JPH0341730A - Drying using pure water vapor - Google Patents

Abstract

PURPOSE:To dry a material to be cleansed in a container by boiling pure water at the lower part of a container whose upper side is tightly closed, guiding pure water vapor to the upper part of the container, removing the air in the container through the lower part of the container, and filling the container with the pure waver vapor. CONSTITUTION:A pure water well 2 is provided at the lower part of a container 1 whose upper side is tightly closed. A heater 3 is provided at the lower side of the well 2. When the pure water is heated and boiled (a) with the heater 3, the pure water vapor rises up. The vapor is guided to the upper part of the container 1. The air in the container 1 is outputted to the outside from the lower part of the container 1 through a filter 4. Thus, a pure water vapor layer (b) is formed from the upper part of the container 1. A spiral shaped cooling water duct 5 is provided along the inner wall of the container 1. Cooling water (c) is supplied into the cooling water duct 5. Since the inside of the container 1 is cooled in this way, the pure water layer is moved downward in the container 1. During this step, a material to be cleaned 10 in the container is dried.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a method for drying wafers, glass substrates, etc. used in semiconductor devices after cleaning them, particularly a method for drying these objects using pure water, using an organic solvent. The purpose of the present invention is to obtain a method for drying pure water paper using pure water that is free from dangers and hazards, provides high-purity washing and drying quality, and is also easily and inexpensively available. boiling pure water at the bottom and guiding the pure water paper to the upper part of the container, and removing air from the container from the lower part of the container to fill the container with the pure water paper;
Next, the deionized water paper drying method is characterized in that the object to be cleaned in the container is dried by lowering the temperature in the container and moving the layer of deionized water paper downward in the container.

[Industrial application field]

The present invention relates to a method for drying wafers, glass substrates, etc. used in semiconductor devices after cleaning them, and particularly to a method for drying these objects to be cleaned using pure water.

BACKGROUND OF THE INVENTION In various industries, there is a demand for safe and high performance cleaning and drying without causing any risk of explosion or environmental pollution. In particular, in recent years in the semiconductor industry, high-performance cleaning technology is required for cleaning wafers, and among these, the final cleaning and drying technology is important, and it is necessary to prevent dust from adhering to the wafer during drying. Furthermore, there is a good possibility that various organic solvents that have the risk of having an adverse effect on the environment will no longer be able to be used for cleaning in the future from the standpoint of environmental conservation.

Therefore, it is necessary to establish a safe and high-performance technique for drying these objects to be cleaned.

[Conventional technology]

Conventionally, there have been methods such as Freon paper, IPA paper, spin drying, natural drying, dry gas blowing, etc. as the final stage drying method for Ueno used for semiconductor devices.

Each of these methods has its advantages and disadvantages. Among these, drying with organic solvent paper is widely used.

The reason for this is that organic solvents have high molecular polarity and paper density is higher than air density, so paper zones can be easily created and a high cleaning effect can be obtained. However, although cleaning and drying methods using organic solvents can provide a high degree of cleaning, restrictions on their use will become stricter in the future due to air pollution, flammability, carcinogenicity, and other reasons. In addition, other cleaning and drying methods currently do not provide a high degree of cleaning as with paper drying using organic solvents.

[Problem to be solved by the invention]

As mentioned above, the use of paper drying using organic solvents will be restricted in the future, and the cost of solvent recovery equipment and safety measures will increase, as well as the development of alternative chemicals.

Therefore, the present invention aims to provide a pure water paper drying method using pure water that is free from the dangers of organic solvents, provides high purity cleaning and drying quality, and is also easily and inexpensively available. purpose.

[Means to solve the problem]

In order to solve such problems, according to the present invention, pure water is boiled below a container whose upper side is sealed, and pure water paper is guided to the upper part of the container, and the water inside the container is drawn from the lower part of the container. The object to be cleaned in the container is dried by removing air and filling the container with deionized water paper, and then lowering the temperature in the container and moving the layer of deionized water paper downward in the container. A method of drying paper with pure water is provided.

[Effect]

After placing the object to be cleaned in the container, the container is filled with high-temperature pure water paper as described above. Since the object to be cleaned is initially in a wet state and has a lower temperature than the paper in the container, condensed droplets adhere to the surface of the object to be cleaned and wash away dirt. When the temperature of the object to be cleaned increases, the droplets no longer adhere to the object and the object becomes dry. At this point, the temperature inside the container is lowered, the layer of pure water paper is moved downward into the container, and the object to be cleaned is removed from the top of the container.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram showing the principle of the pure water paper drying method of the present invention.

A pure water reservoir 2 is located below a container l whose upper side is sealed, and a heater 3 is located further below that. When the pure water is heated by the heater 3 and boils, the pure water paper rises and is guided to the upper part of the container 1. The air inside the container 1 is discharged from the lower part of the container 1 to the outside through a filter 4. In this way, container 1
Inside, a pure water paper layer is formed from above. container l
A spiral cooling water conduit 5 is provided along the inner wall of the
Cooling water is supplied to this cooling water conduit 5.

As a result, the inside of the container 1 is cooled, so that the pure water paper layer moves downward within the container 1. In this process, container 1
The object to be cleaned 10 inside is dried.

FIG. 2 shows an embodiment of the pure water paper drying method of the present invention.

This embodiment is used, for example, in the final cleaning and drying process of semiconductor wafers, glass substrates, and the like.

There is a lid 12 on the top of the container l that can be opened and closed, and the carrier 1
The object to be cleaned 10 loaded on the container 3 can be carried into and out of the container 1 while the lid 12 is open. The inside of the container 1 is divided into an upper part and a lower part by a wire mesh 14 made of stainless steel, for example. At the top of the container 1, a conduit 5 similar to the cooling water conduit 5 shown in FIG. 1 is spirally provided along the inner wall of the container 1.

However, this conduit 5 can not only be supplied with cooling water to cool the container, but also can be supplied with high temperature (for example, about 140° C.) steam to heat the upper region of the container 1. Another cooling/heating pipe 15 is provided at the bottom of the container 1.

The lower region of the container 1 can be cooled and heated by supplying cooling water or high temperature (for example, about 140° C.) steam to this pipe 15 as well. Plumber 5 has many cooling and heating fins 1
6 is installation. At the bottom of the container 1, there is a part that communicates with the outside via a filter 4, as in FIG. As in Figure 1, below the container 1 is a pure water reservoir 2 and a heater 3.
However, in the embodiment, water overflowing from the pure water reservoir 2 or inside the container 1 is further added around the pure water reservoir 2! ! There is an overflow groove 17 that collects and receives fallen water, and the pure water in this overflow groove 17 is transferred to the pure water reservoir 2 by a pure water circulation pump 18 and a filter
will be returned to.

The drying process according to the embodiment of FIG. 2 is as follows. First, with the lid 12 on the top of the container 1 closed, pure water is heated with the heater 3 to a boiling state and a paper layer is formed on the top of the container 1. Do not let cooling water flow through the coiled conduit 5 yet. Immediately before the carrier 13 containing the object to be cleaned 10 is placed in the container 1, cooling water is flowed through the pipe 5.15 to remove the paper layer in the upper region of the container 1. In this state, the lid 12 on the top of the container 1 is opened, and the carrier 13 is placed in the container 1 and set on the wire mesh 4.

When the lid 12 is closed and the supply of cooling water to the pipe 5.15 is stopped, the pure water paper layer rises again. As a result, the wafer 10, which is the object to be cleaned, is cleaned and dried as described above. At this time, in order to promote the rise of the pure water paper, the cooling water accumulated in the pipe 5.15 can be pushed out with air, or the cooling water can be immediately removed by flowing high-temperature (for example, about 140°C) steam as described above. Extrude and heat container 1.

After drying, to take out the carrier 13, once again run cooling water through the pipe 5.15, remove the pure water paper inside the container, open the lid 12, and take out the carrier 13 together.

〔Effect of the invention〕

As explained above, according to the present invention, by performing drying using pure water paper, there are no problems such as explosion risk, air pollution, carcinogenicity, etc. compared to conventional organic solvent paper drying methods. Also, there is no need to pay for solvent recovery or disposal. In addition, since pure water can be easily obtained with higher purity than solvents, high cleaning effects can be expected.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the principle of the invention, and FIG. 2 is a diagram showing the configuration of an embodiment of the invention. 1... Container, 12... Opening/closing lid, 2...
...Pure water reservoir, 13...Carrier, 3...
・Heater, 14... Wire mesh, 4... Filter, 15... Cooling/heating piping, 5...
- Cooling/heating conduit, 16...Fin, 10...Object to be cleaned, 17...Overflow groove, 18...Pure water circulation pump, 19...Filter. Fig. 1 7...Container 2...Pure water tank...Heater 4...Filter 5...Cooling water conduit 10...Object to be cleaned

Claims (1)

[Claims] 1. Boil pure water below the container (1) whose upper side is sealed and introduce the pure water paper to the upper part of the container, and remove the air from the bottom of the container and place the pure water paper into the container. A pure water paper drying method characterized in that the object to be cleaned (10) in the container is dried by filling the container with water, then lowering the temperature inside the container and moving the layer of pure water paper downward in the container. .