JPH10173254A - Nonaqueous chemical conversion liquid for manufacture of two-terminal type nonlinear device, manufacture of two-terminal type nonlinear device, two-terminal type nonlinear device and liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an MIM(metal-insulator-metal) type nonlinear device which is small enough in device capacitance, possessed of current-voltage characteristics high enough in steepness, and has a sufficiently constant device resistance in a wide range of applied voltage, a liquid crystal display panel which is of high picture quality and quipped with the MIM nonlinear devices, nonaqueous chemical conversion liquid for manufacturing the MIM nonlinear device, and manufacture of the MIM nonlinear device by using the nonaqueous chemical conversion liquid. SOLUTION: Nonaqueous chemical conversion liquid containing organic solvent and solute has an electric conductivity of 1 to 100ms/cm. It is preferable that the solute comprises either one of calboxylate and salt of inorganic oxo- acid. An MIM nonlinear device 20 is provided with an insulating film 24 which is formed by anodization using nonaqueous chemical conversion liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous chemical liquid for producing a two-terminal nonlinear element used for a switching element, a method for producing a two-terminal nonlinear element using this non-aqueous chemical liquid, and a method for producing the same. The present invention relates to a two-terminal nonlinear element obtained by the method and a liquid crystal display panel using the same.

[0002]

2. Description of the Related Art In an active matrix type liquid crystal display device, a liquid crystal is filled between an active matrix substrate in which a switching element is provided for each pixel region to form a matrix array and a counter substrate in which, for example, a color filter is provided. Controlling the alignment state of the liquid crystal for each pixel region,
This is for displaying predetermined image information. The switching element is generally a three-terminal element such as a thin film transistor (TFT) or a metal-insulator-metal (MIM terminal).
A two-terminal element such as a type nonlinear element (hereinafter, also referred to as an “MIM element”) is used. The switching element using the two-terminal element is superior to the three-terminal element in that no crossover short-circuit occurs and the manufacturing process can be simplified.

In order to realize a liquid crystal display panel using an MIM element having a high contrast and a high image quality in which phenomena such as display unevenness, afterimages and image sticking cannot be recognized, the characteristics of the MIM element are as follows. It is important to satisfy the following conditions.

(1) The capacity of the MIM element is sufficiently smaller than the capacity of the liquid crystal display panel. (2) The current-voltage characteristic of the MIM element has a sufficiently small change with time. (3)
Good symmetry of current-voltage characteristics of the MIM element;
(4) The steepness of the current-voltage characteristics of the MIM element is sufficiently large. (5) The element resistance of the MIM element is sufficiently uniform over a wide voltage range.

That is, in order to increase the contrast, it is necessary that the capacity of the MIM element is sufficiently smaller than the capacity of the liquid crystal display panel, and that the sharpness of the current-voltage characteristics of the MIM element is sufficiently large. is there. In order to prevent display unevenness from being recognized, the element resistance of the MIM element needs to be sufficiently uniform over a wide voltage range. In order to prevent the afterimage from being recognized, it is necessary that the change with time of the current-voltage characteristics of the MIM element is sufficiently small. Further, in order to prevent burn-in from being recognized, it is necessary that the change with time of the current-voltage characteristics of the MIM element is sufficiently small and that the current-voltage characteristics of the MIM element have good symmetry.

Here, the "afterimage" is a phenomenon in which when a certain image is displayed for several minutes and then a different image is displayed, the previously displayed image is recognized. Further, “burn-in” is a phenomenon in which, when a certain image is displayed for several hours and then a different image is displayed, the previously displayed image is recognized. Furthermore, “good symmetry of current-voltage characteristics” means that a current flows from the first conductive film to the second conductive film at a certain voltage, and that the current flows from the second conductive film to the first conductive film. The difference between the absolute value of the current and that when the current is supplied is sufficiently small.

The following are examples of documents that disclose the technology of the MIM element.

(A) For example, Japanese Patent Application Laid-Open No. Sho 52-14909
In Japanese Patent Publication No. 0, there is disclosed a first conductive film made of tantalum, an insulating film made of a metal oxide film formed by anodizing the first conductive film, and a chromium formed on the surface of the insulating film. And a second conductive film
An element is disclosed. The insulating film is formed by anodizing the surface of the first conductive film and has a uniform thickness without pinholes. Also, Japanese Unexamined Patent Publication No.
JP-A-122478 discloses that a dilute aqueous solution of citric acid is used as a chemical solution (electrolytic solution) for anodic oxidation.

In these techniques, the MIM described above is used.
The characteristics (2) to (5) among the characteristics of the device were not always sufficiently satisfactory. That is, the current-voltage characteristics were not sufficient in terms of aging, symmetry and steepness, and the element resistance was not sufficiently uniform over a wide voltage range. Therefore, in the liquid crystal display panel using the MIM element, it is difficult to maintain a high contrast in a wide temperature range, and there is a problem that display unevenness easily occurs.

(B) Internationally Published International Application PCT / J
P94 / 00204 (International Publication Number WO94 / 1860)
0) discloses a structure in which an alloy film in which tungsten is added to tantalum is used as the first conductive film of the MIM element.

In this technique, since the first conductive film of the MIM element is changed to tantalum and is an alloy film of tantalum and a specific element such as tungsten, the above-mentioned characteristics (2) and (3), that is, MIM, The time-dependent change and the symmetry of the current-voltage characteristics of the device are described in the above-mentioned reference (a).
Because of the improvement over the technique described above, it is possible to reduce the afterimage level to a level that cannot be recognized, and to maintain a high contrast over a wide temperature range. However, even in this technique, there is a problem that the margin is insufficient in applications where contrast characteristics at high temperatures are required.

(C) Jpn. J. Appl. Phys,
31, 4582 (1992) discloses the use of a dilute aqueous solution of phosphoric acid or ammonium borate as an anodizing chemical solution for forming an insulating film of a MIM element.

In this technique, the above-mentioned characteristics (2) and (3), that is, the change with time and the symmetry of the current-voltage characteristics of the MIM element are improved as compared with the above-mentioned document (a). The level can be set so that an afterimage cannot be recognized, and the contrast can be kept high over a wider temperature range. However, even with this technology,
There has been a problem that the reliability of the element is low, the element is easily broken by a short circuit, and display unevenness easily occurs.

(D) Further, JP-A-2-93433 discloses a structure in which an alloy film of tantalum and silicon is used as the first conductive film of the MIM element.

In this technique, the sharpness of the current-voltage characteristics can be improved and the contrast can be kept high with a sufficient margin over a wide temperature range, as compared with the technique of the above-mentioned document (a). It became so.
However, this technique also has a problem that the reliability of the element is low and the element is easily broken, and display unevenness is likely to occur.

[0016]

SUMMARY OF THE INVENTION An object of the present invention is to provide excellent characteristics (1) to (5) required for the above-mentioned MIM element, and particularly to a sufficiently small element capacity and a sharp current-voltage characteristic. To provide a two-terminal non-linear element having a sufficiently large element resistance and a sufficiently uniform element resistance in a wide voltage range, and a high-quality liquid crystal display panel using the two-terminal non-linear element, which has high contrast and no display unevenness. is there.

Still another object of the present invention is to provide a non-aqueous chemical liquid for producing a two-terminal nonlinear element having the above-mentioned excellent characteristics, and a production method using the chemical liquid.

[0018]

SUMMARY OF THE INVENTION A non-aqueous chemical liquid for producing a two-terminal nonlinear element (hereinafter referred to as "MIM nonlinear element") according to the present invention contains an organic solvent and a solute, and is electrically conductive. Rate is 1 ms / cm or more and 100 ms / c
m or less. In addition, M according to the present invention
In the IM nonlinear element, the second conductive film is not limited to metal, but includes a conductive film such as ITO.

The first conductive film made of tantalum or a tantalum alloy formed on the substrate is anodically oxidized using the chemical conversion solution, so that the oxidized film has a uniform film quality and a sufficiently uniform film thickness over the entire surface of the substrate. A film can be formed. Therefore, the MIM type nonlinear element obtained by anodic oxidation using the above-mentioned chemical conversion solution has a sufficiently uniform element resistance in a wide voltage range.

The solute and / or solvent are taken into the oxide film during the anodic oxidation,
The relative permittivity of the oxide film (insulating film) can be reduced to a proper range. As a result, the obtained MIM type nonlinear element has a sufficiently small capacitance and a large current-voltage characteristic.

The solute preferably comprises at least one of a carboxylate and an inorganic oxoacid salt.

The carboxylate is preferably a salt of at least one carboxylic acid selected from the group consisting of aromatic monocarboxylic acids and aliphatic dicarboxylic acids having no hydroxyl group.

In the inorganic oxo acid salt, the central atom of the oxo acid is preferably an atom belonging to Group 3 to Group 7.
Further, the inorganic oxo acid salt is at least one selected from the group consisting of nitrate, vanadate, phosphate, chromate, tungstate, molybdate, silicate, perrhenate and sulfate. It is desirable that

The organic solvent desirably comprises at least one of ethylene glycol and γ-butyrolactone.

As described above, the MIM type nonlinear element of the present invention obtained by using the non-aqueous chemical conversion solution and the production method of the present invention has a small capacity, a large current-voltage characteristic, And excellent characteristics such that the element resistance is sufficiently uniform over a wide voltage range.

Further, the liquid crystal display panel of the present invention is characterized by comprising the above-mentioned MIM type nonlinear element, and more specifically, a transparent substrate, one of which is provided in a predetermined pattern on this substrate. A signal line, a MIM-type nonlinear element of the present invention connected to the signal line at a predetermined pitch, and a pixel electrode connected to the MIM-type nonlinear element.
And a second substrate provided with the other signal line at a position facing the pixel electrode; and a liquid crystal layer sealed between the first substrate and the second substrate. Features. According to this liquid crystal display panel, the contrast is high, display unevenness is unlikely to occur, and therefore, high-quality image display is possible, and it can be applied to a wide range of applications.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

(MIM Nonlinear Element and Liquid Crystal Display Panel) FIG. 1 is a plan view schematically showing one unit of a liquid crystal drive electrode using the MIM nonlinear element of the present invention.
FIG. 2 is a cross-sectional view schematically showing a portion along line AA in FIG. 1.

The MIM type non-linear element 20 includes a substrate (first substrate) 30 made of, for example, glass, plastic, or the like having an insulating property and a transparency.
An insulating film 31 formed on the surface of the first conductive film 22, a first conductive film 22 made of tantalum or a tantalum alloy, and an insulating film 2 formed on the surface of the first conductive film 22 by anodic oxidation
4 and a second conductive film 26 formed on the surface of the insulating film 24. The first conductive film 22 of the MIM nonlinear element 20 is connected to a signal line (scanning line or data line) 12, and the second conductive film 26 is connected to a pixel electrode 34.

The insulating film 31 is made of, for example, tantalum oxide. The insulating film 31 is formed by heat treatment performed after deposition of the second conductive film 26.
It is formed for the purpose of preventing peeling off of the substrate and preventing diffusion of impurities from the substrate 30 to the first conductive film 22. Therefore, it is not always necessary if these do not cause a problem.

The first conductive film 22 is made of tantalum alone,
Or tantalum as the main component,
An alloy film containing an element belonging to Group 7 or 8 may be used. Preferable examples of elements added to the alloy include tungsten, chromium, molybdenum, rhenium, yttrium, lanthanum, and displorium. In particular, tungsten is preferable as the element, and its content is preferably, for example, 0.2 to 6 atomic%.

As will be described in detail later, the insulating film 24
It is formed by anodizing in a specific non-aqueous chemical conversion solution. The insulating film 24 includes an additive element contained in the first conductive film 22 and a substance constituting at least one of a solvent and a solute in a chemical conversion solution, preferably a carbon atom and / or an inorganic oxo acid salt. Central atom of
It is configured to contain hydrogen and the like.

The second conductive film 26 is not particularly limited, but is usually made of chromium. The pixel electrode 34 is formed of a transparent conductive film such as an ITO film.

Further, as shown in FIG. 3, the second conductive film and the pixel electrode may be formed of the same transparent conductive film 36. By forming the second conductive film and the pixel electrode as a single film in this manner, the number of manufacturing steps required for forming the film can be reduced.

Next, an example of a liquid crystal display panel using the MIM type nonlinear element 20 will be described.

FIG. 4 shows an example of an equivalent circuit of an active matrix type liquid crystal display panel using the MIM type nonlinear element 20. The liquid crystal display panel 10 includes a scanning signal driving circuit 100 and a data signal driving circuit 110. The liquid crystal display panel 10 is provided with signal lines, that is, a plurality of scanning lines 12 and a plurality of data lines 14. The scanning lines 12 are provided by the scanning signal driving circuit 100, and the data lines 14 are provided by the data signal driving circuit 110. Driven by Then, in each pixel region 16, the scanning line 1
The MIM type nonlinear element 20 and the liquid crystal display element (liquid crystal layer) 40 are connected in series between the signal line 2 and the signal line 14. In FIG. 4, the MIM type nonlinear element 20 is connected to the scanning line 12 side and the liquid crystal display element 40 is connected to the data line 14 side. Conversely, the MIM type nonlinear element 20 is connected to the data line 14 side. The liquid crystal display element 40 may be provided on the scanning line 12 side.

FIG. 5 is a perspective view schematically showing an example of the structure of the liquid crystal display panel according to the present embodiment. The liquid crystal display panel 10 has two substrates, that is, a first substrate 3
0 and a second substrate 32 are provided facing each other, and liquid crystal is sealed between these substrates 30 and 32. On the first substrate 30, the insulating film 31 is formed as described above. On the surface of the insulating film 31, signal lines (scanning lines)
12 are provided. A plurality of data lines 14 are formed on the second substrate 32 in a strip shape so as to intersect the scanning lines 12. Further, the pixel electrode 34 has M
It is connected to the scanning line 12 via the IM device 20.

Then, based on signals applied to the scanning lines 12 and the signal lines 14, the liquid crystal display element 40 is displayed,
The display operation is controlled by switching to a non-display state or an intermediate state. As a control method of the display operation, a generally used method can be applied.

(Chemical Conversion Solution) Next, the chemical conversion solution of the present invention will be described in detail.

The chemical conversion solution of the present invention is a non-aqueous chemical conversion solution containing an organic solvent and a solute. And the electric conductivity of this non-aqueous chemical conversion liquid is 1 to 100 ms / cm, preferably 1 to 10 ms / cm. Generally, the electric conductivity of an electrolytic solution depends on the concentration of a solute, and the higher the solute concentration, the higher the electric conductivity. Therefore, it is preferable that the solute is easily soluble in an organic solvent.

The solute is not particularly limited and may be an organic acid salt or an inorganic acid salt, but is preferably a carboxylate or an inorganic oxo acid salt.

Examples of the carboxylate include salts of one or more carboxylic acids selected from the group consisting of aromatic monocarboxylic acids and aliphatic dicarboxylic acids having no hydroxyl group. The carboxylic acid preferably has a low molecular weight having 2 to 8 carbon atoms.

Specific examples of the aromatic monocarboxylic acid include:
Benzoic acid, toluic acid, salicylic acid, resorcinic acid, and the like, as specific examples of the aliphatic dicarboxylic acid having no hydroxyl group, oxalic acid, malonic acid, succinic acid, glutaric acid, saturated carboxylic acid such as adipic acid, and maleic acid, Examples thereof include unsaturated carboxylic acids such as citraconic acid.

The inorganic oxo acid salt is preferably a salt in which the central atom of the oxo acid is an atom belonging to Group 3 to Group 7 in the periodic table. Oxo acids are non-metallic at the central atom, such as nitric acid, phosphoric acid, boric acid, silicic acid and sulfuric acid.
The central atom may be a metal, such as chromic, vanadic, tungstic, molybdic, and perrhenic acids. The oxo acid may be a polyacid, and may be an isopoly acid or a heteropoly acid.

Examples of the cation forming a salt include an ammonium ion, an alkali metal ion, a 1,2,3 or quaternary alkylammonium ion, a phosphonium ion and a sulfonium ion. Ions and 1,2,3 or quaternary alkylammonium ions are preferred. In the case of an alkyl ammonium ion, the size of the alkyl group may be selected in consideration of solubility in an organic solvent.

Among the above solutes, ammonium salicylate, ammonium γ-resorcinate, ammonium benzoate, ammonium malonate, ammonium adipate and ammonium maleate are preferred, and ammonium salicylate is most preferred.

As the organic solvent, ethylene glycol,
Alcohol solvents such as methyl cellosolve, lactone solvents such as γ-butyrolactone, γ-valerolactone, δ-valerolactone; carbonate solvents such as ethylene carbonate, propylene carbonate, butylene carbonate; N-methylformamide, N-ethylformamide Amide solvents such as N, N-dimethylformamide, N, N-diethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidinone; nitriles such as 3-methoxypropionitrile and glutaronitrile System solvent: One or more solvents selected from the group of phosphate solvents such as trimethyl phosphate and triethyl phosphate, and a mixed solvent can be used. To these organic solvents, non-polar solvents such as hexane, toluene and silicone oil can be added.

Among the above organic solvents, ethylene glycol and γ-butyrolactone alone or in a mixed solvent are preferred. Although 20% by weight or less of water can be added to these organic solvents, the added water is preferably 10% by weight or less.

The concentration of the solute is determined in consideration of the electric conductivity of the chemical conversion solution, the amount of the solute added to the anodic oxide film, the pH and the like. For example, the concentration of the carboxylate dissolved in the organic solvent is preferably 1 to 30% by weight, more preferably 1 to 10% by weight. Further, the concentration of the inorganic oxoacid salt dissolved in the organic solvent is preferably 1 to 30% by weight, more preferably 1 to 10% by weight.

(Manufacturing Process of MIM Nonlinear Element) Next, a method of manufacturing the MIM nonlinear element 20 shown in FIG. 2, for example, will be described. In the production method of the present invention,
It is characterized in that the first conductive film is anodized in a specific non-aqueous chemical conversion solution.

The MIM type nonlinear element 20 is manufactured, for example, by the following process.

(A) First, an insulating film 31 made of tantalum oxide is formed on a substrate 30. The insulating film 31 can be formed by, for example, a method of thermally oxidizing a tantalum film deposited by a sputtering method, or a sputtering or co-sputtering method using a target made of tantalum oxide. The insulating film 31 is provided to improve the adhesion of the first conductive film 22 and to prevent diffusion of impurities from the substrate 30.
It is formed with a thickness of about 0 to 200 nm.

Next, a first conductive film 22 made of tantalum or a tantalum alloy is formed on the insulating film 31. A suitable value is selected for the thickness of the first conductive film depending on the use of the MIM type nonlinear element, and is usually 100 to 500 nm.
Degree. The first conductive film can be formed by a sputtering method or an electron beam evaporation method. As a method for forming the first conductive film made of a tantalum alloy, a sputtering method using a mixed target, a co-sputtering method, an electron beam evaporation method, or the like can be used.
The elements included in the tantalum alloy include 6, 6 in the periodic table.
Group 7 and 8 elements, preferably the aforementioned elements such as tungsten, chromium, molybdenum, rhenium and the like can be selected.

The first conductive film 22 is patterned by commonly used photolithography and etching techniques. Then, the signal line (scanning line or data line) 1 is formed in the same step as the step of forming the first conductive film 22.
2 are formed.

(B) Next, the surface of the first conductive film 22 is oxidized by an anodic oxidation method to form an insulating film 24. At this time, the surface of the signal line 12 is simultaneously oxidized to form an insulating film. The thickness of the insulating film 24 is preferably selected depending on its use, and is, for example, about 20 to 70 nm.

The anodic oxidation is performed in a temperature range in which the chemical conversion solution is stably present as a liquid, and this temperature range is generally -2.
It is 0-150 degreeC, Preferably it is room temperature-100 degreeC. The method of controlling the current and voltage at the time of anodic oxidation is not particularly limited, but usually, a predetermined formation voltage (V
Anodization is performed at a constant current until f), and after reaching the formation voltage Vf, the voltage is maintained for a certain period of time. The current density at this time is preferably 0.001 to 10 mA / cm ² , more preferably 0.01 to 1 mA / cm ² . Also,
The formation voltage Vf is usually 5 to 100 V, preferably 10 to 40 V, although it depends on the design of the driving circuit when manufacturing the liquid crystal display panel.

As described above, the chemical conversion solution used for the anodic oxidation is a non-aqueous chemical conversion solution having a specific electric conductivity, and an insulating film having a uniform film thickness and characteristics in the substrate surface by this chemical conversion solution. Can be obtained. Then, at the time of anodic oxidation, at least one of the solute and the solvent in the chemical conversion solution is taken into the oxide film, and the element constituting the solute or the solvent, preferably, the central atom of carbon and / or the inorganic oxo acid salt, hydrogen, etc. By being taken into the oxide film, the relative dielectric constant of the insulating film can be set in a suitable range.

(C) Next, a second conductive film 26 is formed by depositing a metal film of chromium, aluminum, titanium, molybdenum or the like by, for example, a sputtering method. The second conductive film has a thickness of, for example, 50 to 30.
It is formed to a thickness of 0 nm and then patterned using commonly used photolithography and etching techniques. Next, an ITO film is deposited to a thickness of 30 to 200 nm by a sputtering method or the like, and a pixel electrode 34 having a predetermined pattern is formed by using a commonly used photolithography and etching technique.

The MIM type nonlinear element 20 shown in FIG.
In this case, the second conductive film and the pixel electrode are made of the same ITO.
It is formed by a transparent conductive film 36 such as a film. in this case,
Since the second conductive film and the pixel electrode can be formed in the same step, the manufacturing process can be further simplified.

[0060]

The present invention will be described in more detail with reference to specific examples and comparative examples of the present invention.

Example 1 A 200 nm-thick tantalum film was deposited on a glass substrate by a sputtering method to form a first conductive film. Then, using a 10% by weight solution of ammonium salicylate in ethylene glycol as a chemical conversion solution, a constant current electrolysis was performed at a current density of 0.1 mA / cm ² until the voltage reached 30 V, and then a constant voltage electrolysis was performed at a voltage of 30 V for about 2 hours. And anodizing the tantalum film. As a result, a tantalum oxide film having a thickness of about 50 nm was formed. When the electric conductivity of the chemical conversion solution was measured using an electric conductivity meter, it was 2.74 m
S / cm.

Further, at 400 ° C. in a nitrogen atmosphere,
Heat treatment to stabilize the anodic oxide film (insulating film), and then deposit chromium to a thickness of 150 nm on the insulating film by a sputtering method to form a second conductive film.
An M-type nonlinear element was manufactured.

The capacitance of the MIM type nonlinear element having the pattern of 4 μm square prepared by the above method was 51 fF. The measurement of the capacitance was performed using the above-described MIM of 4 μm square.
1000 non-linear elements are connected in parallel and the frequency is 10
This was performed by applying an alternating current of kHz. The thickness of the insulating film was measured with an ellipsometer.
It was 8.3 nm. Then, the relative dielectric constant of the insulating film was calculated from the obtained capacitance and thickness to be 17.5.

FIG. 5 shows the result of measuring the current-voltage characteristics of the MIM type nonlinear element and plotting the average value.
It was shown to. The nonlinear coefficient (β value) representing the steepness was calculated from the slope of this curve to be 6.1.

Further, in order to examine the uniformity of the device, the maximum value of the logarithm of the current value (unit: A) flowing when a voltage of 10 V was applied to five MIM type nonlinear devices manufactured on the same substrate was calculated. The difference between the minimum values (hereinafter, this value is referred to as “r value”) was 0.24. The evaluation of the r value is performed in the following three stages.

◎ 0.5 or less ○ 0.5 to 1 × 1 or more Electric conductivity of chemical conversion liquid, relative dielectric constant of insulating film, β value and r
The values are shown in Table 1.

Further, when a liquid crystal display panel was manufactured using the MIM type nonlinear element manufactured by the above method,
A contrast of 100 or more could be obtained in a temperature range of 0 to 80 ° C, and no display unevenness was observed.

(Comparative Example 1) An MIM type nonlinear element was manufactured in the same manner as in Example 1 except that an ethylene glycol solution of 2% by weight of citric acid was used instead of the chemical conversion solution in Example 1. Example 1 of this MIM type nonlinear element
Similarly, the electrical conductivity of the chemical conversion solution, the relative dielectric constant of the insulating film, β
Values and r values were determined. The results are shown in Table 1.

(Examples 2 to 7, Comparative Example 2) Except that the following chemical conversion liquid was used instead of the chemical conversion liquid in Example 1,
A MIM type nonlinear element was manufactured in the same manner as in Example 1.
That is, in Example 2, 9% by weight of the chemical conversion solution was used.
In Example 3, a 10% by weight ethylene glycol solution of diammonium malonate was used as a chemical conversion solution in Example 3, and in Example 4, 10% by weight ammonium salicylate was used as a chemical conversion solution. The γ-butyrolactone solution was prepared in Example 5
In Example 6, a 10% by weight solution of ammonium nitrate in ethylene glycol was used as a chemical conversion solution. In Example 6,
Comparative Example 2 A 10% by weight solution of tetraethylammonium vanadate in ethylene glycol was used as a chemical conversion solution.
In the above, a 2% by weight solution of diammonium tartrate in ethylene glycol was used as a chemical conversion solution.

Further, with respect to the obtained MIM type nonlinear element, the electric conductivity of the chemical conversion liquid, the relative dielectric constant of the insulating film, the β value and the r value were obtained in the same manner as in Example 1. Table 1 shows the results.
It was shown to.

[0071]

[Table 1] As is clear from Table 1, according to the example of the present invention, it was confirmed that the dielectric constant of the insulating film was small and the β value indicating the steepness of the current-voltage characteristics was sufficiently large. Furthermore, according to the example of the present invention, it was confirmed that since the electric conductivity of the chemical conversion solution was large, a small r value, that is, a uniform oxide film was obtained. On the other hand, in the comparative example, the relative dielectric constant of the insulating film is small and the β value is sufficiently large, but the variation of the current-voltage characteristics is large, and the unevenness is so large that the r value is large and cannot be measured. Only a proper oxide film was obtained. Further, in the element of the comparative example, when a voltage used for normal driving was applied, the element was sometimes short-circuited and destroyed.

[0072]

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of a liquid crystal display panel to which an MIM type nonlinear element of the present invention is applied.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a sectional view showing another configuration example of the MIM type nonlinear element of the present invention.

FIG. 4 is a diagram showing an equivalent circuit of the liquid crystal display panel of the present invention.

FIG. 5 is a perspective view showing a liquid crystal display panel of the present invention.

FIG. 6 is a diagram illustrating a relationship between an applied voltage and a current value of the MIM type nonlinear element according to the example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Liquid crystal display panel 12 Scan line 14 Data line 16 Pixel area 20 MIM type nonlinear element 22 First conductive film 24 Insulating film 26 Second conductive film 30 First substrate 32 Second substrate 34 Pixel electrode 40 Liquid crystal display element Reference Signs List 100 scanning signal driving circuit 110 data signal driving circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takumi Seki 3-3-5 Yamato, Suwa City, Nagano Prefecture Inside Seiko Epson Corporation (72) Inventor Makoto Ue 8-3-1 Chuo, Ami-cho, Inashiki-gun, Ibaraki Prefecture Inside the Tsukuba Research Laboratory, Mitsubishi Chemical Corporation (72) Bunichi Mizutani 8-3-1 Chuo, Ami-cho, Inashiki-gun, Ibaraki Prefecture Inside the Tsukuba Research Laboratory Mitsubishi Chemical Corporation (72) Sachie Takeuchi, Ami-cho, Inashiki-gun, Ibaraki Prefecture 8-3-1, Inside Tsukuba Research Laboratory, Mitsubishi Chemical Corporation

Claims (11)

[Claims] 1. A non-aqueous chemical liquid for producing a two-terminal nonlinear element, comprising an organic solvent and a solute, and having an electric conductivity of 1 ms / cm or more and 100 ms / cm or less. 2. The non-aqueous chemical liquid according to claim 1, wherein the solute comprises at least one of a carboxylate and an inorganic oxo acid salt. 3. The two-terminal terminal according to claim 2, wherein the carboxylate is a salt of at least one carboxylic acid selected from the group consisting of an aromatic monocarboxylic acid and an aliphatic dicarboxylic acid having no hydroxyl group. Non-aqueous chemical liquid for the production of non-linear elements. 4. The method according to claim 3, wherein the carboxylate is a salicylate, a resorcylate,
A non-aqueous chemical liquid for producing a two-terminal nonlinear element, which is at least one member selected from the group consisting of benzoate, malonate, maleate and adipate. 5. The non-aqueous inorganic oxoacid salt according to claim 2, wherein a central atom of the oxo acid is an atom belonging to Group 3 to Group 7. Chemical conversion liquid. 6. The method according to claim 5, wherein the inorganic oxo acid salt is a nitrate, a vanadate, a phosphate, a chromate, a tungstate, a molybdate,
A non-aqueous chemical liquid for producing a two-terminal nonlinear element, which is at least one selected from the group consisting of silicates, perrhenates and sulfates. 7. The non-aqueous chemical liquid according to claim 6, wherein the inorganic oxo acid salt is an ammonium ammonium nitrate or an alkyl ammonium salt of vanadic acid. 8. The method according to claim 1, wherein the organic solvent comprises at least one of ethylene glycol and γ-butyrolactone.
Non-aqueous chemical liquid for manufacturing terminal type non-linear elements. 9. The method according to claim 1, wherein (a) a step of forming a first conductive film made of tantalum or a tantalum alloy on the substrate; and (b) forming the first conductive film on the substrate. (C) forming an insulating film on the surface of the first conductive film by anodizing in the non-aqueous chemical conversion solution described above, and (c) forming a second conductive film on the surface of the insulating film. A method for manufacturing a two-terminal nonlinear element, characterized by comprising: 10. A two-terminal non-linear element manufactured by the manufacturing method according to claim 9. 11. A two-terminal nonlinear element according to claim 10, wherein the substrate is a transparent substrate, one of the signal lines arranged on the substrate in a predetermined pattern, and the signal terminal is connected to the signal line at a predetermined pitch. A first substrate having a pixel electrode connected to the two-terminal nonlinear element, a second substrate having the other signal line at a position facing the pixel electrode, the first substrate and the first A liquid crystal layer sealed between the first and second substrates.