JPH01284315A - Filter device - Google Patents

Abstract

PURPOSE:To efficiently and easily remove the impurities, particles, and air in a resist, etc., by providing an air vent respectively at the upper parts of the front and rear liq. chambers of a filter. CONSTITUTION:A liq. to be filtered such as a resist is introduced into a housing 1 from an intake 3. The air 5 in the resist 2 is firstly discharged to the outside through the air vent mechanism 6, before the resist is passed through the filter 4. The resist is then passed through the filter 4, and the impurities and particles contained in the resist are removed. In this case, the air 8 passed through the filter 4 along with the resist is accumulated at the upper part of the filter, and then removed through the air vent mechanism 9. Accordingly, since the filtered resist does not contain air, the number of the defective products having a nonuniform film thickness distribution is remarkably reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a filter device having an air bleed mechanism for removing air accumulated before and after a filter.

2. Description of the Related Art A conventional liquid filter device, for example, when filtering resist, is used as shown in a schematic cross-sectional view in FIG. In the figure, 1 is a housing for storing resist; 2 is a housing for storing resist;
3 is the resist before filtration, 3 is the inlet for the resist before filtration into the housing, 4 is the filter that traps impurities and particles in the liquid and also prevents air from passing through, 5 is the resist that passes through the filter 6 is an air release mechanism that removes the air that has accumulated at the top of the housing, 7 is the resist that has been filtered by the filter, 8 is the air that has passed through the filter together with the resist, 10 is the filtered air This is the port for taking out the resist to the outside. According to this device, the resist 2 is taken into the housing 1 and the filter 4
Impurities and particles in the liquid are trapped by this, and since it is difficult for the air 5 to pass through the filter, the resist is filtered by being taken out to the outside of the housing by the air bleed mechanism 6 from the front stage of the filter, and then supplied to the outside. .

Problems to be Solved by the Invention A filter device having a size of 0.2 μm is usually used so that the resist can pass through the filter and impurities and particles in the liquid can be trapped.

Therefore, air may pass through the filter.

However, although conventional filter devices have an air bleed mechanism to remove air that does not pass through the filter, they do not have an air bleed mechanism to remove air that has passed through the filter. Spin coating was performed while the particles were present, which had a serious effect on the film thickness distribution.

In addition, the air that has passed through the filter has no choice but to be pushed out by the flow of the resist, resulting in the problem of using a large amount of resist.

An object of the present invention is to provide a filter device that can also remove air that has passed through the filter.

Means for Solving the Problems In order to solve this problem, the filter device of the present invention is provided with air bleed mechanisms for removing air, respectively, above the liquid chambers at the front and rear stages of the filter.

Function: With this filter device, impurities, particles, and air in the resist can be efficiently and easily removed.

EXAMPLE A filter device which is an example of the present invention will be described below with reference to FIG. In the figure, 1 is the housing that stores the resist, 2 is the resist before being filtered, 3 is where the resist is taken into the housing before being filtered, 4 is the filter, and 5 is the housing where the resist cannot pass through the filter. The air accumulated at the upper part, 6 is an air release mechanism for removing the air accumulated at the upper part of the housing, 7 is the resist filtered by the filter, and 8 is the air which passed through the filter together with the resist and accumulated at the upper part of the filter. The difference from the configuration shown in FIG. 2 is that an air bleed mechanism 9 is provided to remove air 8 accumulated in the upper part of the filter.

Note that the outlet 10 for taking out the filtered resist to the outside is the same as in the conventional apparatus. In this way, the air that cannot pass through the filter and accumulates at the top of the housing 5
The resist filtered by the filter is free from impurities, particles, and The ability to remove air has been improved by 30%.

Effects of the Invention According to the present invention, by improving the ability to remove impurities, particles, and air in the resist, the vertical width of the resist film thickness distribution can be suppressed to 500A or less, and defective products with uneven film thickness distribution can be reduced. It has been demonstrated that this is highly effective in improving the yield of semiconductor device manufacturing. In addition, since air no longer accumulates inside the filter and it is no longer necessary to push air out through the resist, the amount of resist used can be reduced by approximately 5%, which has a significant effect on improving productivity. Ta.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a filter device of the present invention, and FIG. 2 is a sectional view of a conventional filter device. 1...Housing for storing resist, 2...
...Resist before filtration, 3...Resist intake, 4...Filter, 5...Air that did not pass through the filter, 6... Air bleed mechanism for taking out air that has not passed through the filter, 7...Filtered resist, 8...
・Air that has passed through the filter, 9... Air bleed mechanism that takes out air that has passed through the filter, 10
...Regist ejection port. Name of agent: Patent attorney Toshio Nakao and 1 other person No-housing'2-='P front L shi nut j--1 syji nut hemp 5 slot 6--filter 2i far rinl・■ air 9-- −
Philku and Value Release Core-1 Figure 2

Claims (1)

[Claims] A filter device that has an air vent mechanism above the liquid chambers in the front and rear stages of the filter, and can remove air bubbles in the liquid chambers.