JP2513160Y2 - Semiconductor wafer-transfer device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for transferring a semiconductor wafer used in semiconductor manufacturing from a cassette to another cassette.

[0002]

2. Description of the Related Art Conventionally, in the transfer of semiconductor wafers, a box-shaped container having an opening is provided with partition grooves so that about 25 wafers can be transferred in a lump, and the wafers are separated vertically. A wafer cassette formed so as to hold the wafer is used. The cassette is used properly according to the purpose, such as a transport cassette and a process cassette, and it is frequently transferred from one cassette to another cassette during semiconductor manufacturing.
Conventionally, when a semiconductor wafer is transferred to another cassette and transferred to another step, for example, 1) a method of aligning the openings of the cassette case and inverting the cassette to drop it by gravity, or 2) There is known a transfer device that uses a method in which only a wafer is pushed up from under the cassette, and the wafer is held from both side surfaces by another holder such as an arm and transferred to another cassette.

[0003]

However, in the above-mentioned conventional apparatus, in the apparatus of 1), since the wafer slides in the cassette, the peripheral portion of the wafer comes into contact with the partitioning groove of the cassette, There were problems such as scratches on contact, dust generation, and charging. Also, in the case of the device of 2), there are two or more opportunities for contact when pushing up from below and holding it with another holder such as an arm that has come out from both sides. However, there is a problem that the number of wafers that are contaminated by the contact of the wafers becomes large. In recent years, the degree of integration of semiconductors has increased and a cleaner environment has been required, and it has been required to reduce the dust generation as described above. Also, there is a tendency that the size of the wafer becomes large in order to reduce the production cost of the semiconductor, and when the size of the wafer becomes large, the wafer slides on the cassette when transferring using the above-mentioned conventional transfer device. In some cases, there is a risk that the wafer may be damaged, and there has been a demand for a semiconductor wafer transfer device capable of handling a wafer having a particularly large diameter. The present invention has been made in order to solve the above-mentioned drawbacks of the prior art. It is a semiconductor that can prevent dusting, electrification, contamination, etc. that occur when a semiconductor wafer is transferred, and can reliably transfer a wafer with a large diameter. An object is to provide a wafer transfer device.

[0004]

A semiconductor wafer transfer device according to the present invention is a cassette capable of holding a plurality of semiconductor wafers.
From one source cassette to the other loading cassette.
Equipment for transferring semiconductor wafers to a set at once
And a cassette moving stage having means for horizontally moving two cassettes , a source cassette and a loading cassette, and a wafer that can vertically hold the semiconductor wafer in the cassette by sandwiching the edge portion of the semiconductor wafer. and holding pallet, holding the wafer holding pallet cassette on Hogaibu
Holdable pallet holding means and wafer holding pallet
Can be connected / disconnected, and the pallet can be placed outside the cassette below
Equipped with a pusher that can be moved vertically from above to outside
Well, only the pusher can be applied to the cassette movement stage.
And pusher with wafer holding pallet connected
The opening that can pass in the direction corresponds to the cassette mounting position
Provided, cassette only pusher and wafer holding
Can pass vertically through the pusher to which the pallet is connected
It has a structure formed in .

[0005]

The semiconductor wafer transfer device constructed as described above operates as follows. First, the source cassette 21 in which the semiconductor wafers 4 are stored is placed on the cassette moving stage 3, then the moving stage 3 is moved in the horizontal direction, and the source cassette 21 is stopped at a position above the pusher 5. Next, when the pusher 5 is operated and the wafer holding pallet 6 provided at the tip of the pusher 5 approaches the wafer 4, the semiconductor wafer 4 holds the edge portion of the wafer holding pallet 6 vertically and holds it. When the holding pallet 6 moves above the outside of the source cassette 21, since the wafer 4 is held vertically inside the cassette 2, it comes out of the cassette 2 without coming into contact with the groove of the cassette, and the pallet holding arm 15 Held in. When the wafer 4 and the wafer holding pallet 6 are stopped outside, the cassette holding stage 6 moves horizontally while the wafer holding pallet 6 is held by the upper and outer parts of the cassette 2, and the loading cassette 22 Is stopped under the wafer holding pallet 6, the pusher 5 descends and the wafer 4 and the wafer holding pallet 6 move to the inside of the loading cassette 22 together with the pusher 5. At this time, since the wafer 4 is held vertically, the wafer 4 enters the loading cassette 22 without coming into contact with the groove inside the cassette, and when the holding of the wafer 4 by the wafer holding pallet 6 is released, the wafer holding pallet 6 Moves down, the wafer 3 is stored and held in the loading cassette 22, and the transfer is completed.

[0006]

Embodiments of the present invention will be described in detail below with reference to the drawings. 1 shows an embodiment of the present invention, FIG. 1 is an explanatory view showing an example of a semiconductor wafer transfer device of the present invention when viewed from the front, and FIG. 2 is a side view of the device shown in FIG. It is explanatory drawing which shows a case. As shown in FIGS. 1 and 2, the semiconductor wafer transfer device 1 of the present invention comprises a cassette moving stage 3 having means for horizontally moving two cassettes 2 of a source cassette 21 and a loading cassette 22, and a cassette moving stage 3. 2 is provided with a pusher 5 for pushing up the semiconductor wafer 4 from below, and a wafer holding pallet 6 for holding the wafer 4 in a vertically standing state is provided at the tip of the pusher 5, and the pusher 5 above the pusher 5 is provided. A pallet holding arm 15 for holding the wafer holding pallet 6 on the upper portion of the cassette 2 is provided on the wafer cassette 2. Further, in the device of the present invention, the orientation flat aligning machine 16 may be provided below the source cassette 21 as shown.

FIG. 3 is an exploded perspective view showing an example of the wafer holding pallet 6. As shown in FIG. 3, the wafer holding pallet 6 comprises a pallet body 7 and a moving pressure contact portion 8. The pallet body 7 is provided with a groove 9 for holding the edge portions of the plurality of wafers 4, and two fitting grooves 10 are provided in a direction orthogonal to the groove 9. The moving press contact portions 8 are provided on the two legs 11 that fit into the fitting grooves 10 of the pallet body 7 in a toothed shape according to the number of the wafer holding grooves 9 of the pallet body 7. A pressure contact plate 12 is provided. The number, size, position and the like of the wafer holding grooves 9 can be arbitrarily formed as long as the wafer can be securely held vertically, and can be changed depending on the size of the wafer cassette 2 to be transferred. It may be decided as appropriate.
For example, in the case of a device for an 8-inch wafer, normally 25 grooves 9 are provided so that 25 wafers 3 are held, the width of each groove 9 is about 3 mm, and the width of the groove ridge 91 is 2.5 mm. It is preferable that the groove 9 is provided to a certain extent and the depth of the groove 9 is 3 mm. Incidentally, it is preferable that the tip of the groove ridge 91 is obliquely cut as shown in FIG. 4 because the wafer 4 can be smoothly accommodated when it enters the groove 9.
Further, the pressure contact plate of the moving pressure contact portion 8 can be formed according to the size of the groove 9. Materials of the pallet body 7 and the moving press contact portion 8 of the wafer holding pallet 6 are not particularly limited,
It is preferable that the portion contacting the wafer 4 is made of a fluororesin.

As a means for holding and releasing the wafer 4 by moving the moving pressure contact portion 8 of the wafer holding pallet 6, an actuator 14 is provided below the wafer holding pallet 6 as shown in FIG. 1, for example. The wafer can be held and released by the actuator 14. Specifically, the moving pressing portion 8 is formed so as to be pressed by a pressure of a spring or the like, and is kept in a wafer holding state (a pressed state) at all times, and the actuator 14 is forced by a solenoid or the like to hold the wafer holding pallet. It may be formed so that the force of the spring of the moving pressure contact portion 8 of 6 is weakened to release the pressure contact. When the wafer is held by pressing it again, the solenoid of the actuator 14 is turned off, and the spring of the pallet operates in reverse to hold the wafer.

4A and 4B are explanatory views showing the state of holding and releasing the wafer on the wafer holding pallet 6, where FIG. 4A shows the state where the wafer is released, and FIG. 4B shows the state where the wafer is held. As shown in FIG. 4, the pallet body 7 and the moving pressure contact portion 8 are formed such that the pressure contact plate 12 of the moving pressure contact portion 8 is movable inside the wafer holding groove 9, and the normal pressure contact plate 12 is formed by a spring. Is pressed against the holding wall 13. When holding the wafer 4, the moving pressure contact portion 8 is moved to open the groove 9 so that the peripheral edge of the wafer 4 contacts the holding wall 13 of the groove 9 (see FIG. a)). Next, the moving pressure contact portion 8 can be moved in the direction of arrow A, and the wafer 4 can be held by the holding wall 13 and the pressure contact plate 12 to hold the wafer 4 vertically.
It is important for the apparatus of the present invention to use the wafer holding pallet 6 described above. By using the wafer holding pallet, a plurality of wafers can be vertically held and moved at one time. It is possible to transfer with the minimum.

Wafer cassette 2 for storing wafers
Can use a cassette used for this kind of semiconductor manufacturing, and is usually formed in a box shape with a groove having an open upper part and a lower part so that 25 wafers can be stored. Use one.

The cassette moving stage 3 is provided with a stepping motor for moving the cassette 2 in the horizontal direction and is formed so as to move smoothly on the guide rail 7.
It has positioning sensors on the left and right so that the cassette can be stopped at a predetermined position, and is further equipped with a cassette presence detection sensor, a wafer confirmation sensor, and the like.

The pusher 5 is for moving the wafer holding pallet 6 up and down, and it is sufficient that the wetter holding pallet 6 can move a distance from the bottom to the top of the outside of the cassette 2, and at a predetermined position. A positioning sensor is provided at a predetermined position so that the wafer holding pallet can be stopped, and is moved up and down by a stepping motor to move the wafer holding pallet at an arbitrary speed.

The pallet holding arm 15 may have a mechanism capable of holding the pallet moved to the upper part of the cassette. For example, in the apparatus shown in FIG. 2, the arm tip portion 18 can extend and contract horizontally in the direction of the wafer holding pallet 6. The wafer holding pallet 6 can be supported from below and forward by extending the arm tip portion 18.

An example of use when actually transferring a wafer using the semiconductor wafer transfer device of the present invention will be described below with reference to FIGS. 1 and 2. In the apparatus shown in FIGS. 1 and 2, first, the power is turned on to return the respective positions of the cassette moving stage 3, pusher 5, and orientation flat aligning machine 16 to the origin, and the holding portion of the wafer holding pallet 6 is opened. After that, the source cassette 2 containing the wafers
Place 1 on top of the orientation flat. Next, the orientation flat aligning machine 16 is moved up to perform the orientation flat alignment, and the stage 3 is moved so that the source wafer cassette 21 subjected to the orientation flat alignment is on the wafer holding pallet.
The load cassette 22 is horizontally moved so as to come to a certain position of the load cassette 22 in the direction of, and the load cassette 22 is set at a predetermined position on the stage 3. Next, the pusher 5 is raised to bring the wafer 4 into the bottom of the groove 9 of the wafer holding pallet 6.
Contact with the pressure contact plate 12
To hold the wafer 4 vertically. In addition, it is preferable to control the moving speed of the pusher so that the wafer 4 and the holding pallet 6 come into soft contact with each other. When it is confirmed that the wafer 4 is normally held in the groove 9 of the wafer holding pallet 6, the pusher 5 is further raised and stopped when the wafer holding pallet 6 comes out of the cassette 21. The pallet support arm 15 holding the pallet 6
After being held by holding it from both sides in the horizontal front-rear direction, the pusher 5 is lowered until the tip end thereof is below the cassette. At this point, the wafer 4 stored in the wafer source cassette 21 is completely removed from the cassette 2.

Next, while the wafer holding pallet holding the wafer is held on the upper part of the cassette by the pallet supporting arm, the empty loading wafer cassette 22 containing no wafer is positioned below the wafer holding pallet 6. As described above, the cassette moving stage is horizontally moved in the direction of arrow B, the pusher 5 is raised again, and the pusher 5 is passed through the inside of the empty loading wafer cassette 22 to be connected again to the upper wafer holding pallet 6. And the inside of the cassette is lowered to move the wafer 4 to a predetermined position (the position where the wafer 4 comes into contact with the bottom of the cassette 2), and the moving press contact portion 8 pressing the wafer 4 is moved to move the wafer 4 Release the hold. After the release, the pusher 5 is lowered to separate the wafer holding pallet 6 from the wafer 4, the wafer 4 is stored in the loading wafer cassette 22, and the transfer is completed.

The size of the semiconductor wafer applied to the semiconductor wafer transfer apparatus of the present invention is not limited to 4 inches, 5 inches, 6 inches, 8 inches, etc., and a wafer holding pallet of any size can be used. The size and the like can be appropriately formed and used accordingly. In particular, the device of the present invention is most suitable for transferring a large size wafer such as an 8-inch wafer.

[0016]

As described above, the semiconductor wafer transfer device of the present invention has the following effects by adopting the above-mentioned configuration. The semiconductor wafer transfer device of the present invention, compared with the conventional transfer device, uses a wafer holding pallet to hold semiconductor wafers, so that the wafer can be held vertically and moved up and down inside the cassette. Therefore, it is possible to move without rubbing against the groove or side wall of the cassette, and it is possible to suppress the generation of dust and charging due to rubbing. Furthermore, since the edge of the semiconductor wafer is held by the wafer holding pallet, only the peripheral edge of the wafer comes into contact with the transfer device only once, and the contact point and contact area by the transfer device are minimized. In addition, it has the effect of preventing the wafer itself from being contaminated by contact. In addition, since the wafer itself is securely held by the wafer holding pallet during the transfer of the semiconductor wafer, there is no possibility that the wafer will be scratched or damaged, and the semiconductor wafer of a particularly large size is transferred. Reliable transfer can be performed even on a wafer.

[Brief description of drawings]

FIG. 1 shows an example of a semiconductor wafer transfer device according to the present invention,
It is explanatory drawing at the time of seeing from the front.

FIG. 2 shows an example of a semiconductor wafer transfer device according to the present invention,
It is explanatory drawing at the time of seeing from a side surface.

FIG. 3 is an exploded perspective view showing an example of a wafer holding pallet used in the transfer device of the present invention.

FIG. 4 is an explanatory view showing a state of holding and releasing a wafer on a wafer holding pallet, (a) showing a released state, and (b) showing a held state.

[Explanation of symbols]

 1 Semiconductor Wafer Transfer Device 2 Wafer Cassette 3 Cassette Moving Stage 4 Semiconductor Wafer 5 Pusher 6 Wafer Holding Pallet 7 Pallet Main Body 8 Moving Pressing Section 15 Pallet Holding Arm

Claims (1)

(57) [Scope of utility model registration request] 1. A cassette capable of holding a plurality of semiconductor wafers.
And load one cassette from one source to the other
For transferring semiconductor wafers collectively to a cassette
An apparatus, which is capable of holding a cassette moving stage having means for horizontally moving two cassettes , a source cassette and a loading cassette, and vertically holding the semiconductor wafer in the cassette by sandwiching an end edge portion of the semiconductor wafer. and the wafer holding pallet on a cassette the wafer holding pallet Hogaibu
Pallet holding means that can hold the
The pallet can be connected to or disconnected from the
With a pusher that can move up and down from outside to above
Only the pusher is provided on the cassette moving stage.
And push up the pusher to which the wafer holding pallet is connected.
The opening that allows passage downward corresponds to the cassette mounting position.
The cassette is installed only on the pusher and the wafer
Can pass vertically through pushers to which holding pallets are connected
A semiconductor wafer transfer apparatus characterized by being formed on the ability.