JPH0717628A - Thin plate transport method and apparatus - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a thin plate carrying method and a device for holding and carrying a thin plate such as a semiconductor wafer in a non-contact state with a wet surface. [Structure] By holding a holder 10 having a shallow recess 11 capable of accommodating the semiconductor wafer 1 facing the surface of the semiconductor wafer 1, and forming a water film between the wafer 1 and the recess 11 of the holder 10. , Holder 1 by surface tension of water
The wafer 1 is held in non-contact with 0. [Effect] Since the wafer is transferred in the state where the water film is formed between the wafer and the holder, it can be transferred without drying the surface of the wafer. Further, unlike the conventional case, no gas is sprayed and particles are not scattered even in an environment of low cleanliness, and other wafers are not contaminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin plate transfer method and apparatus for holding and transferring a thin plate such as a semiconductor wafer in a non-contact manner, and a water film between the thin plate and a holding member facing the thin film. The present invention relates to a thin plate conveying method and apparatus for generating thin sheets and holding the thin plates in a non-contact manner and supplying a large amount of water to separate the thin plates.

[0002]

2. Description of the Related Art In the manufacture of semiconductors, it is necessary to transfer a semiconductor wafer between steps, and a semiconductor wafer holding and transferring apparatus that can hold and transfer a wafer without damaging its surface is required. To be

FIG. 2 shows an apparatus for holding the outer circumference of a wafer. The wafer 1 is transferred by fixing a holding member 2 having a holding claw 3 for holding the outer periphery of the wafer 1 and a holding claw opening / closing mechanism 4 for opening and closing the wafer 1 to a predetermined size to a transfer arm 5. The carrying process is first stopped at the upper part of the wafer 1 on the mounting table 6 with the holding claw 3 being opened from the outer diameter of the wafer 1, and the carrying arm 5 is lowered and stopped at a predetermined position. In this state, the holding claw 3 is closed, the wafer 1 is held, and the transfer arm 5 is raised. After the transfer arm 5 moves up to a predetermined position, the transfer arm 5 turns to transfer the wafer 1.
However, in this mechanism, a complicated mechanism for opening and closing the holding claw is required, high precision is required, and a space for opening and closing the holding claw 3 needs to be exclusively provided in the upper portion of the wafer 1. was there. In addition, since the wafer 1 is mechanically held, mechanical damage is likely to occur, and there is a problem that the apparatus itself becomes a factor for generating dust.

On the other hand, a device for holding a wafer by the Bernoulli effect has been put into practical use. In this apparatus, as shown in FIG. 3, a holder 7 is positioned so as to be close to and opposite to the wafer 1, gas is supplied from a gas supply port 8, and gas is supplied from a gas ejection port 9 provided in the holder to the surface of the wafer 1. And the wafer 1 is held without contacting the holder 7. However, in this device, since the gas is blown onto the wafer surface, if it is required to convey the wafer surface in a wet state, there is a problem that the wafer surface is dried and cannot be used because the gas is blown onto the wafer surface. there were. In addition, it has the advantage of not mechanically damaging the wafer, but since it injects a gas, it will scatter particles in an environment with low cleanliness, which may contaminate other wafers, resulting in low cleanliness. Cannot be used in the environment. further,
Due to the Bernoulli effect, it is necessary to inject the gas at all times while holding and transporting the wafer, and a stable supply of the gas is indispensable, and maintenance for this is necessary.

[0005]

The above-mentioned problems have been encountered in the prior art of a wafer holding and carrying apparatus capable of holding and carrying a wafer without damaging the surface of the wafer. That is, in the apparatus for holding the outer periphery of the wafer shown in FIG. 2, there is a problem that the space for opening and closing the claw for holding the wafer is exclusively provided on the upper portion of the wafer. Further, in the apparatus for holding a wafer by the Bernoulli effect shown in FIG. 3, when it is required to convey the wafer in a wet state, the gas is blown on the wafer surface to dry the wafer surface. It could not be used and there was a risk that particles would be scattered by the jet gas.

It is an object of the present invention to provide a thin plate transporting method and apparatus capable of holding and transporting a thin plate such as a semiconductor wafer in a non-contact state in a wet state of the surface, and without fear of scattering particles by a jet gas. .

[0007]

According to the present invention, a water film is formed between a thin plate and a holding body facing the thin plate, the thin plate is held on the surface of the thin plate in a non-contact manner, and the thin film is held after being conveyed. A thin plate transport method characterized in that the amount of water between the thin plate and the body is increased to separate the thin plate from the holder.

Further, according to the present invention, a holding member for holding a thin plate is provided with at least one water supply port and a slip preventing means for the thin plate on the surface of the holding member, and the holding member surface is arranged downward so that the holding member can move up and down. In other words, the thin plate transporting device is provided with a water supply means for supplying a predetermined amount of water from the water supply port to the surface of the thin plate when the surface of the holding portion is opposed to the surface of the thin plate placed horizontally. Further, the present invention is characterized in that, in the above-mentioned structure, the thin plate slip prevention means is a recess formed on the surface of the holder to accommodate the thin plate, or a plurality of protrusions formed on the surface of the holding portion. It is a thin plate carrier.

In the present invention, water is not particularly limited, but pure water is desirable because it is intended for semiconductor wafers,
The surface tension of the water film can be changed by adding a small amount of various additives to water or changing the purity depending on the surface properties of the wafer, that is, whether the surface is hydrophilic or water-repellent.

In the present invention, the holder has a recess for accommodating the thin plate so that the thin plate does not slide when adsorbing by forming a water film, or a means for preventing sliding of the thin plate by providing a pin or a protrusion. is necessary. Further, as a preferable configuration of the above-mentioned recess, it is also possible to appropriately dispose a groove in the recess in order to stably hold the water film, or to arrange a spiral or concentric groove, The preferred positional relationship of the mouth is appropriately selected depending on the size and weight of the semiconductor wafer, but for example, a liquid supply port is provided at the center of the recess to form a water drop at the mouth and the water film spreads at once when touching the semiconductor wafer. It is desirable that the number of supply ports, the diameter and the shape of the supply ports be appropriately selected. Further, as the constitution of the liquid supply source, an optimum amount is supplied at the time of adsorbing the thin plate as described above, and an appropriate amount of the liquid flowing out during holding and carrying is replenished or the water film is destroyed when the thin plate is detached. Any known configuration other than the configuration of the embodiment can be adopted as long as the supply amount can be controlled such as supplying a predetermined amount of liquid. In addition, as the structure of the transfer device, various configurations are adopted according to the type and application of the thin plate such as the wafer, such that the holding body is moved close to the thin plate at a predetermined interval or vice versa, and can be moved to a predetermined position. can do.

[0011]

In the present invention, as shown in FIG. 1A, the surface tension of water is increased by causing the holder 10 to face the surface of the semiconductor wafer 1 and forming a water film between the wafer 1 and the holder 10. The wafer 1 is held without contact with the holder 10. That is, with respect to the semiconductor wafer, the holder is positioned so as to be close to and face each other, and a water film is generated in the gap, so that the surface tension of water causes
The semiconductor wafer is held in non-contact with the holder. Further, since the water film is formed on the surface of the semiconductor wafer, the surface of the semiconductor wafer is transported without being dried.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A in FIG. 1 is a longitudinal explanatory view of a transfer device in an embodiment, and B is a circuit configuration diagram of a liquid supply device. In the embodiment, the holding body 10 is fixed to the transport arm 14 which moves up and down and turns via the shaft 13,
A shallow recess 11 capable of accommodating the semiconductor wafer 1 is formed on the lower surface, and a water supply port 1 for supplying water between the wafer 1 and the holder through the shaft 13 at the center of the recess 11.
2 is provided. Between the water supply pump 14 and the water supply port 12, a supply amount control mechanism 20 in which an electromagnetic valve is arranged on the upstream side of the flow rate adjusting valve is incorporated, and the flow rate adjusting valve 21 and the electromagnetic valve 24 in the upper part of the figure are initially set. The suction flow rate supply valve, the middle-stage flow rate control valve 22 and the solenoid valve 25 are for transport time supply, the lower flow rate control valve 23 and the electromagnetic valve 26 are for separation time supply, and each flow rate control valve 21, 22, 23 is respectively The flow rate is adjusted in advance according to the function of.

Next, the carrying operation of the embodiment will be described. First, the transfer arm 14 rotates and stops on the wafer 1 on the mounting table 6. Next, the transfer arm 14 descends, and the holder 1
Stops when 0 approaches and faces wafer 1. Here, the electromagnetic valve 24 for supply at the time of initial adsorption is operated for a certain period of time to supply a predetermined amount of water from the water supply port 12 to generate a water film in the gap with the wafer 1 in the recess 11 to form the wafer 1 And then the transfer arm 14 is raised and swung to move the wafer 1 to any desired position. After the completion of the movement, when the wafer 1 is detached from the holder 10, the detachment supply electromagnetic valve 26 is operated to supply a large amount of water from the water supply port 12 to lose the retaining force due to the surface tension of the water.
Let go. When the holding time becomes long, the feeding solenoid valve 25 is operated at a proper time to replenish the water.

[0014]

According to the present invention, since the wafer can be transferred to the holder in a non-contact manner, the wafer surface is not damaged and the wafer is transferred in a state where a water film is formed between the wafer and the holder. Therefore, the wafer can be transported without being dried. Further, unlike the conventional case, no gas is sprayed and particles are not scattered even in an environment of low cleanliness, and other wafers are not contaminated.

[Brief description of drawings]

FIG. 1A is a vertical cross-sectional explanatory view showing a configuration of a thin plate holding device according to the present invention, and B is a circuit configuration diagram of a liquid supply device.

FIG. 2 is an explanatory diagram showing a configuration of a conventional thin plate holding device by mechanical holding.

FIG. 3 is an explanatory view showing a configuration of a conventional thin plate holding device by Bernoulli effect.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wafer 2 Holding body 3 Holding claw 4 Holding claw opening / closing mechanism 5 Transfer arm 6 Mounting table 7 Holding body 8 Gas supply port 9 Gas ejection port 10 Holding body 11 Recess 12 Water supply port 13 Shaft 14 Transfer arm 20 Supply amount control mechanism 21 , 22,23 Flow control valve 24,25,26 Solenoid valve

Claims (3)

[Claims] 1. A water film is generated between a thin plate and a holding body facing the thin plate, and the thin plate is held on the surface of the thin plate in a non-contact manner and conveyed, after which the amount of water between the thin plate and the holding body is increased. A method of transporting a thin plate, characterized in that the thin plate is separated from the holder. 2. A holding member for holding a thin plate, the holding member having a surface for holding at least one water supply port and a slide preventing means for the thin plate arranged downward, and a vertically movable holding member. A thin plate transporting device comprising water supply means for supplying a predetermined amount of water from the water supply port to the surface of the thin plate when the surface of the holding portion faces the surface of the thin plate placed. 3. The thin plate slip prevention means is a recess formed on the surface of the holder for accommodating the thin plate, or a plurality of protrusions formed on the surface of the holding portion. The thin plate transport device described.