JPS59195649A - Device for washing photomask - Google Patents

Abstract

PURPOSE:To carry out washing of a scrubbing brush itself easily and effectively in a short time by generating ultrasonic waves in a washing soln. same as that used for washing a photomask, filled in a washing vessel having the brush before washing the photomask. CONSTITUTION:When a washing vessel 4 is filled with a washing soln. from a shower supply pipe 2 to immerse a scrubbing brush 1 in the washing soln. an ultrasonic wave oscillator 8 is actuated. The soln. is continuously supplied but the soln. does not increase up to a liquid level 7 due to an overflow drain pipe 6 kept open, and dust lower in specific gravity than the soln. flows out through the pipe 6. After the lapse of a prescribed time, feed of the soln. through the pipe 2 is stopped, and a drain valve 3 is opened to drain dust higher in specific gravity than the soln. Said processes are carried out in 2-3 times. After the completion of washing of the brush, a photomask is inserted between the two brushes and scrubbed by rotating the brushes to wash the photomask.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reticle or photomask cleaning device used in a projection exposure machine.

In recent years, the miniaturization of semiconductor integrated circuit devices has progressed, and the manufacturing equipment used to manufacture the integrated circuit devices has also become more sophisticated. A good example would be a projection exposure machine. Specifically, it is a one-to-one mirror-type projection public party machine.

There are reduction projection exposure machines and the like, but the cleanliness of photomasks or reticles (hereinafter collectively referred to as photomasks) used in these exposure machines has become a major problem. For example, if dust that can cause an electrical defect is attached to the surface of a reticle used in a reduction projection exposure machine, all chips that hit the dust will be defective because the reticle is subjected to reverse exposure. Also, in the case of a mirror projection type photomask, although the damage is less than that of a reduced projection type, chips that hit the dust attached to the mask surface become defective, which greatly affects the yield. Therefore, photomask cleaning technology becomes important.

A double-sided scrubbing method is common as a photomask cleaning method, but in conventional photomask cleaning equipment, no particular consideration is given to cleaning the plane itself used for scrubbing. That is, if the brush used for scrubbing (hereinafter simply referred to as a brush) becomes dirty, the cleaning effect deteriorates and thorough cleaning becomes impossible. In conventional photomask cleaning equipment, when plaque becomes dirty, the brush is removed and replaced, or the brush is cleaned and reattached. In this method, it took several hours to replace the plaque, and furthermore, it was necessary to carry out empty exercise for several hours in order to maintain the cleanliness of the cleaning tank and brushes even after the replacement.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a photomask cleaning apparatus that has the ability to easily and effectively clean the scrap rough for photomask cleaning in a short period of time.

The present invention is constructed by filling a cleaning tank with a brush with the same cleaning liquid used for photomask cleaning, and equipping the cleaning liquid with an ultrasonic generator that generates ultrasonic vibrations. It is characterized by cleaning dirt adhering to the brush and the tank by generating ultrasonic waves in the filled cleaning liquid.

The advantage of the present invention is that the brushes can be cleaned in a short time because it is no longer necessary to remove and sift the brushes. Further, since there is no dust generated by removing and attaching the book, no dust is brought in from outside.

Therefore, not only the book but also the interior of the cleaning tank can be cleaned while maintaining cleanliness.

Next, embodiments of the present invention will be described in detail using the drawings. FIG. 1 is a sectional view seen from the front direction for explaining the present invention in detail, and FIG. 2 is a partial sectional view seen from the side direction.

First, two scrubbing brushes 1 installed in parallel in the cleaning tank 4 with an appropriate interval are immersed in the cleaning solution.
Cleaning liquid is supplied from the shower supply pipe 2. At this time, the cleaning liquid drain valve 3 is kept closed. When the cleaning tank 4 is filled with the cleaning liquid, an ultrasonic generator 8 attached to the lower surface of the cleaning tank is activated. As is well known, ultrasonic waves have a cleaning effect, and are suitable for cleaning bluffs, especially since they can clean even minute areas. Although the cleaning liquid is continuously supplied, the liquid does not increase above the liquid level 7 because the over 70-drain 6 is kept open.

By this method, dust having a specific gravity lower than that of the cleaning liquid flows out from the over 70-dray/6. Further, if the motor 5 is rotated as necessary, the cleaning effect of the scrubbing bluff 1 can be further improved.

After a certain period of time has elapsed, the supply of cleaning liquid from the shower supply pipe 2 is stopped and the drain valve 3 is opened. As a result, dust that is heavier than the cleaning liquid is discharged through the drain valve 3. The above process 2
The scrubbing plaque 1 can be completely cleaned by performing this procedure ~3 times.

After the cleaning of the brushes is completed in this way, the photomask is sent between the two plans, and the brushes are rotated to perform scrub cleaning, thereby obtaining a high-quality photomask free from dust.

Also, it is effective to use surfactants or aqueous ammonia solutions as a cleaning solution, but pure water passed through a filter,
An organic solution may also be used. Further, although the shower supply pipe located above the brush is used as a means for supplying cleaning liquid, a supply port may be provided below the plan.

[Brief explanation of drawings]

FIG. 1 is a sectional view seen from the front direction for explaining the present invention in detail, and FIG. 2 is a partial sectional view seen from the side direction. 1... Scrub brush, 2... Shower supply pipe, 3... Drain valve, 4...
・Cleaning tank, Morfi-16...Overflow drain, 7...Liquid level, 8...
・Ultrasonic generator. 27 Figure 6 z diagram

Claims (1)

[Claims] A cleaning device equipped with a scrubbing brush for cleaning photomasks for manufacturing semiconductor integrated circuit devices includes a mechanism for showering cleaning liquid into a cleaning tank, a mechanism for overflowing and draining the cleaning liquid from the bottom, and generating ultrasonic waves in the cleaning liquid. a mechanism for immersing the scrubbing brush in a cleaning solution to perform ultrasonic cleaning on the brush; and a means for transporting the photomask into a cleaning tank after cleaning the scrubbing plaque and supplying the cleaning solution to clean the photomask. 1. A photomask cleaning device comprising: scrub cleaning means.