JPS62202419A - Method for manufacturing transparent electrode substrate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a transparent electrode substrate used as an electrode substrate for liquid crystal displays and the like.

(Prior Art and its Problems) As the practical use of various displays such as liquid crystal displays becomes more common and their application fields expand, the demand for transparent electrode substrates that serve as substrates for these displays is increasing.

A transparent electrode substrate is one in which a transparent conductive film made of ITO is arranged in the shape of an electrode pattern on a transparent base material such as synthetic resin, glass, or quartz.

Figure 2 (al to (fl) shows the manufacturing process of a transparent electrode substrate by a conventional method. A transparent conductive film 12) is applied in a shape. (See Figure 2 (bl)) Next, a light shielding film 00 is applied. ) is brought into close contact with the photoresist (3) and exposed to light using high-pressure water steel melting, etc. (see Figure 2 (C1)) After that, development is performed to form a photoresist pattern (5). (Figure 2(d)
(see i) Furthermore, the transparent conductive film 1 is formed by chemical etching.
2) The exposed portion is removed (see FIG. 2 fel).

Thereafter, the photoresist pattern (5) is peeled off to form a transparent electrode pattern (6). (Figure 2 [f
)) When manufacturing a transparent electrode substrate using such a process, there were the following problems. Namely.

One process is complicated and the yield is low.

2. Cost reduction is difficult because expensive photoresist is used.

6. In order to form organic substances such as photoresist on the transparent electrode, the electrode surface is made of photoresist residue.

Contamination on the substrate surface is likely to occur.

4. Photolithography processes such as forming a photoresist pattern and peeling off the photoresist are complicated.

(Object of the Invention) In view of the drawbacks of the conventional methods as described above, the present invention relates to a method for greatly simplifying the transparent electrode substrate manufacturing process, improving product yield and reducing costs. .

(Specific means for solving the problem) The present invention provides laser annealing of an indium-tin oxide film (hereinafter simply referred to as TO film) formed by a low-temperature sputtering method at a substrate temperature of 150°C or lower. The present invention relates to a method of easily forming a transparent electrode pattern without using a photoresist by utilizing changes in chemical properties caused by To be more specific, the T○ film formed by low-temperature sputtering has poor chemical stability (particularly resistance to hydrogen chloride), so it is usually
A predetermined chemical stability is obtained by heat treatment in the air at a temperature of ~350°C. The present invention focuses on this point, and uses laser light as a heating means in the atmosphere, and also partially irradiates the ITO film with the laser by installing a light-shielding pattern plate between the light source and the ITO film. The photoresist is heated by heating, and the non-irradiated area is selectively etched away using a chemical etching solution such as dilute hydrochloric acid, taking advantage of the difference in chemical stability between the non-irradiated area and the irradiated area, that is, the difference in ease of etching. The present invention relates to a method for easily obtaining a transparent electrode substrate by patterning a TO film without using a TO film.

(Details of the invention The described steps will be explained in detail using FIG. 1.

Figure 1 (a) shows a transparent base material (such as synthetic resin, quartz, glass, etc.)
1) A low-temperature formed To film (7) is formed thereon by a low-temperature sputtering method. The low-temperature sputtering method refers to a method in which sputtering film formation is performed while maintaining the substrate temperature at 150° C. or lower during film formation, and the low-temperature formed ITO film (7) obtained by this method has good etching properties, that is, It has the property of being more easily chemically etched than a heat-baked film. The temperature of the base material il+ during film formation is preferably as low as 150
If the temperature exceeds 15°C, the ease of etching will be impaired.
Set the temperature below 0℃. A magnetron type sputtering apparatus is suitable as a sputtering apparatus in order to avoid an increase in the temperature of the base material, but this is not the case for other sputtering systems as long as the above conditions are satisfied.

Regarding the raw material, ie, the target, for TO, both the reactive sputtering method using an oxygen atmosphere using an indium-tin alloy target and the normal sputtering method using an ITO target are applicable.

Next, as shown in FIG. 1(b), a laser beam is irradiated through the light-shielding pattern plate (9). The wavelength of the laser beam irradiated at this time is below the wavelength at which absorption occurs in the low temperature formed ITO film (7) (400 nm or below), and the light shielding pattern plate (9) is a perforated metal plate such as a stencil or a photo mask. Use a pattern board such as As a specific light source,
X e Cl (308 nm), X e F (
351 nm), XeBr (282 nm), KrF (2
An excimer laser such as 49 nm) is preferable, but is not particularly limited to this. Also, the laser to be irradiated
The energy number is set to 150'C or higher, which is the temperature at which sintering of the To film, that is, etching selectivity occurs. As a specific example, when a KrF excimer laser is used, the above conditions can be achieved by irradiating an ITO film with a thickness of 1 .mu.m with an energy of 60 mJ./- or more.

When using a transparent base pattern plate such as a photomask for the light-shielding pattern plate (9), the transparent base material has a wavelength of 400.
A material with good transmittance for ultraviolet light of nm or less (for example, quartz) is preferable.

In Figure 1 (C1) shows the state of the substrate after laser light irradiation. )It is shown.

Next, when the substrate is chemically etched, the low temperature formed ITO film (7) in the non-irradiated area is dissolved and removed.

The irradiated portion (8) has improved chemical resistance (especially acid resistance) compared to the non-irradiated portion, and therefore remains selectively even after etching with diluted acid. Specifically, the diluted acid is an aqueous solution of hydrochloric acid, nitric acid, sulfuric acid, or acetic acid, but is not limited thereto.

FIG. 1(d) shows the completed transparent electrode substrate after etching.

(Effects of the Invention) As described above, when conventionally manufacturing transparent electrode substrates, one step of IJ lithography using photon cyst is essential for patterning the transparent conductive film, which makes the manufacturing process complicated. However, according to the present invention, the present invention uses photoresist. This makes it possible to greatly simplify the process, improve reliability, productivity, and yield, and significantly reduce costs.

Examples according to the present invention are shown below.

(Example 1) A TO film was formed on a silica-coated (thickness: 1000A) soda glass substrate using an ITO target using a magnetron-type high-frequency sputtering device. The film forming atmosphere at this time was argon gas at 5×10' Torr. Although the substrate was not heated, the substrate temperature during film formation was 80°C. The thickness of the ITO film is 2
．． It was 00 OA.

Next, using a chrome mask based on 1 quartz glass,
(2) Laser light was irradiated in close contact with the TO film. The laser beam used at this time was a XeCl excimer laser, and the energy of the laser beam irradiated was 30 mJ/(7. As a result, the ITO film could be dissolved and removed, leaving only the laser irradiated area, and a transparent electrode substrate was completed.

(Example 2) An ITO film was formed on a quartz glass substrate using an n-3n alloy (Sn:
9% by weight) as a target, reactive sputtering was performed in an oxidizing atmosphere using a magnetron direct current sputtering device. No substrate heating was performed, and the substrate temperature during film formation was 60°C. In addition, the sputtering atmosphere at this time had an oxygen partial pressure of 4. OXl 0”Tor
r, the argon partial pressure.

It was 4.0×10 −3 Torr. The thickness of the formed ITO film was 1000A.

Next, a light-shielding pattern plate made of a 1.1 m thick stainless steel plate with patterned holes was tightly attached to the ITO film.
It was irradiated with Cl excimer laser. The irradiation energy at this time was 10 mJ/i. After irradiation, the substrate was immersed in a 4-volume aqueous hydrochloric acid solution to dissolve and remove the ITO film in the non-irradiated area, and the ITO film was patterned to complete a transparent electrode substrate.

[Brief explanation of drawings]

FIGS. 1(a) to d+ are explanatory diagrams showing an example of the method for manufacturing a transparent electrode substrate of the present invention, and FIGS.
f+ is an explanatory diagram showing an example of the method for manufacturing a transparent electrode substrate of the present invention.

Claims (2)

[Claims] (1) ITO (indium-tin oxide) on a transparent substrate
In a method for manufacturing a transparent electrode substrate having a transparent electrode pattern made of a material, (i) ITO is deposited on a transparent substrate by a low-temperature sputtering method performed at a substrate temperature of 150° C. or less during sputtering film formation.
Step of forming a transparent conductive film, (ii) via a light-shielding pattern plate on the surface of the transparent conductive film,
A process in which laser light is irradiated and laser annealing is performed partially to create a difference in the ease of chemical etching between irradiated and non-irradiated areas. (iii) a step of forming a transparent electrode pattern by removing non-irradiated portions by selective etching with a chemical etching solution by utilizing the difference in ease of chemical etching; A method for manufacturing a transparent electrode substrate. (2) The method for manufacturing a transparent electrode substrate according to claim (1), characterized in that the wavelength of the laser beam is 400 nm or less.