KR20090103677A - Substrate Cleaning Apparatus Using Bubble And Method Using The Same - Google Patents

Abstract

PURPOSE: A substrate cleaning apparatus using a bubble is provided to obtain a powerful cleaning effect without damage to a pattern by using a fine diameter bubble. CONSTITUTION: A substrate cleaning apparatus(20) using a bubble includes a source water storage tank(21), a mixing part(25), a bubble storage tank(27,28), and a nozzle. The mixing part forms a fine bubble by mixing a gas in source water supplied from the source water storage tank. The bubble storage tank stores the fine bubble generated in the mixing part. The nozzle coats the fine bubble stored to the bubble storage tank on a substrate. The source water includes one or more thing among hyper pure water, ozonated water, and alkaline water.

Description

Substrate Cleaning Apparatus Using Bubble And Method Using The Same}

The present invention relates to a substrate cleaning apparatus and method, and more particularly, to a substrate cleaning apparatus and method using micro-diameter bubbles.

One of the factors that greatly affect the reliability in semiconductor and FPD manufacturing processes is particles containing metal contamination and organic substances on the substrate surface.

In particular, the adhesion of particles has a large effect on the yield of the device. Particles are generated from process reactions, workers and manufacturing equipment and adhere to the substrate surface. These particles can cause the panel surface to be uneven, and uneven surface conditions can lead to unstable production processes and products, and to other problems.

Therefore, particles must be removed to secure the reliability before and after the process and to improve the yield. This is the cleaning process. As the technology advances, the cleaning process also requires technical development as the panel is enlarged and the pattern is made smaller.

Referring to Figure 1, looks at a conventional general cleaning device 100 and process. As shown, a conveyor for transporting the substrate, excimer ultraviolet (EUV) irradiation means 110 for removing organic matter, a roll brush 120 for removing particles, and spraying water on the substrate And a rinsing unit 130, an air knife 140 for injecting air to the substrate, an ionizer 150 for removing static electricity remaining on the substrate, and a heating means 160 for heating the substrate. . In addition, ultrasonic cleaning means (not shown) for removing particles by vibration may be provided.

Conventional roll brush apparatus is a contact type cleaning apparatus for cleaning by contacting the roll brush on the surface of the substrate. Such a roll brush cleaning method may damage a pattern of a substrate and the like, and there is a problem in that particles are reattached.

In addition, the ultrasonic cleaning means is also a device for removing particles by vibration, there is a problem that can damage the pattern of the substrate.

The present invention has been made to solve the above problems, an object of the present invention to provide a substrate cleaning apparatus and method using a micro-diameter bubble.

In order to solve the above technical problem, the substrate cleaning apparatus according to the present invention comprises: a raw water storage tank for storing raw water such as ultrapure water, ozone water or alkaline water; A mixing unit for mixing the raw water supplied from the raw water storage tank with gas such as air, ozone gas or oxygen gas to form bubbles having a micro diameter in micro units; A bubble storage tank for storing the fine bubbles generated by the mixing unit; And a nozzle for applying the microbubbles stored in the bubble storage tank to the substrate.

In addition, the raw water storage tank is preferably further provided with a heating unit for heating the stored raw water to 25 ~ 99 ℃.

In addition, the diameter of the bubble is preferably 20 ~ 40㎛.

The substrate cleaning method according to the present invention is to remove particles by applying a bubble of a fine diameter on the surface of the substrate.

According to the present invention, it is possible to obtain a strong cleaning effect without damaging the pattern by using a micro-diameter bubble.

1 shows a conventional substrate cleaning apparatus.

2 shows a substrate cleaning apparatus according to the present invention.

3A and 3B show a TFT substrate before cleaning and a TFT substrate after cleaning by the present invention, respectively.

4A to 4C show a TFT substrate before cleaning, a TFT substrate after cleaning by a high pressure air injection method, and a TFT substrate after cleaning according to the present invention, respectively.

Figure 5a shows the structure of the substrate, Figure 5b is a graph showing the damage generation rate after the ultrasonic cleaning of the substrate shown in Figure 5a, and the present invention.

** Description of the symbols for the main parts of the drawings **

20: washing device 21: raw water storage tank

22: supply pipe 23: air injection pipe

24: pump 25: mixing section

26: transfer pipe 27, 28: bubble storage tank

29: discharge tube

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation of the embodiment according to the present invention.

Referring to FIG. 2, the bubble washing means 20 includes a raw water storage tank 21 for storing and supplying ultrapure water, a supply pipe 22 for supplying the ultrapure water, and air injected through an air injection pipe 23. And a mixing unit 25 for mixing the ultrapure water to form a microbubble, a pump 24, a transfer pipe 26 for transferring bubbles generated by the mixing unit 25, and a first storing the bubble. And a second bubble storage tank 27 and 28, a discharge tube 29 for discharging bubbles stored in the second bubble storage tank 28 to a nozzle (not shown), and connected to an end of the discharge tube. And a nozzle for applying the bubble to the surface of the substrate. In addition, the raw water storage tank 21 is provided with a heating unit (not shown) for heating the ultrapure water to 25 ~ 99 ℃.

The transfer pipe and the discharge pipe are preferably formed of polyvinyllidene fluoride (PVDF) material in order to minimize bursting of bubbles.

In the present embodiment, but is illustrated that the raw water is ultra-pure water, it may alternatively include ozone water or alkaline water or these. In addition, ozone gas or oxygen gas may be mixed instead of air.

The operating state and cleaning method of the cleaning apparatus according to the present invention configured as described above will be described.

First, the ultrapure water stored in the raw water storage tank 21 is heated, and then mixed with air in the mixing unit 25 to form bubbles having a fine diameter. The bubbles formed as described above are transferred to the first and second bubble storage tanks 27 and 28 through the transfer pipe 26, and when the second bubble storage tank 28 is above a predetermined pressure, the discharge pipe 29 ) And bubbles are applied to the upper and lower surfaces of the substrate.

The applied bubble shrinks and ruptures with surface tension, causing micro vibrations, which remove particles from the substrate. In particular, the bubble can penetrate into the minute gaps between the patterns of the substrate, so the cleaning effect is excellent.

The bubble also contracts and bursts, increasing the pressure and temperature inside the bubble. Furthermore, in the present invention, since the ultrapure water is preheated to generate bubbles, the particle or organic matter cleaning effect is further enhanced.

On the other hand, since the bubble of the fine diameter is charged with (-), it is possible to effectively remove the particles charged with (+).

Substrate cleaning effect using such a micro diameter bubble is demonstrated through the following experimental example.

FIG. 3A shows an image of a TFT substrate (t = 0.7mm) taken at 150 magnification before cleaning, and FIG. 3B shows an image after cleaning the substrate shown in FIG. 3A using bubbles. In Figure 3b it can be seen that the cullet has been significantly removed.

4A is an image taken at 150 times magnification of a TFT substrate (t = 0.7mm) before cleaning. FIG. 4B is an image after dry cleaning by spraying high pressure air with an air knife on the substrate shown in FIG. 4A. According to the present invention, the image after washing using a bubble is shown. The dry cleaning conditions here are 0.3 MPa of air pressure and 4 mm of distance.

It can be seen that particles of the substrate of FIG. 4C are significantly removed from the substrate of FIG. 4B.

FIG. 5A shows the structure of the substrate to be treated, and FIG. 5B shows the pattern damage incidence after cleaning the substrate of the structure shown in FIG. 5A using bubbles and cleaning by ultrasonic waves. In the cleaning method using ultrasonic waves, it can be seen that the damage to the pattern is severe when the distance from the spray center is 5 to 10 mm. On the other hand, it can be seen that the cleaning method using bubbles has little damage to the pattern regardless of the distance from the spray center (area of 1 Map = 0.62 mm ² ).

Meanwhile, Table 1 below shows the removal rate according to the size of particles (P / T) after cleaning the substrate by the conventional roll brush method, and Table 2 shows the size of the particles after cleaning the substrate using bubbles. According to the removal rate.

That is, the particle removal rate was remarkably higher in the method using bubbles than the roll brush method.

Claims (10)

Raw water storage tanks; A mixing unit which forms a fine bubble by mixing gas into raw water supplied from the raw water storage tank; A bubble storage tank for storing the fine bubbles generated by the mixing unit; And And a nozzle for applying a microbubble stored in the bubble storage tank to a substrate. The method of claim 1, The raw water is a substrate cleaning device using a bubble, characterized in that any one or more of ultrapure water, ozone water and alkaline water. The method of claim 1, The gas cleaning device using a bubble, characterized in that any one or more of air, ozone gas and oxygen gas. The method of claim 1, The raw material storage tank further comprises a heating unit for heating the stored raw water, the substrate cleaning apparatus using a bubble. The method of claim 1, The heating unit is a substrate cleaning device using a bubble, characterized in that for heating the raw water in the range of 25 ~ 99 ℃. The method of claim 1, Substrate cleaning apparatus using a bubble, characterized in that the diameter of the bubble is 20 ~ 40㎛. Substrate cleaning method using a bubble, characterized in that to remove particles by applying a bubble of a fine diameter on the surface of the substrate. The method of claim 7, wherein The bubble is a substrate cleaning method using a bubble, characterized in that formed by mixing the raw water containing any one or more of ultrapure water, ozone water and alkaline water with a gas containing any one or more of air, ozone gas and oxygen gas. The method of claim 7, wherein The raw water is a substrate cleaning method using a bubble, characterized in that mixed with the gas in a heated state in the range of 25 ~ 99 ℃. The method of claim 7, wherein The diameter of the bubble is a substrate cleaning method using a bubble, characterized in that 20 ~ 40㎛.