JPS63247232A - Transporting method for semiconductor wafer - Google Patents

Abstract

PURPOSE:To certainly adsorb and transport a wafer even if the attitude of the wafer is not fixed, by allowing an adsorbing part to adsorb the wafer and to contract, correcting the attitude of the wafer in the vertical direction. CONSTITUTION:When a transport device shifts, and one among a plurality of adsorbing parts 7 contacts a wafer, the adsorbing part 7 is deformed in conformity with the attitude of the wafer and performs vacuum adsorption, since the adsorbing part 7 is made of soft material. Then the inside of a pipe part 8 is decompressed, and the adsorbing part 7 is contracted to the position balanced with the elasticity of a spring 9, correcting the wafer adsorbing state in the vertical direction, and contacts also the adsorbing parts 7 of other vacuum adsorbing jigs in this process. Therefore, the wafer is adsorbed and fixed by a plurality of adsorbing parts 7 and transported as it is to a prescribed position.

Description

[Detailed description of the invention] (a) Technical field of the invention The present invention relates to a method for transferring semiconductor wafers.

(b) Technical background Devices such as semiconductor ICs and LSIs are made of silicon (Si).
.

It is formed using a single crystal substrate made of a single or compound semiconductor such as gallium arsenide (GaAs).

This single-crystal substrate is called a wafer, and is made by slicing a rondo-shaped single crystal grown by a pulling method or the like into a thickness of about 500 μm, and polishing the surface.

The diameter of wafers has been increasing in proportion to the mass production of semiconductor parts. For example, in the case of Si, wafer diameters have progressed to 3 inches, 4 inches, and even 5 inches.

Additionally, many of the work processes are being automated.

(C) Prior art and problem 1 Thin film formation technology and photolithography are used to form semiconductor components, and epitaxial growth,
Processes such as formation of the conductive layer, resist coating, and selective etching are performed on a wafer basis, and in the final stage, the wafer is scribed to form chips.

Here, processing in each step is often carried out in this state with a plurality of wafers mounted on a wafer boulder or cassette.

For example, when performing chemical vapor deposition (CVD), a wafer holder is used, while for processes such as spackling and etching, a cassette is attached to the processing equipment, and the wafers are automatically pulled out one by one for processing. can be mass-produced without changing the environmental conditions by repeating the operation of storing it in another cassette.

In this case, once the wafers have been loaded onto the wafer holder and have been processed in bulk, it is necessary to take them out one by one and transfer them to another processing step, but a vacuum suction jig, also known as vacuum tweezers, is used for this method. ing.

Figure 1 shows a Si wafer 2 mounted on a wafer holder 1.
The figure (A) is a front view and (B) is a side view.

In the case of the embodiment shown in the figure, a wafer holder 1 made of quartz
has four sets of claws 3 to hold the Si wafer vertically.
are provided to hold the Si wafer 2 from the front and back, but the spacing between the front and rear claws 3 is set to be sufficiently larger than the thickness of the wafer in consideration of workability. As shown in , the Si wafer 2 is not strictly perpendicular to the bottom surface of the wafer holder 1, but is held slightly tilted back and forth with a margin.

On the other hand, as a vacuum suction jig for transporting the Si wafer 2, there is a flat one whose cross-sectional view is shown in FIG. 2 (A) and a plan view is shown in FIG. 2 (B). It was applied to the back side of the wafer 2 and transferred to a predetermined position by performing vacuum suction.

That is, the vacuum suction jig 4 has a suction hole 5 in the center of the lower surface, and is connected to a vacuum pump to suction the Si wafer 2 under reduced pressure in the direction of the arrow 6, thereby adsorbing the Si wafer 2 and transferring it to a predetermined location. It is something to do.

When transferring the wafer 2 manually in this way, it can be done by adjusting the posture of the object no matter what posture it is held in. However, if you try to automate the transfer of the wafer 2 using a robot, the wafer boulder 1 Since the postures of the Si wafers 2 arranged side by side are not constant, it is difficult to transfer them using a conventional vacuum suction jig 4.

(d) Purpose of the Invention An object of the present invention is to provide a wafer transfer method that can reliably perform suction and transfer even when the wafer is not in a uniform posture.

(e) Structure of the Invention The object of the present invention is to provide a device that sequentially suctions a plurality of wafers held in a vertical direction by claws provided on a wafer holder from a horizontal direction and transfers them to a predetermined position. In preparation for this, the system is equipped with a plurality of vacuum suction jigs, each of which has a pipe made of a flexible material with a suction section at its tip that can be contracted into a sleeve by a spring.
The apparatus moves in the horizontal direction, and the suction part of one of the vacuum suction jigs contacts and suctions the wafer, and contracts while correcting the posture of the wafer in the vertical direction, so that the other suction parts also absorb the wafer. This can be achieved by using a method of transferring semiconductor wafers that involves touching, suctioning, and transporting semiconductor wafers.

(f) Embodiment of the invention FIG. 3 is a perspective view of a wafer transfer apparatus according to the present invention, and FIG.
The figure is a sectional view of the vacuum suction mechanism.

The wafer transfer apparatus according to the present invention is equipped with two or more (three in the embodiment shown in FIG. 3) vacuum suction jigs, and the suction part 7 at the tip thereof is made of a flexible material such as Teflon or rubber. A pipe portion 8 having a suction hole 5 in the center and a suction portion 7 is formed to be contractible.

That is, the pipe portion 8 is made of synthetic resin or a metal pipe coated with synthetic resin, and has a structure in which a flexible suction portion 7 is fitted at the tip as shown in FIG. 4.

Further, a spring 9 is provided on the opposite side, which allows the pipe 8 to expand and contract.

Further, the end face 11 of the pipe 8 that is in contact with the sleeve 10 is configured to be airtight by making it approximate the inner diameter of the sleeve part.

A wafer transfer mechanism having such a structure is installed in an automatic machine and is connected to a vacuum pump by an exhaust system.

To explain the operation of the transfer device, when the transfer device shown in FIG. Since it is formed of wafer 2, it deforms to adapt to the posture of the wafer 2 and vacuum-chucks it.

Then, the pressure inside the pipe section 8 is reduced, and the pipe section 8 contracts while returning to its vertical position while holding the wafer 2 to a position balanced with the elasticity of the spring 9, but in the process, the suction section 7 of the other vacuum suction jig is As a result, it is suctioned and fixed by a plurality of suction parts 7, and is transferred as it is to a predetermined position.

As described above, the transfer device according to the present invention can pick up the wafer 2 even when the posture of the wafer 2 is not constant, and since the wafer 2 is fixed by suction using the plurality of suction sections 7, reliable automatic transfer is possible.

(g) Effects of the invention Until now, the posture of the wafer placed in the wafer holder was not constant, and the size of the wafer was increasing, making it difficult to automate the transfer, but it was fixed by suction at multiple positions. By implementing the present invention, automation of the transfer becomes possible.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of the wafer holder, and (A) is a front view.
Figure 2 (B) is a side view, Figure 2 is a configuration diagram of the vacuum suction jig, Figure (A) is a sectional view, Figure (B) is a plan view, and Figure 3 is a wafer transfer according to the present invention. An explanatory diagram of the method, and FIG. 4 is a sectional view of the vacuum suction mechanism. In the figure, 1 is a wafer holder, 2 is a silicon wafer, 3 is a claw, 4 is a vacuum suction jig, 5 is a suction hole,
7 is the suction part, 8 is the pipe part,
9 is a spring.

Claims (1)

[Claims] A device that sequentially suctions a plurality of wafers (2) vertically held by claws (3) provided on a wafer holder (1) from a horizontal direction and transfers them to a predetermined position opens a suction hole (5). At the center is a suction part (7) made of flexible material.
A pipe (8) having a pipe (8) at the tip thereof is provided with a plurality of vacuum suction jigs that are formed so as to be contractible inside a sleeve (10) by a spring (9), and the device moves horizontally. , the suction part (7) of one of the vacuum suction jigs contacts and suctions the wafer (2), and contracts while correcting the posture of the wafer (2) in the vertical direction. 7) is also a semiconductor wafer transfer method characterized by touching the wafer (2), suctioning it, and transporting it.