JPH0697147A - Dryer - Google Patents

Abstract

PURPOSE:To suppress adhesion of dust particles to a member to be dries in drying step while allowing mass processing in a short time and to carry out cleaning step and drying step of the member to be dried in assembly-line operation. CONSTITUTION:The dryer comprises a filter 2 for purifying the air 1 and a heater 6 for heating the purified air 1 and a wafer (member to be dried) 3 is dried through convection of purified and heated air 1. The wafer (member to be dried) 3 is contained in a cartridge (containing means) 5 and transferred on a transferring means 4 continuous with a cleaning equipment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drying apparatus, and more particularly to a technique effectively applied to a drying apparatus for a semiconductor wafer (hereinafter simply referred to as a wafer) in a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art For example, as a drying device after cleaning a wafer, a rotary drying device and a steam drying device are widely known.

Here, the rotary drying device is a device for rotating a wafer contained in a cassette at a high speed to remove moisture on the wafer by centrifugal force to dry the wafer.

Further, the vapor drying apparatus is provided with a solvent heated to a temperature higher than the boiling point in the lower portion of the apparatus, and vapor of the solvent rises to remove moisture remaining on the wafer suspended above. It is an apparatus for drying a wafer by melting it.

[0005]

However, on the wafer dried by the rotary dryer, the water droplets that have jumped off are reflected and re-attached on the wall around the apparatus, or due to the difference between the internal and external pressures of the apparatus, the external air is removed. In many cases, foreign matter in the air is caught by being caught.

Further, foreign matter in the solvent adheres to the wafer dried by the steam drying device, or foreign matter in the air adheres when the cleanliness of the room in which the drying process is performed is low, In any of the devices, the foreign matter attached to the wafer was often a problem.

Since the ions and foreign substances attached to the wafer deteriorate not only the device characteristics but also the process yield, there is an urgent need to reduce the attached foreign substances. In addition, if the foreign matter on the wafer is not reduced, it will be difficult to miniaturize the device process in the future.

If a large number of wafers can be dried at the same time and the wafers can be dried in a short time, the wafer drying process can be made efficient.

Further, although wafer cleaning and drying are currently separate processes, if they can be made consistent, the production efficiency can be greatly improved.

Therefore, an object of the present invention is to provide a technique relating to a drying device capable of further reducing the adhesion of foreign matter to a member to be dried in a drying process after cleaning the member to be dried such as a wafer. .

Another object of the present invention is to provide a technique relating to a drying device capable of simultaneously drying a large amount of members to be dried.

Another object of the present invention is to provide a technique relating to a drying device capable of drying a member to be dried in a shorter time.

Still another object of the present invention is to provide a technique relating to a drying device capable of making cleaning and drying processes of a member to be dried consistent.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0015]

The typical ones of the inventions disclosed in the present application will be outlined below.

That is, the invention according to claim 1 is a drying device in which a filter for cleaning air is provided, and the member to be dried is dried by convection of the air cleaned by the filter.

According to a second aspect of the present invention, there is provided a drying device in which the filter comprises a filter for cleaning air by a charging action and a filter for cleaning air by a chemical action.

According to a third aspect of the invention, a heater for heating air is provided in the drying device, is cleaned by a filter, and the member to be dried is dried by convection of the air heated by the heater. It is a device.

According to a fourth aspect of the invention, a static electricity removing device is provided between the filter and the member to be dried, and the member to be dried is dried by the air passing through the static electricity removing device.

According to a fifth aspect of the invention, there is provided a drying device provided with a microwave generator instead of the heater used in the drying device according to the third aspect.

The invention according to claim 6 is a drying device in which a member to be dried is housed in a housing means and dried while being carried by a carrying means continuous with a cleaning device.

The invention according to claim 7 is a drying device in which a large number of gaps are provided in the conveying means.

[0023]

According to the first aspect of the present invention, since the member to be dried is dried by the convection of the cleaned air, it is possible to reduce the number of foreign matters attached to the member to be dried after drying.

According to the second aspect of the present invention, the amount of ions adhering to the member to be dried can be reduced by the action of the filter for cleaning the air by the chemical action.

According to the third aspect of the invention, since the member to be dried is dried by the convection of the air heated by the heater, the drying time can be shortened.

According to the fourth aspect of the present invention, the static electricity charged on the foreign matter when passing through the filter is removed by passing through the static electricity removing device. Can be reduced.

According to the fifth aspect of the present invention, since the member to be dried is dried by the microwave generator, the drying time can be further shortened as compared with the case where the heater is used for heating and drying.

According to the sixth aspect of the present invention, since the member to be dried is stored in the storing means and is dried while being conveyed by the conveying means connected to the cleaning device, a large amount of the member to be dried can be dried at the same time. In addition, each step of cleaning and drying the member to be dried can be made consistent.

Further, according to the invention as set forth in claim 7, since a large number of gaps are provided in the conveying means, for example, when it is not possible to secure an air discharge space on both sides of the conveying means, this gap is used as the discharge space. Can be

[0030]

[Embodiment 1] FIG. 1 is an explanatory view of a main portion of a drying apparatus according to an embodiment of the present invention, and Table 1 shows the number of foreign matters attached to a wafer after drying by the drying apparatus and a conventional rotary drying apparatus. It is a comparison table showing.

First, the construction of the drying apparatus in this embodiment will be described with reference to FIG.

A filter 2 for cleaning the air 1 is provided at the upper part of the apparatus, and a transfer means 4 for laterally transferring a wafer (member to be dried) 3 is provided at the lower part of the apparatus. . Then, the wafer (member to be dried) 3 is housed in a cartridge (housed means) 5 and carried by the carrying means 4.

Here, the conveying means 4 is provided with a large number of gaps 4a, and the convection of the air 1 is discharged to the outside of the apparatus through the gaps 4a.

By the carrying means 4, a cleaning device (not shown) and this drying device are connected. That is, the plurality of wafers (members to be dried) 3 accommodated in the cartridge (accommodating means) 5 are first cleaned and dried while being conveyed by the conveying means 4.

Next, the operation of the drying device in this embodiment will be described.

After the cleaning, the plurality of wafers (members to be dried) 3 housed in the cartridge (housed means) 5 are carried by the carrying means 4 from the cleaning device (not shown) to the drying device and the drying device It is transported laterally inside.

Here, the wafer (member to be dried) 3 is stored in the cartridge (storage means) 5, and the filter 2
It is applied to the convection of the air 1 cleaned by the above and dried.

On the other hand, the air 1 which has dried the wafer (member to be dried) 3 is discharged to the outside through the gap 4a provided in the transfer means 4 as described above.

Here, comparing the number of foreign matters adhering to the wafer (member to be dried) 3 after drying by the drying apparatus of the present embodiment, which the inventor of the present invention has experimented with, with the conventional rotary drying apparatus, It is as 1.

[0040]

[Table 1]

Wafer (member to be dried) 3 in this experiment
Has a diameter of 3 inches, and foreign particles of 0.3 μm or more are targeted. Further, the cleanliness of the drying apparatus of this embodiment is 0.2 μm for foreign matter, class 10, and the temperature of air 1 is 40 ° C.

As is apparent from the results of this experiment, according to the drying apparatus of this embodiment, the average value of the number of foreign matters adhering to the wafer (member to be dried) 3 is 1.0, which is a conventional rotary drying apparatus. It was reduced by 60% from 2.5 in the case of.

Also, the maximum value of the number of foreign matters adhering to the wafer (member to be dried) 3 is 4.0 in the drying apparatus of this embodiment, which is also lower than 10.0 in the conventional rotary drying apparatus. 60
% Reduced.

[0044]

[Embodiment 2] FIG. 2 is an explanatory view of a main part of a drying apparatus according to another embodiment of the present invention, and Table 2 shows ion attachment to a wafer after drying by the drying apparatus and a conventional rotary drying apparatus. It is a comparison table showing the amount.

In the drying device of this embodiment, the filter 2 of the drying device of the first embodiment is a filter (hereinafter, simply referred to as an electrostatic filter) 2a for cleaning air by a charging action.
And a filter (hereinafter, simply referred to as a chemical filter) 2b for cleaning air by a chemical action.

Also in this embodiment, a plurality of wafers (members to be dried) 3 accommodated in the cartridge (accommodating means) 5 are used.
Are dried by convection of the cleaned air 1 as they are transported laterally through the dryer.

Here, the amount of ions adhering to the wafer (member to be dried) 3 after drying by the action of the chemical filter 2b of the drying device in the present embodiment that the inventor of the present invention has experimented with is determined by the conventional rotary drying device. Table 2 shows the comparison with that in Table 1.

[0048]

[Table 2]

Similar to the experiment in the first embodiment, in this experiment, the wafer (member to be dried) 3 has a diameter of 3 inches, and the drying apparatus of the present embodiment has a cleanness of class 10 with a foreign substance of 0.2 μm. The temperature of the air 1 is 40 ° C.

As is clear from the results of this experiment, according to the drying apparatus of this embodiment, the amount of ions adhering to the wafer (member to be dried) 3 was such that Cl ⁻ ions and SO ₄ ²⁻ ions were negative ions. Both of them were 0.0 ng, and when using the conventional rotary dryer, they were 20.0 ng and 5.0 ng, respectively, so these negative ions could be completely eliminated.

Regarding the attached amount of positive ions,
The Fe ³⁺ ion and the Cu ⁺ ion have the same numerical values in the drying device of this example and the conventional rotary drying device, and no difference was observed.

[0052]

[Embodiment 3] FIG. 3 is an explanatory view of a main portion of a drying apparatus according to another embodiment of the present invention.

The drying apparatus of the present embodiment comprises the heater 6 provided below the filter 2 of the drying apparatus of the first embodiment.

That is, the air 1 provided at the top of the device
The heater 6 is located below the filter 2 for cleaning the air, and the air 1 which is passed through the filter 2 and cleaned
Is heated by passing through the heater 6.

In this embodiment, a plurality of wafers (members to be dried) 3 housed in a cartridge (housed means) 5 is used.
Is transported laterally through the dryer, cleaned by filter 2 and dried by convection of air 1 warmed by heater 6.

That is, since the wafer (member to be dried) 3 is dried by the convection of the air 1 heated to a predetermined temperature, the wafer 3 is dried faster than the case of the convection of the air 1 at room temperature. The time can be shortened.

[0057]

[Embodiment 4] FIG. 4 is an explanatory view of a main part of a drying apparatus showing another embodiment of the present invention.

The drying apparatus of this embodiment comprises a static eliminating device 7 added below the filter 2 of the drying apparatus of the first embodiment.

Also in this embodiment, the plurality of wafers (members to be dried) 3 accommodated in the cartridge (accommodating means) 5 are conveyed in the drying device in the lateral direction, and the cleaned air 1 is supplied. Is dried by convection.

Here, in the drying apparatus of this embodiment,
Since the static electricity removing device 7 is used, the static electricity which has passed through the filter 2 and is charged by the extremely small foreign matter is removed by the static electricity removing device 7. Therefore, these extremely small foreign matters are subjected to the action of static electricity on the wafer (member to be dried).
3 is prevented from adhering.

[0061]

[Embodiment 5] FIG. 5 is an explanatory view of a main portion of a drying apparatus showing still another embodiment of the present invention.

The drying apparatus of the present embodiment comprises a microwave generator 8 instead of the heater 6 of the drying apparatus of the third embodiment.

That is, in the drying apparatus of this embodiment, since the microwave generator 8 is provided between the filter 2 and the wafer (member to be dried) 3, the wafer after cleaning (member to be dried). The drying time of No. 3 can be further shortened as compared with the drying device of the third embodiment.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the above-mentioned embodiment, the case where the wafer (member to be dried) is stored in the cartridge (storage means) and is dried while being laterally transported by the transporting means provided with a gap is described. However, the wafer (member to be dried) can be dried as it is without being stored in the cartridge (storage means), and, for example, when air is discharged to the outside through both sides of the transfer means. However, it is not necessary to provide a gap in the conveying means itself. Further, it is possible to use a method in which a wafer (member to be dried) is placed in a drying device and taken out after drying, without using a transfer means.

Further, the chemical filter, the heater or the microwave generator, and the static eliminator used in the above-mentioned embodiment may be used in any combination, and the heater mentioned in the above-mentioned Embodiment 3 is an infrared heater. Etc. are also included.

Furthermore, in each of the above-described embodiments, the case where the wafer is used as the member to be dried has been described, but the present invention is not limited to this, and for example, quartz, glass, and various other types are used. It is also possible to use a component material as the member to be dried.

[0068]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1). That is, according to the first aspect of the present invention, the member to be dried is dried by the convection of the cleaned air, and the number of foreign matters attached to the member to be dried after drying is reduced. As a result, for example, when the member to be dried is a wafer, it is possible to improve the yield of the wafer and not only improve the quality of device products such as LSI, but also support the miniaturization of future device processes. It becomes possible to manufacture an acceptable wafer.

(2) According to the second aspect of the invention, the amount of ions adhering to the member to be dried is reduced by the action of the filter for cleaning the air by the chemical action. Therefore,
Similarly, when the member to be dried is a wafer, the yield of wafers can be improved, the quality of device products such as LSI can be improved, and wafers that can respond to the miniaturization of device processes can be manufactured. become.

(3) According to the invention of claim 3, the member to be dried is dried by the convection of the air heated by the heater, so that the drying process can be made efficient by shortening the drying time. it can.

(4) According to the invention described in claim 4, since the number of extremely minute foreign matter adhered due to the action of static electricity is reduced, the number of foreign matter adhered to the member to be dried is further reduced. When the member is a wafer, it is possible to further improve the quality of a device product such as an LSI by using the drying apparatus according to the first or second aspect of the present invention, and to manufacture a wafer that is more suitable for a finer device process. Will be possible.

(5) According to the invention of claim 5, the member to be dried is dried by the microwave generator, so that the drying time is further shortened as compared with the drying device of the invention of claim 3. The efficiency of the member drying process can be improved.

(6) According to the invention described in claim 6, since a large amount of members to be dried can be simultaneously dried by the storing means, the efficiency of the drying process by simultaneous large amount drying can be improved.

(7) Further, according to the invention described in claim 6, since the respective steps of cleaning and drying the member to be dried can be made consistent, the production efficiency can be improved.

(8) According to the invention described in claim 7, since a large number of gaps are provided in the conveying means, for example, when air discharge spaces cannot be secured on both sides of the conveying means, The gap can be the discharge space.

[Brief description of drawings]

FIG. 1 is an explanatory view of a main part of a drying device according to a first embodiment of the present invention.

FIG. 2 is an explanatory view of a main part of a drying device according to a second embodiment of the present invention.

FIG. 3 is an explanatory view of a main part of a drying device according to a third embodiment of the present invention.

FIG. 4 is an explanatory view of a main part of a drying device according to a fourth embodiment of the present invention.

FIG. 5 is an explanatory view of a main part of a drying device according to a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air 2 Filter 2a Electrostatic filter 2b Chemical filter 3 Wafer (member to be dried) 4 Conveying means 4a Gap 5 Cartridge (accommodating means) 6 Heater 7 Static eliminator 8 Microwave generator

Claims (7)

[Claims] 1. A drying apparatus comprising a filter for cleaning air, wherein a member to be dried is dried by convection of the air cleaned by the filter. 2. The drying apparatus according to claim 1, wherein the filter includes a filter that cleans air by a charging action and a filter that cleans air by a chemical action. 3. The drying according to claim 1, wherein a heater for heating the air is provided, and the member to be dried is dried by convection of the air heated by the heater. apparatus. 4. A static electricity removing device is provided between the filter and the member to be dried, and the member to be dried is dried by the air passing through the static electricity removing device. Or the drying device according to 3. 5. The drying apparatus according to claim 1, wherein a microwave generator is provided between the filter and the member to be dried. 6. The member to be dried is housed in a housing means and dried while being carried by a carrying means continuous with a cleaning device. Drying device. 7. The drying apparatus according to claim 6, wherein the conveying means is provided with a large number of gaps.