JPH06275593A - Washing device - Google Patents

Abstract

PURPOSE:To prevent or suppress adhesion of washing water inside a washing water bath and live germs and TOC to the inner wall of the washing water bath and wafer surface by installing an ultraviolet ray lamp inside the washing water bath. CONSTITUTION:Washing water, for example pure water 3, is supplied Into a washing water bath 1 from a washing water supply part 2. One lot of wafers 4 where treatment process is completed and the surface is subjected to washing treatment as a pretreatment before proceeding to a next process is set to a wafer tool 5. Then, a plurality of ultraviolet ray lamps 7 are aligned inside the washing water bath 1, where the wavelength of the ultraviolet ray lamps may be partially set to for example 254 nm for preventing and extinguishing increase in live germs and microorganism and may be partially set to for example 184.5nm for decomposing an organic matter. A transparent pipe 8 separating the pure water 3 from the ultraviolet ray lamps is formed by for example a crystal pipe so that the ultraviolet ray lamps 7 can be replaced freely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for suppressing the production of viable bacteria in a liquid to remove organic substances such as TOC, and particularly when it is used in a state where ultrapure water is stored between each step. It is related to the technology effectively applied to.

[0002]

2. Description of the Related Art Water (hereinafter referred to as raw water) drawn from tap water or groundwater contains ions of inorganic substances such as Ca and Mg, organic substances and microorganisms. LSI and super L
Since semiconductors such as SI become defective even with the above-mentioned ions and minute foreign substances, groundwater and tap water cannot be used as raw water as they are. Therefore, "LSI Process Engineering" of Ohmsha Co., Ltd. (October 25, 1982)
Issued daily) As described in 192, it is passed through an ion exchange resin, a filter, sterilized by ultraviolet rays, and then supplied to each processing step.

The pure water produced as described above is generally used in the semiconductor manufacturing process in a cleaning process for removing foreign matters and chemicals from the front surface (including the back surface) of a wafer to be cleaned between the processing steps. It is used. For example, a wafer is cleaned by immersing the wafer in cleaning water (pure water) and applying ultrasonic vibration.

[0004]

However, there is no problem if new pure water constantly contacts the wafer surface, but in the case where the cleaning water is collected in the cleaning water tank and overflowed, the wafer surface is cleaned. However, there is a possibility that live bacteria and TOC are brought in from the wafer or the external atmosphere, and the wafer may be contaminated in the cleaning water tank where the wafer should be cleaned.

[0005]

The outline of the representative one of the inventions disclosed in the present application will be briefly described as follows. That is, an ultraviolet lamp is installed in the washing water tank.

[0006]

By the above means, it becomes possible to suppress the generation of viable bacteria and decompose TOC by the sterilizing action and the decomposing action of ultraviolet rays, and the washing water in the washing water tank, the inner wall of the washing water tank and the washing water are convected. It is possible to prevent or suppress live bacteria and TOC from adhering (contaminating) or growing on the corners and the surface of the wafer where foreign matter is difficult to settle.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a schematic sectional view of a wafer cleaning apparatus. A cleaning water tank 1 is supplied with cleaning water, for example, pure water 3 from a cleaning water supply unit 2. Reference numeral 4 denotes a wafer whose surface has been cleaned as a pretreatment for completing a certain processing step and proceeding to the next step. A wafer jig made of quartz or fluororesin that can store one lot, for example, 25 pieces 5
Is set to. Reference numeral 6 denotes a cleaning water recovery unit that recovers the pure water 1a overflowing from the cleaning water tank 1. 7
Is an ultraviolet lamp that generates ultraviolet rays, and the thickness and the number of ultraviolet lamps 7 are set according to the capacity of the cleaning water tank 1. In addition, a plurality of the ultraviolet lamps 7 are arranged in parallel, a part of which has a wavelength suitable for preventing the growth of live bacteria and microorganisms and sterilization, for example, 254 nm, and the other has a wavelength suitable for decomposing organic substances. For example, 184.5 nanometers may be irradiated. 8 is an ultraviolet lamp 7
Is a transparent tube that separates the pure water 3 and the ultraviolet lamp from each other, for example, a quartz tube. In this embodiment, the cleaning water tank 1 uses electrolytically polished stainless steel in order to prevent leakage of ultraviolet rays and to prevent elution of impurities such as ions from the inner wall of the water tank.

In the present embodiment, the cleaning of the wafer is taken as an example. However, a jig for storing other solids such as a wafer, a quartz tube used for oxidizing the wafer or a process such as CVD is cleaned. Can also be applied to.

Next, another embodiment of the present invention will be described. FIG. 2 is a schematic sectional view of the gas cleaning device. Reference numeral 10 denotes a cleaning water tank, in which cleaning water according to the characteristics of the gas to be cleaned is put. For example, sodium hydroxide solution for acidic gas, hydrochloric acid or sulfuric acid for alkaline gas,
Alternatively, water is used as the washing water if it has a property of being easily dissolved in a solvent such as water in a large amount like ammonia. 12
Is a cleaning water supply unit for supplying the cleaning water 11.
Reference numeral 13 is a spray that divides the cleaning water 11 sucked up by the pump 14 from the cleaning water tank 10 and supplies it to the gas-liquid contact portion 15. The gas-liquid contact portion 15 is filled with a ring-shaped or saddle-shaped filler such as a Raschig ring or a Lessing ring so that the cleaning water and the gas can be efficiently contacted with each other. 16 is a supply port of the gas to be cleaned, 17 is
It is an outlet for the cleaned gas. Reference numeral 18 denotes an ultraviolet lamp that emits the ultraviolet light described in the first embodiment.

Next, the function and effect of this embodiment will be described.

(1) By installing an ultraviolet lamp in the washing water tank, it is possible to prevent the growth of fungi in the washing water, sterilize it, and decompose TOC. Even when the water stays for a relatively long time, the cleaning water can be prevented from deteriorating and the wafer surface can be prevented from being contaminated.

(2) By installing an ultraviolet lamp in the cleaning water tank, even if there is no contamination source of the wafer in the supplied cleaning water, the cleaning water tank can be used to remove live bacteria and organic substances brought in from the outside during use. (3) By installing an ultraviolet lamp in the cleaning water tank, ultraviolet rays can be reliably applied to the corners of the cleaning water tank where convection of the cleaning water is less likely to occur, and deterioration of the cleaning water To prevent contamination of the wafer surface.

(4) By the above (1) and (2), the supply amount of washing water can be reduced.

(5) Since the ultraviolet lamp is separated from the washing water and protected by a transparent tube, it is possible to easily replace an ultraviolet lamp that has been cut and cannot be used.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the above embodiments, and various kinds of modifications can be made without departing from the scope of the invention. Needless to say. For example,
The present invention may be applied to a filter for filtering fine particles and microorganisms. FIG. 3 is a schematic cross-sectional view of a filter for producing pure water. As shown in the figure, an ultraviolet lamp 22 is installed in the vicinity of or between the filters 21 and 21 in the filter housing 20 so that microorganisms propagate on the filter surface. Alternatively, clogging may be prevented.

Further, in this embodiment, the ultraviolet lamp is installed in the lower part of the cleaning water tank, but it may be installed in the substantially central part of the cleaning water tank so that the cleaning water tank is uniformly irradiated with ultraviolet rays.

[0017]

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

That is, it is possible to prevent contamination of the object to be cleaned, reduce the amount of cleaning water used, extend the service life of the filter, etc., and reduce the maintenance time, the manufacturing cost, and the material cost.

[0019]

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a wafer cleaning apparatus.

FIG. 2 is a schematic sectional view of a gas cleaning device.

FIG. 3 is a schematic sectional view of a filter for producing pure water.

[Explanation of symbols]

1 ... Washing water tank, 2 ... Washing water supply unit, 3 ... Pure water, 4
・ ・ Wafer, 5 ・ ・ Wafer jig, 6 ・ ・ Washing water recovery unit, 7 ・ ・ UV lamp, 8 ・ ・ Quartz tube, 10 ・ ・ Washing water tank, 11 ・ ・ Washing water, 12 ・ ・ Washing water supply unit , 13 ...
・ Spray, 14 ・ ・ Pump, 15 ・ ・ Gas-liquid contact part, 1
6 ... Gas supply port, 17 ... Gas discharge port, 18 ...
UV lamp, 20 ... Filter housing, 21 ...
・ Filter, 22 ・ ・ UV lamp, 23 ・ ・ Quartz tube.

Claims (4)

[Claims] 1. A cleaning apparatus comprising: a cleaning water supply unit for supplying cleaning water into a cleaning water tank; and a cleaning water tank for collecting cleaning water and immersing the object to be cleaned in the cleaning water for cleaning. A cleaning device with an ultraviolet lamp installed inside. 2. The cleaning apparatus according to claim 1, wherein the ultraviolet lamp is enclosed in a quartz tube. 3. The cleaning apparatus according to claim 1 or 2, wherein the cleaning water tank is made of stainless steel which is electrolytically polished. 4. A supply unit for supplying cleaning water into the cleaning water tank,
A cleaning water tank for storing cleaning water, a spray for pumping the cleaning water from the cleaning water tank and supplying it in a divided manner, a contact portion for bringing the sprayed cleaning water into contact with a gas, and a gas supply portion for supplying an object to be cleaned. And a cleaning device having a gas discharge part for discharging the cleaned gas, wherein an ultraviolet lamp is installed in the cleaning water tank.