JPH05224220A - Formation of pattern of substrate for liquid crystal display element - Google Patents

Abstract

PURPOSE:To obtain good patterns with decreased side etching by patterning a transparent conductive film, after the formation thereof, by using a liquid mixture composed of hydrochloric aid, ferric chloride and acetic acid as an etching liquid. CONSTITUTION:The transparent conductive film 1 to constitute at least electrode patterns is formed in the method for forming striped transparent electrodes and electrode groups consisting of metallic wiring patterns by etching on the surface of a substrate 4. This film is patterned by using the liquid mixture composed of the hydrochloric aid, ferric chloride and acetic acid as the etching liquid. The etching liquid to be used is preferably the liquid mixture composed of 2 to 5:2 to 5:1 (by volume ratio) ratios of 37% acetic acid, 35% ferric chloride and 95% acetic acid (by weight). The transparent electrode patterns consist preferably of indium oxide and the metallic wiring patterns 2 of molybdenum. The side etching quantity at the time of patterning is decreased by adding the acetic acid to the etching liquid in such a manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an electrode pattern on a substrate for a liquid crystal display device by using an etching solution for metals which is a mixture of hydrochloric acid, ferric chloride and acetic acid.

[0002]

2. Description of the Related Art Conventionally, since ITO (indium-tin-oxide) and indium oxide films have low resistance and high transmittance, they are optimal as transparent conductive films and are essential as electrodes for liquid crystal display device substrates. It has become impossible. Further, in recent years, with the increase in definition and screen size of liquid crystal elements, the resistance value of ITO and indium oxide film alone cannot cope with it, and a metal wiring pattern of a metal film is usually formed along the transparent electrode pattern of ITO and indium oxide film. By forming it, low resistance is realized. Molybdenum or the like is used as the metal wiring material.

As an etching solution, a mixed solution of two solutions of hydrochloric acid and ferric chloride is used for the ITO and indium oxide film, and for the metal wiring material,
A mixture of phosphoric acid, nitric acid and acetic acid has been most often used.

[0004]

However, in the above-mentioned conventional example, there is a drawback that the side etching amount is large and it is difficult to control during etching, so that the wiring resistance value largely changes. Further, conventionally, the etching of the transparent electrode pattern and the etching of the metal wiring pattern are
Since different etching liquids are used, the manufacturing process is complicated and the substrate is chipped between the processes, pattern defects due to dust adhesion, short circuits between adjacent electrodes, and the cell assembly process. It also leads to a defective cell gap and causes a significant decrease in the manufacturing yield of products.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and by using an etching solution obtained by adding acetic acid to hydrochloric acid and ferric chloride,
An object of the present invention is to provide a method for forming a pattern on a substrate for a liquid crystal display device with a small amount of side etching.

Further, according to the present invention, two kinds of etching solutions which were conventionally required for etching transparent electrodes and metal wiring patterns are etched with one kind of etching solution obtained by adding acetic acid to hydrochloric acid and ferric chloride. Patterning method for a liquid crystal display device substrate, which enables the production yield to be increased and the production cost to be reduced by reducing the side etch amount and eliminating the complexity of the production process. It is intended to provide.

[0007]

According to the present invention, in patterning transparent electrodes and metal wiring, conventional hydrochloric acid,
By adding acetic acid to the mixed etching solution of ferric chloride, the side etching amount at the time of patterning can be reduced, and both the transparent electrode film and the metal wiring film can be patterned by the same etching solution. .

That is, according to the present invention, in a method for forming an electrode group consisting of transparent electrodes in stripes and metal wiring patterns by etching on the surface of a substrate for a liquid crystal display element, at least a transparent conductive film serving as an electrode pattern. After forming a film, the method for patterning a substrate for a liquid crystal display element is characterized by patterning using a mixed solution of hydrochloric acid, ferric chloride and acetic acid as an etching solution.

The etching solution used in the present invention is hydrochloric acid (37 wt%): ferric chloride (35 wt%):
The ratio of acetic acid (95 wt%) is 2-5: 2-5: 1 (V
(Ol ratio), preferably 3: 3: 1 (Vol ratio).

The transparent electrode pattern is preferably made of ITO or indium oxide, and the metal wiring pattern is preferably made of molybdenum.

In the present invention, only the transparent electrode pattern may be patterned using a mixed solution of hydrochloric acid, ferric chloride and acetic acid as an etching solution. Alternatively, both the transparent electrode and the metal wiring pattern may be patterned by using a mixed solution of hydrochloric acid, ferric chloride and acetic acid as an etching solution. In the case of patterning only the transparent electrode pattern of the former case, a conventionally used etching solution, for example, a mixed solution of phosphoric acid, nitric acid and acetic acid can be used for patterning the metal wiring pattern.

[0012]

EXAMPLES The present invention will be specifically described below with reference to examples.

Embodiment 1 FIG. 1 is a process diagram showing a first half of steps of an embodiment of a method for forming a pattern for a liquid crystal display device substrate of the present invention, and FIG. 2 is a pattern of the liquid crystal display device substrate of FIG. FIG. 6 is a process drawing showing a latter half of the process for forming a battery. As shown below, a pattern of a liquid crystal display device substrate was formed by the steps shown in FIGS.

ITO having a film thickness of 1500 Å is formed on the glass substrate 4.
The thin film 1 was formed by a sputtering method (see FIG. 1 (a)). Then, about 1 part of photoresist 3 is applied to the glass substrate.
It was applied to a thickness of μm, exposed with a pixel electrode pattern mask, and then developed to form a pixel electrode pattern resist image (see FIG. 1B).

Next, the glass substrate was treated with hydrochloric acid (37 wt.
%), Ferric chloride (35 wt%) and acetic acid (95 wt)
%) Is mixed at a ratio of 3: 3: 1 (vol ratio), and etching is performed at 45 ° C. for 180 seconds (see FIG. 1C), and the side etching is small and extremely good. A pixel electrode pattern was obtained (Fig. 1 (d))
reference).

Similarly, after forming the molybdenum film 2 to a film thickness of 3000 Å by the sputtering method (see FIG. 2E), the photoresist 3 is applied to the substrate to a thickness of about 1 μm (FIG. 2F). )), After exposure with a metal wiring mask, development is performed to form a metal wiring pattern resist image, and etching is performed with phosphoric acid-based etching solution 6 at room temperature for 120 seconds (see FIG. 2 (g)). A substrate for a liquid crystal display element having a wiring pattern was obtained (see FIG. 2 (h)).

Embodiment 2 FIG. 3 is a process diagram showing the first half of the process of another embodiment of the method for forming a pattern for a liquid crystal display device substrate according to the present invention, and FIG.
FIG. 4A is a process diagram showing a latter half of the pattern forming method for the liquid crystal display element substrate of FIG. 3; As shown below, a pattern of a liquid crystal display device substrate was formed by the steps shown in FIGS.

ITO having a thickness of 1500 Å is formed on the glass substrate 4.
After the thin film 1 was formed by the sputtering method (see FIG. 3A), the molybdenum film 2 was formed on the ITO film by the same sputtering method with a thickness of 3000 Å (FIG. 3B).
reference). Next, a photoresist 3 is formed on the substrate on which the film has been formed.
Was applied to a thickness of about 1 μm, and this was exposed using a metal wiring pattern mask and developed (see FIG. 3C).

Next, the glass substrate was treated with hydrochloric acid (37 wt.
%), Ferric chloride (35 wt%) and acetic acid (95 wt)
%) Is mixed at a ratio of 3: 3: 1 (vol ratio), and etching is performed at 25 ° C. for 180 seconds (see FIG. 3D), and the side etching is small and extremely good. A metal wiring pattern was obtained (Fig. 4 (e))
reference). At this time, the exposed ITO film was not significantly affected.

Next, the photoresist 3 was applied again on the substrate having the metal wiring pattern formed thereon to a thickness of about 1 μm, exposed by a pixel electrode pattern mask, and then developed to form a pixel electrode pattern resist image. Next, the substrate was treated with a mixed etching solution 5 prepared by mixing hydrochloric acid (37 wt%), ferric chloride (35 wt%) and acetic acid (95 wt%) at a ratio of 3: 3: 1 (vol ratio) to 45 ℃, 180
Etching was performed for 2 seconds (see FIG. 4 (f)). Example 1
Similarly to the above, a liquid crystal display element substrate having a very good pixel electrode pattern with little side etching was obtained (FIG. 4).
(See (g)).

[0021]

As described above, according to the present invention,
By using a mixed solution of hydrochloric acid, ferric chloride and acetic acid as an etching solution, a good pattern with less side etching can be obtained.

Further, since it is possible to use only one type of etching solution, which has been required for patterning the transparent electrode and the metal wiring up to now, the complexity of the manufacturing process can be eliminated and the manufacturing yield can be improved. It is also effective in reducing the manufacturing cost. Furthermore, by changing the temperature of the etching solution, it is possible to stack two layers of a transparent conductive film and a metal film, and then pattern from the upper film.

[Brief description of drawings]

FIG. 1 is a process drawing showing a first half process of one embodiment of a pattern forming method for a liquid crystal display element substrate of the present invention.

FIG. 2 is a process drawing showing a latter half of the pattern forming method for the liquid crystal display element substrate of FIG.

FIG. 3 is a process drawing showing a first half process of another embodiment of the pattern forming method for a liquid crystal display element substrate of the present invention.

FIG. 4 is a process drawing showing a latter half of the method for forming a pattern on the liquid crystal display element substrate of FIG. 3;

[Explanation of symbols]

 1 ITO 2 molybdenum 3 photoresist 4 glass substrate 5 mixed etching solution 6 phosphoric acid type etching solution

Claims (4)

[Claims] 1. A method of forming an electrode group composed of a stripe-shaped transparent electrode and a metal wiring pattern on a surface of a liquid crystal display element substrate by etching, wherein a transparent conductive film serving as at least an electrode pattern is formed. Then, a pattern forming method of a substrate for a liquid crystal display element, which comprises patterning using a mixed solution of hydrochloric acid, ferric chloride and acetic acid as an etching solution. 2. The etching solution is hydrochloric acid (37 wt%):
Ferric chloride (35 wt%): acetic acid (95 wt%) = 2
The method for forming a pattern on a substrate for a liquid crystal display element according to claim 1, which is a mixed solution having a ratio of 5: 2 to 5: 1 (Vol ratio). 3. The pattern formation of a substrate for a liquid crystal display device according to claim 1, wherein the transparent electrode pattern is made of ITO (indium-tin oxide) or indium oxide, and the metal wiring pattern is made of molybdenum. Method. 4. The pattern of a substrate for a liquid crystal display device according to claim 1, wherein both the transparent electrode and the metal wiring pattern are patterned by using a mixed solution of hydrochloric acid, ferric chloride and acetic acid as an etching solution. Forming method.