JPH09236811A - Transparent conductive substrate for liquid crystal display and forming method for transparent electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a transparent conductive substrate for a LCD having low specific resistance, excellent durability and excellent micro fabrication performance for electrodes by alternately depositing films essentially comprising ZnO and films essentially comprising Ag to form layers of an odd number as a transparent conductive film so that outermost layer is a film essentially comprising ZnO. SOLUTION: Films are alternately deposited to form (2n+1) layers, wherein n>=1, in such a manner that a film 2 essentially comprising ZnO is formed as the first layer from the substrate 1, a film 3 essentially comprising Ag is formed as the second layer and then a ZnO film 4 as the third layer. As for the film essentially comprising ZnO, a ZnO film containing Ga is preferable. As for the film essentially comprising Ag, an Ag film containing Pd or Au is preferable. The ZnO film is easily crystallized, and when the ZnO film is formed as the base film for an Ag layer, the ZnO film not only promotes crystallization of the Ag layer and prevents aggregation of Ag but improves the adhesion strength on the interface between the ZnO film and the Ag film. Thereby, moisture resistance and patterning characteristics with an acid soln. are significantly improved.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a transparent conductive substrate for a liquid crystal display (hereinafter referred to as LCD) and a transparent electrode forming method for the substrate.

[0002]

2. Description of the Related Art At present, an ITO film is widely used as an electrode for LCD. In particular, in the STN type color LCD, the line width of the transparent electrode for driving the liquid crystal is narrower and the shape thereof is required to be longer due to the higher definition and the larger screen.

Therefore, a transparent conductive film having a sheet resistance of 3Ω / □ or less and having an extremely low resistance is required. In order to achieve this sheet resistance, the transparent conductive film should be thickened (300 n
m or more) or low resistivity (100 μΩ · cm or less).

However, the thicker film requires 1) an increase in the cost of forming the transparent conductive film, 2) an increase in the difficulty of electrode patterning, and 3) an increase in the step due to the presence or absence of the transparent conductive electrode. However, there is a limit because it causes a problem that it becomes difficult to control the orientation.

On the other hand, a method for lowering the specific resistance of the ITO film itself has been studied, but a low resistance I of 100 μΩ · cm or less is obtained.
A method for stably producing a TO film has not yet been established.

On the other hand, as a method for easily obtaining a low resistance transparent conductive film of 100 μΩ · cm or less, a structure of ITO / Ag / ITO in which an Ag layer is sandwiched between ITO layers is known. However, this structure is also low in specific resistance, but the durability is insufficient enough to cause white defects that are considered to be film peeling when left indoors, and even during electrode processing by etching using an acidic aqueous solution, The workability is insufficient such that side etching progresses and peeling is observed at the pattern edge.

Therefore, the ITO / Ag / ITO substrate has the advantage that low resistance can be easily obtained,
It has not been put to practical use as a transparent conductive substrate.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a transparent conductive substrate for an LCD, which has low specific resistance, excellent durability, and fine electrode processing performance, and a transparent electrode forming method for the substrate.

[0009]

According to the present invention, in a transparent conductive substrate for a liquid crystal display in which a transparent conductive laminated film is formed on a substrate, the transparent conductive laminated film mainly contains ZnO as a first layer from the substrate side. A film containing a component, a film containing Ag as a main component in the second layer, and a film containing ZnO as a main component in the third layer were alternately laminated up to (2n + 1) (where n ≧ 1) layers. Provided is a transparent conductive substrate for LCD, which is a laminated film.

In the transparent conductive laminated film, a film containing ZnO as a main component and a film containing Ag as a main component are alternately laminated to form an odd number of layers such as three layers, five layers and seven layers. The outermost layer is a film containing ZnO as a main component.

[0011]

1 is a sectional view of a representative example of a three-layer transparent conductive substrate of the present invention, and FIG. 2 is a sectional view of a representative example of a five-layer transparent conductive substrate of the present invention. Reference numeral 1 is a substrate, 2, 4, 6 are films containing ZnO as a main component, and 3 and 5 are films containing Ag as a main component.

FIG. 3 shows a substrate for a color LCD, which corresponds to the substrate 1 shown in FIGS. Reference numeral 7 is a color filter layer to be a color pixel, 8 is a transparent resin protective layer, and 9 is an inorganic intermediate film layer. ZnO is formed on the inorganic interlayer film layer 9.
And a film containing Ag as a main component are alternately laminated in order to form a transparent conductive laminated film.

As the substrate 1 in the present invention, a glass plate, a resin film or plate can be used, and a substrate on which a color filter layer 7 to be a color pixel is formed,
Further, on the color filter layer, a transparent resin layer 8 for protecting and smoothing the color filter layer, silica for increasing the adhesion between these resin layers and the transparent conductive film, and SiN _x.
You may use the base | substrate which laminated | stacked the inorganic intermediate film layer 9 of these.

As the film containing ZnO as a main component, a ZnO film containing Ga (hereinafter referred to as a GZO film) is preferable. The reason is that ZnO, which is an insulator, exhibits conductivity when a trivalent dopant such as Al is added, but one in which Ga is added exhibits the best conductivity and visible light transmittance. In addition, when DC sputtering with high mass productivity is assumed as the film forming method, Zn metal can be used as a target, but there is a problem that the margin of film forming conditions is narrow, but addition of Ga causes the ZnO target to be separated from the ZnO target. This is because DC sputtering becomes possible and the margin of film forming conditions becomes very wide.

Particularly, the content ratio of Ga in the GZO film is such that Ga is 1 to 15 atomic% with respect to the total of Zn and Ga.
It is preferred that If it is less than 1%, the film formation rate becomes slow, and if the doping amount exceeds 15%, the visible light transmittance becomes low, which is not preferable. The thickness of the GZO film is preferably 10 to 200 nm from the viewpoint of color tone and visible light transmittance.

As the film containing Ag as a main component, an Ag film containing Pd (hereinafter referred to as Ag-Pd film) or Au.
An Ag film containing (hereinafter, referred to as Ag-Au film) is preferable. By adding Pd or Au, the aggregation phenomenon of Ag can be prevented and a highly durable Ag film can be obtained. An Ag film containing Pd and Au can also be preferably used.

In this case, the Ag-Pd film is formed by adding Pd in Ag like (1) alloy film (hereinafter referred to as PdAg alloy film).
May be a uniform film, a film in which (2) Pd is locally present, or a film in which the Pd concentration is continuously changed, such as (3) a gradient material film.

The same applies to the case of an Ag-Au film, and as in (1) alloy film (hereinafter referred to as AuAg alloy film), A is contained in Ag.
It may be a film in which u is uniformly present, a film in which (2) Au is locally present, or a film in which the Au concentration is continuously changed like (3) a gradient material film.

In any case, Ag-Pd film, Ag-
The film thickness of the Au film is preferably 3 to 20 nm. If it is less than 3 nm, the sheet resistance becomes high, and if it exceeds 20 nm, the visible light transmittance decreases, which is not preferable.

The content ratio of Pd in the above-mentioned PdAg alloy film (1) is such that Pd is 0.1 with respect to the total of Ag and Pd.
˜5.0 at% is preferred. If it is less than 0.1 atom%, the durability becomes insufficient, and if it exceeds 5.0 atom%, the visible light transmittance is lowered and the specific resistance is increased, which is not preferable. The same applies to the content ratio of Au in the AuAg alloy film.

As an example of the film (2) in which Pd is locally present, at least one of the interfaces between the film containing ZnO as a main component and the film containing Ag as a main component in the transparent conductive laminated film is used. An intervening Pd layer having a thickness of 0.1 to 1 nm can be mentioned.

By interposing a Pd layer of 0.1 to 1 nm, the same effect as the effect of adding Pd can be obtained. If the thickness of the Pd layer is less than 0.1 nm, the durability becomes insufficient, and if it exceeds 1 nm, the visible light transmittance decreases, which is not preferable. In this case, the film containing Ag as a main component and P
The total film thickness with the d layer is preferably 3 to 20 nm.

The specific laminated structure is as follows: a) substrate / G
ZO film / Ag / Pd / GZO film, b) substrate / GZO film /
Pd / Ag / GZO film, c) substrate / GZO film / Pd / A
Examples thereof include g / Pd / GZO film. The same applies to a film in which Au is locally present.

An example of the gradient material film (3) is an Ag-Pd film having a Pd-rich layer on its surface. Examples of the Pd-rich layer include layers in which Pd is 50 atomic% or more with respect to the total sum of Ag and Pd. If the thickness of the Pd-rich layer is 0.1 nm, the durability becomes insufficient, and if it exceeds 3 nm, the visible light transmittance tends to decrease.
A thickness of ~ 3 nm is suitable. Ag containing Au-rich layer
The same applies to the Au film.

By selecting the thickness of each layer constituting the transparent conductive laminated film in the present invention within the above range, it is possible to adjust the transmittance and color tone and the sheet resistance value due to the optical interference effect.

Further, the transparent conductive laminated film in the present invention is
Shows low sheet resistance, high visible light transmittance, and high durability, but in order to further improve the characteristics, 100-300 ° C after film formation
May be subjected to heat treatment.

The present invention also provides a method for forming a transparent electrode of a transparent conductive substrate for a liquid crystal display having the transparent conductive laminated film, wherein the transparent conductive laminated film is etched using an acidic aqueous solution of 0.01 to 0.5 N. Then, a method for forming a transparent electrode for a transparent conductive substrate for an LCD is provided.

In patterning, a desired resist pattern is formed on the transparent conductive laminated film by photolithography, and then etching and patterning are performed using an acidic aqueous solution of 0.01 to 0.5N.

At this time, etching hardly progresses with an acidic aqueous solution of less than 0.01 N, and side etching proceeds with an acidic aqueous solution of more than 0.5 N. In particular, it is preferable to use an acidic solution containing ferric chloride (FeCl ₃ ) as a main component as the etching solution because it has a higher etching rate and smaller side etching than other acidic aqueous solutions.

The acidic aqueous solution containing FeCl ₃ as a main component is preferably an acidic aqueous solution containing ferrous ions. Ferrous ions can be included, for example, by adding FeCl ₂ . By adding FeCl ₂ to control the redox potential of the etching solution,
The margin of the etching end time is widened, and the electrode width can be formed accurately.

The molar ratio of ferrous ions to ferric ions is preferably 0.1-2. If it is less than 0.1, the above effect cannot be obtained, and if it exceeds 2, the progress of etching is hindered and an electrode having a designed size cannot be obtained.

[0032]

In the present invention, the conventional ITO film has an amorphous structure under the low temperature film forming condition of 150 ° C. or lower,
The O film is easy to crystallize, and when it becomes the above-mentioned base film of the Ag layer, it not only promotes the crystallization of the Ag layer and prevents the aggregation phenomenon of Ag, but also improves the adhesive force between the ZnO film and the Ag film interface. As a result, it has an effect of significantly improving the humidity resistance and the patterning characteristics of the acidic aqueous solution.

[0033]

【Example】

[Example 1] A color filter layer 7 and an acrylic resin layer protective layer 8 for smoothing the color filter are previously formed on a soda lime glass plate, and a silica film is further formed thereon by a high frequency sputtering method. To 10 nm
The formed substrate 1 was prepared.

Next, by a DC sputtering method, Ar
GZ with a film thickness of 16 nm in an atmosphere of gas and 3 mTorr
An O film, an 11 nm PdAg alloy film, and a 38 nm GZO film were sequentially laminated to form a transparent conductive laminated film.

At this time, Zn and G are used to form the GZO film.
Using a ZnO sintered body target containing 5 atomic% of Ga with respect to the sum of a and Ag and P for forming the PdAg alloy film.
A PdAg alloy target containing 1 atomic% of Pd with respect to the total of d was used. Further, the sputtering power density at the time of forming the GZO film was set to 5.7 W / cm ² , and the PdAg film was set to 0.57 W / cm ² . The substrate was not heated during film formation.

Sheet resistance value of the obtained transparent conductive laminated film,
The visible light transmittance is shown in Table 1. Also, 40 ° C, relative humidity 9
When a humidity resistance test was carried out by leaving it in an atmosphere of 0% for 1 week, no white defects with a diameter of 0.5 mm or more were observed and good results were shown.

Example 2 The procedure of Example 1 was repeated except that the transparent conductive laminated film of Example 1 was changed as follows. The transparent conductive laminated film is a GZO film having a thickness of 40 nm, a PdAg alloy film having a thickness of 10 nm, a GZO film having a thickness of 85 nm, a PdAg alloy film having a thickness of 10 nm,
A 40 nm GZO film is sequentially laminated. The target, sputtering power density, and atmosphere used are the same as in Example 1. The substrate was not heated during film formation.

The sheet resistance value of the obtained transparent conductive laminated film,
The visible light transmittance is shown in Table 1. Further, when a moisture resistance test similar to that of Example 1 was carried out, no white defect having a diameter of 0.5 mm or more was observed and a good result was shown.

Example 3 The procedure of Example 1 was repeated except that the transparent conductive laminated film of Example 1 was changed as follows. The transparent conductive laminated film is formed by sequentially laminating a GZO film having a thickness of 16 nm, a PdAg alloy film having a thickness of 11 nm, and a GZO film having a thickness of 38 nm. The target, sputtering power density, and atmosphere used are the same as in Example 1. Note that the substrate was not heated during film formation, and heat treatment was performed at 250 ° C. for 20 minutes after film formation.

Sheet resistance value of the obtained transparent conductive laminated film,
The visible light transmittance is shown in Table 1. Further, when a moisture resistance test similar to that of Example 1 was carried out, no white defect having a diameter of 0.1 mm or more was observed and good results were shown.

Example 4 Example 4 was repeated except that the transparent conductive laminated film of Example 1 was changed as follows. The transparent conductive laminated film is a GZO film having a thickness of 40 nm, a PdAg alloy film having a thickness of 10 nm, a GZO film having a thickness of 85 nm, a PdAg alloy film having a thickness of 10 nm,
A 40 nm GZO film is sequentially laminated. The target, sputtering power density, and atmosphere used are the same as in Example 1. Note that the substrate was not heated during film formation, and heat treatment was performed at 250 ° C. for 20 minutes after film formation.

Sheet resistance value of the obtained transparent conductive laminated film,
The visible light transmittance is shown in Table 1. Further, when a moisture resistance test similar to that of Example 1 was carried out, no white defect having a diameter of 0.1 mm or more was observed and good results were shown.

Example 5 The procedure of Example 1 was repeated except that the transparent conductive laminated film of Example 1 was changed as follows. The transparent conductive laminated film includes a GZO film having a film thickness of 16 nm, an Ag film having a film thickness of 11 nm, a 0.
A 3 nm Pd film and a 38 nm GZO film are sequentially stacked. For the GZO film, the same target and sputtering power density as in Example 1 were used. An Ag target and a Pd target are used for forming the Ag film and the Pd film, respectively, and the sputtering power density is 0.57 W / for the Ag film.
cm ² , and the Pd film was 0.28 W / cm ² . The atmosphere is the same as in Example 1. The substrate is not heated during film formation,
After film formation, heat treatment was performed at 250 ° C. for 20 minutes.

Sheet resistance value of the obtained transparent conductive laminated film,
The visible light transmittance is shown in Table 1. Further, when a moisture resistance test similar to that of Example 1 was carried out, no white defect having a diameter of 0.1 mm or more was observed and good results were shown.

[Example 6] The procedure of Example 1 was repeated except that the transparent conductive laminated film of Example 1 was changed as follows. The transparent conductive laminated film includes a GZO film having a thickness of 16 nm, an Ag film having a thickness of 11 nm, a 38
nm GZO films are sequentially laminated. The same target and sputtering power density as in Example 1 were used for the GZO film, and the same target and sputtering power density as in Example 5 were used for the Ag film. The atmosphere is the same as in Example 1. Note that the substrate is not heated at the time of film formation and 25
Heat treatment was performed at 0 ° C. for 20 minutes.

Sheet resistance value of the obtained transparent conductive laminated film,
The visible light transmittance is shown in Table 1. Further, when a moisture resistance test similar to that of Example 1 was carried out, although a white defect having a diameter of about 0.5 mm was partially observed, the moisture resistance was generally good.

Example 7 The procedure of Example 1 was repeated except that the transparent conductive laminated film of Example 1 was changed as follows. The transparent conductive laminated film is formed by sequentially laminating a 16 nm thick GZO film, an 11 nm AuAg alloy film, and a 38 nm GZO film. GZO
The same target and sputtering power density as in Example 1 were used for the film, and Ag and Au were used for forming the AuAg alloy film.
The AuAg alloy target containing 1 atomic% of Au was used for the total of the above, and the sputtering power density was 0.57 W /
cm ² . The atmosphere is the same as in Example 1. Note that the substrate was not heated during film formation, and heat treatment was performed at 250 ° C. for 20 minutes after film formation.

Sheet resistance value of the obtained transparent conductive laminated film,
The visible light transmittance is shown in Table 1. Further, when a moisture resistance test similar to that of Example 1 was carried out, no white defect having a diameter of 0.1 mm or more was observed and good results were shown.

Example 8 (Comparative Example) The procedure of Example 1 was repeated except that the transparent conductive laminated film of Example 1 was changed as follows. The transparent conductive laminated film is an ITO film with a film thickness of 16 nm and a P film with a film thickness of 11 nm.
A dAg alloy film and a 38 nm ITO film are sequentially laminated. For the formation of the ITO film, the total sum of In and Sn is S
Using an indium oxide sintered body target containing 10 atomic% of n and a sputtering power density of 5.7 W / cm ² ,
A film was formed with an Ar gas containing 3% oxygen in an atmosphere of 3 mTorr. The same target, sputtering power density, and atmosphere as in Example 1 were used for forming the PdAg film. Note that the substrate was not heated at the time of film formation, and 250 ° C. after film formation.
A heat treatment was performed for 20 minutes.

The sheet resistance value of the obtained transparent conductive laminated film,
The visible light transmittance is shown in Table 1. Further, when a moisture resistance test similar to that of Example 1 was carried out, a large number of white defects having a diameter of 1 mm or more occurred and the moisture resistance was poor.

Example 9 (Comparative Example) The procedure of Example 8 was repeated, except that the transparent conductive laminated film of Example 8 was changed as follows. The transparent conductive laminated film is an ITO film having a thickness of 40 nm and a P film having a thickness of 10 nm.
dAg alloy film, 85 nm ITO film, 10 nm PdA
A g-alloy film and a 40 nm ITO film are sequentially laminated.
The target, sputtering power density and atmosphere used are the same as in Example 8. Note that the substrate was not heated during film formation, and heat treatment was performed at 250 ° C. for 20 minutes after film formation.

The sheet resistance value of the obtained transparent conductive laminated film,
The visible light transmittance is shown in Table 1. Further, when a moisture resistance test similar to that of Example 1 was carried out, a large number of white defects having a diameter of 1 mm or more occurred and the moisture resistance was poor.

[Patternability] Further, the patternability of the transparent conductive laminated films of Examples 1 to 9 was also investigated. After forming a desired resist pattern on the transparent conductive laminated film by a photolithography method, etching was performed using A) hydrochloric acid aqueous solution of various concentrations to form a fine electrode pattern having a line width of 130 μm and a space width of 20 μm.

In FIG. 4, the thick stripe portion is the portion of the transparent conductive laminated film which remains without being etched (that is, the portion which becomes the transparent electrode), and the thin stripe portion is the etched portion. The same applies to FIG.

Regarding the transparent conductive laminated films of Examples 1 to 7,
When a 0.1 N hydrochloric acid aqueous solution was used, as shown in FIG. 4, good electrode patterning was obtained in which side etching was small and the pattern edge shape was sharp. 0.
Similar results were obtained when hydrochloric acid aqueous solutions having various concentrations of 01 to 0.5 N were used. With an etching solution of less than 0.01 N, etching hardly progressed, and with a solution of more than 0.5 N, side etching proceeded.

Instead of A) hydrochloric acid aqueous solution, B) nitric acid aqueous solution, C) sulfuric acid aqueous solution, D) ferric chloride aqueous solution or E) ferrous chloride-containing ferric chloride aqueous solution (ferrous ion) The molar ratio of iron to ferric ion is 0.
When 7) was used at various concentrations, similar results were obtained. Further, among the above-mentioned etching solutions A) to E),
The solution E) had the smallest side etching amount.

On the other hand, with regard to the transparent conductive laminated films of Examples 8 to 9, side etching of 10 μm or more as shown in FIG. , Pd near the pattern edge
Peeling of the Ag film was observed.

The results are shown in Table 1. In Table 1, column A shows patterning property, and column B shows moisture resistance.
⊚ in the column A means that no matter which of the etching solutions A) to E) is used, a) the edge shape is sharp, b) there is no residue, and c) the side etching is less than 10 μm, X means that all of the above a) to c) cannot be satisfied. ◎ in column B is 0.1 m in diameter
No white defects with a diameter of 0.
A slight white defect of 1 to 1 mm is observed, ×
Means that many white defects of 1 mm or more are observed.

For the transparent conductive laminated films of Examples 2, 4, 7 and 9, the above-mentioned etching solutions A) to E) were added in the amount of 0.
Table 2 shows detailed data regarding the amount of side etching when used at a concentration of 1 normal.

[0060]

[Table 1]

[0061]

[Table 2]

[0062]

According to the present invention, not only on glass, but also on plastic having a low film forming temperature (100 ° C. or lower) or on a substrate with a color filter for color LCD (25
A transparent conductive substrate for LCD having a transparent conductive laminated film formed at 0 ° C. or lower can be provided.

Moreover, the total thickness of the transparent conductive laminated film is 300.
It has a sheet resistance value of 3 Ω / □ or less and a low specific resistance of not more than nm, and also has excellent durability and excellent fine electrode processing performance with an acidic aqueous solution.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an example of a transparent conductive substrate for a liquid crystal display of the present invention.

FIG. 2 is a schematic sectional view of another example of the transparent conductive substrate for a liquid crystal display of the present invention.

FIG. 3 is a schematic cross-sectional view of a color liquid crystal display substrate used in the present invention.

FIG. 4 is a micrograph showing a patterning state of transparent conductive laminated films of Examples 1 to 6.

FIG. 5 is a photomicrograph showing a patterning state of transparent conductive laminated films of Examples 7 to 8.

[Explanation of symbols]

 1: Substrate 2: ZnO-based film 3: Ag-based film 4: ZnO-based film 5: Ag-based film 6: ZnO-based film 7: Color filter layer 8: Resin protective layer 9: Inorganic interlayer film such as silica

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuki Kawamura 1150 Hazawa-machi, Kanagawa-ku, Yokohama-shi, Kanagawa Asahi Glass Co., Ltd. Central Research Laboratory

Claims (10)

[Claims] 1. A transparent conductive substrate for a liquid crystal display having a transparent conductive laminated film formed on a substrate, wherein the transparent conductive laminated film is a film containing ZnO as a main component as a first layer from the substrate side,
The second layer is a film containing Ag as a main component, and the third layer is a film containing ZnO as a main component. A transparent conductive substrate for a liquid crystal display, which is characterized by: 2. The transparent conductive substrate for a liquid crystal display according to claim 1, wherein the film containing ZnO as a main component is a ZnO film containing Ga. 3. The transparent conductive substrate for a liquid crystal display according to claim 2, wherein the content ratio of Ga in the ZnO film containing Ga is 1 to 15 atomic% with respect to the total sum of Zn and Ga. 4. A transparent conductive substrate for a liquid crystal display according to claim 1, wherein the film containing Ag as a main component contains Pd and / or Au. 5. The content ratio of Pd and / or Au in a film containing Ag as a main component is 0.1 to the total amount of Ag and Ag.
It is 5.0 atomic%, The transparent conductive substrate for liquid crystal displays of Claim 4. 6. At least one of the interfaces between a film containing ZnO as a main component and a film containing Ag as a main component in a transparent conductive laminated film.
The transparent conductive substrate for a liquid crystal display according to claim 1, 2, 3, 4 or 5, wherein a Pd layer and / or an Au layer having a thickness of 0.1 to 1 nm is interposed at one interface. 7. The method for forming a transparent electrode of a transparent conductive substrate for a liquid crystal display according to claim 1, 2, 3, 4, 5 or 6, wherein the transparent conductive laminated film is an acidic aqueous solution of 0.01 to 0.5N. A method of forming a transparent electrode for a transparent conductive substrate for a liquid crystal display, which comprises: etching, patterning. 8. The method for forming a transparent electrode of a transparent conductive substrate for a liquid crystal display according to claim 7, wherein an acidic aqueous solution containing ferric chloride as a main component is used as the acidic aqueous solution. 9. The method for forming a transparent electrode of a transparent conductive substrate for a liquid crystal display according to claim 8, wherein an acidic aqueous solution containing ferrous ions is used as the acidic aqueous solution containing ferric chloride as a main component. 10. An acidic aqueous solution having a molar ratio of ferrous ions to ferric ions of 0.1 to 2 is used.
For forming a transparent electrode on a transparent conductive substrate for a liquid crystal display.