JPS638135A - Chuck device - Google Patents

Abstract

PURPOSE:To hold a wafer without entailing any contact with the semiconductor wafer and perform its conveyance so effectively, by installing a nozzle mechanism, feeding air, in a chuck surface, facing an article, of a pad. CONSTITUTION:When a high pressure air flow is made so as to be fed into the air flow passage 26 formed in an arm 24, a film of the high pressure air flow is formed on a chuck surface 25 at each underside of pads 231-233 from the circumference of a nozzle 28 by a flow of air, and a semiconductor wafer 11 comes into a state of being attracted toward each chuck surface 25 of these pads 231-233. And, when the wafer 11 is attached so as to comes nearer to the chuck surface 25, a space D becomes narrowed whereby resistance of the air flow grows large, and the flow velocity comes down so that attraction is lowered. And, again the space D becomes larger, and air flow velocity in this space D part is increased and the attraction is increased as well.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a semiconductor wafer in the manufacturing process of a semiconductor device, or a glass plate for a liquid crystal cell, etc., which is subjected to surface treatment, and this surface portion is treated. The present invention relates to a chuck device for conveying articles that cannot be touched.

[Prior Art] For example, in the process of manufacturing a semiconductor device, a large number of chips are sectioned on a semiconductor wafer 11 as shown in FIG. 3, and a predetermined semiconductor circuit device is incorporated into each chip. That's what I do. In this case, the wafer 11 is transported between manufacturing devices according to the manufacturing process, and in particular, during this transport, there is no need to contact the surface of the wafer 11 that has been surface-treated during the manufacturing process of the semiconductor circuit device. Care must be taken to ensure that there is no

In other words, a semiconductor wafer consists of a front surface 111 on which circuit elements and the like are formed and a back surface 112 which is a raw material. When the surface 111 becomes dirty or scratched, the soiled part and the scratched part will be damaged. The chip becomes defective, and therefore, it is not possible to set up a transport operation state in which it comes into contact with this surface 111.

Therefore, in the semiconductor manufacturing process, a transport mechanism 12 as shown in FIG. 4, for example, is used to transport the semiconductor wafer 11 between processing steps. That is, this transport mechanism 12 has a pair of claws 131 and 132, and the semiconductor wafer 11 is held by the claws 131 and 132 such that the outer circumference of the semiconductor wafer 11 is sandwiched between the claws 131 and 132.

However, in a chuck device having such a configuration, there is a risk of damaging the outer diameter portion of the semiconductor wafer 11, and it is difficult to reliably protect the wafer 11.

It has also been considered to attach a suction cup-like chuck device to the surface of the semiconductor wafer 11 to transport the semiconductor wafer. If the back side of the semiconductor wafer is used, the front side of the wafer 11 can be protected, but there are restrictions on the transportation method.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned points. An object of the present invention is to provide a chuck device that can effectively transport a wafer between processing devices in, for example, a semiconductor manufacturing process.

Means for Solving Problem E] That is, the chuck device according to the present invention includes a pad having a flat surface facing a predetermined surface of an article to be transported, such as a semiconductor wafer, to be held, A nozzle mechanism for sending out a gas such as air is formed on the chuck surface of this pad facing the article. The nozzle mechanism is configured to generate a gas flow substantially parallel to the chuck surface of the pad.

[Operation] In the chuck device as described above, when a gas flow is sent out from the nozzle mechanism, a high-speed air flow is generated between the chuck surface of the pad and the holding surface of the held article. In particular, when the gap between the surface of the semiconductor wafer and the chuck surface of the pad is set to be small, a suction force known from Bernoulli's theorem acts on the wafer being transported by the film of the high-speed gas flow. It becomes like this. Therefore, the semiconductor wafer is in the same state as if it were held by the pad, and a gap is set between the pad and the wafer, so that they do not come into contact with each other. That is, the semiconductor wafer is held in a non-contact state and transferred between predetermined processing mechanisms.

[Embodiments of the invention] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows one of the chuck devices 21 that holds one semiconductor wafer 11. For example, three pads 2 are mounted on a base 22 constituting this chuck device 21.
81 to 233 are installed on the same plane. The semiconductor wafer 11 is held by these three pads 231 to 234.
The base 22 with 31 to 233 attached is held by an arm 24, which is connected to a transfer device not shown in this figure, so that the chuck device 21 is transferred along a predetermined transfer path. .

FIG. 2 shows a portion of the chuck device 21 as described above, which corresponds to one pad 281.
The other pads 232 and 233 are similarly constructed.

This pad 231 is connected to the semiconductor wafer 1 to be held.
A flat chuck surface 2 that faces the holding surface of 1
5, and the arm 2 is opened at the center of the chuck surface 25 through the base 22.
An airflow passage 26 is formed that communicates with four parts. Then, air flow from a pump mechanism (not shown) is supplied to this air flow passage 26 as shown by the arrow (
There are 7.

This airflow passage 26 is configured so that the portion opening to the chuck surface 25 of the pad 231 is tapered so that the diameter increases in the direction of the chuck surface 25. The nozzle 27 is formed in the portion where the hole is removed. And this tapered nozzle 2
A valve 28 is set within the valve 7.

This valve 28 is configured in a tapered shape so as to correspond to the tapered nozzle 27 described in 1.
8 is held and set within the air flow passage 26 by a cylindrical main body portion 281. In this case, a conically widening gap is formed between the outer circumferential surface of the valve 28 and the inner circumferential surface of the air outlet 27, and air flows from this gap. is sent out toward the holding surface of the semiconductor wafer 11 so that it is substantially parallel to the chuck surface of the pad 231.

That is, if the semiconductor wafer 11 is set in a state sufficiently close to the chuck surface 25 of the pad 231 and the air flow is sent out from the nozzle 27 in this state, the holding surface of the semiconductor wafer 11 and A thin layer of air is formed between the chuck surface 25 and the chuck surface 25.

The base 22 is provided with three locking claws 291 to 293 located between the pads 231 to 233 and extending in the outer circumferential direction. The end portions of each of the locking claws 291 to 293 are bent downwardly so as to be located on the outer periphery of the semiconductor wafer 11 to be held. This is to prevent the position from shifting in the direction.

That is, in the chuck device configured as described above, when a high-pressure air flow is sent into the air flow passage 26 formed in the arm 24, this air flow causes the pads 231 to A film of high-speed airflow is formed on the chuck surface 25 on the lower surface of the chuck 233 as shown by the arrow in the figure. In particular, this chuck surface 2
When the gap between the chuck surface 25 and the surface of the semiconductor wafer 11 to be held is small, the air velocity flowing in this gap becomes high, and as known from Bernoulli's theorem, the chuck surface 25 and the semiconductor wafer 11 are The space between the holding surface of the wafer 11 and the holding surface becomes a space with reduced pressure. Therefore, the semiconductor wafer 11 is sucked toward the chuck surface 25 of each of the pads 231 to 233. And wafer 11
When the air is sucked close to the chuck surface 25, the above-mentioned interval becomes small, the resistance of the air flow increases, the flow velocity decreases, and the above-mentioned suction force decreases. Then, the gap becomes larger again, the air flow velocity in this gap increases, and the suction force increases.

That is, each of the pads 231 to 233 suctions and holds the semiconductor wafer 11, for example, 6 pads.
When supplying an air flow of Kg/IIl [112], the above-mentioned spacing is such that it remains between 0.6 and 0.81. Then, without contacting this semiconductor wafer 11,
The semiconductor wafer 11 is held by this chuck device.

If the semiconductor wafer 11 is held in this state, there is no frictional force due to contact between the semiconductor wafer 11 and the chuck device, so if a slight tilt occurs,
The held semiconductor wafer 11 may shift laterally. However, such displacement of the semiconductor wafer 11 is prevented by the locking claws 291 to 293.

In this way, this chuck device can hold the semiconductor wafer 11 in a non-contact state on either side of the semiconductor wafer 11, and prevents damage to the semiconductor wafer 11. For example, it becomes possible to transport the material between processing steps in a safe manner without causing any damage. In addition, since this chuck device uses a high-pressure air flow,
The holding surface of the semiconductor wafer 11 is protected by the airflow, and the adhesion of dust and the like generated during the transportation of the wafer 11 can be effectively prevented. Since there is no frictional force between this chuck device and the semiconductor wafer 11 being transported, the semiconductor wafer 11 that is being held can be precisely positioned and further rotated. This makes it possible to reliably prevent damage to the semiconductor wafer 11 during the transportation process by this chuck device and further during handling during the processing process.

In the first embodiment, the chuck device is equipped with three pads 23.
Although it has been explained that the pads are composed of pads 1 to 233, it is possible to use only one pad, depending on the condition of the object to be transported, and of course, it is also possible to use a larger number of pads. It is. Further, the gas used is not limited to ordinary air, but nitrogen gas or the like may be used depending on the usage situation. Furthermore, by appropriately setting the arrangement shape of the pad, it is possible to give rotation to this story while holding an object, and it is also possible to clean the holding surface of the object. Therefore, it can be used more effectively in the manufacturing process of semiconductor wafers and the like.

[Effects of the Invention] As described above, the chuck device according to the present invention can hold an article to be transported, such as a semiconductor wafer, without contacting the object, and can transport the article, for example, between processing steps in a manufacturing process. Moreover, during this conveyance process, dust and the like are effectively prevented from adhering to the holding surface of the article. Therefore, it is possible to adsorb and transport not only semiconductor wafers but also surface-treated items such as glass plates for liquid crystal cells without contacting the treated surface. It is possible to transport the articles in such a way that they can be reliably protected from damage, and it can be effectively used in the manufacturing process of semiconductor devices and the like.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a chuck device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG.
The figure shows a semiconductor wafer being transported by a chuck device.
FIG. 4 is a diagram illustrating an example of a conventional chuck means for a semiconductor wafer. 11... Semiconductor wafer, 21... Chuck device, 2
2...Base, 231-233...Pad, 24.
...Arm, 25...Chuck surface, 26...Air flow path, 27...Nozzle, 28...Valve, 291~
293...Latching claw. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (1)

[Claims] Set to face a flat holding surface of an article to be transported,
A pad whose surface facing the holding surface is flat and used as a chuck surface; A nozzle mechanism formed on this pad so as to face the holding surface of the article; and a gas flow set to a pressure in the nozzle mechanism. The nozzle mechanism includes a valve having a tapered surface such that a portion corresponding to the chuck surface of the pad has a large diameter, and the gas is supplied along the tapered surface of the valve. A chuck device characterized in that a gas flow passage is formed, and the gas flow is set to be substantially parallel to a chuck surface of the pad.