JPH11282383A - Electrode substrate and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode substrate on which a conducting film having excellent optical characteristics (transmission, reflectivity), low electrical connection resistance, good patternability, and high reliability is formed. SOLUTION: In an electrode substrate 9 for a display device, having a substrate and a multilayered conducting film, the multilayered conducting film has a lower amorphous oxide layer 2 made of an amorphous or quasi-amorphous oxide inhibiting the migration of silver at an interface to a silver thin film, the silver thin film 3, and an upper amorphous oxide layer 4 made of an amorphous or quasi-amorphous oxide inhibiting the migration of silver at the interface to the silver thin film 3, the film thickness of at least the upper amorphous oxide layer 4 being 20 nm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode substrate for a display device used for a liquid crystal display device or EL (electroluminescence), a transparent electrode or a reflective electrode for a solar cell, an electromagnetic wave shielding film, or an antireflection film. Applicable to an electrode substrate in which an electrode composed of a multilayered conductive film sandwiching a silver-based thin film with an oxide is disposed on the substrate,
In particular, it relates to an electrode substrate having a highly reliable and high-performance conductive film having high moisture resistance, low electrical connection resistance, and adjusting the thickness of the silver-based thin film while keeping the structure of the conductive film almost the same. Accordingly, the present invention relates to an electrode substrate having a conductive film having a wide application range that can be of a transmission type or a reflection type.

[0002]

2. Description of the Related Art An electrode plate provided with a transparent conductive film having a predetermined electrode shape and transmitting light on a glass substrate, a plastic substrate, or a substrate on which a semiconductor element is formed is used for various types of liquid crystal displays and the like. It is widely used as a display electrode of a display device, an input / output electrode capable of directly inputting from a display screen of the display device, and the like.

FIG. 4 is a sectional explanatory view showing an example of a transparent electrode plate 41 used for a liquid crystal display device. As shown in FIG. 4, the transparent electrode plate 41 includes at least a glass substrate 40,
The transmitted light for each pixel provided in the pixel portion on the glass substrate 40 is, for example, R (red), G (green), and B (blue).
A color filter 42 layer for coloring each color, a light-shielding film 47 provided at a portion (inter-pixel portion) between the pixels on the glass substrate 40 and preventing light transmission from the inter-pixel portion, A main part of a protective layer 45 provided on the entire surface of the color filter 42 layer, a transparent electrode 43 formed on the protective layer 45, and an alignment film 44 formed on the transparent electrode 43 It is configured.

[0004] The transparent electrode 43 is formed of a transparent conductive film which is formed by sputtering and then etched into a predetermined pattern.
As this transparent conductive film, an ITO thin film obtained by adding tin oxide to indium oxide is widely used, paying attention to its high conductivity. The specific resistance of the ITO thin film is about 2.
It is about 4 × 10 ⁻⁴ Ω · cm, and in the case of a film thickness of about 240 nm normally used as a transparent electrode, the sheet resistance is about 10 Ω / □.

[0005] In addition to the transparent conductive film,
A thin film formed by adding antimony oxide to tin oxide, a thin film formed by adding antimony oxide to tin oxide, and a thin film formed by adding aluminum oxide to zinc oxide are known. However, these are not widely used because they are inferior in conductivity to the above-mentioned ITO thin film, and have insufficient chemical resistance or water resistance against acids and alkalis.

On the other hand, at the seventh ICVM held in Japan in 1982, a three-layered transparent structure in which an ITO thin film or an indium oxide thin film (IO thin film) is laminated on the front and back surfaces of a silver thin film as a heat ray reflective film. Conductive films have been proposed. The transparent conductive film having the three-layer structure has a low sheet resistivity of about 5 Ω / □, and is expected to be applied to the transparent electrode by utilizing its high conductivity.

A liquid crystal display device is generally a transmissive liquid crystal display device having a light source (lamp) as a backlight. However, these transmissive liquid crystal display devices consume a large amount of power due to a backlight lamp and have a short operating time when driven by a battery, and thus cannot fully utilize the characteristics of a liquid crystal display device that should be possessed as a portable device. There was a problem. For this reason, in recent years, the development of a reflective liquid crystal display device using external light (that is, not incorporating a backlight lamp) has been actively developed.

FIG. 5 shows an example of a schematic configuration of a reflection type liquid crystal display device 50. In the figure, the reflection type liquid crystal display device 50 includes a pair of substrates including a reflection electrode plate 51 and a transparent electrode plate 52, and a transparent electrode 505 and a transparent electrode 507.
Are opposed to each other with the liquid crystal 509 interposed therebetween.
Arranged by 0. In the reflective electrode plate 51, a reflective film 502 and a color filter 503 are sequentially laminated on a rear substrate 501 made of glass or the like, and further, protection of the color filter 503 and the color filter 503 are performed.
A protective layer 504 for flattening the surface and a transparent electrode 505 such as ITO are sequentially laminated. The color filter 503 is, for example, an R (red) color, a G (green) color.
Light-transmitting pixels (hereinafter, referred to as B (blue) colors)
Are simply formed in accordance with a predetermined pattern. In some cases, the reflective film 502 is used as a reflective electrode that also serves as an electrode for driving a liquid crystal.

Next, the transparent electrode plate 52 has a polarizing film 508 disposed on one side of a transparent substrate 511 such as a glass substrate, and a TFT (thin film transistor) 506 disposed on the other side.
The transparent electrode 507 connected to the terminal is periodically arranged.

Conventionally, an aluminum thin film has been widely used as a reflection film 502 formed on a back substrate 501 shown in FIG. This is because aluminum is a metal having a high reflectance of light in the visible region. However, in recent years, improvement in display quality of liquid crystal display devices has been demanded,
The reflectivity of aluminum thin films has not always been satisfactory. Aluminum is
There is also a problem that the reflectance is reduced when it comes into contact with a liquid crystal or a glass substrate.

For this reason, it has been proposed to use silver as a material of the reflection film. It can be said that silver has an excellent light reflectance of about 10% as compared with aluminum.

However, silver has a problem that it has a low adhesion to a substrate made of glass, plastic, or the like, and is easily peeled off from the substrate when formed on the substrate as a silver thin film. In addition, a silver thin film formed on a substrate with high-purity silver is likely to aggregate and become cloudy under the influence of heat and oxygen.
There is also a problem that light reflectance and transmittance are apt to decrease.
In addition, in the configuration where the silver thin film is exposed and comes into direct contact with the outside air,
Another disadvantage is that silver sulfide and silver oxide are formed on the surface of the silver thin film to cause discoloration. Furthermore, when a silver thin film is formed on a substrate such as a glass substrate, there is a problem that silver is clouded due to diffusion of an alkali metal from the substrate, and the reflectance and the transmittance are reduced.

As a technique for compensating the above-mentioned problems and disadvantages caused when a silver thin film is used, a technique of forming a three-layered conductive film in which a silver thin film is sandwiched between oxides (oxide layers) has been proposed. . However, in this technique, when the conductive film is processed into a predetermined pattern shape using an etchant, the conductive film is damaged by etching (particularly, damage to the interface between the silver thin film and the oxide layer), and particularly the upper oxide layer is damaged. There is a problem that the layer is easily peeled. In addition, when a transmission type transparent electrode is formed with the three-layered conductive film, the upper oxide layer (oxide layer formed on the silver thin film) is in an amorphous state in order to optimize optical characteristics. In addition, it is necessary to form the upper and lower oxide layers with a relatively large thickness of about 40 nm. That is, when the upper oxide layer is not made to be in an amorphous state and crystals or grains are present in the oxide layer, silver easily moves along the grain boundaries, and the reliability of the three-layered conductive film is greatly reduced. This is because

In order to form an amorphous film that is stable as an oxide, it is desirable to form a mixed oxide layer in which different kinds of oxides are mixed. In this case, the electrical connection resistance to this conductive film is low. It becomes undesired as a conductive film. Furthermore, since the interface between the silver thin film and the oxide layer is damaged as described above, the reliability such as moisture resistance is greatly reduced, and has not reached a practical level.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has excellent optical characteristics (transmittance and reflectivity), low electrical connection resistance, good patternability,
Another object of the present invention is to obtain an electrode substrate on which a conductive film having both high reliability is formed.

[0016]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and have reached the present invention. In the following description, the lower amorphous oxide layer is an oxide layer formed on the substrate before the formation of the silver-based thin film, and an oxide layer formed on the silver-based thin film after the formation of the silver-based thin film. The upper amorphous oxide layer or the upper oxide layer is used.

That is, the invention according to claim 1 is an electrode substrate for a display device comprising a substrate and a multilayer conductive film having a predetermined pattern shape, wherein the multilayer conductive film is formed at an interface with a silver-based thin film. A lower amorphous oxide layer made of an amorphous or amorphous-like oxide that suppresses the movement of silver, a silver-based thin film, and an amorphous material that suppresses the movement of silver at the interface between the silver-based thin film and the silver-based thin film Or an upper amorphous oxide layer made of an amorphous-like oxide, wherein at least the upper amorphous oxide layer has a thickness of 20 nm or less. Things.

Further, in the invention according to claim 2, there is provided an electrode substrate for a display device comprising a substrate and a multilayer conductive film having a predetermined pattern shape, wherein the multilayer conductive film has an interface with a silver-based thin film. A lower amorphous oxide layer made of an amorphous or amorphous-like oxide that suppresses the movement of silver in, a silver-based thin film, and an upper oxide layer, wherein the upper oxide layer is A display comprising an amorphous or amorphous upper amorphous oxide having a thickness of 20 nm or less for suppressing silver movement at an interface with a silver-based thin film, and an oxide layer. This is a device electrode substrate.

According to this structure, the upper amorphous oxide layer and the lower amorphous oxide layer have a function of suppressing the movement of silver at the interface with the silver-based thin film (in other words, a function of silver). (A role as an anchor for fixing the movement), and it is possible to suppress aggregation, white turbidity caused by silver movement under high temperature and high humidity, and a decrease in reflectance or transmittance accompanying the movement.

This point will be further described. Silver is easy to move, and when heat is applied while the surface of the silver-based thin film is exposed to air, for example, in the case of heating at about 200 ° C. to 300 ° C., silver atoms diffused and moved to the surface of the silver-based thin film Recrystallizes and grows into a large crystal mass. As a result, aggregation and cloudiness occur on the silver surface, and the reflectance or transmittance of the silver-based thin film decreases. Here, the surface of the silver-based thin film (microscopically, the surface of each fine silver crystal before recrystallization)
Here, it is assumed that several molecules of oxide nuclei are implanted by film forming means such as sputtering. In this case, the implanted oxide nucleus serves as an anchor that suppresses the movement of silver atoms, preventing the diffusion of silver atoms to the surface of the silver-based thin film, and causing silver atoms on the surface of the silver-based thin film to diffuse. This suppresses recrystallization and prevents deterioration of the optical characteristics of the silver-based thin film. That is, by implanting oxide nuclei on the surface of the silver-based thin film, it is possible to prevent the optical characteristics of the silver-based thin film from deteriorating even if a heat treatment is performed, for example, during the manufacture of a liquid crystal display device.

The arrangement of the nuclei of the oxide implanted on the surface of the silver-based thin film is the upper amorphous oxide layer and the lower amorphous oxide layer. That is, the upper amorphous oxide layer and the lower amorphous oxide layer can be said to be fixed layers that fix the movement of silver at the interface with the silver-based thin film like an anchor. Therefore, the lower amorphous oxide layer functions as a lower fixed layer, and the upper amorphous oxide layer functions as an upper fixed layer.
In addition, from the viewpoint of reliability, the fixed layer desirably has a similar electrochemical property (for example, corrosion potential) to the silver-based thin film,
In order to prevent the grain boundary diffusion of silver, it is desirable that the material is amorphous (amorphous) or amorphous-like (amorphous like). Further, the fixing layer desirably has high adhesion to the silver-based thin film.

The amorphous oxide serving as the fixed layer is desirably a transparent and highly alkali-resistant material. Considering that the amorphous oxide is processed into a predetermined pattern after film formation, an acid such as an acid used for etching may be used. Desirably, it is soluble in an etchant. When the electrode substrate for a liquid crystal display device according to the present invention is used as an electrode substrate for driving a liquid crystal, a mixed oxide containing a conductive oxide as a base material is preferable as a material for the fixed layer.

The multilayer conductive film according to the present invention has a three-layer structure in which a silver-based thin film is sandwiched between an upper amorphous oxide layer and a lower amorphous oxide layer having a function as the fixed layer. Or in order to make the multilayer conductive film have predetermined optical characteristics such as reflection and transmission, in contact with the silver-based thin film of the upper amorphous oxide layer or the lower amorphous oxide layer sandwiching the silver-based thin film. A structure in which an oxide layer (for example, a transparent oxide layer) is stacked on a surface opposite to the surface may be employed. The configuration of the multilayer conductive film may be appropriately selected depending on the use of the electrode substrate for a liquid crystal display device according to the present invention.

Next, the thicknesses of the upper amorphous oxide layer and the lower amorphous oxide layer serving as the fixed layer are as follows:
If only heat and moisture resistance is considered, even about 1 nm is sufficient to serve as a fixing layer (that is, to suppress movement of silver at the interface, that is, to function as an anchor for fixing movement of silver). It can be said that. When the thickness of the amorphous oxide layer (fixed layer) is smaller, the time required for etching performed to form the amorphous oxide layer (fixed layer) into a predetermined pattern shape can be reduced, and the thickness of the silver-based thin film can be reduced. Since the damage to the interface with the oxide is reduced, the thinner the amorphous oxide layer (fixed layer), the better. However, the film thickness 1
When the thickness is around nm, it can be said that the film is somewhat unstable in consideration of variations in the film thickness at the time of film formation, and the flow-down of the film that occurs during cleaning using an alkaline solution or the like. Therefore, it is preferable to form the amorphous oxide layer (fixed layer) with a thickness of 2 nm or more.

Here, the upper limit of the thickness of the amorphous oxide layer (fixed layer) is set at the interface between the silver-based thin film and the oxide during etching performed to form a predetermined pattern after the film formation. It can be said that it is desirable to consider the two factors of the degree of damage to be received and the optical characteristics (transmittance and reflectance). First, the degree of damage at the interface is considered.

That is, the present inventors find that it is appropriate to judge the degree of damage due to etching based on the degree of change in connection resistance under high temperature and high humidity, which is one of the great indicators of reliability. I found it. For this reason, the general conditions used in the durability test (leave in an atmosphere at a temperature of 70 ° C. to 90 ° C. and a humidity of 90% to 95% for 1000 hours)
Below, the change in connection resistance was tested by changing the thickness of the amorphous oxide layer (fixed layer) in various ways. As a result, it has been found that if the thickness of the amorphous oxide layer (fixed layer) is 20 nm or less, more preferably 10 nm or less, the connection resistance can be stabilized.

The materials of the oxide layer and the silver-based thin film,
If the thickness of the amorphous oxide layer (fixed layer) is in the range of 2 to 10 nm, depending on the surface condition of the underlying layer (for example, the substrate or the like), the oxide will not become a uniform film and It is a film having a refractive index lower than that of a bulk, including voids optically. In that case, when the electrode substrate of the present invention is of a reflection type, a high reflectance can be obtained because the refractive index of the amorphous oxide layer (fixed layer) is low.

In the multilayer conductive film formed on the electrode substrate of the present invention, the thickness of the silver-based thin film sandwiched between the amorphous oxide layers (fixed layers) is, for example, about 100 to 200 nm or larger. It becomes a practically good reflective electrode. Here, the present inventors compared the reflectance of a reflective electrode plate using a silver-based thin film with the reflectance of a conventional reflective electrode plate using an aluminum thin film from the viewpoint of optical characteristics. As described above, it is necessary to form an amorphous oxide layer (fixed layer) having a thickness of 20 nm or less in order to secure the heat resistance and moisture resistance of the silver-based thin film. When this film thickness is examined in terms of an optical characteristic called reflectance, the following is obtained. That is, silver can be said to be a good metal having a reflectance of about 10% higher than that of aluminum, but the reflectance on the short wavelength side decreases depending on the thickness of the fixed layer, which is an oxide, or the amount of alloying element added to silver. It is easy to do.

The reflectance of aluminum at 430 nm (blue wavelength) is about 85%. For this reason, the present inventors aimed at securing a higher reflectance than aluminum at a wavelength of 430 nm in the electrode substrate of the present invention. As a result of many studies, the present inventors have found that the optical film thickness of the amorphous oxide layer (fixed layer) is determined by the value of the optical film thickness which is the product of the film thickness (unit: nm) and the refractive index. It has been found that when the thickness is 20 nm or less, a reflectance of 85% or more can be almost secured at a wavelength of 430 nm. That is, the invention according to claim 3 is characterized in that the upper amorphous oxide layer is an oxide layer in which the value of the optical film thickness, which is the product of the film thickness and the refractive index, is 20 nm or less. This is an electrode substrate for a display device. According to such a configuration, when the electrode plate is of a reflection type, the refractive index of the upper amorphous oxide layer (the upper fixed layer) can be reduced, and the reflectance can be improved. .

Next, the multilayer conductive film formed on the electrode substrate of the present invention is formed by forming the thickness of the silver-based thin film sandwiched between the amorphous oxide layers (fixed layers) to, for example, about 7 to 25 nm. It becomes a practically good transparent electrode. However, when the thickness of the amorphous oxide layer (fixed layer) sandwiching the silver-based thin film is 20 nm or less, the reflection component of light from the silver-based thin film becomes strong, and a sufficient transmittance cannot be secured. In a three-layer conductive film sandwiching a silver-based thin film with oxides having a refractive index of about 2,
Unless the oxide film thickness is set to about 40 to 45 nm, it is difficult to secure a high transmittance. Therefore, when the electrode substrate according to the present invention is used as a transmission type, it is desirable that an oxide layer is laminated on the fixed layer to have predetermined optical characteristics (for example, transmittance).

The present inventors have proposed an electrode substrate in which the thickness and refractive index of such general constituent members are optimized and used.

That is, the invention according to claim 4 includes a protective layer on the upper amorphous oxide layer or the upper oxide layer in which the upper amorphous oxide layer and the oxide layer are stacked, An electrode substrate for a display device, wherein the total optical film thickness of the upper amorphous oxide layer or the upper oxide layer and the protective layer is 70 nm or more. According to such a configuration, when the electrode plate is of a transmission type, the transmittance of the electrode plate can be improved.

Further, the present inventors have proposed a case where the electrode substrate for a display device of the present invention is of a transmissive type and a silver-based thin film is sandwiched between multilayer oxide layers in which oxide layers having different refractive indices are stacked. It has been found that it is difficult to increase the transmittance of the electrode substrate unless the refractive index of the oxide layer in contact with the silver-based thin film is increased.

That is, the invention according to claim 5 is characterized in that the protective layer is an oxide layer having a refractive index equal to or lower than that of the upper amorphous oxide layer. This is an electrode substrate for a display device. Also,
The invention according to claim 6 is characterized in that the lower amorphous oxide layer is equal to the lower amorphous oxide layer, or the lower amorphous oxide layer is made of an oxide having a lower refractive index than the lower amorphous oxide layer. An electrode substrate for a display device characterized by having a structure including a layer. According to such a configuration, when the display device electrode substrate is of a transmission type, the refractive indexes of the upper amorphous oxide layer and the lower amorphous oxide layer are increased, and as a result, the electrode substrate Can be improved.

Here, as the material of the protective layer, chemical resistance,
By using a material having excellent heat resistance, light resistance, and the like, a highly reliable electrode substrate can be provided. When the material of the substrate is soda glass, the undercoat layer serves as an alkali barrier layer for preventing diffusion of alkali metal from the substrate. When the adhesion between the substrate and the lower amorphous oxide layer is low, the undercoat layer also functions as an adhesive layer.

In a conventional conductive film having a three-layer structure in which a silver-based thin film is sandwiched between oxides, an alloying element exceeding 3 at% (atomic percent) is added to silver in order to stabilize easily movable silver. As a result, the conductivity has been reduced. However, in the present invention, since the silver-based thin film is sandwiched between the fixed layers, the movement of silver is reduced, and even if the amount of alloying elements added to silver is reduced, the production process such as photolithography is stable. After flowing the substrate and forming the pattern, the protective layer can be formed. That is, in the electrode substrate of the present invention, the amount of the alloying element added to silver can be minimized, and as a result, the performance of the conductive film can be further improved.

That is, in the invention according to claim 7, in the silver-based thin film, silver and at least one metal selected from platinum, palladium, gold, copper, and nickel are added in an amount of 3 at% (atomic percent) or less. An electrode substrate for a display device, comprising a silver alloy.

As described above, in the present invention, the silver-based thin film is sandwiched between the amorphous oxide layers (fixed layers), and the thickness of at least the upper amorphous oxide layer is set to 20 nm or less. When a conductive film is formed into a predetermined electrode shape, a photolithography process can be flowed, so that etching can be easily performed, and an interface between the amorphous oxide layer (fixed layer) and the silver-based thin film can be formed. Pattern processing can be performed with high accuracy without causing damage to the site due to etching.

Accordingly, the invention according to claim 8 provides a multilayer structure in which a silver-based thin film is sandwiched between a substrate and an amorphous oxide layer made of an amorphous or amorphous-like oxide which suppresses silver movement. In a method of manufacturing an electrode substrate for a display device having a conductive film having a structure, at least a lower amorphous oxide layer, a silver-based thin film, and an upper amorphous oxide layer having a thickness of 20 nm or less are formed by stacking at least. A process for forming an electrode by patterning after forming, and a step of laminating and depositing a protective layer having a thickness adjusted so as to have optimal optical characteristics as an electrode on the electrode. This is a method for manufacturing an electrode substrate.

Here, when the display device is constructed, if the electrode substrate of the present invention and the opposing substrate are electrically short-circuited, normal operation is not performed. For this reason, in order to prevent an electrical short circuit between the electrode substrate of the present invention and the opposing substrate, and to eliminate the above-mentioned operation of the display device, it is desirable that the protective layer has electrical insulation. However, each of the formed electrode patterns needs to be electrically connected to the outside, but when forming the protection layer on the electrode substrate, the protection layer is formed up to the electrode pattern portion where the external connection is made. Then, since electrical connection cannot be made, it is preferable that a protective layer is not formed at an electrode pattern portion that requires electrical connection with the outside. Therefore, the invention according to claim 9 is
An electrode substrate for a display device, wherein the protective layer is an electrically insulating material, and a protective layer is laminated on the electrode with a thickness sufficient for protection except for a portion where the electrode is electrically connected. This is a method of manufacturing.

According to a tenth aspect of the present invention, the pattern processing means for forming the multilayer conductive film into a predetermined electrode pattern is a photolithography method using a photoresist, and the electrode is formed by a photolithography process. When the photoresist is removed after the pattern is formed, the resist at the electrode portion for making electrical connection is left, and this is used as a mask when depositing the protective layer, and then the resist is removed to remove the electric current. 12. A method of manufacturing an electrode substrate for a display device, wherein electrode portions for making electrical connections are exposed from a protective layer. The invention according to claim 11, wherein the multilayer conductive film is formed by a predetermined electrode pattern. Wherein the pattern processing means is a mask sputtering method.

With such a configuration, if the method of selectively forming the protective layer on the electrode substrate is a photographic method using a photoresist, it is possible to form a protective layer having a highly accurate pattern shape. A manufacturing method suitable for a high-definition device such as a liquid crystal display device can be used.If the mask sputtering method is used, a protective layer can be easily formed with a slightly lower accuracy than the photolithography method. And a manufacturing method suitable for a relatively coarse pattern such as a solar cell.

Next, the substrate used for the electrode substrate for a display device of the present invention does not need to be transparent, and may be a substrate colored white, black, or other colors depending on the use of the display device. I do not care. Further, the substrate itself may be a substrate on which an electric circuit is formed, a silicon wafer substrate on which a solar cell is formed, or a heat-resistant organic film, such as amorphous silicon, polysilicon, or M
A substrate on which a semiconductor element such as an IM (diode element) is formed may be used.

Further, a polarizing element, a diffraction grating, a hologram, a light scattering film, a λ / 4 wavelength plate, a retardation film, a micro lens, a color filter, or the like is directly or indirectly provided on the electrode substrate for a display device of the present invention. May be formed.

Since the conductive film according to the present invention has a low resistance, it can be used for signal lines and bus lines of elements such as TFTs (thin film transistors) and MIMs, and can be used simultaneously with these and pixel electrodes.

The amorphous oxide layer (fixed layer), the upper oxide layer, and the lower oxide layer constituting the present invention are desirably made of a transparent and alkali-resistant material. When processing into a predetermined pattern by
It must be soluble in an etchant such as an acid used for etching. Furthermore, the desired optical properties of the oxide, especially the refractive index, differ depending on whether the electrode formed on the electrode substrate of the present invention is of a reflection type or a transmission type. That is, in the case of the reflection type, the refractive index of the upper amorphous oxide layer (the upper fixed layer) is preferably lower in order to obtain a high reflectance of the electrode. In the case of a transmission type, an upper amorphous oxide layer (an upper fixed layer),
The higher the refractive index of the transparent oxide layer formed on the upper amorphous oxide layer and the lower amorphous oxide layer (the lower fixed layer), the higher the transmittance of the electrode. Can be secured.

The undercoat layer may be selected from a material having good adhesion between the substrate and the lower amorphous oxide layer (lower fixed layer), for example, SiO ₂ or the like. When soda glass is used as the substrate, the undercoat layer or the lower amorphous oxide layer (the lower fixed layer) may also serve as an alkali barrier layer.

Next, the protective layer is desirably selected from materials having high resistance (durability) having chemical resistance, insulation resistance, and the like. In addition to oxides, nitrides, organic resins, and fluororesins are used. , A Teflon resin, a silicone resin, or the like, or a coating film in which a transparent pigment is mixed therewith may be used. Further, an antireflection film or a water-repellent layer may be laminated on the protective layer.

When the electrode substrate of the present invention is used for a solar cell (in this case, a semiconductor element such as amorphous silicon is formed on the substrate), in order to ensure high reliability (high durability). Alternatively, a sufficiently thick protective layer may be formed. Furthermore, generally called an overcoat,
The protective layer may be formed by a sol-gel method used for forming a layer formed on a liquid crystal substrate. Further, the protective layer is made of a ferroelectric liquid crystal, an antiferroelectric liquid crystal, or TF.
When a high dielectric constant is preferable for driving the liquid crystal, such as T, a material having a high dielectric constant may be used.

Next, the electrode plate according to the present invention is used for liquid crystal display.
When used in equipment, etc., the material of the oxide layer that constitutes the multilayer film
The following materials can be used from the viewpoint of refractive index and conductivity.
Noh. In other words, if you want a low refractive index oxide,
For example, SiO_Two, MgO, Al _TwoO_Three, GeO_Two, B
i_TwoO_ThreeAnd oxides of light elements. Also high bending
If you want to make the oxide of the fold rate_Two, CeO_Two, Zr
O_Two, HfO_Two, Nb_TwoO_Five, Ta_TwoO_FiveEtc. can be used
It is. When considering conductivity, use conductive oxide.
In_TwoO_Three, SnO_Two, ZnO and the like. Ma
Adjust the number of added oxides or oxygen other than the above
Mixed acid obtained by selecting and mixing two or more of the above oxides and the like
The upper amorphous oxide layer (upper fixed layer) or upper
Oxide layer, lower amorphous oxide layer (lower fixed layer)
May be used.

If a mixed oxide based on In ₂ O ₃ and ZnO is used, the etching process can be easily performed. Also, by adding a small amount of an oxide easily soluble in an acid such as ZnO or MgO to the mixed oxide and bringing the oxidation-reduction potential of the mixed oxide closer to the silver-based thin film, the shape of the electrode pattern formed on the electrode substrate of the present invention can be improved. Also, it is possible to further improve the reliability of the electrodes.

Further, from the viewpoint of the refractive index, a high-refractive-index layer may be inserted at the center in the thickness direction of the silver-based thin film used for the electrode substrate of the present invention. In the case of a transmission-type conductive film, a conductive film having a lower reflectance can be obtained by inserting a layer having a high refractive index between silver-based thin films. At this time, the transmittance may be improved.

The electrode substrate of the present invention can be further improved in reliability by performing a heat treatment (a so-called annealing treatment) after forming the conductive film or after forming a predetermined pattern by etching. is there.

[0054]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. (Example 1) FIG.
1 shows a schematic configuration diagram of an electrode substrate according to the first embodiment. In FIG. 1, the electrode substrate 9 according to the first embodiment includes:
0.7 mm thick glass substrate 10 (Corning Co., 1
737 materials) and sequentially laminated on the glass substrate 10.
An undercoat layer 1 having a thickness of 29 nm, a lower amorphous oxide layer 2 having a thickness of 10 nm (lower fixed layer), a silver-based thin film 3 having a thickness of 15 nm, and an upper amorphous oxide layer 4 having a thickness of 10 nm The main part is composed of the fixed layer) and the protective layer 5 having a thickness of 29 nm. The electrode substrate 9 according to the first embodiment is a light transmission type electrode substrate since the thickness of the silver-based thin film 3 is 15 nm (within a range of about 7 to 25 nm).

The electrode substrate 9 according to the first embodiment is manufactured by the following manufacturing process. That is, first, the washed glass substrate 10 was housed in a vacuum chamber (sputtering apparatus) and evacuated. Next, the undercoat layer 1 is formed by sputtering. Next, the glass substrate 10 is taken out from the vacuum chamber (sputtering apparatus), and is heated at 300 ° C. for 1 hour to perform an annealing process. Next, the glass substrate 10 is housed in a vacuum chamber (sputtering apparatus) and evacuated. Next, the lower amorphous oxide layer 2, the silver-based thin film 3, and the upper amorphous oxide layer 4 were successively laminated by sputtering. Next, the glass substrate 10 is taken out of the vacuum chamber (sputtering apparatus), and a resist pattern having a predetermined shape pattern (for example, a stripe pattern in plan view) is formed on the upper amorphous oxide layer 4 by photolithography. Formed. Next, a sulfuric acid-based etchant containing 1% by weight of nitric acid and iron nitrate is used as an etchant, and the lower amorphous oxide layer 2, the silver-based thin film 3, and the upper amorphous oxide are exposed at positions exposed from the resist pattern. The three material layers 4 were simultaneously removed by etching. Next, re-exposure is performed on the resist pattern portion corresponding to the display surface 16 shown in FIG. 1 (at this time, no exposure is performed on the terminal portion 17).
The resist pattern at the site was removed with an organic alkaline solution.

Next, the protective layer 5 was formed on the entire surface of the glass substrate 10 using a vacuum chamber (sputtering apparatus). Then, after exposing the substrate again, the resist pattern at the terminal portion 17 is removed with an organic alkali solution, and then an annealing process (heating process) of heating the substrate at 200 ° C. for 1 hour is performed. Thus, an electrode substrate 9 of Example 1 was obtained.

By the above-described manufacturing process, the terminal portion 17 is formed.
In the portion, electrical connection with the outside can be obtained with a low connection resistance with the silver-based thin film 3 through the thin upper amorphous oxide layer 4. Further, the protective layer 5 on the display surface 16 becomes a good insulating protective layer. (In a liquid crystal display device such as STN, the protective layer 5 is a film for preventing an electric short circuit with the opposite substrate. ), It is possible to realize an electrode plate with high electrical reliability.

In the above-described manufacturing process, the undercoat layer 1 and the protective layer 5 are each formed using a sputtering target of a mixed oxide composed of tin oxide, cerium oxide, and gallium oxide. The composition of the sputtering target was 80 at% of tin (at%), 10 at% of cerium (at%), and 10 at% of gallium (at%) in terms of atomic percentage in terms of metal atoms (oxygen atoms are no count).

Next, a sputtering target of a mixed oxide composed of indium oxide, cerium oxide, tin oxide and titanium oxide is used for forming the lower amorphous oxide layer 2 and the upper amorphous oxide layer 4. The composition is 88 atomic% of indium, 8.5 atomic% of cerium, 3.0 atomic% of tin, and 0.5 atomic% of titanium in atomic percent in terms of metal atoms (oxygen atoms are no count).
at%. Further, the silver alloy target used for forming the silver-based thin film 3 had a composition of 98.5 at% of silver, 1 at% of gold, and 0.5 at% of copper.

The present inventors have made the same material as the above-mentioned protective layer 5 (or undercoating layer 1) and lower amorphous oxide layer 2 (or upper amorphous oxide layer 4), respectively. Thickness 10
A 0 nm film was formed, and the refractive index of the film was measured. As a result, at a wavelength of 550 nm, the refractive index of the former was 2.06 and the refractive index of the latter was 2.10.

On the other hand, the optical thickness of the protective layer 5 (or undercoat layer 1) having a thickness of 29 nm and the upper amorphous oxide layer 4 (or lower amorphous oxide layer 2) having a thickness of 10 nm. The optical film thickness obtained by summing the optical film thicknesses of (29 × 2.06 + 1)
0 × 2.10) = (59.74 + 21.0) = 80.7
It was 4. Under these optical characteristics, the transmittance of the electrode substrate 9 at a wavelength of 550 nm is as high as 96% at the display surface 16 portion where the protective layer 5 is formed (the glass substrate 10 alone is used as a reference). The rate was confirmed.

Therefore, each of the undercoat layer 1, the protective layer 5, the lower amorphous oxide layer 2, and the upper amorphous oxide layer 4 has the above-described material, and the composition and thickness of the material. By doing so, the above-mentioned refractive index and optical film thickness are obtained, and as a result, an electrode substrate having high transmittance can be realized. The silver-based thin film 3
The lower amorphous oxide layer 2 and the upper amorphous oxide layer 4 sandwiching are both amorphous, and the aggregation and white turbidity caused by the movement of silver at the interface with the silver-based thin film 3 , Etc., the transmittance of the silver-based thin film 3 can be suppressed.

In the first embodiment, the optical film thickness of the protective layer 5 (or the undercoat layer 1) and the upper amorphous oxide layer 4 (or the lower amorphous oxide layer 2 ) Was set to 80.74 nm, but the value was
If it is 70 nm or more, the same effect can be obtained.

(Embodiment 2) FIG. 2 is a schematic structural view of an electrode substrate according to Embodiment 2. In FIG. 2, the electrode substrate 1
Reference numeral 9 denotes an undercoat layer 21 made of SiO _{2 having} a thickness of 40 nm formed on a 0.7 mm thick glass substrate 20 (manufactured by Nippon Sheet Glass Co., Ltd., H-coated product). 2
A lower amorphous oxide layer 22 (lower fixed layer) of 0 nm, a silver-based thin film 23 having a thickness of 150 nm, and an upper amorphous oxide layer 24 (upper fixed layer) having a thickness of 7 nm are laminated. It constitutes a part. In addition, the electrode substrate 19 according to the second embodiment
Indicates that the silver-based thin film has a thickness of 150 nm (100 to 200 nm).
Therefore, it is a light reflection type electrode substrate.

The electrode substrate 19 according to the second embodiment is manufactured by the following manufacturing process. That is, first, the washed glass substrate 20 was housed in a vacuum chamber (sputtering apparatus) and evacuated. Next, the undercoat layer 21 is formed by a sputtering method. Next, the glass substrate 20 is taken out from the vacuum chamber (sputtering apparatus), heated at 300 ° C. for 1 hour, and subjected to an annealing treatment.

Next, the glass substrate 20 is housed in a vacuum chamber (sputtering apparatus) and evacuated. Next, a lower amorphous oxide layer 22, a silver-based thin film 23, and an upper amorphous oxide layer 24 were successively deposited by sputtering. Next, the glass substrate 20 is taken out of the vacuum chamber,
A resist pattern having a predetermined shape pattern (for example, a stripe pattern in plan view) was formed on the upper amorphous oxide layer 24 by a photolithographic technique. Next, a sulfuric acid-based etchant containing 1% by weight of nitric acid and iron nitrate is used as an etchant, and the lower amorphous oxide layer 22, the silver-based thin film 23, and the upper amorphous oxide at portions exposed from the resist pattern are exposed. The three material layers 24 were simultaneously removed by etching.

Next, after the entire resist pattern was re-exposed, the resist pattern was removed with an organic alkali solution. Thereafter, an annealing process (heating process) of heating the substrate at a temperature of 200 ° C. for one hour was performed to obtain the electrode substrate 19 according to the second embodiment.

In the above manufacturing process, the undercoat layer 21
Is formed using a sputtering target of silicon oxide (SiO ₂ ), and the undercoat layer 21 has a function as an alkali barrier layer. Further, the lower amorphous oxide layer 22 also has a role of an adhesion layer between the undercoat layer 21 and the silver-based thin film 23.

The mixed oxide target used for forming the lower amorphous oxide layer 22 and the upper amorphous oxide layer 24 was composed of indium oxide, cerium oxide, and tin oxide. In terms of atomic percentage in terms of metal atoms (oxygen atoms are assumed to be no count), the ratio was 77 at%, cerium at 20 at%, and tin at 3 at%. Furthermore, a silver-based thin film 2
The silver alloy target used for the film formation of No. 3 was silver 98.5 at.
%, 1 at% gold, and 0.5 at% copper.

The present inventors measured the refractive index of the upper amorphous oxide layer 24 having the above-mentioned material and composition.
1.447 at a wavelength of m and 1.488 at a wavelength of 430 nm
Met. The upper amorphous oxide layer 24 has a thickness of 7 nm.
It was thin (because there was no oxide layer on top) and had a value lower than the bulk refractive index.

Further, the reflectance of the laminated film of the silver-based thin film 23 and the upper amorphous oxide layer 24 is measured by using an integrating sphere with barium sulfate as a reference.
When measured from the side, the reflectance was high at 96% at a wavelength of 550 nm and 88% at a wavelength of 430 nm. The optical thickness of the upper amorphous oxide layer 24 having a thickness of 7 nm and a refractive index of 1.447 (wavelength: 550 nm) is 7 × 1.447 =
10.129 nm. The optical thickness (the value of the product of the thickness and the refractive index) of the upper amorphous oxide layer 24 according to the second embodiment was 10.129 nm, but the optical thickness for obtaining the same effect was obtained. The threshold value of the target film thickness is considered to be 20 nm or less.

Next, in order to confirm the reliability, the electrode substrate 9 according to the first embodiment and the electrode substrate 19 according to the second embodiment were each heated to a high temperature and a high humidity of 70 ° C. and 95% humidity. The samples were stored in a bath for 1000 hours and examined for changes. As a result, the optical characteristics (transmittance or reflectance) and the adhesion of the electrode pattern did not change,
The reliability (durability) was extremely good. Therefore, according to the electrode substrate 9 and the electrode substrate 19, a durable electrode can be realized.

In order to confirm the heat resistance of the electrode substrate 9 according to the first embodiment and the electrode substrate 19 according to the second embodiment, the temperature of the electrode substrate 9 and the electrode substrate 19 was set to 2 degrees.
Heating was performed at 50 ° C. for 1 hour or at a temperature of 300 ° C. for 1 hour, and the heat resistance of the electrode substrates 9 and 19 was examined. As a result, the same change as in the durability was not observed, and it was found that the material had good heat resistance. Therefore, according to the electrode substrate 9 and the electrode substrate 19, a durable electrode can be realized.

Further, in order to confirm the alkali resistance of the electrode substrate 9 according to the first embodiment and the electrode substrate 19 according to the second embodiment, the electrode substrate 9 and the electrode substrate 19 were checked.
Are each dissolved in an aqueous alkali solution (NaOH at 40 ° C.).
(Including% by weight) for 10 minutes, and the alkali resistance was examined. No change was observed, and the electrode substrates 9 and 19 according to the present example had sufficient alkali resistance for practical use. Indicated. Therefore, according to the electrode substrate 9 and the electrode substrate 19, an electrode having alkali resistance can be realized.

The lower amorphous oxide layer 22 and the upper amorphous oxide layer 24 sandwiching the silver-based thin film 23 are both amorphous, and the movement of silver at the interface with the silver-based thin film 23. Aggregation and white turbidity due to this, and a decrease in the reflectance of the silver-based thin film 23 due to the aggregation and the like can be suppressed.

As described above, the electrode substrate according to the present embodiment (that is, the electrode substrate of the present invention) has been shown to have high reliability and high optical characteristics.

Next, the connection resistance between the electrode substrate 9 according to the first embodiment and the electrode substrate 19 according to the second embodiment was measured in consideration of electrical mounting in a liquid crystal display device such as an STN (evaluation was made). , Measured with a beryllium-copper alloy needle), which was about 0.5 to 1 Ω, which was lower than the commonly used transparent electrode (ITO). Therefore, it was found that the electrode substrate 9 according to the first embodiment and the electrode substrate 19 according to the second embodiment were also excellent in connection resistance.

(Embodiment 3) FIG. 3 is a schematic structural view of an electrode substrate according to Embodiment 3. In FIG. 3, the electrode substrate 30 according to the third embodiment is made of SiO ₂ (silicon oxide).
A layer is coated on the surface, and a laminated film 37 is formed on a soda glass substrate 31 having an alkali barrier function. The laminated film 37 is composed of a lower amorphous oxide layer 32 (lower fixed layer), a silver-based thin film 33 and an upper oxide layer 34, and the upper oxide layer 34 is an upper amorphous oxide layer. 35 (upper fixed layer) and an amorphous oxide layer 36 laminated on the upper amorphous oxide layer 35. The thickness of the lower amorphous oxide layer 32 is 25 nm, the thickness of the silver-based thin film 33 is 15 nm, and the thickness of the upper amorphous oxide layer 35 is 10 n.
m, and the thickness of the amorphous oxide layer 36 was 30 nm. Therefore, the electrode substrate 30 according to the third embodiment has a silver-based thin film 33.
Is a light-transmitting electrode substrate because its thickness is 15 nm (within a range of about 7 to 25 nm).

Here, the lower amorphous oxide layer 32 is composed mainly of cerium oxide, and is composed of at least 15 atomic% of niobium oxide in terms of at% (atomic percentage) of only metal atoms not including oxygen atoms. % Mixed oxide. Also,
The upper amorphous oxide layer 35 is a mixed oxide composed of indium oxide, cerium oxide, tin oxide and titanium oxide, and has a composition of only metal atoms excluding oxygen atoms.
At t% (atomic percent), indium oxide is 88a
t% (atomic percent), cerium oxide 8.5 at
%, Tin oxide 3.0at%, titanium oxide 0.5at
%.

The amorphous oxide layer 36 is mainly composed of cerium oxide, and is composed of at least 15 atomic% of niobium oxide at at% (atomic percent) of metal atoms not including oxygen atoms.
% Mixed oxide. The silver-based thin film 33 is formed of a silver alloy obtained by adding gold and copper to silver, and has a composition of 98.5 at% (atomic percent) of silver and 1.0 a of gold.
t% and copper 0.5 at%.

Next, the electrode substrate 30 according to the third embodiment
Was manufactured by the following manufacturing process. First, the soda glass substrate 31 was degreased, washed, and dried, and then the soda glass substrate 31 was put into a sputtering apparatus, and the inside of the apparatus was evacuated.

The degree of vacuum in the sputtering apparatus is 5 × 10
^-FourWhen the pressure reaches Pa, Ar (argon) gas and O
_Two(Oxygen) gas is introduced and gas in the sputtering device
The pressure was adjusted to 0.35 Pa. At this time,
O_Two(Oxygen) is O _Two% To 10% (for example,
If the introduced Ar gas is 100 SCCM, the introduced O_Twogas
Was adjusted to 10 SCCM).

Next, after introducing the above gas, a voltage is applied to the mixed oxide (cerium oxide and niobium oxide) target having the above composition, and the lower amorphous material is applied to the soda glass substrate 31 by RF (high frequency) sputtering. An oxide layer 32 was formed.

When the formation of the lower amorphous oxide layer 32 was completed, the discharge and gas introduction were stopped, and the inside of the sputtering apparatus was evacuated to a degree of vacuum of 5 × 10 ⁻⁴ Pa. Next, Ar gas was introduced into the sputtering apparatus, and the gas pressure was increased to 0.4.
Adjusted to Pa, and the silver alloy (silver,
A voltage was applied to a (gold, copper) target, and a silver-based thin film 33 was formed by DC (direct current) sputtering.

At the stage when the formation of the silver-based thin film 33 has been completed, discharge is performed.
And the introduction of gas are stopped, and the inside of the sputtering device is evacuated.
Degree 5 × 10^-FourIt exhausted to Pa. In sputtering equipment
Vacuum degree of 5 × 10^-FourAr (Argo)
G) Gas and O_Two(Oxygen) gas is introduced and sputtered
The gas pressure in the fueling apparatus was adjusted to 0.35 Pa. This and
And O in the introduced gas_Two(Oxygen) is O _Two%
At 0.75% (for example, 100 SCCM of Ar gas introduced)
On the other hand, introduction O_TwoGas is 0.75 SCCM)
Was adjusted as follows.

Next, after introducing the above gas, a voltage is applied to the mixed oxide (indium oxide and cerium oxide) target having the above composition, and the upper amorphous layer 33 is formed on the silver-based thin film 33 by DC (direct current) sputtering. An oxide layer 35 was formed.

Next, the soda glass substrate 31 was unloaded from the sputtering apparatus, and the soda glass substrate 31 was subjected to the following photolithography process. First, a photosensitive resin (positive resist) was applied to a thickness of 1 μm on a soda glass substrate 31 by a spin coater, and then dried in an oven at 90 ° C. for 20 minutes. Next, using a photomask for exposure having a predetermined pattern (for example, a stripe pattern in plan view), pattern exposure is performed on the photosensitive resin with an exposure apparatus, and then an alkali developer (potassium hydroxide 10 % By weight). This allows
The photosensitive resin portion exposed to the pattern exposure was dissolved, and the photosensitive resin was left at a predetermined portion. Next, drying was performed again in an oven at 90 ° C. for 20 minutes.

Next, the soda glass substrate 31 is immersed in an etching solution at a liquid temperature of 40 ° C. for about 30 seconds using an etching solution in which sulfuric acid, nitric acid and acetic acid are mixed, and the laminated film portion exposed from the photosensitive resin is removed. Etched. Although the lower amorphous oxide layer 32 was not etched during the etching and remained in a film-like state at the time of film formation, the lower amorphous oxide layer 32 having the above composition has a conductive property. Therefore, even if it remains in the form of a film, it does not cause an electrical short circuit in the electrode pattern. After the entire substrate was irradiated with light after etching, the photosensitive resin pattern was stripped using an alkali stripping solution (1% by weight of potassium hydroxide).

Next, after the soda glass substrate 31 is put into the sputtering apparatus again, the inside of the apparatus is evacuated, and a voltage is applied to the mixed oxide (cerium oxide and niobium oxide) target having the above composition, and RF ( Amorphous oxide layer 3 on soda glass substrate 31 by (high frequency) sputtering
6 was formed. Note that the atmosphere in the sputtering apparatus at this time was the same as that at the time of forming the lower amorphous oxide layer 32 described above (that is, the gas pressure of the mixed gas of Ar and O ₂ was 0.35 Pa, ₂ % was 10%). Next, after forming the amorphous oxide layer 36, the soda glass substrate 31 carried out from the sputtering apparatus was placed at 180 ° C.
Drying was performed for one hour to obtain the electrode substrate 30 shown in FIG. Note that, during the above-described sputtering film formation, the substrate was not heated, and the film formation was continuously performed while maintaining the vacuum.

The transmittance of the electrode substrate 30 obtained in Example 3 is as high as 70% or more at a wavelength in the visible region (400 to 700 nm), and the sheet resistance is 2.7 Ω / □.
And low resistance. Therefore, the electrode substrate 30 according to the third embodiment can realize an electrode substrate having high transmittance and low resistance. Further, since both the lower amorphous oxide layer 32 and the upper amorphous oxide layer 35 sandwiching the silver-based thin film 33 are amorphous, the movement of silver at the interface with the silver-based thin film 33 is a cause. Aggregation, white turbidity, and accompanying silver-based thin film 3
3 can be suppressed from decreasing. The amorphous oxide layer 36 is assumed to be amorphous in the third embodiment. However, since the oxide layer fulfills the function of protecting the silver-based thin film by improving the transmittance by adjusting the refractive index, it is not limited to amorphous as long as it has the same function. Absent. Note that the amorphous oxide layer 36 according to the third embodiment has no conductivity and has a role of a protective layer. Further, the laminated film 37 obtained in Example 3 is formed as a transparent electrode, and the side etching at the time of etching is suppressed to be small.

[0091]

As described above, according to the present invention, a transmissive electrode substrate having a high transmittance and a reflective electrode substrate having a high reflectivity can be provided with high reliability. It becomes possible. Further, in the present invention, it is possible to provide an electrode substrate having a small change in optical characteristics, a low connection resistance in electrical connection, and a good patterning property at a practical level.

In the present invention, since the amorphous oxide layer (fixed layer) for suppressing the movement of silver is formed extremely thin, the heat resistance of the electrode substrate can be ensured and the production of the electrode substrate can be improved. High precision pattern processing is possible. Note that when the amorphous oxide layer (fixed layer) is formed thick, the pattern shape deteriorates during etching. Further, in the present invention, since a protective layer having a function as an insulating film can be laminated on the electrode in a form that optimizes the optical characteristics, it is called an overcoat required for a conventional electrode substrate. This has the advantage that the formation process of the insulating film can be omitted, and the manufacturing process can be simplified.

The amorphous oxide layer (fixed layer) formed on the electrode substrate of the present invention, which suppresses the movement of silver, has a very small thickness of 20 nm or less, more preferably 2 to 10 nm. With this fixing layer, the electrode substrate has temperature and heat resistance up to around 300 ° C. Further, in a normal silver thin film, silver sulfide or silver oxide is formed on the surface, and the reflectance or transmittance is reduced, but in the present invention, the discoloration of the silver-based thin film due to aging changes. Does not occur,
An electrode substrate with high stability and high quality can be provided.

[0094]

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing a main part of an embodiment of an electrode substrate according to the present invention.

FIG. 2 is an explanatory sectional view showing a main part of another embodiment of the electrode substrate according to the present invention.

FIG. 3 is an explanatory sectional view showing a main part of another embodiment of the electrode substrate according to the present invention.

FIG. 4 is an explanatory cross-sectional view illustrating an example of a transparent electrode plate used for a liquid crystal display device.

FIG. 5 is an explanatory cross-sectional view showing a main part of an example of a reflection type liquid crystal display device.

[Explanation of symbols]

 1, 21 Undercoat layer 2, 22, 32 Lower amorphous oxide layer 3, 23, 33 Silver-based thin film 4, 24, 35 Upper amorphous oxide layer 5 Protective layer 9, 19, 30 Electrode substrate 10 , 20, 31 Substrate 16 Display surface 17 Terminal portion 34 Upper oxide layer 36 Oxide layer 37 Laminated film 40 Substrate 41, 51, 52 Electrode plate 42, 503 Color filter 43 Transparent electrode 44 Alignment film 45, 504 Protective layer 47 Light shielding Film 50 Liquid crystal display device 501 Back substrate 502 Reflective film 505, 507 Transparent electrode 506 TFT 508 Polarizing film 509 Liquid crystal 510 Sealant 511 Substrate

Claims (11)

[Claims] 1. An electrode substrate for a display device comprising a substrate and a multilayer conductive film having a predetermined pattern shape, wherein the multilayer conductive film is an amorphous substrate for suppressing movement of silver at an interface with a silver-based thin film. Amorphous or amorphous-like oxide that suppresses the movement of silver at the interface between the lower amorphous oxide layer composed of a crystalline or amorphous-like oxide, a silver-based thin film, and an interface between the silver-based thin film and the silver-based thin film And an upper amorphous oxide layer comprising: an upper amorphous oxide layer, wherein at least the upper amorphous oxide layer has a thickness of 20 nm or less. 2. An electrode substrate for a display device, comprising: a substrate; and a multilayer conductive film having a predetermined pattern shape, wherein the multilayer conductive film is an amorphous film for suppressing movement of silver at an interface with a silver-based thin film. A lower amorphous oxide layer made of a crystalline or amorphous-like oxide, a silver-based thin film, and an upper oxide layer, wherein the upper oxide layer is formed of silver at an interface with the silver-based thin film. An electrode substrate for a display device, comprising: an amorphous or amorphous upper amorphous oxide having a thickness of 20 nm or less for suppressing movement, and an oxide layer. 3. The oxide layer according to claim 1, wherein the upper amorphous oxide layer has an optical thickness of 20 nm or less, which is a product of the thickness and the refractive index. 4. The electrode substrate for a display device according to item 1. 4. A protective layer is provided on the upper amorphous oxide layer or the upper oxide layer, and the total optical thickness of the upper amorphous oxide layer or the upper oxide layer and the protective layer is 70 nm. The electrode substrate for a display device according to claim 1, 2 or 3, wherein: 5. The method of claim 1, wherein the protective layer is equal to the upper amorphous oxide layer.
5. The display device electrode substrate according to claim 1, wherein the electrode substrate is an oxide layer having a lower refractive index than the upper amorphous oxide layer. 6. 6. The lower amorphous oxide layer includes an undercoat layer made of an oxide having a refractive index equal to or lower than that of the lower amorphous oxide layer. The electrode substrate for a display device according to claim 1, wherein the electrode substrate has a configuration. 7. A silver-based thin film comprising silver, platinum, palladium,
7. A silver alloy containing at least 3 at% (atomic percent) of a metal selected from the group consisting of gold, copper, and nickel.
4. The electrode substrate for a display device according to item 1. 8. A multi-layer conductive film comprising a substrate and a silver-based thin film sandwiched by an amorphous oxide layer made of an amorphous or amorphous-like oxide for suppressing silver movement. In the method of manufacturing an electrode substrate for a display device, the electrode is formed by patterning after forming at least a lower amorphous oxide layer, a silver-based thin film, and an upper amorphous oxide layer having a thickness of 20 nm or less. A method of manufacturing an electrode substrate for a display device, comprising at least a step of forming a protective layer having a film thickness adjusted so as to have optimal optical characteristics as an electrode on the electrode. 9. The method according to claim 1, wherein the protective layer is an electrically insulating material, and the protective layer is laminated on the electrode in a thickness sufficient for protection except for a portion where the electrode is electrically connected. A method for manufacturing an electrode substrate for a display device according to claim 8. 10. A pattern processing means for forming a multilayer conductive film into a predetermined electrode pattern is a photolithography method using a photoresist, and after forming an electrode pattern by a photolithography process, the photoresist is formed. At the time of removal, the resist at the electrode portion for electrical connection is left, and this is used as a mask when depositing a protective layer, and then the resist is removed to protect the electrode portion for electrical connection. The method of manufacturing an electrode substrate for a display device according to claim 8, wherein the electrode substrate is exposed from a layer. 11. The method of manufacturing an electrode substrate for a display device according to claim 8, wherein the pattern processing means for forming the multilayer conductive film into a predetermined electrode pattern is a mask sputtering method.