wafers W at their lower ends at a constant pitch.

Therefore, as shown in FIG. 3, by moving the push-up plate 62 upward through the insertion opening 24, the lower ends of the plurality of wafers W stored in the cassette 20 are supported by the push-up plate 62. In this state, it is separated from the cassette 20 and transported upward.

Then, the wafer W is transferred to a predetermined upper position from which the wafer W is completely detached from the carrier 20, for example, at an upper row point position, where the wafer W is transferred to a chuck device 4 that functions as a wafer clamping means.
The wafers are held between the wafers 0 and 30 and transferred to the wafer boat 30 via a predetermined movement route.

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, and a pair of chucks that are attached to the head 44 via an arm 46 and are an example of a chuck member that clamps the wafer W. 48.48. Grooves for chucking the wafer W are formed on the inner surfaces of the chucks 48 and 48, respectively.
The grooves are formed at a desired pitch conversion value, for example, double the pitch of the groove pitch of the carrier 20, that is, 8/16 inch pitch.

Next, this pitch conversion will be explained in more detail.

In the case of this embodiment, the arrangement pitch of the cassettes on which the wafers W are initially mounted is 8,718 inches, and the wafer rows are arranged at the groove pitch of the boat 30, for example, 8/1, which is a double pitch.
The case of transferring to 6 inches will be explained.

First, as shown in FIG. 3, with the chucks 48 and 48 in an open state waiting above the carrier 20, the wafer pushing device 60 is driven from below the carrier 20, and the pushing plate 62 move upward. Then,
All the wafers housed in the carrier 20 engage with the grooves formed on the upper surface of the pusher plate 62 and move upward together with the pusher plate 62. Then, as shown in the figure, the drive of the push-up plate 62 is stopped at the position where the wafer W is completely removed from the carrier 20. Next, head 4
A pair of chucks 48 are connected via the arm 46 by the drive of the
．． The push-up plate 62 is driven to narrow the distance between the opposing sides of the
The wafer W supported by the pair of chucks 48.
It will be chucked at 48.

Here, the pair of chucks 48 and 48 are connected to the wafer W.
Since the pitch of the grooves supporting the carrier 20 is 6/16 inches, which is double the pitch of the grooves of the carrier 20, half of all the wafers pushed up by the push-up plate 62 are The groove of the chuck is formed so as to chuck only the wafer W. After this, push up plate 6
2 to avoid the chuck position, for example, while moving downward,
A pair of chucks 4 supporting half of these wafers W
8.48 is moved in a straight line and placed above the boat 30.

Then, as shown in FIG. 4, above the boat 30,
By releasing the chucked state by the pair of chucks 48, 48 and moving the push-up plate 62 downward, it becomes possible to mount the wafer W supported by the pair of chucks 48, 48 onto the boat 30. The pitch of the wafers mounted on this boat 30 is 8716 inches, which is the pitch of the chuck 48.48.

Further, half of the wafers W remaining in the carrier 20 are transferred to the boat 30 in the same manner, and then the wafers W in a different carrier 20 are transferred to the boat 30 in the same manner, so that a predetermined position is placed on the boat 30. It becomes possible to mount several wafers W at double pitch.

The boat 30 on which the wafers W are loaded in double pitch in this manner is carried into a heat treatment furnace by a boat liner elevator mechanism (not shown), where the wafers W are subjected to batch processing by heat treatment.

Next, the wafer W that has undergone this heat treatment is transferred to the carrier 2.
The transfer method to return to 0 will be explained.

First, as shown in FIG.
The boat 30 carrying the is placed on the boat stage 32, and a pair of chucks 48, 48 in an open state are placed above the boat 30.
Place. Thereafter, the wafer W is pushed up by the push-up plate 62, the pair of chucks 48, 48 are driven to close, and a predetermined number of wafers W are chucked by the pair of chucks 48, 48.

Thereafter, the pair of chucks 48, 48 are placed above the empty carrier 20. Here, the pair of chucks 48
．． 48 is located at the upper stop position of the wafer W as shown in FIG.
The lower end of the wafer W is not in the position where it is completely separated from the carrier 20, but the lower end of the wafer W is in the position where it is completely separated from the carrier 20, as shown in FIG. 1(A).
It is stopped at the position where it overlaps the groove 208 of 0. That is, the position of the entrance of the wafer row is corrected.

After this, as shown in FIG.
The lower end of the wafer W is supported by the pair of chucks 48 and 48 and the lower end of the wafer W is resting on the entrance of the groove of the carrier 20. Continue this upward movement until it touches the. The upper stop position of the push-up plate 62 is a position as shown in FIG.
This is different from the upper position shown in FIG. 3 when the wafer W is taken out from zero.

Thereafter, as shown in FIG. 4B, the head 44 is driven to open the wafer row so as to widen the facing distance between the pair of chucks 48 and 48, and the wafer W row is placed in the twice-pitch groove of the push-up plate 62. are fitted and supported. At this time, the above wafer W
is supported not only by the push-up plate 62, but also by some grooves 20a of the carrier 20, so even if it is supported by the push-up plate 62 at double pitch, the carrier 20 The inclination of the wafer W is suppressed by the grooves 20a.

After the pair of chucks 48, 48 are opened as described above, the push-up plate 62 is moved downward. Then, this push-up plate 62
Since the wafer W supported above moves along the groove 20a of the carrier 20 when descending together with the push-up plate 62, the return transportation of the wafer W into the carrier 20 cannot be accurately carried out. And it will be possible to implement it smoothly. In this way, it is returned in the carrier 20 in double-pitch.

Note that the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the gist of the present invention.

For example, although the above embodiment is applied to a case where wafers are transferred at a pitch different from the array pitch of the carriers 20, the carriers 20 are simply transferred without changing the pitch. The present invention can be similarly applied to a device in which wafers are transferred between boats 30.

Further, although the present invention is effective for transferring the wafer W back to the carrier 20, this method can be similarly implemented for transferring the wafer W from the carrier 20. chuck 48
．． When chucking the wafer W at 48, it is additionally possible to accurately position the wafer W in the grooves of the pair of chucks 48°48.

[Effects of the Invention] As explained above, according to the present invention, when transferring a wafer held between a pair of chucks back to the container via the push-up member, the wafer is inserted into the groove of the container. Since the wafer can be transferred after partially mating and correcting the position, even if the wafer arrangement pitch is large and the wafer is tilted significantly, it can also be used if the wafer diameter is large and the wafer is tilted. Also, wafers can be transferred accurately and smoothly without causing interference between the wafer and the container to be transferred.

[Brief explanation of the drawing]

FIGS. 1(A), (B), and (C) are schematic explanatory diagrams showing an example of the transfer process of the method of the present invention, and FIG. 2 is a diagram of a wafer transfer apparatus for carrying out the method of the present invention. FIG. 3 is a schematic perspective view showing the overall configuration; FIG. 3 is a schematic explanatory view showing the positional relationship among the wafer chuck, carrier, and wafer support; FIG. 4 is a schematic explanatory view showing the positional relationship among the wafer chuck, boat, and wafer support. be. 20... Second storage container, 30... First storage container, 48.48... Chuck member, 62... Push-up member, W... Wafer. Agent Patent attorney Inoue - (1 other person) Figure 1 (A) CB) (C)

Claims (2)

[Claims] (1) When a plurality of wafer rows are pushed up from a first storage container that fits and supports wafers in a plurality of grooves, and transferred to a second storage container by being held by a chuck member, the chuck member While holding a plurality of wafers, a part of the wafers is fitted into the groove of the second storage container to correct the position, and in this corrected state, the row of wafers is supported on the push-up member, and the wafer is placed in the chucked state. A wafer transfer method characterized in that the wafers are transferred to a second storage container by opening the container and lowering a push-up member that supports a row of wafers. (2) The chuck member chucks the wafer at a groove pitch different from the groove pitch of the second storage container,
The wafer transfer method according to claim 1, wherein the wafer arrangement pitch is changed.