KR960012270B1 - Forming pattern method of transparent electrode - Google Patents

Abstract

The method includes the steps of; evaporating a transparent conduction layer(2) on a transparent quartz substrate(1); evaporating a metal layer(3); scattering with a photoresist(4) and patterning; masking the photoresist(4) to pattern the metal layer(3) with an wet etching; masking the metal layer to pattern the transparent conduction layer; removing the photoresist and the metal layer.

Description

Transparent conductive engine manufacturing method

1 (a) to 1 (e) are cross-sectional views showing the ITO film pattern manufacturing process of a transparent substrate according to the prior art.

2 (a) to 2 (f) are cross-sectional views showing the ITO film pattern manufacturing process of the transparent substrate according to the first embodiment of the present invention.

3 (a) to 3 (g) are cross-sectional views showing an ITO film pattern manufacturing process of a transparent substrate according to a second embodiment of the present invention.

4 (a) to 4 (g) are sectional views showing the ITO film pattern manufacturing process of the transparent substrate according to the third embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display device, and more particularly, to a method of forming an ITO pattern and a metal electrode pattern used in manufacturing a liquid crystal display (hereinafter referred to as LCD).

In the image information age, much expectation is gathered in the display device which is the largest person in charge of information transmission. As a result, various flat label devices which have replaced the cathode ray tube have been developed and are rapidly spreading.

Among them, liquid crystal displays are extremely lightweight, thin, low-cost, low-power driving, and have good compatibility with integrated circuits. have.

Among the LCD devices, electronic view finder products are manufactured using a semiconductor manufacturing process. The device is a device in which a liquid crystal is injected by forming a transparent conductive film called indium tin oxide (ITO) on an upper / lower panel made of a quartz engine.

In order to realize the display by the liquid crystal using the device, it is necessary to form an ITO pattern on the substrate. Conventional techniques related to ITO etching of the process have been known using hydrochloric acid based solution or ferric chloride based etching solution.

Among them, hydrochloric acid-based solution called ITO etchant (HCl: 47.5%, NHO3: 5%, DI: 47.5%) is a photopolymer used in forming the ITO pattern is an organic polymer is etched by the etchant to form a pattern Difficult problems arise.

As such, recently, a dry etching method using CH 4 and H 2 or CH 3 and Ar + ions has been realized, as known from US Pat. No. 517,401.

In addition, US Pat. No. 4,736,229 is known to introduce a metal film as a film for protecting the ITO film in order to prevent changes in the properties of the ITO in connection with the process, but the metal film is removed using a dry etching method. The known art is shown in FIGS. 1 (a) to 1 (e).

A general ITO pattern forming method according to the prior art based on the drawings, first, as shown in Figures 1 (a) to 1 (c), the ITO film 2 on the transparent quartz substrate 1 After deposition, a photoresist is applied on the ITO film 2, and a photoresist pattern 4 is formed by using photolithography.

Thereafter, as shown in FIG. 1 (d), the ITO pattern 2 is formed by a wet etching method using the photoresist pattern 4, and then the photoresist pattern is completely removed. You will complete the same ITO pattern.

In this process, since the mutual adhesion between the ITO films of the photoresist is not good, the photoresist film is etched together during the ITO wet etching process, so that the interface between the photoresist and the ITO becomes unstable, so that the photoresist film may Some are dropped off.

This phenomenon occurs because the organic photoresist film is etched because the ITO etching solution is acid-based, which leads to difficulty in forming the ITO pattern. In addition, the separated photoresist contaminates the etching bath. This creates a problem that makes the process difficult to use.

Another problem related to ITO pattern formation is that anodized metals such as aluminum, chromium, tantalum, and ITO, which are mainly used as wiring materials and transparent pixel electrodes in active matrix LCD fabrication, are electrically contacted by two different metals. When exposed to electrolyte, developer, photoresist removal solution, etching solution, etc., both metals or either metal may cause abrupt reactions that cannot be explained by chemical etching and cause erosion.

This phenomenon is a corrosion phenomenon caused by the electron transfer between the two metals and the transfer of charge between the metal and the solution in the electrolyte due to the difference in the potential of each of the two metals. During wet etch, defects such as erosion of pad chromium and gate aluminum and ITO erosion of the pixel electrode are developed in the development process of the source-drain pattern.

As described above, the transparent electrode which is essentially used for the flat panel display device is difficult to etch, and thus it is difficult to obtain a desired pattern. This deepens as the line width of the pattern becomes smaller. Among the transparent electrodes, indium tin oxide (ITO) is relatively etchable, but still satisfactory results have not been obtained.

Particularly problematic in the ITO etching is that it is difficult to form a fine pattern and to ensure the reliability of pixel operation due to the electrochemical corrosion phenomenon caused by the developer and the etchant (gas or liquid) when it comes in direct contact with the metal film. As a way to improve this problem, a method of minimizing electrochemical corrosion by devising a low temperature oxide film or nitride film on ITO and greatly reducing the area in direct contact with the metal film has been devised. However, this method also exposes the side of the ITO pattern, so contact with the metal electrode is inevitable, and thus cannot be a perfect method.

As the etching method of ITO which is normally used, wet etching, dry etching, etching by laser irradiation, etc. are mentioned. Wet etching has the advantages of simple process, high through-put, etc., but problem of formation of fine pattern due to adhesion problem of photoresist, electrochemical corrosion phenomenon by wet etching solution and developer. There are many. Dry etching is possible to form a fine pattern of 5㎛ or less, but there is a problem that the through-foot is low and the polymer (polymer) is formed. Etching by laser irradiation has been a problem for low through-put, but recently it is a level enough to be applied to production and the degree of pattern is very high as 1 占 퐉. However, the ITO pattern has a disadvantage in that it is effective only for STNs having a simple matrix type stripe.

Accordingly, the present invention is to solve the above problems, the first object is to form a metallic conductive film pattern by a wet etching method using a metal film resistant to ITO etching chemicals as a masking layer (masking layer) of the photoresist It is to provide a method for manufacturing a transparent conductive substrate that can prevent undesirable phenomena such as falling.

On the other hand, a second object of the present invention is to provide a method for manufacturing a transparent conductive substrate configured to prevent the electrochemical corrosion of ITO and metal wiring and to achieve a low resistance of the pixel electrode.

A first aspect of the method for manufacturing a transparent substrate according to the present invention for achieving the above object is a film quality pattern forming step of forming the upper and lower panels of the liquid crystal display device, the conductive film pattern forming step is transparent on a transparent quartz substrate Depositing a conductive film; Depositing a metal film on the transparent conductive film; Forming a photoresist pattern using a photolithography process after coating the photoresist on the metal film; Selectively etching the metal film by wet etching to pattern the metal film in the same manner as the photoresist pattern; Wet etching the transparent conductive film using the second metal film pattern as a mask, patterning the same, and removing the photoresist pattern; And removing the metal film pattern formed on the transparent conductive film.

According to a second aspect of the method of forming a conductive film pattern according to the present invention, in the transparent conductive film pattern forming process of forming the upper and lower panels of the liquid crystal display device, the transparent electrode and the metal electrode forming process are formed on an ITO transparent electrode on a transparent substrate on which a semiconductor layer is formed. Forming a; Forming an oxide film or a nitride film on the ITO transparent electrode; Applying a photoresist on the oxide film or nitride film and then performing exposure, development, and etching to form an oxide film or nitride film pattern; Etching the transparent conductive film after removing the photoresist; Forming a metal film on the substrate on which the pattern is formed; Exposing, developing and etching the photoresist on the pattern; And etching the metal film using the photoresist pattern as a mask and removing the photoresist to form a metal electrode.

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

2 (a) to 2 (f) are cross-sectional views showing the ITO film pattern manufacturing process of the transparent substrate according to the first embodiment of the present invention. As can be seen from the figure, the ITO film pattern manufacturing process according to the present invention is a process for forming the transparent conductive film pattern 2 forming the upper and lower panels of the liquid crystal display device, wherein the metal film 3 different from the transparent conductive film 2 is formed. ) And the conductive film pattern 2 is formed as a mask layer.

Referring to the process of forming the conductive film pattern 2 according to the first embodiment having the above characteristics is as follows. That is, as shown in FIGS. 2 (a) and 2 (b), the transparent conductive film 2 on which the pattern is to be formed is deposited on the transparent quartz substrate 1, and the metal film 3 is then transparent conductive. It is deposited on the film 2.

After that, a photoresist is applied onto the metal film 3 and a photoresist pattern 4 as shown in FIG. 2C is formed by using photo-lithography of a semiconductor manufacturing process.

Subsequently, as shown in FIG. 2 (d), the substrate on which the pattern is formed is precipitated in hydrogen peroxide at 20 ° C. to 90 ° C. for 1 to 30 minutes, and optionally the metal film 3 is etched to form a photoresist pattern 4. The metal film 3 is patterned in the same manner as in the above, wherein the hydrogen peroxide is used at a concentration of 10-50%.

Subsequently, after wet etching the transparent conductive film 2 using the metal pattern 3, the photoresist pattern 4 is removed to form a pattern as illustrated in FIG.

Thereafter, the metal pattern 3 formed on the transparent conductive film pattern 2 is again precipitated in hydrogen peroxide at 20 ° C. to 90 ° C. for 1 to 30 minutes to completely remove the metal film, as shown in FIG. 2 (f). The transparent conductive film 2 as described above is completed. In this case, the photoresist pattern 4 may be removed immediately after the metal pattern 3 is formed, and is 30 wt% of hydrogen peroxide used for removing the metal pattern 3.

The transparent conductive film used to form the transparent conductive film pattern 2 is ITO, and the metal 3 used as the mask layer to form the pattern 2 is titanium-tungsten (TiW). Since TiW has etching resistance to ITO wet etching chemicals, the TiW has an advantage of easily forming an ITO pattern than using a photoresist.

3 (a) to 3 (g) are views illustrating a process of manufacturing an ITO film pattern of a transparent substrate according to a second embodiment of the present invention. A cross-sectional view showing an ITO film pattern manufacturing process of a transparent substrate according to a third embodiment of the present invention. The ITO film pattern manufacturing process according to the second and third embodiments is a process for forming a transparent conductive film pattern forming the upper and lower panels of the liquid crystal display device, in order to improve the etching property of the transparent conductive film on the transparent conductive film 30. After the oxide film or nitride film 40 is formed at a low temperature, the transparent electrode and the metal electrode pattern are formed using the oxide film or the nitride film as a mask layer.

The manufacturing process of the conductive substrate having the above characteristics will first be described based on the second embodiment. That is, as shown in FIG. 3 (a), the transparent conductive film 30, for example, ITO, is sputtered by using an oxide target of 10% Sn on the transparent substrate 10 on which the semiconductor layer 20 is formed. To form. The transparent substrate 10 may be any one selected from glass, quartz, or a silicon substrate on which an oxide film is formed, and the semiconductor layer 20 may use any one selected from amorphous silicon, polycrystalline silicon, or single crystal silicon. As a result, the crystallinity of the film is improved by the heat treatment effect applied to the ITO when the oxide film or the nitride film is formed on the transparent electrode film, thereby forming a clean pattern in a subsequent process. In addition, when the oxide film or nitride film is formed by plasma enhanced chemical vapor deposition (PECVD), such an effect may be expected to have a synergistic effect due to hydrogen injection into the ITO film (for example, improvement in resistivity and stability of etching characteristics).

Then, as shown in FIG. 3 (b), an oxide film or nitride film 40 (eg, SiO 2, SiN x) is formed on the transparent conductive film 30 at 400 ° C. or less, and a photoresist on the pattern After application of P / R), an oxide film or nitride film pattern 40 'as shown in FIG. 3 (c) is formed through exposure, development and etching processes (dry etching or wet etching).

Subsequently, as shown in FIG. 3 (d), the P / R pattern 50 is removed and ITO is etched to form a transparent conductive film pattern 30 '.

On the thus formed pattern, as shown in FIG. 3 (e), a metal film 60 made of aluminum or chromium is deposited by sputtering, and P / R is applied. Thereafter, a P / R pattern 50 is formed as shown in FIG. 3 (f) through an exposure, development, and etching process (dry etching or wet etching), and the third P / R pattern 50 is masked. As shown in (g), the metal electrode pattern 60 'is formed. After the process, the P / R pattern 50 is removed. As a result, a direct contact between the ITO and the metal electrode is prevented by the masking effect of the oxide film or the nitride film, and thus the pixel electrode (ITO) 30 'and the metal electrode pattern ( 60 ') can be formed.

Next, a third embodiment will be described. 4 (a) to 4 (c) are formed through the same process as in the second embodiment, and thus description thereof is omitted. This embodiment is different from the second embodiment in the following points. That is, the ITO pattern is etched, but is over etched as shown in FIG. 4 (d) so that the oxide film or the nitride film 40 'is formed between the transparent conductive film pattern (ITO) 30. It is. When the metal film 60 is deposited on the thus formed pattern by a sputtering method, as shown in FIG. 4 (e), an empty space a is formed on the sidewall of the ITO due to the masking effect of the oxide film or the nitride film pattern 40 '. Formed to prevent direct contact between the ITO pattern 30 and the metal electrode layer 60, so that P / R coating, exposure, development, etching (dry etching or wet etching), and P / R removal processes are performed. The good pixel electrode (ITO) 30 and the metal electrode pattern 60 'can be formed. At this time, the air gap (a) generated by the jaws of the oxide film or nitride film pattern 40 'and the transparent electrode film pattern 30 may be wet-etched to the oxide film or nitride film pattern 40'. After the partial etching, the process may be solved by proceeding thereafter. However, the air gap a naturally occurs because the protective film deposition process performed after the manufacturing process shown in FIG. 4 (g) is usually performed by the CDV method. It is filled so that a process such as the former is substantially unnecessary.

As described above, according to the first embodiment of the present invention, since the mutual adhesion between the photoresist and the ITO film is not good, it is possible to prevent the photoresist falling due to the unstable interface between the photoresist and the ITO during ITO wet etching. As a result, the ITO pattern forming process can be performed more easily, and as a result, the phenomenon in which the separated photoresist contaminates the etching bath can be prevented, so that the process can be widely used in a semiconductor manufacturing apparatus.

Meanwhile, according to the second and third embodiments of the present invention, 1) when the oxide film or nitride film is formed on the transparent electrode film, the crystallinity of the film is improved by the heat treatment effect applied to the ITO to form a clean pattern in a subsequent process. In addition to being able to lower the resistance of the pattern. In addition, this effect can be expected synergistic effect (for example, improving the stability of the resistivity and etching characteristics) due to hydrogen injection into the ITO film when the oxide film or nitride film formed by plasma enhanced chemical vapor deposition (PECVD). 2) In the photolithography process, the P / R adhesion is more improved on the ITO film to obtain a good pattern. 3) When the metal electrode is formed after the ITO pattern is formed, the electrochemical corrosion phenomenon caused by the contact between the ITO film and the metal film can be prevented by the masking effect of the oxide film or the nitride film on the ITO pattern, thereby obtaining a good pattern. .

Claims (12)

Depositing a transparent conductive film on a transparent substrate, depositing a metal film, applying and patterning a photoresist, wet patterning the metal film using the photoresist as a mask, and using the metal film as a mask Patterning a transparent conductive film, removing the photoresist, and removing the pattern of the metal film pattern forming method of a transparent conductive film. The method of claim 1, wherein the transparent conductive film is deposited by ITO. The method of claim 1, wherein the metal film is patterned by being precipitated in hydrogen peroxide at a temperature of 20-90 ° C. for 1-30 minutes. The method of claim 1, wherein the photoresist is removed after the metal film is patterned. The method of claim 3, wherein the hydrogen peroxide has a concentration of 10-50%. Coating a transparent conductive film on a transparent substrate, forming an oxide film or a nitride film, forming and patterning a first photoresist film, etching the oxide film or nitride film using the first photoresist film as a mask, and 1) removing the photoresist film, patterning the transparent conductive film using the oxide film or nitride film as a mask, depositing a metal film, forming and patterning a second photoresist film, and using the second photoresist film as a mask Patterning the metal film and removing the second photoresist film. The method of claim 6, wherein the transparent conductive film is formed of ITO. The method of claim 7, wherein the transparent conductive layer is over-etched to form a jaw inside the oxide layer or the nitride layer. The method of claim 8, wherein the metal film is deposited by a sputtering method. The method of claim 9, wherein the metal film is formed of aluminum. The method of claim 2, wherein the metal layer is formed of a material that is resistant to wet etching of the transparent conductive layer. The method of claim 3, wherein the metal film is deposited by TiW.