JPS5936930A - Wafer drying apparatus - Google Patents

Abstract

PURPOSE:To always keep the air in the dust-free condition in the vessel and prevent inverse contamination of wafer surface by providing a means which executes forced air and water exhaustion from the vessel with the air and water absorbing tube which is formed integrally. CONSTITUTION:A cylindrical rotatable body 5 having the bottom and holding a wafer carrier 4 accommodating wafer 3 is placed within a wafer drying apparatus consisting of a body 1 and an upper cover 2. The rotatable body 5 is rotated at a high speed by a motor 6 provided at the lower part of vessel through a rotating shaft 7. The air and water exhausting tube 8 is formed at the lower part of vessel in order to perform forced air and water exhaustion with the same tube. Thereby, the dust-free condition in the vessel can be maintained and inverse contamination of wafer surface can be prevented by drying.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a wafer drying apparatus used after wafer cleaning in the field of complete wafer cleaning using a solvent, an alkaline cleaning solution, an acid cleaning solution, or pure water.

[Technical background of the invention]

In the Type 18 wafer cleaning process, it is necessary to completely remove moisture remaining on the wafer surface in the final process. For this purpose, a method is often used in which the wafer storage container is attached to a rotary disk, and the rotary disk f is rotated at a high speed of about 1.00 rpm to centrifugally dehydrate the liquid on the wafer surface. Other methods include steam drying using chemicals such as triclene, freon, and alcohol, and using heat from infrared lamps, but each of these methods has the following problems.

(b) Centrifugal dehydration method The high-speed rotation of the two-rotation disc generates a complex airflow inside the container to which the rotary disc is attached, and this airflow causes fine particles to fly up inside the container and contaminants from outside the container to be sucked in. The wafer surface is back-contaminated.

Furthermore, when drying wafers of different sizes, there is the inconvenience of having to replace the parts that hold the wafer container each time.

Steam drying method, lamp heating drying method: There is back contamination from the chemicals used, the atmosphere, and the surrounding atmosphere, and it is difficult to maintain the cleanliness of the wafer surface before drying at the drying diameter. In addition, the time required for drying is generally longer than that for centrifugal dehydration and drying.

[Purpose of the invention]

This invention improves the above-mentioned drying device for centrifugal dehydration by eliminating its drawbacks, and by eliminating dust in the centrifugal dehydration container, it eliminates the need for back-contamination of all wafers. [Summary of the Invention] That is, the present invention provides a drying container having a main body, an upper lid, a T-shaped wafer drying device, and a circle which accommodates the internal pressure of the container and is provided with a dehydration port. It consists of a bottomed cylindrical rotary disk in which wafer carriers for storing wafers are arranged radially in a well-balanced manner on the inside of the nodal surface. It is rotated by an externally driven force, and the bottom of the container has a forced intake water pipe opened, and the top lid has an opening metal, and a cylindrical atmosphere sampling tube is guided through this opening in the wafer drying equipment. .

The present invention is equipped with a means for forcibly exhausting and draining the inside of the container from the intake water pipe, which is the same pipe body, so that the air inside the container is always dust-free and the surface of the wafers to be stored and dried is kept clean. It is characterized by being protected from back-contamination. Additional features include means for constantly measuring the number of dust particles in the container and means for replacing parts of wafer storage carriers of different sizes.

[Embodiments of the invention]

Embodiments of the invention will be described with reference to the drawings. 1st
The figure is a sectional view showing the wafer drying apparatus of this example. This device consists of a wafer drying container consisting of a main body (1) and an upper lid (2), and a wafer carrier (4) for storing one wafer (3) and a bottomed cylindrical rotary plate (5) for holding all the wafers (3). ing. This rotary disk (5) is rotated at high speed via a rotary shaft (7) by a motor (6) jc provided at the bottom of the container. At the bottom of the container, a path is branched upward and downward to allow water inside the container to be drained and exhausted by the backwater pressure of the supplied water. In addition, the rotating disk (5) has its inner wall ≠
- A dewatering port (9) is provided that leads to the outer wall. The aperture of the dehydration port (9) is a conical shape in which the aperture ratio of the inner wall side to the outer wall side is more than twice, to prevent water splashing from the inner wall of the main body (11) from adhering to the wafer surface. The number of dehydration ports (9) is provided on the entire surface of the cylindrical surface of the r rotary plate (5) in order to improve the dehydration effect.The intake air from the intake water pipe (8) uses the vacuum method, and is used as a vacuum source. A vacuum pump may be used, but in order to more stably reduce dust generation, use an aspirator using pure water as shown in the figure to further improve the cleanliness inside the container.

In addition, a sampling tube 0υ for sampling the air inside the cylinder through the hole Qi provided in the upper cover (2) is inserted into the center of the rotary disk (5), and the air sampled from the end of the hole is It is sent into the attached dust measuring instrument (not included) to constantly monitor the cleanliness inside the container and to emit dust when an abnormality occurs.

The wafer (3) is normally mounted on a wafer carrier (4), undergoes a cleaning process, and is finally transferred to this wafer drying apparatus. lFirst, the upper lid of the wafer drying equipment (2
) and place the wafer carrier (4) inside the turntable (5). However, in order to maintain balance, it is necessary to mark the location of the wafer carriers on the rotary disk and place multiple wafer carriers. Thereafter, the upper lid (2) is closed, and the rotary disk (5) is rotated at a high speed of 500 to 4.00 rpm to perform centrifugal dehydration of the liquid remaining on the surface of the wafer (3).

The suction (8) is constantly discharged to a vacuum pump or in this example. Air from the outside is supplied from the open end of the top cover (2), and the entire drying device is installed inside gold clean pliers.
It is necessary to always supply clean air within class 100 into the drying equipment. The cleanliness inside the container is controlled by measuring dust in the air sampled from the open end of the sampling tube aυ.

Figure 2 shows that this wafer drying equipment is operated and the 0.3μ
The number of dust particles of m or more is measured and shown. However, the broken line indicates the value measured by the device of the present invention, and the line indicates the value measured by the conventional drying device without forced exhaust. In the former, the number of dust particles is always controlled within 1 particle/100cc, indicating that almost no dust is generated inside the container, but in the latter, up to 17 particles/CC are generated inside the container.
The wafer is back-contaminated.

[Effects of the Invention] According to the apparatus of the present invention, exhaust and drainage are forcibly carried out from the same pipe body, making it possible to keep the inside of the container dust-free and preventing back contamination of the wafer surface due to drying. It can be prevented. In conventional devices, exhaust and drainage are carried out through separate pipes, but these devices sometimes cause contamination due to backflow of the drain line during exhaust. In addition, since the wafer carrier is simply placed on the rotary disk in a well-balanced manner against the inner wall of the cylinder, wafer carriers of all sizes can be dried without replacing parts. Furthermore, the cleanliness inside the container during operation of the drying device can be constantly monitored, and back contamination of the wafer surface can be prevented. Furthermore, since the diameter of the dewatering port provided on the side wall of the rotary disk is conical, with the inner side being larger and the outer side being smaller, water does not splash back onto the wafer surface at all.

[Brief explanation of the drawing]

FIG. 1 is a simplified sectional view of a wafer drying bag according to an embodiment of the present invention, and FIG. 2 is a measurement of the number of dust particles inside the container when the wafer drying apparatus is in operation. In Figure 1, (1)...Main body, (2)...Top lid. (9)...Dehydration port, (3)...Wafer. (4)...Wafer carrier, (5)...Rotary disk. (7)...rotating shaft, (6)...motor. (8)...Intake water pipe, Ol...Top lid opening. αt... Atmosphere Sampling Management Agent Patent Attorney Inoue - Male 1st Figure 2vI! J Kue to Inui Daito equipment
occ Month 3≧a l
p 4 place ρ-J) tgu, state of mind g! - 2 Procedural Amendment (Voluntary) 58.422 Showa Year, Month, Date Kazuinu Wakasugi, Commissioner of the Patent Office 1. Indication of the case 1982 Patent H No. 146263 2. Name of the invention Wafer drying device 3. Person making the amendment Relationship to the case Patent applicant (307) Tokyo Shibaura Electric Co., Ltd. 4, Agent No. 4-41-11 Kamata, Ota-ku, Tokyo 144 - Tsunoda Building Benjo Patent Office Telephone: 736-3558 (3257) Patent attorney Inoue - male jj,,
l11□K Full text of specification U Drawing 6, contents of amendment! As per the separate document ■ Figure 1 of the drawings has been amended to Figure 1 of the attached drawings. Amended specification 1, name of invention wafer drying device 2, %lr! r-Wafer drying equipment equipped with exhaust and drain pipes with a wide range of requirements. 3. Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a wafer drying apparatus used after wafer cleaning in the field of cleaning wafers using a solvent, an alkaline cleaning solution, an acid cleaning solution, or pure water. [Technical Background of the Invention] In the wet wafer cleaning process, it is necessary to completely remove moisture remaining on the wafer surface in the final process.
For this purpose, the wafer storage container is attached to a cylindrical rotating body 4-, and this rotating body 'k1. A commonly used method is to centrifugally dehydrate the liquid on the wafer surface by rotating the wafer at high speed around OOOrpm. There are also methods that use steam drying using chemicals such as trichlene, freon, and alcohol, and methods that use heat from infrared lamps, but each of these methods has the following problems. (a) Centrifugal dehydration method The high-speed rotation of two rotating bodies generates a complex airflow inside the container with additional rotating bodies, and this airflow causes fine particles to fly up inside the container and contaminate the outside of the container. This causes material to be sucked in and back-contaminates the wafer surface. Furthermore, when drying wafers of different sizes, there is also the inconvenience of having to replace the parts that hold the IW wafer storage container. In the steam drying method and lamp heating drying method, there is back contamination from chemicals and the atmosphere, making it difficult to maintain the cleanliness of the wafer surface before drying until after drying. Further, the time required for drying is generally longer than that for centrifugal dehydration drying. [Purpose of the Invention] This invention is intended to improve the above-mentioned drawbacks of wafer drying equipment, especially those related to centrifugal dehydration, and by eliminating all dust in the centrifugal dehydration container, wafers can be dried without back contamination. An object of the present invention is to provide a wafer drying apparatus for centrifugal dehydration drying. [Summary of the Invention] A wafer drying apparatus according to the present invention includes a container, a rotating body rotatably housed in the container and provided with a wafer carrier, and a drive for rotating the rotating body. 1 () 1 means;
The apparatus includes an air supply port provided in the container above the rotating body, and an exhaust/drain pipe connected to the container. That is, the present invention always makes the air inside the container dust-free by providing a means for forcibly exhausting and draining the inside of the container from the intake water pipe, which is the same pipe body. This is to avoid back-contaminating the waeno surface being dried. It also includes means for constantly measuring the number of dust particles in the container and means for installing and removing wafer storage carriers of different sizes without replacing parts. [Embodiments of the Invention] Examples of the invention will be described with reference to the drawings. 1st
The figure is a sectional view of the wafer drying apparatus of this example. This device consists of a wafer drying container consisting of a main body (1) and an upper lid (2), and a wafer drying container (3) a wafer carrier (4) a rotary body (t5) with a bottom cylindrical shape that holds all the wafers. It's dark. This rotating body (5) is rotated at high speed via a rotating shaft (7) by a motor (6) provided at the bottom of the container. An exhaust/drain pipe (8) is formed at the bottom of the container to forcibly drain and exhaust the inside of the container using the same pipe body. Note that this exhaust/drainage pipe has a path branched upward and downward in order to drain and exhaust the water by the backwater pressure of the supplied water. Further, the rotating body (5) is provided with a dewatering port (9) communicating from its inner wall to its outer wall. Dehydration port (
The aperture of 9) is a conical shape in which the aperture ratio of the inner wall side to the outer wall side is more than twice, which prevents water splashing from the inner wall of the main body (1) from adhering to the waeno surface. There is. The number of dehydration ports (9) is determined by rotating body (
5) is provided on the entire cylindrical surface. Exhaust and drain pipe (8
) can be taken in by a vacuum method, and a vacuum pump may be used as the vacuum source, but in order to more stably reduce dust generation, it is recommended to use an aspirator using pure water as shown in the figure. The cleanliness inside will be further improved. Further, in the central part of the rotating body (5), there is an opening (Il) provided in the upper lid (2).
A sampling tube (I) for sampling the air inside the cylinder through
D is inserted, and the air sampled from the open end is sent into the attached dust measuring device (not included), which constantly monitors the cleanliness inside the container and issues an alarm if an abnormality occurs [7]. It makes it possible to emanate. The wafer (3) is normally mounted on a wafer carrier (4) through the entire cleaning process and finally transferred to the wafer drying apparatus. Top lid of Masuueno/drying device (
2) Excluding wa/carrier (4) and rotating body (5)
Place it inside. However, in order to maintain balance, it is necessary to arrange the wafer carriers at appropriate intervals on the rotary disk, and to provide a unique number of devices. After that, close the top lid (2) and close the rotating body (5).
) The liquid remaining on the surface of Ueno (3) is centrifugally dehydrated by rotating at a high speed of 500 to 4,1 l at 100 rpm. Since the exhaust/drain pipe (8) is constantly forcibly suctioned by a vacuum pump or an aspirator in this example, the centrifugally dehydrated liquid is discharged to the outside from the exhaust/drain pipe (8) together with air. Air from the outside is supplied through the hole in the top cover (2), so the entire drying device is installed in a clean bench, for example using an ASTM (American 5o) dryer.
Society for Te+sting and Ma
It is necessary to supply clean air within class 100 of the standard (terialg) into the drying equipment. The cleanliness inside the container is controlled by measuring dust in the air sampled from the open end of the sampling tube 00. Figure 2 shows 03 when the 9 wafer dryer is operated.
The measurement results of the number of dust particles larger than μm are shown. However, the broken line (a) is the value measured by the device of the present invention, and the broken line (1) is the value measured by the conventional drying device without forced exhaust. In the former case, the number of dust particles is always controlled within 1 piece/1oocc, indicating that almost no dust is generated inside the container, but in the latter case, up to 17 pieces/CC of dust particles are generated inside the container, and the wafer has been shown to back-contaminate the [Effects of the Invention] According to the device of the present invention, exhaust and drainage are forcibly carried out through the same pipe body, making it possible to keep the inside of the container dust-free and preventing back contamination of the wafer surface due to drying. . In the conventional device, #i exhaust and drainage are performed from separate pipe bodies, but contamination may occur between these folds due to backflow of the drainage line during exhaustion. Further, since it is only necessary to place the wafer carrier on the rotary body so as to lean it against the inner wall of the cylinder in a well-balanced manner, wafer carriers of any size can be dried without replacing parts. In addition, the cleanliness inside the container can be constantly monitored when the drying equipment is operating.
Back contamination of the wafer surface can be prevented. Furthermore, there is a sword installed on the side wall of the rotating body! Since the aperture of the water inlet is conical, with a large inner diameter and a smaller outer diameter, there is also the advantage that no water splashes back onto the wafer surface. 4. Brief Description of the Drawings FIG. 1 is a cross-sectional view showing the main parts of a wafer drying apparatus according to an exemplary embodiment of the present invention, and FIG. 2 is a measurement of the number of dust particles in the container during wafer drying R& operation. (9)...Dehydration port (3)...Wafer (
4)...Wafer carrier (5)...Rotating body (7)...Rotating shaft (6
)...Motor (8)...Exhaust/drainage pipe 1. Top cover opening 0. Sampling management agent Patent attorney Inoue -Male

Claims (1)

[Claims] A drying container comprising a main body and an upper lid, and a bottomed cylindrical rotary disk which is housed in the container and which arranges wafer carriers for storing wafers in a well-balanced radial manner inside a cylindrical surface provided with a dehydration port. The rotary disk consists of a rotating shaft that is attached to the outside of the bottom and penetrates the bottom of the container! −
The container is rotated by being driven externally, and the bottom of the container opens the forced intake water pipe, and the top lid has an opening.
A wafer drying apparatus characterized in that a sampling tube for the surrounding air inside the cylinder is guided through this opening.