JP3082603B2 - Wafer transfer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer transfer apparatus for transferring a wafer between a wafer transfer line and a wafer processing apparatus such as a wafer polishing apparatus.

[0002]

2. Description of the Related Art FIG. 5 is a schematic plan view showing a main part of a semiconductor manufacturing line. In the drawing, reference numeral 1 denotes a transfer line for mounting the wafer 2 on the belt 1a and transferring the wafer 2 in a direction indicated by an outline arrow. A circular rotary table 3 of a wafer processing apparatus that performs processing of the wafer 2 such as polishing is installed on a side portion of the transfer line 1. A plurality of wafer holders 4 are provided on the rotary table 3, and the wafer 2 is placed on the wafer holder 4 to perform processing. A wafer transfer device 5 is provided between the transfer line 1 and the rotary table 3.

FIG. 6 is a schematic longitudinal sectional view showing a conventional wafer transfer device 5, which is disclosed in Japanese Patent Application Laid-Open No. 4-206946. The wafer transfer device 5 includes an arm 6 and a wafer holder 7, and can rotate the wafer holder 7 around one end of the arm 6 as a rotation axis. In the wafer holding unit 7, a water-containing suction pad 22 having an air hole 22a communicating with the air passage 21a is attached to a lower surface of a ceramic plate 21 having a plurality of air passages 21a. It has a configuration in which a ring-shaped retainer 23 that fits outside is attached. The air passage 21a communicates with the air passage 6a of the arm 6.

The wafer 2 is attracted to the water-containing suction pad 22 by bringing the wafer 2 into contact with the lower surface of the water-containing suction pad 22 and evacuating the air through the air passages 6a, 21a and the air holes 22a by a vacuum pump. And stop the vacuum pump or
Alternatively, when pressure is applied by blowing air, the wafer 2 can be easily removed.

FIG. 7 is a schematic longitudinal sectional view showing a wafer transfer device disclosed in Japanese Patent Application Laid-Open No. 4-225229. The wafer receiving table 31 holds the wafer 2 in a floating state through water, and a water tank 33 in which a cassette 35 for storing a wafer is submerged is installed at one end of the wafer receiving table 31. The wafer receiving table 31 is provided with a plurality of water jet nozzles 32 for supplying water between the wafer receiving table 31 and the wafer 2, and the wafer receiving table 31 has a shaft 34 provided at one end thereof. It rotates 180 ° in the vertical direction as the center.

The wafer 2 held on the wafer pedestal 31 with the polished surface down is turned upside down by the rotation of the wafer pedestal 31 by 180 °, and is immersed in the water in the water tank 33. .
Then, when water is supplied from the water injection nozzle 32 at this time, the wafer 2 separates from the wafer receiving table 31 and falls under water by its own weight. At this time, the wafer 2 can be stored in the cassette 35 by controlling the water flow in the water tank 33 by any means.

[0007]

In the wafer transfer apparatus shown in FIG. 6, since the wafer 2 is held in contact with the water-containing suction pad 22, the wafer 2 is detached from the water-containing suction pad 22 so that the wafer 2 can absorb water. Adhesion marks of the pad 22 remain. The adsorption traces are, for example, those to which silicon particles or silicon fine particles are attached and become contaminants on the surface of the wafer 2, and place a heavy burden on the subsequent cleaning process. When the wafer transfer device transfers the polished wafer 2, the abrasive grains are likely to adhere to the water-containing suction pad 22. And wafer 2
When the transfer is repeated, the abrasive grains are deposited on the water-containing suction pad 22, and the surface of the wafer 2 transferred by the wafer transfer device may be damaged.

In the wafer transfer apparatus shown in FIG. 7, the mechanism for turning (turning) the wafer receiving table 31 is complicated. The mechanism for supplying a water flow for storing the wafer 2 falling in the water into the cassette 35. There are many problems such as the need for

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a relatively simple structure without causing contamination and damage to the wafer surface by bringing the concave surface into contact with the wafer and reducing the pressure. An object of the present invention is to provide a wafer transfer device capable of transferring a wafer. It is another object of the present invention to provide a wafer transfer device that supplies pure water while reducing pressure, thereby preventing particles from adhering and achieving a cleaning effect.

[0010]

A wafer transfer apparatus according to the present invention holds a wafer in a wafer holding section having an air passage connected to a pressure reducing means, and rotates the wafer holding section by an arm section. in the wafer conveying device for conveying the said wafer holder is a surface facing the wafer forms a concave, said air passage is reached to the surface, the or tip
Rod that can supply pure water from the surface protrudes from the surface
It is characterized by having been done.

[0011]

[0012]

[0013]

[0014]

In the the present invention, since holding the wafer in a concave surface, the contact area between the wafer holder and the wafer is greatly reduced than conventionally, in preventing contamination and damage of the wafer surface
When holding the wafer under reduced pressure, the wafer
The rod prevents it from bending along the surface and thus breaks
Can be prevented. Also, at this time,
Since water is supplied, direct contact between the rod and the wafer
Absent. As a result, no trace of adsorption as in the related art remains. Further
To prevent particles from adhering and obtain a cleaning effect
Can be.

[0015]

[0016]

[0017]

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments. Embodiment 1 FIG. FIG. 1 is a schematic sectional view showing a first embodiment of the wafer transfer device according to the present invention. The wafer transfer device 5 includes:
An arm 6 made of stainless steel having a substantially U-shape and a wafer holder 7 made of resin (for example, vinyl chloride, acrylic, Teflon, or the like) that is rectangular or circular in plan view are provided. One end of the arm unit 6 is connected to the upper surface side of the wafer holding unit 7, and the other end of the arm unit 6 is used as a rotation axis for the wafer holding unit 7.
Can be rotated in the horizontal direction. The arm unit 6 has an air passage 6a connected to the decompressor 8, and the wafer holding unit 7 has a plurality of air passages 11a connected to the air passage 6a.

The lower surface of the wafer holding portion 7 is a concave surface 7a having an arc shape in cross section, and the ends of the plurality of air passages 11a reach the concave surface 7a. The concave surface 7a is formed of a material such as a resin having good wettability with water, or a coating is applied to the surface to improve the wettability of the surface. A notch 7b for fitting the edge of the wafer 2 is provided at a peripheral edge of the concave surface 7a, and the wafer 2 is held on the concave surface 7a in a state where only the edge contacts.

Next, a method of transferring the wafer 2 by the wafer transfer device 5 will be described. The wafer 2 transported on the transport line 1 shown in FIG. 5 stops at a designated location, and aligns the position of the wafer 2 with the wafer holding unit 7 of the wafer transport device 5.
The wafer holding part 7 is lowered to bring them into contact with each other. Then, the vacuum between the wafer 2 and the concave surface 7a is reduced by performing the reduced pressure suction by the decompressor 8, and the wafer 2 is adsorbed on the concave surface 7a of the wafer holding unit 7. In this state, the wafer 2 is lifted, and the wafer holder 7 is rotated to move it to a predetermined position on the rotary table 3 (for example, the wafer holder 4 in FIG. 5).
When the wafer holding unit 7 is lowered until it comes into contact with the rotary table 3 and the vacuum suction of the pressure reducing device 8 is stopped, the wafer 2 is separated from the concave surface 7 a of the wafer holding unit 7 and is placed on the wafer holding table 4 of the rotary table 3. . The decompression suction may be stopped either by turning off the decompressor 8 or closing the pipe between the decompressor 8.

According to the present invention, the wafer 2 comes into contact with the wafer holding portion 7 only at the peripheral portion thereof at the time of transfer, and the area thereof is greatly reduced as compared with the conventional case, so that contamination or damage on the surface of the wafer 2 can be prevented. . Further, it is possible to prevent the particles from re-adhering due to repetition of the transport operation.

Embodiment 2 FIG. FIG. 2 is an enlarged cross-sectional view illustrating a main part of a wafer transfer device according to a second embodiment of the present invention. In this embodiment, a portion of the wafer holding portion 7 near the notch 7b that comes into contact with the wafer 2 is formed of an elastic body 9 such as rubber having a large friction coefficient. Other configurations are the same as those shown in FIG.

With this configuration, the decompressor 8
The adhesion between the wafer holder 7 and the wafer 2 at the time of decompression is improved, and the wafer 2 is stably held on the wafer holder (concave surface 7a).

Embodiment 3 FIG. FIG. 3 is a schematic vertical sectional view showing a wafer transfer device according to the third embodiment of the present invention. In this embodiment, a support rod (rod) 10 connected to a pipe 12 for supplying pure water has a concave surface 7a.
From the center of the wafer 2 to the vicinity of the surface of the wafer 2. Pure water can be supplied to the support bar (bar) 10 via a pipe 12 by a pump 13. Other configurations are the same as those shown in FIG.

FIG. 4 is a cross-sectional view showing the support rod (rod) 10. The number of holes 10a for supplying pure water may be one as shown in FIG. 4 (a) or a plurality of holes as shown in FIG. 4 (b).

When the wafer 2 is held by suction, the pressure reducing device 8
The pressure is constantly reduced at, and at the same time, pure water is constantly supplied from the support rod (rod) 10. When the wafer 2 is detached, the suction under reduced pressure and the supply of pure water are stopped.

In this embodiment, the wafer 2 has a concave surface due to the reduced pressure.
Even if it bends along 7a, the presence of the support rod (rod) 10 can prevent cracking. Since pure water is ejected from the tip of the support rod (rod) 10 At this time, a support rod (rod) 10 and the wafer 2 is not in direct contact. In addition, since the surface of the wafer 2 is constantly in contact with pure water, the burden of cleaning, which is a subsequent step, is reduced. Furthermore, the effect of removing particles such as abrasive grains and the effect of preventing re-adhesion can be obtained.

Although FIG. 3 shows a case where the number of the support rods (rods) 10 is one, a plurality of the support rods may be used. However, in this case, in order to avoid direct contact with the wafer 2, it is necessary to adopt a configuration in which pure water can be supplied from all the support rods (bars) 10.

[0029]

As described above, in the wafer transfer apparatus according to the present invention, the contact area between the wafer and the wafer holding portion is reduced by bringing the concave surface into contact with the wafer and reducing the pressure. The wafer can be transferred without causing contamination and damage and without requiring a complicated mechanism. In addition, the rod makes the wafer a concave surface
To prevent wafer cracking
Can and also with the rod by pure water supplied from the tip of the rod
No direct contact with wafer, no trace of suction
And, further, to prevent adhesion of particles, such as cleaning effect is also obtained, et al., The present invention provides excellent effects.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a first embodiment of a wafer transfer device according to the present invention.

FIG. 2 is an enlarged sectional view illustrating a wafer holding unit according to a second embodiment of the present invention.

FIG. 3 is a schematic longitudinal sectional view illustrating a wafer transfer device according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional view of the support rod (rod) shown in FIG.

FIG. 5 is a schematic plan view showing a main part of a semiconductor manufacturing line.

FIG. 6 is a schematic vertical sectional view showing a conventional wafer transfer device.

FIG. 7 is a schematic vertical sectional view showing a conventional wafer transfer device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transfer line 2 Wafer 3 Rotary table 5 Wafer transfer device 6 Arm part 6a, 11a Air path 7 Wafer holding part 7a Concave surface 7b Notch 8 Pressure reducer 9 Elastic body 10 Support rod (rod) 10a Hole 12 Piping 13 Pump

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-272744 (JP, A) JP-A-2-283011 (JP, A) Japanese Utility Model 63-106139 (JP, U) (58) Survey Field (Int.Cl. ⁷ , DB name) H01L 21/68 B65G 49/07 H01L 21/304 648

Claims (1)

(57) [Claims] 1. A wafer transfer device for holding a wafer by a wafer holding portion having an air passage connected to a pressure reducing means and transferring the wafer by rotating the wafer holding portion by an arm portion. , the surface facing the wafer has no concave, the air passage is reached to the surface, beyond
A rod that can supply pure water from the end protrudes from the surface
A wafer transfer device characterized by being formed .