JPH06234521A - Electric conductive transparent film and its production - Google Patents

Abstract

PURPOSE:To obtain an electric conductive transparent film more excellent in etchability than an ITO film, having electric conductivity comparable to that of the ITO film and also more excellent in moisture resistance than the ITO film. CONSTITUTION:This electric conductive transparent film is made of amorphous oxide of indium and zinc and the atomic ratio between In and Zn satisfies In/(In+Zn)=0.55 to 0.75, or this film is made of amorphous oxide of indium, zinc and at least one kind of 3rd element selected among Sn, Al, Sb, Ga and Ge and the atomic ratio between In and Zn satisfies In/(In+Zn)=0.55 to 0.75. The percentage of the 3rd element is <=20 atomic % of the total amt. of the 3rd element, In and Zn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent conductive film and its manufacturing method.

[0002]

2. Description of the Related Art A liquid crystal display device can be made lighter and thinner, and has a low driving voltage, so that it is actively introduced into OA equipment such as personal computers and word processors. Then, the liquid crystal display device having the above-mentioned advantages inevitably has a large area,
There is a demand for high-quality liquid crystal display devices having no display defects in the direction of increasing the number of pixels and increasing the definition. One of the important factors for obtaining a high quality liquid crystal display element is a transparent electrode, and an ITO film is currently the mainstream of this transparent electrode. Further, although the ITO film has excellent light transmittance and conductivity, it has a relatively low moisture resistance and has a drawback that the electric resistance value increases due to moisture, so that it is a substance having high chemical stability. Attempts have been made to obtain a transparent conductive film that is more chemically stable than an ITO film by combining certain zinc oxide with indium oxide.

For example, in Japanese Patent Laid-Open No. 61-205619, a heat-resistant material containing a specific amount of In within 1 to 20 atomic% with respect to zinc atoms in a zinc oxide transparent conductive film containing zinc oxide as a main component. Zinc oxide transparent conductive film is disclosed.
In addition, Japanese Patent Publication No. 5-6289 discloses a zinc oxide-added indium oxide film in which the atomic ratio In / (In + Zn) of In and Zn calculated at the stage of the starting material is 0.8.

[0004]

However, the heat-resistant zinc oxide transparent conductive film disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 61-205619 has the advantage that the change in electrical resistivity is small over a wide temperature range. However, it has a drawback that the electric resistance value is higher than that of the ITO film. Further, the zinc oxide-added indium oxide film disclosed in the above Japanese Patent Publication No. 5-6289 also has a drawback that its electric resistance value is higher than that of the ITO film.

The present invention provides a transparent conductive film which has excellent etching characteristics as compared with an ITO film, has conductivity equivalent to that of the ITO film, and has better moisture resistance than the ITO film, and a manufacturing method thereof. With the goal.

[0006]

The transparent conductive film of the present invention which achieves the above object is made of an amorphous oxide of indium and zinc and has an atomic ratio of In to Zn of In / (In + Zn).
= 0.55 to 0.75 (hereinafter,
This transparent conductive film is referred to as a transparent conductive film I).

Another transparent conductive film of the present invention which achieves the above object is indium and zinc, and Sn, Al and S.
In and Z, which is composed of an amorphous oxide of at least one third element selected from the group consisting of b, Ga and Ge,
The atomic ratio of n is In / (In + Zn) = 0.55 to 0.7
5, the ratio of the third element to the total amount of In, Zn and the third element is 20 at% or less (hereinafter, this transparent conductive film is referred to as transparent conductive film II).

On the other hand, in the method of manufacturing a transparent conductive film of the present invention which achieves the above object, the indium compound and the zinc compound have an atomic ratio of In and Zn of In / (In + Zn) = 0.5.
A coating solution was prepared by dissolving the coating solution in a ratio of 5 to 0.75, and the coating solution was applied to the substrate to
It is characterized in that it is subjected to reduction treatment after firing at 0 to 650 ° C. to obtain an amorphous transparent conductive film (hereinafter, this method is referred to as method I).

Another method of manufacturing the transparent conductive film of the present invention that achieves the above object is to use an indium compound, a zinc compound, a Sn compound, an Al compound, an Sb compound, and a Ga compound.
At least one third element compound selected from the group consisting of a compound and a Ge compound, the atomic ratio of In to Zn is In / (In + Zn) = 0.55 to 0.75, and In
A coating solution is prepared by dissolving the third element with respect to the total amount of Zn, Zn, and the third element in a ratio of 20 at% or less, and the coating solution is applied to a substrate to
It is characterized by obtaining an amorphous transparent conductive film by performing a reduction treatment after firing at 0 to 650 ° C. (hereinafter, this method is referred to as a method.
II).

The present invention will be described in detail below. First, the transparent conductive film I of the present invention will be described. The transparent conductive film I is made of an amorphous oxide of indium and zinc as described above, and the atomic ratio of In to Zn is In / (In + Z).
n) = 0.55 to 0.75. Here, the amorphous oxide generally has a composition formula In _x Zn _1-x O _y (where x is
Indicates a numerical value within the range of 0.55 to 0.75, and y indicates a stoichiometric amount. ), And oxygen in indium zinc oxide may be partially deficient. Further, this oxide includes all forms of oxides such as a mixture, a composition, a solid solution and the like.

The reason for limiting the atomic ratio of In to Zn in this amorphous oxide to In / (In + Zn) = 0.55 to 0.75 is that the electric resistance value becomes large when the atomic ratio deviates from this range. Because it will be. In / (In + Zn)
The preferred range is 0.60 to 0.75, and the particularly preferred range is 0.65 to 0.75. Also, the crystallized one is Zn (2) at the In (trivalent) position of In ₂ O _3.
Since the conductivity value is inferior to that of an amorphous material even if the composition is the same, the transparent conductive film I is limited to an amorphous material.

The transparent conductive film I made of such an amorphous oxide is superior in etching characteristics to the ITO film and has the same conductivity as the ITO film, and also has excellent visible light transmittance. have. The increase in electric resistance value due to humidity is smaller than that in the ITO film. The transparent conductive film I can be manufactured by various methods such as a sputtering method and a CVD method, but the composition can be accurately and easily controlled, and the manufacturing cost can be low. Therefore, it is preferably produced by the method I of the present invention described later.

Next, the transparent conductive film II of the present invention will be described. The transparent conductive film II is at least one selected from the group consisting of indium and zinc, and Sn, Al, Sb, Ga and Ge as described above. It is composed of an amorphous oxide with a third element, and the atomic ratio of In and Zn is In / (I
n + Zn) = 0.55 to 0.75, and the ratio of the third element to the total amount of In, Zn and the third element is 20 at% or less. Here, the atomic ratio of In and Zn is In / (In + Z
The reason for limiting n) to 0.55 to 0.75 is the same as the reason for the transparent conductive film I described above. Transparent conductive film I
As in the case of No. 2, the preferable range of In / (In + Zn) is 0.60 to 0.75, and the particularly preferable range is 0.
It is 65 to 0.75.

The reason for limiting the proportion of the third element to 20 at% or less is that if the third element exceeds 20 at%, ion scattering occurs and the conductivity of the film is lowered too much.
The preferable ratio of the third element is 1 to 10 at%, and the particularly preferable ratio is 2 to 10 at%. Further, the crystallized material is inferior in conductivity to the amorphous material even if the composition is the same, so that the transparent conductive film II is also limited to the amorphous material.

The transparent conductive film II made of such an amorphous oxide has higher conductivity than the transparent conductive film I described above. Further, it has excellent etching characteristics and excellent visible light transmittance as compared with the ITO film. The increase in electric resistance value due to humidity is smaller than that in the ITO film. This transparent conductive film II can also be manufactured by various methods such as the sputtering method and the CVD method, but for the same reason as the above-mentioned transparent conductive film I, it can be manufactured by the method II of the present invention described later. preferable.

Next, the method I and the method II of the present invention will be described. First, the method I of the present invention will be described.
In this method I, as described above, the indium compound and the zinc compound have an atomic ratio of In and Zn of In / (In + Z
n) = 0.55 to 0.75 to prepare a coating solution, and apply the coating solution to a substrate, bake at 300 to 65 ° C, and then perform a reduction treatment to obtain an amorphous transparent conductive material. It is characterized by obtaining a film.
The coating solution used in Method I contains, in addition to the indium and zinc compounds described above, a solvent and a solution stabilizer.

Specific examples of the indium compound include carboxylates such as indium acetate, inorganic indium compounds such as indium chloride, and indium alkoxides such as indium ethoxide and indium propoxide. Specific examples of zinc compounds include carboxylates such as zinc acetate, inorganic zinc compounds such as zinc chloride, zinc fluoride and zinc iodide, zinc methoxide, zinc ethoxide,
Examples thereof include zinc alkoxide such as zinc propoxide.

As the solvent, methanol, ethanol, isopropyl alcohol, 2-methoxyethanol, 2-
Alcohols such as ethoxyethanol and hydrocarbons such as toluene and benzene can be used. As the solution stabilizer, alkanolamines such as monoethanolamine, diethanolamine, triethanolamine and the like can be used.

The coating solution can be prepared by mixing a predetermined amount of indium compound, zinc compound, solvent and stabilizer. The mixing order at this time is not particularly limited. The mixing may be stirring and mixing by a conventional method such as a stirrer, and heating may be performed at this time. The stirring time is preferably 0.01 to 100 hours. If it is less than 0.01 hours, it is difficult to obtain a uniform transparent solution. On the other hand, if it exceeds 100 hours, the economy becomes poor. Particularly preferable stirring time is 0.1 to 100 hours. When heating with stirring, the heating temperature is 100 ° C.
The following is preferable. When the temperature exceeds 100 ° C, the solvent evaporates and the solution concentration changes.

The atomic ratio of In to Zn in the coating solution is In / (In + Zn) = 0.55 as described above.
Limited to ~ 0.75. When the atomic ratio deviates from this range, the electric resistance value of the obtained transparent conductive film increases, as will be apparent from Examples and Comparative Examples described later. In / (In + Zn) in the coating solution is 0.6
0 to 0.75 is preferable, and 0.65 to 0.75 is particularly preferable.

In and Z in the coating solution
The concentration of the total amount of n is preferably 0.01 to 10 mol%. If it is less than 0.01 mol%, the film thickness per coating is small, and a large number of coatings are required to obtain a desired film thickness, resulting in poor economic efficiency.
On the other hand, if it exceeds 10 mol%, the film thickness becomes uneven during coating. A particularly preferable concentration of the total amount of In and Zn is 0.1 to 10 mol%.

The concentration of the stabilizer in the coating solution is preferably 0.01 to 10 mol%. 0.
If it is less than 01 mol%, it becomes difficult to dissolve the indium compound and the zinc compound in the solvent. On the other hand, if it exceeds 10 mol%, carbon generated by decomposition of the stabilizer during baking will remain in the film even after baking, and the conductivity of the film will be reduced. A particularly preferred concentration of stabilizer is 0.1-
It is 10 mol%.

In Method I, the coating solution prepared as described above is applied to a substrate and then 300 to 650 ° C.
Bake at. Although various substrates can be used depending on the application, examples of the transparent substrate include alkali glass, non-alkali glass, quartz glass, and transparent polymer. The substrate may have an undercoat layer. As a specific example of the undercoat layer, Zn
Examples of the thin film include O, SiO ₂ , and TiO ₂ . Also,
The coating method is not particularly limited, and various methods conventionally applied when manufacturing a thin film from a solution can be used. Specific examples include a spray method, a dipping method, a spin coating method and the like.

The firing method is not particularly limited,
Methods such as normal pressure firing, vacuum firing, and pressure firing can be applied, but the firing temperature is limited to 300 to 650 ° C. The reason for limiting the lower limit of the firing temperature to 300 ° C. is 30
If the temperature is lower than 0 ° C., the carbon generated by the decomposition of the solvent or the stabilizer remains in the film after baking, which lowers the conductivity of the film. On the other hand, the reason for limiting the upper limit of the firing temperature to 650 ° C. is that if the temperature exceeds 650 ° C., the obtained film becomes crystalline and the conductivity of the film decreases. The preferable firing temperature is 300 to 600 ° C.

The firing time is 0.0 although it depends on the firing temperature.
1 to 10 hours is preferable. If it is less than 0.01 hours, the carbon generated by the decomposition of the solvent or the stabilizer remains in the film even after firing, and the conductivity of the film is lowered. On the other hand, if it exceeds 10 hours, the economy becomes poor. A particularly preferable firing time is 0.1 to 10 hours.

When the desired film thickness cannot be obtained by performing the operation of coating and baking only once,
It is preferable to perform the operation of calcining after coating a required number of times and then performing the main calcination. The temperature for calcination is 3
The temperature is preferably 00 to 650 ° C. If the temperature is lower than 300 ° C., the carbon generated by the decomposition of the solvent or the stabilizer remains in the film even after the calcination, which lowers the conductivity of the film. On the other hand, if the temperature exceeds 650 ° C., the obtained film becomes crystalline and the conductivity of the film decreases. A particularly preferable temperature is 300 to 600 ° C.

The calcination time varies depending on the calcination temperature, but is preferably 0.01 to 1 hour. In less than 0.01 hours,
Since the solvent or stabilizer does not fly off and remains,
No matter how many times coating and calcination are repeated, the previously coated film will melt at the next coating and the film will not become thick. On the other hand, if it exceeds 1 hour, the economy becomes poor.

In method I, reduction treatment is performed after firing as described above. As the reduction method, reduction with a reducing gas, reduction with an inert gas, reduction by vacuum firing, or the like can be applied. Hydrogen gas as the reducing gas,
Steam or the like can be used. As the inert gas, nitrogen gas, argon gas, a mixed gas of these gases and oxygen, or the like can be used.

The reduction temperature is preferably 100 to 650 ° C.
If it is less than 100 ° C, it is difficult to perform sufficient reduction.
On the other hand, when the temperature exceeds 650 ° C, the film becomes crystalline and the conductivity of the film decreases. Particularly preferable reduction temperature is 200 to 500.
℃. The reduction time is 0.01 depending on the reduction temperature.
10 hours is preferable. If it is less than 0.01 hours, it is difficult to perform sufficient reduction. On the other hand, if it exceeds 10 hours, the economy becomes poor. Particularly preferred reduction time is 0.1
10 hours.

The transparent conductive film I of the present invention which can be produced by the above-mentioned method I has the same conductivity as that of the ITO film, and has excellent etching characteristics and excellent visibility as compared with the ITO film. Has optical transparency. The increase in electric resistance value due to humidity is smaller than that in the ITO film. The transparent conductive film I can be used as an electrode for various applications such as an electrode for a liquid crystal display element and an electrode for a solar cell.

Next, the method II of the present invention will be described.
Method II includes indium compound and zinc compound, and Sn compound, Al compound, Sb compound, Ga as described above.
At least one third element compound selected from the group consisting of a compound and a Ge compound, the atomic ratio of In to Zn is In / (In + Zn) = 0.55 to 0.75, and In
And Zn and the total amount of the third element (Sn,
A coating solution is prepared by dissolving Al, Sb, Ga, Ge) in a proportion of 20 at% or less, and the coating solution is applied to a substrate, baked at 300 to 650 ° C., and then subjected to reduction treatment to be amorphous. It is characterized in that a high quality transparent conductive film is obtained.

Here, the atomic ratio of In and Zn in the coating solution is In / (In + Zn) = 0.55-0.
The reason for limiting the number to 75 is the same as the reason in Method I described above. In / (In + Z in coating solution
n) is preferably 0.60 to 0.75, and 0.65 to 0.
75 is especially preferred.

The reason why the ratio of the third element to the total amount of In, Zn and the third element is limited to 20 at% or less is 20.
This is because if it exceeds at%, the conductivity of the obtained film is excessively lowered by the scattering of ions. The proportion of the third element is 20 at%
By dissolving the third element compound as described below, a transparent conductive film having higher conductivity than the transparent conductive film I can be obtained. The proportion of the third element is preferably 1 to 10 at%, particularly preferably 2 to 10 at%.

In this method II, in addition to an indium compound and a zinc compound, a predetermined amount of at least one third element compound selected from the group consisting of Sn compounds, Al compounds, Sb compounds, Ga compounds and Ge compounds is dissolved. This is different from Method I described above in that the coating solution is prepared. The other points, that is, the types of the indium compound and the zinc compound, the method for preparing the coating solution, the type of the substrate, the firing method, and the reduction method are the same as those in Method I. For the same reason as in Method I, the total concentration of In, Zn, and the third element in the coating solution was
0.01 to 10 mol% is preferable, especially 0.1 to 10 m
ol% is preferred.

Specific examples of the Sn compound used as the third element compound in Method II include tin acetate (divalent), dimethoxytin, diethoxytin, dipropoxytin, dibutoxytin,
Tetramethoxytin, tetraethoxytin, tetrapropoxytin, tetrabutoxytin, tin chloride (divalent), tin chloride (4
Value) and the like. Further, specific examples of the Al compound include aluminum chloride, trimethoxyaluminum, triethoxyaluminum, tripropoxyaluminum,
Tributoxy aluminum and the like can be mentioned.

Specific examples of the Sb compound include antimony chloride (trivalent), antimony chloride (pentavalent), trimethoxyantimony, triethoxyantimony, tripropoxyantimony, tributoxyantimony and the like. G
Specific examples of the compound a include gallium chloride (trivalent), trimethoxygallium, triethoxygallium, tripropoxygallium, tributoxygallium and the like.
Specific examples of the Ge compound include germanium chloride (tetravalent), tetramethoxygermanium, tetraethoxygermanium, tetrapropoxygermanium, tetrabutoxygermanium and the like.

The transparent conductive film II of the present invention which can be produced by the above method II has higher conductivity than the transparent conductive film I described above, and is more excellent in etching characteristics than the ITO film. It also has excellent visible light transmittance. And the increase of the electric resistance value due to the humidity is due to the ITO
Less than a membrane. This transparent conductive film II can also be used as an electrode for various applications such as an electrode for a liquid crystal display element and an electrode for a solar cell.

[0038]

EXAMPLES Examples of the present invention will be described below. Example 1 (Production Example of Transparent Conductive Film I by Method I: In /
(In + Zn) = 0.67, main firing temperature 300-600
C.) Indium acetate is used as the indium compound, anhydrous zinc acetate is used as the zinc compound, 2-methoxymethanol is used as the solvent, monoethanolamine is used as the stabilizer, and a quartz glass plate is used as the substrate. Thus, the transparent conductive film I was manufactured. First, 2
-To 21.5 g of methoxymethanol, 4.6 g of monoethanolamine and 3.0 g of indium acetate were added and mixed with stirring for 10 minutes to obtain a transparent solution. 0.9 g of anhydrous zinc acetate was added to the transparent solution while stirring, and the mixture was stirred and mixed for 10 minutes to prepare a transparent and uniform coating solution. The atomic ratio of In and Zn in this coating solution was In / (In + Zn) = 0.67, and the total concentration of In and Zn was 0.5 mol / liter (4 mol%).

Next, a quartz glass plate (70 × 20 × 1.5 mm) was dipped in the obtained coating solution for dip coating (coating speed: 1.2 cm / min), and then 500 ° C. using an electric furnace. It was calcined for 10 minutes. The above-mentioned operation of performing dip coating and then calcining was repeated 10 times in total, and then main firing was performed at 500 ° C. for 1 hour. Then, vacuum (1 x 1) at 400 ° C for 2 hours.
0 ^-2 torr) was reduced to obtain the target transparent conductive film I.
In addition, as shown in Table 1, the calcination temperature is 300 ° C, 400
℃, 500 ℃ and main firing temperature 300 ℃, 4
Separately, except that the temperature was set to 00 ° C and 600 ° C.
A total of three types of transparent conductive films I were obtained.

From the results of XRD (X-ray diffraction) measurement, all four kinds of transparent conductive films I thus obtained were amorphous oxides of In and Zn. In addition, 500 ℃
FIG. 1 shows the XRD measurement results of the transparent conductive film I obtained by main firing in
Shown in. Moreover, when the composition of each transparent conductive film I was measured by X-ray photoelectron spectroscopy (XPS), the atomic ratio of In to Zn was In / (In + Z
n) = 0.67. Furthermore, when the film thickness was measured from an electron micrograph of the cross section of each transparent conductive film I, the film thickness of each transparent conductive film I was 200 nm.

Table 1 shows the results of measuring the surface resistance of each transparent conductive film I by the four-terminal method. Table 1 also shows the measurement results of visible light (wavelength 550 nm) transmittance of each transparent conductive film I on the quartz glass plate. Furthermore, Table 1 also shows the results of performing a moisture resistance test on each transparent conductive film I under the conditions of 40 ° C. and 90% RH and measuring the surface resistance after a test time of 1000 hours.

Comparative Example 1 (In / (In + Zn) = 0.6
7. Main firing temperature 700 ° C.) The main firing temperature is 700 ° C., which is outside the limit range of the present invention.
Except that the calcination temperature was 500
C.) and a transparent conductive film (film thickness 200 nm) was obtained. The transparent conductive film thus obtained was crystalline according to the result of XRD measurement. When the composition was measured by XPS, the atomic ratio of In and Zn was In / (In + Zn) = 0.
It was 67. The surface resistance and visible light transmittance of this transparent conductive film were measured in the same manner as in Example 1, and the same moisture resistance test as in Example 1 was performed to determine the surface resistance after 1000 hours of testing as in Example 1. Was measured. The results are shown in Table 1.

Example 2 (Production Example of Transparent Conductive Film I by Method I: In / (In + Zn) = 0.75, Main Burning Temperature 3
(00-600 ° C.) Monoethanolamine (4.45 g) and indium acetate (2.97 g) were added to 2-methoxymethanol (21.91 g), and the mixture was stirred and mixed for 10 minutes to obtain a transparent solution. While stirring this clear solution, add 0.6% anhydrous zinc acetate to the clear solution.
7 g was added and mixed by stirring for 10 minutes to prepare a transparent and uniform coating solution. The atomic ratio of In to Zn in this coating solution was In / (In + Zn) = 0.
And the total concentration of In and Zn was 0.5 mol / liter (4 mol%). After this, as in Example 1, the main firing temperature was 300 ° C., 40 ° C. as shown in Table 1.
A total of four kinds of transparent conductive films I (film thickness 200 nm) different from 0 ° C., 500 ° C. and 600 ° C. were obtained.

The four types of transparent conductive films I thus obtained were all amorphous oxides of In and Zn according to the result of XRD measurement. Moreover, when the composition of each transparent conductive film I was measured by XPS, the atomic ratio of In to Zn in any transparent conductive film I was In / (In + Zn) =
It was 0.75. The surface resistance and visible light transmittance of each transparent conductive film I were measured in the same manner as in Example 1, and
The same moisture resistance test as in Example 1 was conducted and the test time was 1000
The surface resistance after the elapse of time was measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 (In / (In + Zn) = 0.7
5, main baking temperature 700 ° C.) The main baking temperature is 700 ° C., which is outside the limit range of the present invention.
The same procedure as in Example 2 except that the calcination temperature was 500
C.) and a transparent conductive film (film thickness 200 nm) was obtained. The transparent conductive film thus obtained was crystalline according to the result of XRD measurement. When the composition was measured by XPS, the atomic ratio of In and Zn was In / (In + Zn) = 0.
It was 75. The surface resistance and visible light transmittance of this transparent conductive film were measured in the same manner as in Example 1, and the same moisture resistance test as in Example 1 was performed to determine the surface resistance after 1000 hours of testing as in Example 1. Was measured. The results are shown in Table 1.

Example 3 (Production Example of Transparent Conductive Film I by Method I: In / (In + Zn) = 0.55, Main Firing Temperature 3
(00-600 ° C.)) To 21.32 g of 2-methoxymethanol, 4.93 g of monoethanolamine and 2.41 g of indium acetate were added, and mixed by stirring for 10 minutes to obtain a transparent solution. While stirring the transparent solution, add 1.3 g of anhydrous zinc acetate to the transparent solution.
4 g was added and mixed by stirring for 10 minutes to prepare a transparent and uniform coating solution. The atomic ratio of In to Zn in this coating solution was In / (In + Zn) = 0.
The total concentration of In and Zn was 0.5 mol / liter (4 mol%). After this, as in Example 1, the main firing temperature was 300 ° C., 40 ° C. as shown in Table 1.
A total of four kinds of transparent conductive films I (film thickness 200 nm) different from 0 ° C., 500 ° C. and 600 ° C. were obtained.

The four types of transparent conductive films I thus obtained were all amorphous oxides of In and Zn according to the result of XRD measurement. Moreover, when the composition of each transparent conductive film I was measured by XPS, the atomic ratio of In to Zn in any transparent conductive film I was In / (In + Zn) =
It was 0.55. The surface resistance and visible light transmittance of each transparent conductive film I were measured in the same manner as in Example 1, and
The same moisture resistance test as in Example 1 was conducted and the test time was 1000
The surface resistance after the elapse of time was measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 3 (In / (In + Zn) = 0.5
5, main baking temperature 700 ° C.) The main baking temperature is 700 ° C., which is outside the limit range of the present invention.
The same procedure as in Example 3 except that the calcination temperature was 500
C.) and a transparent conductive film (film thickness 200 nm) was obtained. The transparent conductive film thus obtained was crystalline according to the result of XRD measurement. When the composition was measured by XPS, the atomic ratio of In and Zn was In / (In + Zn) = 0.
It was 55. The surface resistance and visible light transmittance of this transparent conductive film were measured in the same manner as in Example 1, and the same moisture resistance test as in Example 1 was performed to determine the surface resistance after 1000 hours of testing as in Example 1. Was measured. The results are shown in Table 1.

Comparative Example 4 (In / (In + Zn) = 0.5
0, main baking temperature 500 to 700 ° C.) In / Zn atomic ratio In / Zn in coating solution In /
A transparent and uniform coating solution was prepared in the same manner as in Example 1 except that (In + Zn) was set to 0.50, which is outside the range of the present invention. Thereafter, a total of three types of transparent conductive films (film thickness) were prepared in the same manner as in Example 1 (calcination temperature: 500 ° C.) except that the main firing temperature was set to 500 ° C., 600 ° C., and 700 ° C. shown in Table 1. 200 nm) was obtained.

When the composition of each transparent conductive film thus obtained was measured by XPS, the atomic ratio of In to Zn in any transparent conductive film was In / (In + Zn) =
It was 0.50. Further, the surface resistance and the visible light transmittance of each transparent conductive film were measured in the same manner as in Example 1, and the moisture resistance test was performed in the same manner as in Example 1 for a test time of 10
The surface resistance after 00 hours was measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 5 (In / (In + Zn) = 0.3
3, main firing temperature 500 ° C) Atomic ratio of In and Zn in coating solution In /
A transparent and uniform coating solution was prepared in the same manner as in Example 1 except that (In + Zn) was set to 0.33, which is outside the range of the present invention. After this, coating and firing were performed in the same manner as in Example 1 (calcination temperature 500 ° C., main firing temperature 5
00 ° C.) and reduction treatment to obtain a transparent conductive film (film thickness 2
00 nm) was obtained.

When the composition of the transparent conductive film thus obtained was measured by XPS, the atomic ratio of In to Zn was In.
/(In+Zn)=0.33. Moreover, the surface resistance and visible light transmittance of this transparent conductive film were measured in the same manner as in Example 1, and the same moisture resistance test as in Example 1 was performed to determine the surface resistance after 1000 hours of test in Example 1.
It measured similarly to. The results are shown in Table 1.

Comparative Example 6 (In / (In + Zn) = 0.8
0, main baking temperature 500 to 700 ° C.) In / Zn atomic ratio In / Zn in coating solution In /
A transparent and uniform coating solution was prepared in the same manner as in Example 1 except that (In + Zn) was set to 0.80, which is outside the range of the present invention. Thereafter, in the same manner as in Comparative Example 4, a total of three types of transparent conductive films (film thickness 200 nm) were obtained.

When the composition of each transparent conductive film thus obtained was measured by XPS, the atomic ratio of In to Zn in any transparent conductive film was In / (In + Zn) =
It was 0.80. Further, the surface resistance and the visible light transmittance of each transparent conductive film were measured in the same manner as in Example 1, and the moisture resistance test was performed in the same manner as in Example 1 for a test time of 10
The surface resistance after 00 hours was measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 7 (In / (In + Zn) = 0.9
0, main baking temperature 500 ° C.) In / Zn atomic ratio in coating solution In /
A transparent and uniform coating solution was prepared in the same manner as in Example 1 except that (In + Zn) was set to 0.90, which is outside the range of the present invention. Thereafter, in the same manner as in Comparative Example 5, a transparent conductive film (film thickness 200 nm) was obtained.

When the composition of the transparent conductive film thus obtained was measured by XPS, the atomic ratio of In to Zn was In.
/(In+Zn)=0.90. Moreover, the surface resistance and visible light transmittance of this transparent conductive film were measured in the same manner as in Example 1, and the same moisture resistance test as in Example 1 was performed to determine the surface resistance after 1000 hours of test in Example 1.
It measured similarly to. The results are shown in Table 1.

Comparative Example 8 (In / (In + Zn) = 1.
(0, indium oxide thin film) To 22.2 g of 2-methoxymethanol, 4.0 g of monoethanolamine and 3.8 g of indium acetate were added.
A transparent and uniform coating solution was prepared by stirring and mixing for a minute. In concentration in this coating solution is 4 m
It was ol%. Thereafter, in the same manner as in Comparative Example 5, an indium oxide thin film (film thickness 200 nm) was obtained. The surface resistance and the visible light transmittance of the thus obtained indium oxide thin film were measured in the same manner as in Example 1, and the same moisture resistance test as in Example 1 was performed to determine the surface resistance after a test time of 1000 hours. Was measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 9 (ITO thin film) Comparative Example 8 was repeated except that 0.16 g of Sn (OC ₄ H ₉ ) ₂ was added to the coating solution of Comparative Example 8.
An ITO thin film (Sn 4 at%, film thickness 200 nm) was obtained. The surface resistance and visible light transmittance of the ITO thin film thus obtained were measured in the same manner as in Example 1, and the same moisture resistance test as in Example 1 was performed to determine the surface resistance after 1000 hours of test time. The measurement was performed in the same manner as in Example 1. The results are shown in Table 1.

[0059]

[Table 1]

As is clear from Table 1, In / (In +
Each transparent conductive film I of Examples 1 to 3 made of an amorphous oxide having Zn) of 0.55 to 0.75 is IT of Comparative Example 9.
It has conductivity equal to or higher than that of the O film. Further, each of the transparent conductive films I of Examples 1 to 3 has excellent visible light transmittance. Furthermore, Examples 1 to 3
The surface resistance of each of the transparent conductive films I is almost unchanged before and after the moisture resistance test. From this, Example 1 to Example 3
It can be seen that each of the transparent conductive films I has excellent moisture resistance.
In addition, each of the transparent conductive films I of Examples 1 to 3 is ITO.
It was confirmed that the film had better etching characteristics than the film.

On the other hand, as is clear from Table 1, In /
Even if (In + Zn) is 0.55 to 0.75, the conductivity of each transparent conductive film of Comparative Examples 1 to 3 made of crystalline oxide is extremely low. Further, as is clear from Table 1, the transparent conductive films of Comparative Examples 4 to 7 in which In / (In + Zn) is out of the limited range of the present invention have the same starting material type, firing conditions, and reduction conditions. It is inferior in conductivity to the transparent conductive film I of a certain example. The indium oxide thin film of Comparative Example 8 is inferior to the transparent conductive films I of Examples 1 to 3 in terms of conductivity and moisture resistance, and the ITO film of Comparative Example 9 has excellent conductivity and visible light transmission. It is clear that although it has the rate, the moisture resistance is inferior to that of each transparent conductive film I of Examples 1 to 3.

Example 4 (Production Example of Transparent Conductive Film II by Method II) Indium acetate was used as the indium compound, anhydrous zinc acetate was used as the zinc compound, dibutoxytin was used as the third element compound, and 2-methoxymethanol was used as the solvent. Using monoethanolamine as a stabilizer and a quartz glass plate as a substrate, a transparent conductive film II was produced based on Method II as follows. First, using 2-methoxymethanol, monoethanolamine, indium acetate, and anhydrous zinc acetate, 30 g of a transparent and uniform solution (corresponding to the coating solution of Example 1) was carried out in exactly the same manner as in Example 1. Prepared. Next, 0.16 g of dibutoxytin was added to this solution and mixed by stirring for 10 minutes to prepare a transparent and uniform coating solution. The atomic ratio of In to Zn in this coating solution is In / (In + Zn)
= 0.67, the ratio of Sn to the total amount of In, Zn and Sn {[Sn / (In + Zn + Sn)] × 100} is 4 at
%, The total concentration of In, Zn and Sn was 0.5 mol / liter (4 mol%).

Next, a glass plate (7059: 70 × 20 × 1.5 m manufactured by Corning Incorporated) was added to the obtained coating solution.
m) was dipped, dip-coated under the same conditions as in Example 1, and then calcined at 500 ° C. for 10 minutes using an electric furnace. The above-mentioned operation of performing dip coating and then calcining was repeated 10 times in total, and then main firing was performed at 500 ° C. for 1 hour. Then, vacuum (1 × 10 ^-2 torr) reduction is performed at 400 ° C. for 2 hours to obtain the target transparent conductive film II.
(Film thickness 200 nm) was obtained.

The transparent conductive film II thus obtained is
From the result of XRD measurement, it was an amorphous oxide of In, Zn, and Sn. Further, the surface resistance and visible light transmittance of the obtained transparent conductive film II were measured in the same manner as in Example 1, and the same moisture resistance test as in Example 1 was performed to determine the surface resistance after 1000 hours of test time. The measurement was performed in the same manner as in Example 1. The results are shown in Table 2.

Example 5 (Production Example of Transparent Conductive Film II by Method II) Tributoxyaluminum 0.1 in place of dibutoxytin
A coating solution {In / (In + Zn) = 0.67, [Al /
(In + Zn + Al)] × 100 = 4at%, In and Zn
And the total concentration of Al = 0.5 mol / liter (4 mol
%)} Was prepared, and using this coating solution, a transparent conductive film II (film thickness 200 nm) was obtained in exactly the same manner as in Example 4.

The transparent conductive film II thus obtained is
From the result of XRD measurement, it was an amorphous oxide of In, Zn, and Al. Further, the surface resistance and visible light transmittance of the obtained transparent conductive film II were measured in the same manner as in Example 1, and the same moisture resistance test as in Example 1 was performed to determine the surface resistance after 1000 hours of test time. The measurement was performed in the same manner as in Example 1. The results are shown in Table 2.

Example 6 (Production Example of Transparent Conductive Film II by Method II) Tributoxyantimony 0.21 in place of dibutoxytin
A coating solution {In / (In + Zn) = 0.67, [Sb /
(In + Zn + Sb)] × 100 = 4 at%, In and Zn
Concentration of total amount of Sb and Sb = 0.5 mol / liter (4 mol
%)} Was prepared, and using this coating solution, a transparent conductive film II (film thickness 200 nm) was obtained in exactly the same manner as in Example 4.

The transparent conductive film II thus obtained is
From the result of XRD measurement, it was an amorphous oxide of In, Zn, and Sb. Further, the surface resistance and visible light transmittance of the obtained transparent conductive film II were measured in the same manner as in Example 1, and the same moisture resistance test as in Example 1 was performed to determine the surface resistance after 1000 hours of test time. The measurement was performed in the same manner as in Example 1. The results are shown in Table 2.

Example 7 (Production Example of Transparent Conductive Film II by Method II) Gallium chloride (trivalent) 0.11 g instead of dibutoxytin
The coating solution {In / (In + Zn) = 0.67, [Ga / (I
n + Zn + Ga)] × 100 = 4 at%, In, Zn and G
Concentration of total amount of a = 0.5 mol / liter (4 mol%)}
Was prepared, and a transparent conductive film II (film thickness 200 nm) was obtained in exactly the same manner as in Example 4 using this coating solution.

The transparent conductive film II thus obtained is
From the result of XRD measurement, it was an amorphous oxide of In, Zn, and Ga. Further, the surface resistance and visible light transmittance of the obtained transparent conductive film II were measured in the same manner as in Example 1, and the same moisture resistance test as in Example 1 was performed to determine the surface resistance after 1000 hours of test time. The measurement was performed in the same manner as in Example 1. The results are shown in Table 2.

Example 8 (Production Example of Transparent Conductive Film II by Method II) A coating solution {In / (In + Zn) was prepared in the same manner as in Example 4 except that 0.15 g of tetrapropoxygermanium was used instead of dibutoxytin. = 0.67,
[Ge / (In + Zn + Ge)] × 100 = 4 at%, I
A total concentration of n, Zn, and Ge = 0.5 mol / liter (4 mol%)} was prepared, and using this coating solution, the transparent conductive film II (film thickness 200
nm) was obtained.

The transparent conductive film II thus obtained is
From the result of XRD measurement, it was an amorphous oxide of In, Zn, and Ge. Further, the surface resistance and visible light transmittance of the obtained transparent conductive film II were measured in the same manner as in Example 1, and the same moisture resistance test as in Example 1 was performed to determine the surface resistance after 1000 hours of test time. The measurement was performed in the same manner as in Example 1. The results are shown in Table 2.

[0073]

[Table 2]

As is clear from Table 2, each of the transparent conductive films of Examples 4 to 8 made of an amorphous oxide of In, Zn and a third element (Sn, Al, Sb, Ga or Ge). II
Has a higher conductivity than each of the transparent conductive films I of Examples 1 to 3 containing no third element. Moreover, each of the transparent conductive films II of Examples 4 to 8 has excellent visible light transmittance. Furthermore, the surface resistance of each transparent conductive film II of Examples 4 to 8 hardly changed before and after the moisture resistance test. From this, it is understood that each of the transparent conductive films II of Examples 4 to 8 has excellent moisture resistance. In addition, each transparent conductive film of Examples 4 to 8
It was confirmed that II has better etching characteristics than the ITO film.

[0075]

As described above, the transparent conductive film of the present invention is superior to the ITO film in etching characteristics, has the same conductivity as the ITO film, and is superior in moisture resistance to the ITO film. . Therefore, according to the present invention, it is possible to provide a transparent conductive film having improved durability.

[Brief description of drawings]

FIG. 1 is a graph showing the results of XRD measurement for a transparent conductive film I (calcination temperature 500 ° C., main baking temperature 500 ° C.) obtained in Example 1.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01B 13/00 503 B 7244-5G

Claims (4)

[Claims] 1. An amorphous oxide of indium and zinc, wherein the atomic ratio of In to Zn is In / (In + Zn) =
A transparent conductive film having a thickness of 0.55 to 0.75. 2. Indium and zinc, Sn, Al,
It is composed of an amorphous oxide of at least one third element selected from the group consisting of Sb, Ga and Ge, and the atomic ratio of In to Zn is In / (In + Zn) = 0.55-0.
75, the third element relative to the total content of In, Zn, and the third element.
A transparent conductive film, wherein the ratio of elements is 20 at% or less. 3. An indium compound and a zinc compound
The atomic ratio of n and Zn is In / (In + Zn) = 0.55.
A coating solution was prepared by dissolving the coating solution at a ratio of 0.75, and the coating solution was applied to a substrate to give 300-
A method for producing a transparent conductive film, comprising: performing a reduction treatment after firing at 650 ° C. to obtain an amorphous transparent conductive film. 4. An atomic ratio of In and Zn, wherein an indium compound and a zinc compound and at least one third element compound selected from the group consisting of Sn compounds, Al compounds, Sb compounds, Ga compounds and Ge compounds are used. Is In /
(In + Zn) = 0.55 to 0.75, and the ratio of the third element to the total amount of In, Zn and the third element is 20 at%.
Prepare a coating solution dissolved in the following ratio, apply this coating solution to a substrate, and apply 300 to 6
A method for producing a transparent conductive film, which comprises firing at 50 ° C. and then performing a reduction treatment to obtain an amorphous transparent conductive film.