JPH0325405Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial field of application] This invention is a method for storing multiple thin substrates (hereinafter referred to as "wafers") of semiconductors, ceramics, glass, etc. in a storage container (hereinafter referred to as "cassette"). In a wafer surface processing device that performs various surface treatments on wafers while they are housed in a cassette, the wafers that have not yet been surface-treated in a cassette for transport are transferred to a cassette for processing, and then processed. This invention relates to a wafer transfer device for transferring surface-treated wafers housed in a dedicated cassette to a transport cassette.

[Conventional technology]

For example, semiconductor devices are manufactured by metal vapor deposition, photoresist coating, pattern baking, etc. on semiconductor wafers.
It is manufactured by performing a number of surface treatments such as development, etching, cleaning, peeling, impurity diffusion, etc. Depending on the type of processing process, there are cases in which wafers are processed one by one, and cases in which a large number of wafers are processed simultaneously while being accommodated in a cassette.

When performing surface treatment on wafers with a large number of wafers stored in a cassette,
Depending on the processing step, it may be necessary to transfer wafers from a transport cassette to a processing cassette prior to processing, and to transfer processed wafers from the processing cassette to a transport cassette after processing. For example, heat treatment equipment uses quartz cassettes, while chemical immersion processing equipment uses fluororesin cassettes, and wafers are transferred between these processing cassettes and polypropylene cassettes used for transport. A change will be made.

Regarding these technologies, for example, on page 75 of the November 1985 issue of the magazine "Semiconductor World", there is a paper that connects the wafer entrance/exit in the diffusion system to the stocker and transfers the wafer between the transport cassette and the quartz board. A flow is disclosed in which a quartz board supporting a wafer is transported into and out of a diffusion furnace.

In addition, as a wafer transfer device, for example, Japanese Patent Publication No. 56-44566 (invention name: ``Object Alignment Device'') has a system in which first and second cassettes are mounted, and through holes are formed at respective predetermined positions. a vertically moving table that moves up and down in the vertical direction through the through hole while holding the wafers housed in the cassette; An apparatus is disclosed that includes an aligning means for collectively clamping and aligning, and a driving means for relatively moving the aligning means and the table.

Furthermore, Japanese Patent Publication No. 61-45381 (title of the invention ``Semiconductor wafer transfer device'') discloses a device that holds the wafers in the cassettes at the respective loading positions of the first and second cassettes and moves them up and down. A holding means for collectively holding the wafers moved above one cassette by one vertical movement means, and a holding means for rotating the holding means 180° above the other cassette. An apparatus is disclosed in which a rotating means is provided for moving the wafer to the other vertically moving means.

[Problem that the invention attempts to solve]

As mentioned above, the manufacturing process of semiconductor devices consists of various surface treatment steps. Among these, when performing surface treatment on wafers while a large number of wafers are still housed in a cassette, depending on the processing step,
Due to problems such as corrosion resistance and dustproofing of the cassettes, dedicated cassettes are used for each processing process. and,
In each surface treatment apparatus, wafers are transferred between a cassette exclusively for transport and a cassette exclusively for processing using the above-mentioned transfer device.

However, conventionally, each surface treatment apparatus was provided with only one transfer mechanism. For this reason, for example, in a wafer cleaning process, when transferred wafers that have been cleaned from a processing cassette to a transport cassette, they may be transferred from the transport cassette to the processing cassette in the same way as uncleaned wafers. The cleaned wafer will come into contact with the contact area. As a result, if dust attached to an uncleaned wafer is transferred and attached to a part of the equipment during the transfer, that dust may re-adhere to the wafer that has been cleaned and cleaned. Therefore, there was a problem that the effectiveness of the cleaning treatment was reduced.

This idea was made to solve the above problem, and is used in surface processing equipment that performs various surface treatments on wafers while the wafers are still housed in the cassette. To provide a wafer transfer device which prevents a processed wafer from touching a part of the unprocessed wafer that is in contact with the wafer when transferring the wafer to a processing-dedicated cassette.

[Means to solve the problem]

In this invention, as a means for achieving the above-mentioned task, a wafer transfer device is configured as follows. That is, the wafer transfer device according to this invention is equipped with a transport-only cassette which is open at the bottom and has accommodation grooves formed at a predetermined pitch on the inner surface for accommodating a plurality of wafers in alignment. at least one cassette table for transport only, which has a placing part and has a through hole formed in the placing part;
Similarly, the lower bottom part is open and the storage grooves for accommodating a plurality of wafers in alignment on the inner surface are formed at the same pitch as the storage grooves of the transport cassette. at least one processing-dedicated cassette table having a through hole formed in its mounting portion; and a table having an outer diameter smaller than the through hole formed in each of the tables, and having an upper surface into which the end of the wafer is inserted. and an elevating plate in which holding grooves for holding the wafers are formed at the same pitch as the accommodation grooves formed in each of the cassettes, and this elevating plate is connected to the through holes of each of the tables and the lower bottom opening of each of the cassettes. An elevating means for penetrating and elevating the cassette, and a wafer holding groove disposed in parallel directly above the elevating plate and having the same pitch as the receiving groove formed in each of the cassettes on at least one of the opposing side surfaces. a pair of holding arms that are narrowly supported and that hold a plurality of wafers that are transferred from inside each of the cassettes to the upper surface of the lifting plate by raising the lifting plate by the lifting means; The apparatus is provided with a wafer surface processing apparatus, and includes a widening means for changing the interval between opposing side surfaces of the clamping arms, and a horizontal movement means for horizontally moving the respective tables, the elevating plate, and the clamping arms relative to each other in the horizontal direction. In the wafer transfer device, the processing-dedicated cassette table is connected to the wafer surface processing device, and the elevating plate and the clamping arms are used exclusively for wafers before surface processing (hereinafter referred to as "pre-processing only") and for surface processing. Only for processed wafers (hereinafter referred to as “processed only”)
A pair of cassettes for processing wafers are provided, and the table for the cassettes for processing is horizontally movable relative to the elevating plate and the clamping arm for surface-treated wafers to positions directly above and directly below them. The table is characterized in that it can be moved in the horizontal direction relative to the elevating plate and the clamping arm for wafers before surface treatment to positions directly above and directly below them.

Further, in the wafer transfer apparatus having the above configuration, instead of providing the transport-only cassette table and the processing-only cassette table as separate bodies, at least one transport-only cassette mounting section on which the transport-only cassette is placed is provided. and at least one processing-dedicated cassette placement section on which a processing-dedicated cassette is placed, and only one table having a through hole formed in each of the placement sections can be provided.

[Effect]

In the wafer transfer device with the above configuration,
When the transport cassette containing the wafers before surface treatment is placed on the table placement section, the table, the pre-processing lifting plate and the clamping arm are moved relative to each other in the horizontal direction by the horizontal moving means. According to
After placing the transport cassette directly above the pre-processing elevating plate, the elevating means moves the pre-processing elevating plate from the standby position below the table through the through-hole of the table and the bottom opening of the transport cassette. It rises to the position where the pair of clamping arms are installed. At this time, the plurality of wafers are transferred from the transport cassette to the upper surface of the pre-processing lifting plate. Next, the gap between the opposing sides of the pair of pre-processing clamping arms is narrowed by the narrowing means, so that the wafer transferred to the upper surface of the elevator plate is clamped by the pair of clamping arms. . After lowering the elevating plate to its original position below the table, the table, the pre-processing elevating plate, and the clamping arm are moved relative to each other in the horizontal direction using the horizontal moving means, so that the position directly below the pre-processing clamping arm is moved. An empty processing-dedicated cassette placed on the placing portion of the table is placed in the table. Subsequently, the pre-processing lifting plate rises again from the standby position below the table through the through hole of the table and the bottom opening of the processing cassette, and the lower end of the wafer is inserted into the holding groove on the upper surface of the lifting plate. Then, the pre-processing holding arms are expanded and the wafer is held on the elevating plate. Then, as the elevating plate descends and returns to its original position below the table, the wafer is transferred from the top surface of the elevating plate into the processing cassette, and the unprocessed wafer is transferred from the transport cassette to the processing cassette. The change is completed.

On the other hand, in the surface processing equipment, after the wafer is housed in a processing cassette and subjected to the required surface treatment, the processing cassette containing the surface-treated wafer is placed on the table. Then, in the same process as described above, the processed wafers are transferred from the processing cassette to the transport cassette by using a lifting plate exclusively for processed wafers and a holding arm exclusively for processed wafers. It can be done.

As mentioned above, this wafer transfer device is capable of transferring unprocessed wafers from a transport cassette to a processing cassette, and transferring processed wafers from a processing cassette to a transport cassette. This is done using separate dedicated lifting plates and clamping arms, so when wafers are transferred between the transport cassette and the processing cassette, there is no possibility that the unprocessed wafer will touch the area where the wafer has been processed. There is no possibility that the other wafers will come into contact with each other, and there is no chance that dust attached to the unprocessed wafer will adhere to the processed wafer.

〔Example〕

Hereinafter, preferred embodiments of this invention will be described with reference to the drawings.

1-1 to 1-4 are schematic front views showing each step of the wafer transfer operation performed by the wafer transfer apparatus according to one embodiment of the present invention.

First, the configuration of this wafer transfer device will be explained. This device has one transport cassette.
0, and has a table 14 for transport-only cassettes with a rectangular planar shape, and a processing-dedicated cassette 12, which also has a rectangular planar shape. Cassette table 1
6 is provided. The transport cassette 10 is
An opening 18 is formed at the lower bottom, and accommodation grooves 20 for accommodating a plurality of wafers W in alignment are formed at a predetermined pitch on the inner surface on the longitudinal side (direction perpendicular to the paper). In addition, processing cassette 1
2 also has an opening 22 formed at its lower bottom,
Accommodating grooves 24 having the same pitch as the accommodating grooves 20 of the transport cassette 10 are formed on the longitudinal inner surface. Rectangular through-holes 26 and 28 are formed in the transport-only cassette table 14 and the processing-only cassette table 16, respectively, in the mounting portions on which the cassettes 10 and 12 are placed.

In addition, at predetermined positions of this device, there are a pre-processing lifting plate 30 and a processed lifting plate 32, each having a rectangular planar shape and a smaller outer diameter than the through holes 26 and 28 formed in the tables 14 and 16. It is disposed so as to be able to rise and fall freely, and is further provided with elevating means (not shown) for elevating and lowering each of the elevating plates 30 and 32. Holding grooves 34 and 36 into which the lower end portions of wafers are inserted and holding the wafers are formed on the upper surfaces of the lifting plates 30 and 32, respectively.
It is formed with the same pitch as 4. These elevating plates 30, 32 can be moved through the through holes 26, 28 of each table 14, 16 and the lower bottom openings 18, 22 of each cassette 10, 12 by driving each elevating means.
It is now possible to go up and down by penetrating it.

Furthermore, at the position directly above each elevating plate 30, 32,
A pair of clamping arms 38, 38 for exclusive use before processing and a pair of clamping arms 40, 40 for exclusive use after processing are respectively disposed in parallel in the same horizontal plane. Each of the clamping arms 38, 38, 40, 40 has wafer clamping grooves 42, 4, which have the same pitch as the housing grooves 20, 24 formed in each cassette 10, 12, on the side surfaces facing each other.
2, 44, and 44 are formed, respectively. still,
The wafer holding groove may be formed only on one side of the pair of opposing holding arms.
These pairs of clamping arms 38, 38, 40, 40
are supported by respective support portions (not shown) so as to be expandable and narrowable. By driving the widening means provided on each support part, the distance between the opposing sides of each pair of clamping arms 38, 38, 40, 40 can be changed, and by narrowing the distance, Elevating plate 3 raised by elevating means
Holding the wafer held on the top surface of 0.32,
Wafers can be received from the lifting plates 30 and 32. Incidentally, the elevating and lowering operations of the elevating plates 30 and 32 and the expanding and narrowing operations of the clamping arms 38 and 40 are as follows.
Both can be performed at the same time.

The cassette table 14 exclusively for transport is
Between the loading/unloading position of the transport cassette 10 and the position of the pre-processing elevating plate 30 and the clamping arms 38, 38, the processing cassette table 16
are capable of reciprocating horizontally between the loading/unloading position of the processing cassette 12 and the position of the processing-dedicated elevating plate 32 and the clamping arms 40, 40, and the respective horizontal movement means (not shown)
are provided for each.

Next, a wafer transfer operation using the wafer transfer apparatus having the above configuration will be described.

The cassette is transported from the processing device in the previous stage by the cassette transport means.
As shown in FIG. 1-1A, when the transport cassette 10 containing the wafers W is carried in and placed on the mounting portion of the transport cassette table 14, the table with the transport cassette 10 placed thereon is placed on the table 14. 14
is moved in the horizontal direction by the horizontal moving means. At this time, an empty processing cassette 12 is placed on the processing cassette table 16. Then, as shown in FIG.
is directly above the elevating plate 30 dedicated to pre-processing and the clamping arm 3
8, 38, the pre-processing elevating plate 30 is raised by the elevating means, passes through the through hole 26 of the table 14 and the bottom opening 18 of the cassette 10, and extends inside the cassette 10. During the passage, the plurality of wafers W stored in the cassette 10 are lifted out of the storage groove 20 of the cassette 10 and held in the holding groove 34 of the elevating plate 30, and the wafers W are held as shown in FIG. The lifting plate 30 stops at the height position of the pre-processing exclusive clamping arms 38, 38. When the elevating plate 30 stops, the widening means is driven to narrow the distance between the opposing sides of the pair of clamping arms 38, 38, so that the elevating plate 30 is held on the upper surface as shown in FIG. 1-2D. The wafer holding grooves 42, 42 of the holding arms 38, 38
to hold it in place. The wafer W is held by the clamping arms 38, 38
Once the wafer is securely held by the
When the lifting plate 30 holding the cassette 10 is lowered and returned to its original standby position as shown in FIG. Move in the direction of.

Along with the movement of the transport-only cassette table 14, the processing-only cassette table 16 on which the empty processing-only cassettes 12 are placed is also moved in the horizontal direction by the horizontal movement means, and as shown in FIG. In place of the cassette table 14, a processing-only cassette table 16 is placed directly above the pre-processing lifting plate 30. When the processing cassette table 16 stops at a position directly above the elevating plate 30, the elevating plate 30 is raised again by the elevating means and passes through the through hole 28 of the table 16 and the bottom opening 22 of the cassette 12. As shown in FIG. 1-3G, the lower end of the wafer W held by the holding arms 38,
4 and hold the wafer W on the upper surface of the elevating plate 30. When the wafer W is securely held by the lifting plate 30, the distance between the pair of holding arms 38, 38 widens, and the wafer W is released from being held by the holding arms 38, 38, as shown in FIG. , Subsequently, the elevating plate 30 holding the wafer W is lowered. Then, while the elevating plate 30 passes inside the processing cassette 12, as shown in FIG.
The wafer W is transferred from the storage groove 24 of the processing cassette 12 to the storage groove 24 of the processing cassette 12, and the elevating plate 30
Lower bottom opening 22 and through hole 28 of table 16
, and moves to the original standby position. Elevating plate 3
When 0 returns to its original standby position below the table 16,
Processing cassette 1 containing multiple wafers W
1-4.
As shown in FIG. 2, a processing cassette 12 containing wafers W is placed at a loading/unloading position. Then, the processing cassette 12 containing the wafers W is sent to the surface treatment apparatus by a cassette transfer means (not shown), and the wafers W are subjected to the required surface treatment while being accommodated in the processing cassette 12. Ru.

Next, FIGS. 2-1 to 2-4 show surface-treated wafers that have been subjected to necessary surface treatment by a surface treatment apparatus and housed in a processing-dedicated cassette 12.
FIG. 3 is a schematic front view showing a work process for transferring W' from the processing cassette 12 to the transport cassette 10.

This transfer work is also carried out through the same steps as explained in FIGS. 1-1 to 1-4, but the transfer from the transport cassette 10 to the processing cassette 12 is , as described above, was carried out using only the pre-processing lifting plate 30 and the pre-processing holding arms 38, 38.
This transfer from the processing-only cassette 12 to the transport-only cassette 10 is carried out using only the processing-specific elevating plate 32 and the processing-specific clamping arms 40, 40. Therefore, when transferring wafers from the processing cassette 12 to the transport cassette 10,
The processed wafer W' does not come into contact with the portion of the unprocessed wafer W that was in contact with it.

The wafer transfer device shown in FIG.
As shown in FIGS. 1 and 2, instead of the configuration in which the transport-only cassette table 14 and the processing-only cassette table 16 are provided separately, one common table 46 is provided so as to be movable back and forth,
The table 46 is provided with a transport-only cassette mounting section on which the transport-only cassette 10 is placed, and a processing-only cassette mounting section on which the processing-only cassette 12 is placed, and each of the mounting sections has a through hole. 48,
50 was formed. Other configurations are
This is the same as the above-mentioned device shown in FIGS. 1-1 to 1-4.

FIG. 4 is an overall perspective view showing a specific example in which the wafer transfer device according to the invention is attached to an immersion type surface treatment device. In this figure, the same reference numerals as in FIGS. 1-1 to 1-4 indicate the same members that have the same functions. The wafer transfer apparatus 52 shown in this embodiment includes two transport-only cassette tables 54 and 56 and two processing-only cassette tables 58 and 60. In the figure, reference numeral 62 denotes a cassette storage shelf provided above the wafer transfer device 52. The inside of the cassette storage shelf 62 is divided into a plurality of compartments, and one side is open so that cassettes can be stored. 10 and 12 are used as entrances and exits. The cassette storage shelf 62 temporarily stores transport-only cassettes 10 or processing-only cassettes 12 depending on the progress of processing, etc., and transfers the cassettes to and from the wafer transfer device 52. Reference numeral 64 denotes an immersion type surface treatment section that is connected to the wafer transfer device 52 at one end and includes a plurality of surface treatment baths 66 . A cassette transport device 68 is provided along one side of the surface treatment section 64 to communicate between the other end of the surface treatment section 64 and the wafer transfer device 52. Further, 70 indicates the cassette transfer device 52.
and the cassette storage shelf 62, the cassette 10,
A cassette transfer device 72 transports the cassettes 12 from the loader 74 to each processing tank 66 in the surface processing section 64.
through the processing cassette 12 to the unloader 76.
A cassette transfer device 78 is a cassette transfer device that transfers the processing-dedicated cassette 12 from the end position of the cassette transfer device 68 to the loader 74 of the surface treatment section 64.

Although the wafer transfer device according to this invention has the above-mentioned configuration, the scope of this invention is not limited by the contents of the above explanation and drawings, and may be modified within the scope of the gist. Various modifications may be included. For example, in the above example,
Although the table on which the cassette is placed is moved in the horizontal direction, it is also possible to fix the table and move the lifting plate and the clamping arms together in the horizontal direction. In addition, in the embodiment shown in FIG.
For example, four through holes may be provided at four locations. Furthermore, it goes without saying that this wafer transfer apparatus is applicable not only to the immersion type surface treatment apparatus but also to various types of wafer surface treatment apparatuses such as heat treatment.

[Effect of idea]

Since this device is constructed and operates as described above, the device according to this device can be used in a surface processing apparatus that performs various surface treatments on wafers while a plurality of wafers are housed in a cassette. When transferring wafers between a transport cassette and a processing cassette, there is no chance that a processed wafer will touch the part of the wafer that was in contact with the wafer before processing. This eliminates the possibility of dust attached to wafers being reattached to processed wafers through parts of the equipment, and wafer transfer work is performed without any human intervention.
Problems such as adhesion of particles to processed wafers due to dust generated when people are involved in the work do not occur, and it is possible to prevent quality deterioration of surface-treated wafers and improve the quality of semiconductor devices, etc. It can contribute greatly. Furthermore, since the device of this invention does not simply have two wafer transfer mechanisms installed in series, the entire device can be miniaturized and the installation space in a clean room etc. can be reduced. At the same time, the wafer transfer work can be performed efficiently.

[Brief explanation of the drawing]

Figures 1-1 to 1-4 and Figures 2-1 to 2
Figure 4 is a schematic front view showing each step of the wafer transfer operation performed by the wafer transfer apparatus according to the first configuration of this invention, and Figure 3 is a schematic front view showing each step of the wafer transfer operation using the wafer transfer apparatus according to the first configuration of this invention. FIG. 4 is a schematic front view of a wafer transfer device showing another configuration example, and is an overall perspective view showing a specific example in which the wafer transfer device according to the invention is attached to an immersion type surface treatment device. 10...Cassette exclusively for transport, 12...Cassette exclusively for processing, 14...Table for cassette exclusively for transport, 16...Table for cassette exclusively for processing, 1
8, 22... Lower bottom opening, 20, 24... Accommodation groove, 26, 28... Through hole, 30... Elevating plate exclusively for before treatment, 32... Elevating plate exclusively for treated, 34, 3
6... Holding groove, 38... Holding arm exclusively for pre-processing, 40
...Processed dedicated holding arm, 42, 44...Wafer holding groove, 46...Common table, 48, 50...
Through hole, 52... Wafer transfer device, 54,
56...Transportation cassette table, 58,6
0...Table for processing cassette, W...Wafer before surface treatment, W'...Wafer with surface treatment.

Claims (1)

[Claims for Utility Model Registration] 1. A loading section for placing a transport cassette, which has an opening at the bottom and has housing grooves formed at a predetermined pitch on the inner surface for accommodating a plurality of wafers in alignment. At least one cassette table for transfer only, which has a through hole formed in its mounting part, and a storage groove that is also open at the lower bottom and for accommodating a plurality of wafers in alignment on the inner surface. at least one processing-only cassette table having a placing part for placing the processing-only cassette formed with the same pitch as the accommodation groove of the transport-only cassette, and having a through hole formed in the placing part;
A holding groove having an outer diameter smaller than the through hole formed in each of the tables, and a holding groove for inserting a lower end of a wafer and holding the wafer is formed on the upper surface at the same pitch as the receiving groove formed in each of the cassettes. an elevating plate, an elevating means for elevating and lowering the elevating plate by passing through the through hole of each table and the bottom opening of each cassette; Wafer holding grooves having the same pitch as the accommodation grooves formed in each of the cassettes are formed on at least one of the cassettes,
a pair of holding arms that are supported in a manner that can be expanded and narrowed, and that hold a plurality of wafers that are transferred from inside each of the cassettes to the upper surface of the lifting plate by raising the lifting plate by the lifting means; a widening means for changing the distance between the opposing sides of the clamping arms; and a horizontal movement means for moving the respective tables, the elevating plate and the clamping arms relative to each other in the horizontal direction; In the wafer transfer device, the processing-dedicated cassette table is connected to the wafer surface treatment device, and a pair of the lifting plates and clamping arms are provided, one for each wafer before surface treatment and one for wafers that have been surface-treated. At the same time, the table for the cassette exclusively for transport is horizontally movable relative to the elevating plate and the clamping arm exclusively for surface-treated wafers to positions directly above and directly below the wafer, and the table for the cassette exclusively for processing is arranged to A wafer transfer device characterized by being able to move horizontally relative to a wafer-dedicated elevating plate and a clamping arm to positions directly above and directly below them. 2. At least one transport cassette mounting section for mounting a transport cassette which has an open lower bottom and has storage grooves formed at a predetermined pitch on the inner surface for accommodating a plurality of wafers in alignment; At least one process in which a processing-dedicated cassette is placed, which is also open at the lower bottom and has storage grooves on the inner surface formed at the same pitch as the storage grooves of the transport-dedicated cassette. A table having a dedicated cassette placement part, each of which has a through hole formed therein, and a table having an outer diameter smaller than each of the through holes formed in the table, and having a lower end of the wafer on the top surface. an elevating plate in which holding grooves for holding the inserted wafers are formed at the same pitch as the accommodation grooves formed in each of the cassettes; an elevating means for elevating and lowering the cassette through the cassette, and a wafer holding groove disposed in parallel directly above the elevating plate and having the same pitch as the receiving groove formed in each of the cassettes on at least one of the opposing side surfaces; a pair of holding arms that are supported in a manner that can be expanded and narrowed, and that hold a plurality of wafers that are transferred from inside each of the cassettes to the upper surface of the lifting plate by raising the lifting plate by the lifting means; and a horizontal moving means for moving the table, the elevating plate and the clamping arm relative to each other in the horizontal direction, and the apparatus is installed in a wafer surface processing apparatus. In the wafer transfer apparatus, the table is connected to the wafer surface treatment apparatus,
A pair of the elevating plate and a pair of clamping arms are provided for exclusive use of wafers before surface treatment and a pair of wafers that have been surface treated, and the table is connected to the lifting plate and the clamping arm by a loading portion of the table for carrying the cassette. to a position directly above and directly below the lifting plate and clamping arm dedicated to wafers that have undergone surface treatment, and the mounting portion of the processing cassette of the table to a position directly above and directly below the lifting plate and clamping arm dedicated to wafers that have not yet been surface treated. A wafer transfer device characterized by being capable of relative movement in the horizontal direction.