JPH02305740A - Substrate transport device - Google Patents

Abstract

PURPOSE:To transport easily a substrate in the non-contact way without flying up dust around and needing an energy source for suction by providing a gas exhaust port in the central portion of a transport plate while arranging a plurality of gas jets directed slantly to the direction of the plate axis on a concentric circle in the transport plate. CONSTITUTION:A gas exhaust port 10 is provided in the central portion of a transport plate 1, while a plurality of gas jets 13 disposed on a concentric circle in the transport plate 1 are inclined toward the axis of the plate 1. Thus, gas (a), after jetted toward the center of a substrate (wafer) 3, enters the gas exhaust port 10 so that no dust around is caused to fly up. Only an energy source for jetting the gas (a) is needed without needing the provision of any separate energy source for sucking the gas, so that a simple and economically advantageous construction is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a substrate transfer device that transfers a substrate such as a semiconductor wafer in a non-contact manner by ejecting gas.

[Summary of the Invention] The present invention provides a substrate transport device that transports substrates in a non-contact manner by ejecting gas, in which a gas discharge port is provided in the center of the transport plate, and a plurality of gas discharge ports are provided on the concentric circumference of the transport plate. By arranging the ejection holes at an angle facing the board axis direction, it is possible to transport the substrate without contact, without raising dust around it or requiring suction energy. It is.

[Conventional technology]

In general, semiconductor devices are becoming more precise and more processed.

As miniaturization progresses, the occurrence of scratches and the adhesion of dirt, especially during the transportation and manufacturing of substrates such as semiconductor wafers, have an extremely large impact on the yield of devices.

Therefore, conventional methods have been used to transport the substrate in a non-contact manner by blowing out gas. That is, gas to the substrate,
For example, by blowing out air, the space between the gas blowing part and the substrate is made smaller (that is, the width of the air flow is narrowed), and the air flow between the gas blowing part and the substrate is increased. As a result, as shown by Bernoulli's equation, the pressure between the gas jetting part and the substrate becomes low, that is, the substrate is attracted and suspended toward the gas jetting part due to the negative pressure effect according to Bernoulli's theorem. The balance with air pressure allows the substrate to be held in a non-contact manner.

Conventional substrate transfer devices of this type include those that eject gas toward the outer circumference of the wafer surface (see Figure 2) and those that combine ejection and suction (see Figure 3).
(see Fig. 4 and Fig. 4).

To explain specifically, first, the substrate transfer device (
B) is provided with an air inlet pipe (21) and a cushion chamber (22) having a diameter larger than that of the air inlet pipe (21) in communication with each other internally, and a lower end of the cushion chamber (22). A flange (23) that opens outward is provided on the outer periphery. The air a supplied to the air supply pipe (21) is
21) and the cushion chamber (22) (i.e., the air inlet) (24).
is sent to the substrate (2) via the flange (23).
5) is ejected in the direction of the outer periphery. This device (B
), the pressure in the cushion chamber (22) decreases due to the blowout of air a from the flange (23), causing the substrate (25
) are suctioned and suspended, and the substrate (25) is held in balance with the air pressure.

Next, the substrate transfer device (C) shown in FIG. 3 has a suction pipe (31) in the center and a discharge pipe (32) in the peripheral part. Then, the gas a is passed downward from the discharge pipe (32) through the orifice (33) and the discharge port (34), that is,
The gas a is ejected toward the substrate (35), and the ejected gas a is sucked through the suction pipe (31) to hold the substrate (35) (see Japanese Patent Laid-Open No. 40343/1983).

Next, the substrate transfer device (D) shown in FIG. 4 has a gas discharge hole (42) provided in the center of a circular transfer plate (41), and a gas suction hole (43) provided in the outer circumference thereof. Become. Then, the gas a is ejected from the gas discharge hole (42) via the orifice (44), and the ejected gas a is ejected from the suction hole (42).
3) to hold the substrate (45) by suction through it (Semicon NEWS 1988.11 P
37).

[Problem to be solved by the invention]

However, in order to hold the substrate (25) in the substrate transfer device (B) shown in FIG. Since it is ejected toward the outer periphery of (25), there is a disadvantage that surrounding dust is thrown up.

On the other hand, the substrate transfer devices (C) and (D) shown in FIGS. 3 and 4 require a suction energy source in addition to a jetting energy source, which makes the structure complicated, and also increases the need for manufacturing or use. There will be a cost. Further, since the adjustment of the gas ejection force and the suction force is delicate, there is a disadvantage that it takes time to adjust the gas before it is transported.

The present invention was made in view of these points, and its purpose is to prevent dust from being thrown up in the surrounding area.
Another object of the present invention is to provide a substrate transport device that can easily transport a substrate without requiring a separate suction energy source.

[Means to solve the problem]

The substrate transfer device of the present invention has the advantage that the substrate (
3) in the substrate transfer device (A) that transfers the substrate in a non-contact manner,
A gas outlet (10) is provided in the center of the conveyor plate (1), and a plurality of gas ejection holes (13) are arranged on the concentric circumference of the conveyor plate (1) so as to be inclined toward the machine axis direction. Configure.

[Effect]

According to the configuration of the present invention described above, the gas exhaust port (10) is provided in the center of the transport plate (1), and the transport plate (1)
Since the plurality of gas ejection holes (I3) arranged on the concentric circumference of the substrate (I3) are inclined in the axial direction of the conveying plate (1), the gas a is ejected toward the center of the substrate (3). Since the air enters the gas outlet (10), it does not stir up surrounding dust.

Further, since only the energy source for ejecting the gas a is required and there is no need to provide a separate energy source for sucking the gas, the structure is simple and cost-effective.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to FIG.

FIG. 1 is a cross-sectional view of the substrate transport device (A) according to this embodiment. In this figure, (1) shows a transfer plate, (2) a gas exhaust pipe, and (3) a semiconductor wafer.

The conveyance plate (1) is formed by combining a disk (4) and a lid (5).

The disk (4) has a hole (6) in the center and a concentric annular groove (7) on the periphery. M(
5) has a hole (8) in the center and one gas supply hole (9) around the hole (8). When the lid (5) and the disk (4) are combined, the hole (6) and the hole (8) communicate with each other to form a gas outlet (10). Further, a joint pipe (12) having a through hole (11) inside is provided at the center of the upper surface of the lid (5), and the gas outlet (10) and the through hole (11) communicate with each other.

The gas discharge pipe (2) is attached to this joint pipe (12).

Furthermore, in this example, a plurality of gas ejection holes (13) are provided on the lower surface of the disc (4). The gas ejection holes (13) are inclined from the bottom of the annular groove (7) toward the axial direction of the disk (4), and are arranged at equal pitches along approximately concentric circles around the circumference of the disk (4). be done. Incidentally, the inclination angle of the gas jet hole (13) is set to about 30 to 60 degrees in this example.

Then, the gas a supplied from the gas supply hole (9) is ejected downward through the annular groove (7) and the gas ejection hole (13), and then enters the gas outlet (10) and enters the ejection hole (
13), an airflow is formed towards the outlet (10).

In this example, holes (6
) and (8) are formed into a continuous arc shape.

When the wafer (3) is brought close to the disk (4) in this state, the wafer (3) will move due to the negative pressure effect according to Bernoulli's theorem.
Although it tries to come into close contact with the disk (4), it is held in a non-contact manner with respect to the disk (4) while maintaining the distance m due to the balance with the gas ejection pressure from the ejection hole (13). In the example shown, 3
An example is shown in which 1-nch wafers are held at intervals of 0.3 mm.

When transporting the held wafer (3), use the lid (5).
) is provided with an L-shaped hook (14) on the outer periphery of the wafer (
It is sufficient to restrict the escape in the lateral direction of 3).

Additionally, as a result of the experiment, when the wafer (3) approaches the disk (4), the amount of gas a blown out from the exhaust port (10) is lower than that when the wafer (3) is absent or when the distance m is large. It was found that the amount of gas a was much smaller (i.e., the flow rate of gas was restricted). This meant that the amount of dust sucked in from the surroundings was also smaller, and the 10) The amount of dust contained in gas a blown out from
is almost negligible. If a filter (15) is provided at the end of the discharge pipe (2), the amount of dust will be further reduced.

Incidentally, no reduction in the negative pressure effect due to the restriction of the gas flow rate due to Bernoulli's theorem was found. This is thought to be because the jet holes (13) are inclined in the direction of the plate axis, so even if the gas flow rate is low, the pressure between the wafer (3) and the disk (4) can be efficiently reduced. .

Also, when carrying this substrate transfer device (A) or attaching it to an automatic transfer arm (not shown), the central joint pipe (
12) may be used, but it is also possible to provide a mounting jig (indicated by a two-dot chain line) (16) around the periphery of M(5) and use this jig (16). good.

Furthermore, in order to release the holding of the wafer (3), the end of the discharge port (10), the through hole (11), or the discharge pipe (2) may be closed.

As described above, according to this example, the gas outlet (10) is provided in the center of the conveyor plate (1), and a plurality of gas ejection holes (13) are arranged on the concentric circumference of the conveyor plate (1). Transport plate (
10) is tilted in the axial direction, the gas a is ejected toward the center of the wafer (3) and then enters the gas outlet (10), so that it does not stir up surrounding dust.

Further, since there is no need to separately provide an energy source for sucking the gas a, the structure is simplified and it is advantageous in terms of cost.

In addition, even if the gas flow rate and supply pressure are reduced, the wafer (
Since the wafer (3) can be transported, no damage is caused to the wafer (3).

In addition, the wafer (3) is transferred to the transfer plate (1) by the ejection of gas a.
) side (and the flow rate of gas a and the amount of dust absorbed from the surroundings are limited, the amount of dust contained in gas a discharged through the outlet (10) is almost negligible. Become something.

In addition, when releasing the holding of the wafer (3), it is only necessary to close the discharge port (process 0) side, so there is no need to turn on the ejection energy source each time.
There is no need to newly install a solenoid valve etc. for 10FF. Therefore, the structure around the energy source is simplified and operation becomes easier.

In the above embodiment, an example was shown in which the present invention was applied to the transportation of a wafer (3), but the present invention is applicable not only to the wafer (3) but also to any plate-shaped object.

〔Effect of the invention〕

A substrate transfer device according to the present invention is a substrate transfer device that transfers a substrate in a non-contact manner by blowing out a gas, in which a gas discharge port is provided in the center of a transfer plate, and a plurality of gas discharge ports are provided on a concentric circumference of the transfer plate. Since the ejection holes are arranged and tilted toward the board axis, the board can be easily transported without contact, without raising dust or requiring a suction energy source. can be done.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing the structure of the substrate transfer device according to the present embodiment, FIG. 2 is a cross-sectional view showing the structure of a conventional example, and FIG. 3 is a cross-sectional view showing the structure of another conventional example. FIG. 4 is a sectional view showing a modification of another conventional example.

(A) is a substrate transfer device, (1) is a transfer plate, (2) is a gas exhaust pipe, (3) is a wafer, (4) is a disk 1, (5) is a lid, and (6).

(8) is a hole, (7) is an annular groove, (12) is a joint pipe, (13)
) is a gas outlet, (14) is a hook, and (15) is a filter.

Claims (1)

[Claims] A substrate transfer device that transfers a substrate in a non-contact manner by ejecting gas, comprising: a gas exhaust port provided in the center of a transfer plate; and a plurality of gas ejection holes provided on a concentric circumference of the transfer plate. A substrate conveying device arranged in an inclined manner so as to face in the direction of the board axis.