KR20030004742A - Wet etching apparatus for liquid crystal display - Google Patents

Abstract

PURPOSE: An LCD wet etching device is provided to prevent the flowing or leaking of a liquid among adjacent units by mounting a prevention plate at an upper part of a boundary wall surface of each unit, thereby preventing the loss of the chemicals. CONSTITUTION: An LCD wet etching device includes a loader part for securing a substrate(305) to etch, an etching part supplied with an etching solution to carry out etching, a first rinsing part for removing the etching solution from the substrate, a mega sonic part for removing fine particles from the substrate by high frequency, a second rinsing part for removing the remaining from the substrate, an air knife part for removing the humidity from the substrate, a chemical tank for storing the etching solution, and a prevention plate(401) mounted on each boundary wall surface(302) of the respective units for preventing the introduction or leak of liquid(303) such as the etching solution sprayed from a nozzle(301), stripper, or DI water into adjacent units when a shutter(304) is opened.

Description

Wet etching equipment of liquid crystal display {WET ETCHING APPARATUS FOR LIQUID CRYSTAL DISPLAY}

The present invention relates to a wet etching apparatus of a liquid crystal display, and in particular, to prevent loss and mixing of chemical liquids generated in a track type wet etching apparatus.

A thin film transistor array, which switches and applies a signal voltage to a liquid crystal, is formed through a plurality of deposition and etching processes.

The structure and function will be described in detail through the thin film transistor shown in FIG.

The thin film transistor includes three electrodes of the gate 102, the source 103 and the drain 104 on the glass substrate 101, the pixel electrode 105 for applying a voltage to the liquid crystal cell, and the positive electrode to the gate electrode. An amorphous silicon channel region 106 that forms a conductive channel through which an electric current flows between the source and drain electrodes by an electric field when a voltage is applied, and a silicon nitride film SiN _x to protect the device. It is comprised by the protective film 107. The thin film transistor is a field effect transistor that controls the flow of current by an electric field. The design of the thin film transistor is the most important factor in determining the image quality obtained by the panel of the liquid crystal display. In order to produce the completed thin film transistor, a plurality of deposition and etching processes are performed.

In general, the etching is a dry etching method and a wet etching method.

The dry etching method is a method of removing a semiconductor layer or metal by using plasma gas. The plasma etching is mainly performed by chemical reaction, and an inert gas such as argon (Ar) is ionized to accelerate the substrate to be etched from the surface. There is an ion reactive etching method combining the sputtering etching to remove and the chemical etching and sputtering etching. An appropriate etching method is selected according to the material to be etched.

The dry etching tends to be anisotropically etched compared to wet etching.

In general, a wet etching method using an etching solution includes a dip etching method and a spray etching method.

The deep etching method is to completely immerse the sample to be etched into the etching solution, and the etching method tends to be isotropic. (anisotropic) is etched.

Typically, wet etching equipment is configured as shown in FIG. 2A.

The loader portion 201 on which the substrate to be etched is placed, the isolation portion 202 provided as a buffer space for preventing corrosion of the loader portion from a strong acid solution, and the etching portion 203 where the etching solution is supplied to be etched substantially. And a first cleaning part 205 for washing away the etching solution existing on the etched substrate, the drain part 204, and the fine substrate on the substrate that was not removed by the first cleaning part 205. A mega sonic unit 206 for completely removing particles through high frequency, a second cleaner 207 for completely washing away the cleaning liquid in which particles separated from the substrate in the mega sonic process are dissolved, and a large amount Aqua knife portion 208 for moving the substrate while the knife-like DI water is sprayed up and down the substrate of the liquid crystal display, and the water remaining on the substrate. That is composed of an air knife (air knife) portion 209 and, and the drug solution storage (chemical tank) in the etching solution are stored to be etched is supplied on the section made of the substrate being removed to the outside. Etching and cleaning in the wet etching equipment is a spray method that is injected through the nozzle from the top.

However, in consideration of space limitations in the design of the wet equipment, each part is designed to a minimum size, so that the distance between the spray nozzle and the boundary wall of the unit is close, thereby causing problems.

The above problem will be described in detail with reference to FIG. 3.

Since the wet etching equipment manufactured in the space-restricted state should be designed with a minimum size, as shown in FIG. 3, the distance between the spray nozzle 301 and the unit boundary wall 302 becomes close. When the distance between the spray nozzle 301 and the unit boundary wall 302 is close, the injection liquid ejected from the first nozzle attached to the boundary surface by the angle of the liquid 303 ejected from the nozzle is When sprayed to the unit boundary wall 302, a large amount of liquid flows into the next unit when the shutter 304 is opened for conveyance of the substrate. Even when the shutter 304 of the unit boundary wall surface is closed, a small amount of liquid leaks.

The chemicals should be used for a period of time, with a continuous supply and return, while maintaining a constant level, stored in the reservoir below.

However, when the above-mentioned chemical liquid to be returned to the reservoir flows into the next unit and flows out, the level of the chemical liquid held constant in the reservoir is lowered. If the level of the reservoir storing the chemical liquid is lowered, an error of the reservoir will occur and the wet etching equipment can no longer be operated.

In addition, due to the above problem, the substrate undergoing the etching process may be less etched or overetched, and chemical defects may occur on the substrate of the liquid crystal display, resulting in process defects.

If the jetting liquid ejected from the first nozzle attached next to the interface spills into the part with other chemicals, it may cause mixing between the chemicals and dilute or contaminate the chemicals to function properly. It should not be.

In addition, when the jetting liquid ejected from the first nozzle attached to the interface immediately flows into the DI water region, the DI water is mixed with the chemical liquid and contaminated.

The mixing and dilution between the chemical liquids and the mixing and contamination with the DI water cause a defect of the liquid crystal display substrate.

An object of the present invention is to solve the above-described problems, and to prevent a process defect caused by mixing different types of chemical liquids by placing a barrier plate on the top of the boundary wall of each unit.

Another object of the present invention is to prevent the loss of chemical liquids that flow out and are lost without being returned back to the reservoir.

Another object of the present invention is to prevent a process failure due to equipment error caused by a certain level of the chemical solution in the chemical reservoir.

Other objects and features of the present invention will be described in detail in the configuration and claims of the following invention.

1 shows a general thin film transistor.

Figure 2a shows the overall configuration steps constituting the wet etching equipment.

Figure 2b shows a storage tank of the chemical liquid for storing the chemical liquid supplied during the wet etching.

Figure 3 shows the boundary wall portion between the wet etching unit with a conventional wet etching equipment.

4 shows that the prevention plate is installed on the upper boundary wall of the unit.

FIG. 5A illustrates a wet etching apparatus in which an angle at which a boundary wall between a preventive plate and a unit is formed is 90 ° or less.

FIG. 5B illustrates defects occurring on the substrate of the liquid crystal display when the prevention plate is installed as shown in FIG. 5A.

6A illustrates a wet etching apparatus in which an angle at which a boundary wall between a preventive plate and a unit is formed is set to 90 ° or more.

FIG. 6B is a schematic diagram showing that the flow of liquid does not affect the substrate when the prevention plate is installed as shown in FIG. 6A.

** Explanation of symbols for main parts of drawings **

211: reservoir of chemical liquid 304: shutter between units

303: liquid 401: preventive plate

The present invention relates to a wet etching apparatus devised to solve the above-described problems, the loader 201 is placed on the substrate 305 to be etched, and the corrosion of the loader 201 from the strong acid solution The isolation part 202 provided as a buffer space for blocking, the etching part 203 which supplies an etching solution, and the etching part is substantially etched, the drain part 204, and the 1st which wash | cleans the thing which exists on the board | substrate with which it was etched. A cleaning part 205, a megasonic part 206 for completely removing the fine particles on the substrate that are not removed by the first cleaning part through a high frequency, and being separated from the substrate in the mega sonic process. The second cleaning unit 207 for washing away the cleaning liquid in which the particles are dissolved, and a large amount of DI water in the form of a knife are sprayed on the upper and lower sides of the substrate 305 of the liquid crystal display, thereby providing the substrate 305. A chemical liquid reservoir in which an aqua knife 208 for moving, an air knife 209 for removing water remaining on the substrate, and an etching solution supplied to an area where the substrate is etched are stored. It is comprised by 207, It is characterized by the prevention plate provided in the upper part of the boundary wall of the part in which each process is performed.

Etching and cleaning in the wet equipment is carried out by a spray method that is sprayed through the nozzle from the top of each part of the process, the prevention plate was installed to prevent mixing with other chemicals.

Hereinafter, the present invention will be described in detail with reference to the drawings.

Fig. 4 shows a preventive plate provided on the upper part of the boundary wall surface of each part through which the liquid crystal display substrate enters and prevents mixing of liquids.

As shown in FIG. 4, by installing the barrier plate 401 between the boundary wall surfaces 302 of each part, liquids such as an etching solution, a stripper, or DI water sprayed through the spray nozzle 301 ( 303 may prevent a phenomenon in which the shutter 304 is opened or flows out to the next unit in the open state, thereby preventing a process defect of the liquid crystal display.

In this case, it is preferable to use the same material as that of the prevention plate installed.

In addition, by using the preventive plate 401 to prevent the liquids 303 from flowing through the other unit to maintain a constant level of the chemical liquid reservoir 211 installed in the lower portion of the wet etching portion of the chemical liquid reservoir The error of 211 can be prevented.

The chemical liquid reservoir 211 (FIG. 2B) maintains a constant amount of the chemical liquid while continuously supplying and returning the chemical liquid. However, if the chemical liquid is lost elsewhere, the level of the chemical liquid in the reservoir is reduced, resulting in an error in the reservoir, which lowers the operation of the equipment.

However, the effect of the prevention plate can be seen only if the above-mentioned prevention plate is installed at an appropriate angle.

Fig. 5A shows that the above-mentioned prevention plate is installed at 90 DEG or more with respect to the surface of the boundary wall between the units.

As shown in FIG. 5A, when the preventive plate 401 is installed at an angle of 90 ° or more with respect to the surface 302 of the boundary wall between units, the liquid 303 ejected from the spray nozzle 301 is the preventive plate. When sprayed onto the 401, the liquid flows down the substrate 305 of the liquid crystal display along the barrier plate. At this time, unnecessary stains are formed on the substrate by the liquid flowing down the substrate 305, causing a process defect of the liquid crystal display.

Fig. 5B shows spots formed on the substrate of the liquid crystal display by providing the prevention plate in the above manner.

When the prevention plate 401 is installed at an angle of 90 ° or more with respect to the surface 302 of the boundary wall between the units, the phenomenon that the liquid ejected from the spray nozzle flows out or flows into another unit can be reduced, but the prevention plate 401 Due to the liquids flowing along the surface, defects occurring on the substrate of the liquid crystal display cannot be prevented.

6A shows another embodiment in which the prevention plate 401 is installed at an angle of 90 ° or less with respect to the surface 302 of the boundary wall between units.

As shown in FIG. 6A, when the prevention plate 401 is installed at an angle of 90 ° or less with respect to the surface 302 of the boundary wall between the units, the angle of the liquid 303 ejected from the spray nozzle 301 is determined. Even if the injection liquid of the first nozzle located immediately next to the entrance and exit is injected into the boundary wall 302, the phenomenon that the prevention plate 401 flows into or out of the next unit can be prevented. In addition, when the prevention plate 401 is not installed even when the shutter 304 is closed, a small amount of liquid 303 leaks. However, by providing the preventive plate 401 described above, the liquid 303 can be prevented from leaking even in a small amount even when the shutter 304 is closed.

If there is no spillage or inflow of liquid to another unit, it will prevent the chemical reservoir error from occurring during the process, process defects caused by less etching or overetching of the liquid crystal display substrate, or staining of the chemical liquid. Can be.

As another advantage of the present invention, if the side unit into which the injection liquid injected from the nozzle flows is another chemical liquid or DI water region, a process defect caused by contamination of the chemical liquid and other chemical liquid and DI water is Can be prevented.

In FIG. 6B, when the prevention plate 401 is installed as shown in FIG. 6A, no defect occurs in the substrate 305 of the liquid crystal display regardless of the flow of the chemical liquid 303 injected from the nozzle 301.

The prevention plate 401 flows to the substrate 305 of the liquid crystal display to prevent all liquids that may cause defects, thereby obtaining a liquid crystal display substrate in which wet etching and cleaning processes are normally performed.

The track type wet etching equipment may be applied to wet processes of all devices requiring a wet etching process as well as a wet process of a liquid crystal display.

As described above, by installing a barrier plate on the boundary wall surface between the units of the track type wet etching equipment, it is possible to prevent the liquid from flowing in or out between the units. As the above problem is solved, it can prevent process defects that occur during wet etching process, increase the process yield, reduce the material cost by preventing the chemical liquid from being lost to other units, and reduce the chemical liquid reservoir by maintaining the constant chemical liquid. As a result, the process time can be shortened as it continues to operate normally.

Claims (6)

The loader portion on which the substrate to be etched is placed, the etching portion supplied with the chemical solution, the first portion to remove the etching solution on the substrate, and the mega to remove the fine particles on the substrate through high frequency. A sonic portion, a second cleaning portion for cleaning residue on the substrate, an air knife portion for removing water remaining on the substrate, a chemical tank in which an etching solution is stored, and Wet etching equipment of the liquid crystal display, characterized in that the prevention plate is installed on top of the unit boundary wall surface. The method of claim 1, Wet etching equipment of the liquid crystal display, characterized in that the spray method by the chemical liquid ejected from the nozzle of the upper unit. The method of claim 1, Wet etching equipment of the liquid crystal display, characterized in that the spray method by distilled water is injected from the nozzle of the upper unit. The method of claim 1, The prevention plate is a wet etching equipment of the liquid crystal display, characterized in that the material installed in the same material as the unit. The method of claim 1, The prevention plate is a wet etching equipment of the liquid crystal display, characterized in that the predetermined angle θ that is inclined with respect to the boundary wall surface of the unit is 0 ° or more and 90 ° or less. The method of claim 1, Wet etching equipment of the liquid crystal display characterized in that it further comprises an aqua knife portion for moving the market while DI water is sprayed from the upper and lower portions of the substrate.