JPH0442530A - Ultrasonic cleaning device - Google Patents

Abstract

PURPOSE:To prevent substance separated from the surface a material to be cleaned from re-adhering to the material in cleanser liquid in a cleaning tank by providing a vertical flow generating nozzle for injecting the liquid to the center of a bottom in the tank. CONSTITUTION:A vertical flow generating nozzle 13 for injecting cleanser liquid 30 upward to the center of a bottom in a cleaning tank 10 is provided in the tank 10. The liquid 30 injected from the nozzle 13 and containing contaminant separated from a material 31 to be cleaned raises as a laminar flow state in the tank 10, and overflows the opening of the tank 10. Thus, the surface of the material 31 is not brought into contact with the liquid 30 containing the contaminant separated from the material 31, but hence the surface of the material 31 is finished in a state without re-adherence of the contaminant substance.

Description

[Detailed Description of the Invention] [Summary] Ultrasonic energy is supplied to the cleaning liquid in the cleaning tank whose surface layer continuously overflows outside the cleaning tank, and the object to be cleaned immersed in the cleaning liquid is Regarding ultrasonic cleaning equipment for cleaning, the purpose of the present invention is to provide an ultrasonic cleaning equipment that can prevent substances separated from an object to be cleaned in the cleaning liquid in the cleaning tank from re-adhering to the object to be cleaned. An ultrasonic cleaning device is constructed by providing a vertical flow generating nozzle in the center of the bottom of the cleaning tank that sprays cleaning liquid upward in the cleaning tank.

[Industrial application field]

The present invention relates to an ultrasonic cleaning device, and particularly to an ultrasonic cleaning device that can prevent substances separated from an object to be cleaned in a cleaning liquid in a cleaning tank from re-adhering to the object to be cleaned.

2. Description of the Related Art In a wafer processing process for manufacturing semiconductor devices, semiconductor wafers, exposure masks, and the like are generally cleaned using an ultrasonic cleaning device.

[Conventional technology]

Next, a conventional ultrasonic cleaning apparatus used for cleaning semiconductor wafers, exposure masks, etc. will be described with reference to the drawings.

FIG. 2 is a schematic side sectional view of the main parts of a conventional ultrasonic cleaning device.

Note that the same symbols are given to the same parts and materials throughout the drawings.

The conventional ultrasonic cleaning device has a cleaning tank 2 as shown in Fig. 2.
0, a cleaning liquid introduction pipe 21 that penetrates the metal cylinder 20a of the cleaning tank 20 and is welded to the cylinder 20a, and a vibration plate 22a.
It is configured to include an ultrasonic transducer 22 fixed to the bottom plate 20b of the cleaning tank 20 with the top facing upward, and an ultrasonic oscillator 23 connected to the ultrasonic transducer 22.

A method of cleaning an object to be cleaned, for example, a semiconductor wafer 31, using such an ultrasonic cleaning apparatus will be explained step by step.

First, a cleaning jig 32 in which a plurality of semiconductor wafers 31 are housed vertically and separated from each other is cleaned using a cleaning liquid that is continuously supplied from the cleaning liquid introduction pipe 21 and overflows from the upper end opening of the cleaning tank 20, for example, pure water. Immerse in water 30.

When the ultrasonic oscillator 23 is operated immediately after the cleaning jig 32 is immersed in the pure water 30, the ultrasonic vibrator 22 vibrates the diaphragm 22a and supplies ultrasonic energy to the pure water 30.

Then, the molecules of the pure water 30 violently collide with the surface of the semiconductor wafer 31, remove contaminants from the surface of the semiconductor wafer 31, and clean the surface of the semiconductor wafer 31.

[Problem to be solved by the invention]

As mentioned above, in the conventional ultrasonic cleaning device, the cleaning liquid introduction pipe 21 is arranged in the cylindrical body 20a of the cleaning tank 20, and the pure water 30 is jetted horizontally from the cleaning liquid introduction pipe 21 as shown by the arrow H. (See Figure 2).

The pure water 30 spouted from the cleaning liquid introduction pipe 21 stirs the pure water 30 in the cleaning tank 20 .

Therefore, the purified water 30 containing contaminants and having a reduced purity comes into contact with the surface of the semiconductor wafer 31 which has been cleansed by removing the contaminants, and the surface of the semiconductor wafer 31 that has been cleaned becomes contaminated. There was a problem with redepositing the material.

The present invention was made to solve such problems, and its purpose is to prevent substances separated from the object to be cleaned in the cleaning liquid in the cleaning tank from re-adhering to the object to be cleaned. An object of the present invention is to provide an ultrasonic cleaning device that can prevent such problems.

[Means to solve the problem]

The purpose is to supply ultrasonic energy to the cleaning liquid 30 in the cleaning tank LO whose surface layer continuously overflows outside the cleaning tank LO, as shown in FIG. The ultrasonic cleaning device for cleaning the cleaning object 31 is characterized in that a vertical flow generating nozzle 13 is provided at the center of the bottom of the cleaning tank 10 to spray the cleaning liquid 3o upward in the cleaning tank 10. This is achieved using an ultrasonic cleaning device.

[For production]

The ultrasonic cleaning apparatus of the present invention is provided with a vertical flow generating nozzle 13 that jets a cleaning liquid 30 vertically upward at the center of the bottom of the cleaning tank lo.

Therefore, the cleaning liquid 30 containing the dirt substances ejected from the vertical flow generating nozzle 13 and separated from the object 31 to be cleaned rises in the cleaning tank 10 in a laminar flow state, and It will overflow from the opening at the top of the.

Therefore, the surface of the object to be cleaned 31 does not come into contact with the cleaning liquid 3o containing the soiled substances that has separated from the object to be cleaned 31, but constantly contacts the cleaning liquid 30 that does not contain any dirty substances.

In this way, the surface of the object to be cleaned 31 is finished without re-deposition of dirt substances.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram for explaining an ultrasonic cleaning device according to an embodiment of the present invention, and FIG. 1 (a) is a schematic side sectional view of the main part of the device;
FIG. 5B is a plan view of the vertical flow generating nozzle.

This ultrasonic cleaning device closes the lower end opening of a metal cylindrical body 10a with a diaphragm 12a of an ultrasonic vibrator 12 and a vertical flow generating nozzle, as shown in FIGS. A cleaning tank 10 configured as above, a cleaning liquid introduction pipe 11 that spouts a cleaning liquid, for example, pure water 30, horizontally as shown by arrow H into the cleaning tank 10, and a diaphragm 12a having a concentric opening. The cylindrical body 10 is inserted through the elastic airtight packing 10b.
an ultrasonic transducer 12 connected to the open end at the lower end of the diaphragm 12a; and an elastic airtight packing 10 inserted into the opening of the diaphragm 12a.
A vertical flow generating nozzle 13 is connected to the ultrasonic transducer 12 via a vertical flow nozzle 13 and has a spout 13a that ejects pure water 30 in an upward vertical direction as shown by an arrow V. It is configured to include an ultrasonic oscillator 14 that supplies ultrasonic energy to the pure water 30 in the cleaning tank 10 by supplying electric power and vibrating the diaphragm 12a of the ultrasonic vibrator 12.

The method of cleaning an object to be cleaned using this ultrasonic cleaning device is carried out in the same procedure as the cleaning method of the conventional ultrasonic cleaning device explained with reference to FIG. 2, so a description thereof will be omitted here.

However, in the ultrasonic cleaning device according to one embodiment of the present invention,
The pure water 30 ejected vertically upward from the vertical flow generation nozzle 13 rises as a laminar flow, and together with the substances separated from the semiconductor wafers 31, etc., overflows from the opening at the upper end of the cleaning tank 10 and becomes water 30a for cleaning. It will flow out from the tank 10.

Therefore, in the ultrasonic cleaning apparatus of the present invention, since the pure water 30 is not stirred in the cleaning tank 10 as described above, -
The removed dirt substances are prevented from re-adhering to the surface of the object to be cleaned, such as a semiconductor wafer, which has been previously cleaned to remove the dirt substances.

In this way, the ultrasonic cleaning apparatus of the present invention makes it possible to finish the surface of the object to be cleaned in an extremely clean state.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a superfluous material that can prevent substances separated from the surface of the object to be cleaned in the cleaning liquid in the cleaning tank from re-adhering to the surface of the object to be cleaned. Therefore, if a semiconductor wafer, etc. is cleaned with the ultrasonic cleaning device of the present invention, the surface of the semiconductor wafer, etc. will be finished in an extremely clean state without any contaminants attached. It happens.

Reference numeral 31 indicates an object to be cleaned (semiconductor wafer), and 32 indicates a cleaning jig.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining an ultrasonic cleaning apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic side sectional view of a main part of a conventional ultrasonic cleaning apparatus. In the figure, 10 and 20 are cleaning tanks, 11 and 21 are cleaning liquid introduction pipes, 12 and 22 are ultrasonic vibrators, 13 is a vertical flow generation nozzle, 13a is a spout, 14 and 23 are ultrasonic oscillators, and 30 is a cleaning tube. liquid (pure water), (0'1t?9[1klF(#ljmXjtb)t
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Claims (1)

[Claims] Ultrasonic energy is supplied to the cleaning liquid (30) in the cleaning tank (10) whose surface layer continuously overflows outside the cleaning tank (10), and the object to be cleaned is immersed in the cleaning liquid (30). In an ultrasonic cleaning device for cleaning (31), a vertical flow generation nozzle (
13) An ultrasonic cleaning device characterized by being provided with.