JPH068086A - Vacuum suction device - Google Patents

Abstract

(57) [Summary] [Construction] In a vacuum adsorption device in which the adsorption member 10 is made of porous ceramics, the upper surface 22 of the support member 20 is also made of porous ceramics, and the average pore diameter of the porous ceramics is 10 μm or less. Or the ratio of the average pore diameter to the adsorption member 10 is 0.2 or less. [Effect] Since the polishing characteristics of the suction surface 11 and the upper surface 22 of the support member 20 are substantially equal to each other, the flatness can be extremely increased when the upper surface of the vacuum suction device is polished. Further, if the average pore diameter of the upper surface 22 of the support member 20 is set within the above range, air leakage is unlikely to occur during vacuum suction, and a suction force with no practical problem can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum suction device for sucking and holding a semiconductor wafer, a glass substrate or the like for carrying and processing.

[0002]

2. Description of the Related Art Conventionally, for example, in the manufacturing process of a semiconductor device, when a semiconductor wafer is transferred, processed, and inspected, a vacuum suction device using a vacuum pressure has been used.

As such a vacuum suction device, there is a vacuum suction device having a plurality of through holes opened on the suction surface. However, since the suction function is exerted only by the through holes, the suction becomes non-uniform, and the semiconductor wafer is processed. There was a problem such as a decrease in accuracy. Therefore, there is a vacuum suction device in which the suction surface is formed of a porous body in order to perform more uniform suction.

For example, in the vacuum suction device shown in FIG. 4, the suction member 10 made of a porous material is joined to the support member 20 with an adhesive 30 such as resin or glass. Then, the semiconductor wafer (not shown) is sucked onto the suction surface 11 on the suction member 10 by vacuum suction from the lower suction hole 21. In addition, in this vacuum suction device, in order to improve wear resistance and maintain excellent flatness, the suction member 10 has a pore diameter of 30 to 150.
It has been performed that the support member 20 is formed of a porous ceramic having a size of about μm and the support member 20 is formed of a dense ceramic (Japanese Patent Laid-Open No. 59-124536, 62-5377).
No. 4, 63-169243, etc.).

[0005]

When this vacuum suction device is used, the flatness of the suction surface 11 must be increased. Therefore, after the suction member 10 is joined to the support member 20, the upper surfaces of both of them are diamond grindstones. And so on. However, as described above, since the adsorption member 10 is made of porous ceramics, it is relatively easy to be polished, but the support member 20 is made of dense ceramics or metal, which makes it difficult to be polished. Therefore, as shown in the enlarged cross-sectional view after polishing as shown in FIG. 5, the suction surface 11 side is largely polished, and a step is likely to be formed between the suction member 11 and the upper surface 22 of the supporting member 20, and the entire upper surface of the vacuum suction device is practically used. It was difficult to achieve a level without problems (flatness 1 μm or less). When used in such a state, there is a problem that leakage occurs at the time of suction to reduce the suction force, or when used for processing a semiconductor wafer, processing accuracy deteriorates.

Therefore, in order to set the flatness of the entire upper surface to 1 μm or less, it is necessary to perform work such as polishing with a plurality of grindstones, which is troublesome.

Further, even if the flatness is polished,
Since only the suction surface 11 is easily worn during use for the same reason as described above, a step is likely to occur between the suction surface 11 and the upper surface 22 of the support member 20 in a relatively short period of use, and polishing is performed again. There was a problem that we had to do it.

[0008]

Therefore, according to the present invention, not only the suction member but also the upper surface of the support member is formed of porous ceramics to form a vacuum suction device. Also,
At this time, as the porous ceramics forming the upper surface of the support member, one having an average pore diameter ratio to the adsorption member of 0.2 or less, or an average pore diameter of 10 μm or less may be used.

[0009]

According to the present invention, since the upper surfaces of both the suction member and the support member are made of porous ceramics, the polishing characteristics of both members are substantially equal. A step is unlikely to occur in the portion, and excellent flatness can be achieved. In addition, since the amount of wear during use is almost the same, the above-mentioned step is unlikely to occur even after long-term use.

Even if the upper surface of the support member is made of porous ceramics, air leakage is less likely to occur and a suction force with no practical problem can be obtained by reducing the average pore diameter as described above.

[0011]

EXAMPLES Examples of the present invention will be described below. The same parts as those in the conventional example are designated by the same reference numerals.

The vacuum suction device shown in FIG. 1 comprises a suction member 10 made of porous ceramics, which is joined to a support member 20 with an adhesive 30 such as glass or resin. The support member 20 is formed by joining a support portion 20a made of dense ceramics and a partition wall portion 20b made of porous ceramics having a pore diameter smaller than that of the adsorption member 10, and the upper surface 22 is porous. Made of quality ceramics. In this vacuum suction device, the support member 20
When vacuum suction is performed through the suction holes 21 of the suction holes 21, the suction target 11 such as a semiconductor wafer is attracted to the suction surface 11 of the suction member 10 having a large pore diameter.
Can be adsorbed.

When the suction surface 11 is polished to increase its flatness, the upper surface 22 of the support member 20 is made of porous ceramics made of the same material as that of the suction surface 11, so that both polishing characteristics are almost the same. Therefore, as shown in FIG. 2, an enlarged cross section after polishing shows that the suction surface 11 and the support member 20 are equal.
There is no step between the upper surfaces 22 of the above, and the flatness as a whole can be made 1 μm or less by simple polishing.

Next, another embodiment of the present invention will be described.

The vacuum suction device shown in FIG. 3 is called a multi-type, and is provided with a second annular suction member 12 around a central suction member 10 with a support member 20 interposed therebetween. Independent suction holes 21 and 23 for 10 and 12 are formed. Then, as in the above-mentioned embodiment, the adsorbing members 10 and 12 are made of porous ceramics having a large pore diameter, and the supporting member 20 is a supporting portion 20a made of dense ceramics and a pore diameter larger than those of the adsorbing members 10 and 12. Partition part 2 made of porous ceramics with small size
It is configured by joining with 0b.

If this vacuum suction device is used, the suction hole 21
If vacuum suction is performed from only the suction member 10, only the central suction member 10 is sucked, so that a relatively small semiconductor wafer can be sucked. Further, when suction is performed from both the suction holes 21 and 23, both suction members 10 and 12 suction, so that a relatively large semiconductor wafer can be suctioned. Therefore, semiconductor wafers of various sizes can be sucked by simply switching the suction holes 21 and 23.

Also in this embodiment, when the upper surface of the vacuum suction device is polished, the upper surface 22 of the support member 20 is made of porous ceramics, so that the respective suction surfaces 11, 13 and the upper surface 22 of the support member 20 are polished. There is no step between them,
The overall flatness can be reduced to 1 μm or less by simple polishing.

According to the above embodiment, since the flatness of the upper surface of the vacuum suction device for sucking a semiconductor wafer can be made extremely excellent, not only the suction power can be increased, but also
When processing a semiconductor wafer that has been suction-fixed, processing accuracy can be increased. Regarding wear characteristics during use, since the suction surfaces 11, 13 and the upper surface 22 of the support member 20 are substantially equal to each other, a level difference is unlikely to occur at the boundary between both members even after long-term use, and excellent flatness can be maintained. .

Further, in the above embodiment, the adhesive 3
0 is made of glass, resin, or the like, but one having the same polishing target characteristics as those of the suction member 10 and the support member 20 is used.

In the above embodiment, as the support member 20, the partition wall portion 20b made of porous ceramics is joined to the support portion 20a made of dense ceramics so that only the upper surface 22 of the support member 20 is porous. Although the ceramics is shown, the invention is not limited to this, and the entire supporting member 20 may be formed of porous ceramics. However, the strength and rigidity of the whole can be increased by using the supporting portion 20a made of dense ceramics as in the above embodiments.

Various ceramics such as alumina, zirconia, silicon carbide and silicon nitride can be used as the porous ceramics constituting the vacuum adsorption device of the present invention. There are various methods for making these ceramics porous, but it is necessary to make the respective pores communicate with each other in order to use them in a vacuum adsorption device. For that purpose, for example, each ceramic may be formed into particles having a predetermined size, and the particles may be solidified with glass or the like and fired. According to this method, the pores can be surely communicated with each other, and the pore diameter can be easily adjusted by adjusting the particle diameter.

Further, as another method, a material which disappears during firing is mixed in the ceramic raw material, and the firing method, firing temperature or firing time is adjusted to obtain pores without densification. The porous ceramics can be obtained by, for example, a method of terminating the firing in the state in which the remaining.

Experimental Example A vacuum adsorption device of the present invention shown in FIG. 1 was prototyped and tested.

Partition wall 20 of suction member 10 and support member 20
All of b were porous ceramics obtained by solidifying alumina particles with glass and firing, and various average pore diameters were prepared as shown in Table 1. Further, as a comparative example, a conventional one in which the whole supporting member 20 is made of dense ceramics is also prepared. In addition, both are adsorption members 1
The diameter of 0 was 6 inches.

First, the suction surface 11 of these vacuum suction devices
After polishing the upper surface 22 of the support member 20 with a # 800 diamond grindstone under certain conditions, the overall flatness is measured.
The above was marked as x. Next, using each vacuum suction device, a 6-inch semiconductor wafer was suctioned by an aspirator at a suction pressure of 500 mmHg, and when the wafer surface was polished, the wafer was not peeled off, and a strong force was applied. The peeling force was evaluated as Δ, and the peeling force was evaluated as x, to evaluate the adsorption force. The results are shown in Table 1.

[0026]

[Table 1]

From these results, it is clear that No. In No. 10, since the whole supporting member 20 was made of dense ceramics, the flatness after polishing was poor, and the adsorption test was performed as it was.

No. 4 has a large average pore diameter of 10 μm of the partition wall portion 20b constituting the support member 20 and a large ratio of the average pore diameter to the adsorption member 10 of 0.2,
At the time of adsorption, air leakage from the partition wall portion 20b was large and the adsorption force was poor. On the other hand, No. No. 1 has a large average pore diameter of the partition wall portion 20b of 10 μm, but the ratio of the average pore diameter is 0.1.
Since it was as small as 125, it showed a practical adsorption power. In addition, No. 7 has a large average pore diameter ratio of 0.24,
Since the average pore diameter of the partition wall portion 20b was as small as 6 μm, a practical adsorption force was exhibited. All other examples are bulkheads 2.
Since the average pore diameter of 0b was 10 μm or less and the ratio of the average pore diameter was 0.2 or less, excellent adsorption was exhibited.

Therefore, in order to obtain a practical adsorption force, the average pore diameter of the partition wall portion 20b constituting the support member 20 is set to 10 μm or less, or the ratio of the average pore diameter to the adsorption member 10 is 0.2. It should be smaller. Further, preferably, the average pore diameter of the partition wall portion 20b is 6 μm or less, or the ratio of the average pore diameter to the adsorption member 10 is 0.1 or less.

In the above experimental example, the partition wall portion 20b and the adsorbing member 10 both have a porosity of 30 to 50% and are set to be substantially the same, and only the average pore diameter is changed. It is also possible to reduce the rate to reduce air leakage and increase the adsorption force. However, it is difficult to adjust the porosity, and if the porosity of the partition wall portion 20b is made small, it becomes difficult to polish it naturally, so that the flatness when polishing the upper surface of the vacuum suction device deteriorates. Therefore, regarding the porosities of the suction member 10 and the partition wall portion 20b,
All of them were excellent in the range of 30 to 50%.

[0031]

As described above, according to the present invention, in the vacuum adsorption device using the porous ceramics as the adsorption member, the upper surface of the supporting member is also the porous ceramics, and the average porosity of the porous ceramics is 10 μm or less. Or by setting the ratio of the average pore diameter to the suction member to 0.2 or less, the polishing characteristics of the suction surface and the upper surface of the support member become substantially equal, so that the flatness when the upper surface of the vacuum suction device is polished. Can be extremely high. In addition, since the amount of wear between the suction surface and the upper surface of the support member during use is almost the same, the flatness of the surface is less deteriorated even during long-term use. Further, since the vacuum suction tool is entirely made of ceramics, it is possible to obtain effects such as excellent corrosion resistance and abrasion resistance.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a vacuum suction device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a portion A in FIG.

FIG. 3 is a vertical sectional view showing another embodiment of the present invention.

FIG. 4 is a vertical sectional view showing a conventional vacuum suction device.

5 is an enlarged cross-sectional view showing a portion B in FIG.

[Explanation of symbols]

 10, 12 ... Adsorption member 11, 13 ... Adsorption surface 20 ... Support member 20a ... Support portion 20b ... Partition portion 22 ... Top surface 21 , 23 ... Suction hole 30 ... Adhesive

Claims (1)

[Claims] 1. A vacuum adsorption device in which an adsorption member made of porous ceramics is joined to a support member, wherein the ratio of the average pore diameter to the adsorption member is 0.2 or less, and / or the average pore diameter is 10 μm or less. Quality ceramics,
A vacuum suction device characterized in that an upper surface of the support member is formed.