JPH01296511A - Formation process for color indicator part on transparent conductive membrane and its device - Google Patents

Abstract

PURPOSE:To produce a color indicator part with no stepwise difference in thickness by preparing a color indicator part on the transparent conductive membrane that is formed on a transparent substrate through reduction of the part to be formed in an indicator part by means of hydrogen plasma. CONSTITUTION:Each surface of an indium tin oxide transparent conductive membrane(ITO membrane) formed on a transparent glass substrate, an antimony- added tin oxide transparent conductive membrane (SnO2:Sb membrane), and a fluorine-added tin oxide transparent membrane (SnO2:F membrane) is covered with aluminum mask and mounted on a transparent, conductive substrate, holding device to be exposed to radiation of ECR hydrogen plasma. By this radiation all of the ITO, SnO2:Sb and SnO2:F membranes undergo a significant reduction in their light transmission factors with no notable change in their surface resistance values. Numerically a color indicator spot is reduced in thickness but the reduction is so small that the grade of stepwise difference associated with it is ignorable.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a novel forming method and apparatus for forming a colored display portion by coloring a transparent conductive film itself without impairing conductivity.

<Conventional technology> As an interface that connects information devices and people.

Optoelectronic devices such as liquid crystals and electroluminescent devices are widely used. A transparent conductive film is essential for such an element, and a so-called transparent conductive substrate, in which a transparent conductive film is provided on a transparent substrate, is used as a transparent electrode. Transparent conductive substrates have a wide variety of configurations, such as glass, plastic films and sheets, and transparent conductive films such as tin oxide, indium-tin oxide, and lead oxide, and are used in a variety of ways.

As one of the usage methods, there are many cases in which it is required to display clearly visible characters, symbols, divisions, etc. (hereinafter referred to as colored display) at predetermined locations on a transparent conductive substrate.

Conventionally, in this case, a method of printing a colored display material on either the transparent conductive film side or the transparent base side of the transparent conductive substrate has been used, and this is still the case today.

<Problems with conventional technology> For example, when displaying a colored display on a transparent conductive substrate using a glass substrate, when the colored display is displayed on the glass surface side and viewed from an oblique direction, the transparent electrode corresponding to the colored display position A parallax occurs between the position of the glass substrate and the colored display due to the thickness and refractive index of the glass substrate. If this parallax is a problem for the transparent electrode of an optoelectronic device, it is necessary to provide a colored display on the transparent conductive film, but if the colored display is provided on the transparent conductive film using a printing method, the colored display material If it is an insulator, the colored part will not work as an electrode, and even if printed using a conductive colored material, there will be a gap between the colored part and the non-colored part. There is a problem in that a level difference corresponding to the thickness of the display material is generated, and when used as a transparent electrode of an optoelectronic element, this level difference adversely affects the function of the element.

As a result of extensive research, we have found that, for example, hydrogen plasma generated by electron cyclotron resonance (hereinafter referred to as rEcRJ) is irradiated onto the surface of a transparent electrode where a colored display is to be provided, and the transparent conductive material at that location is The above-mentioned problems have been solved by inventing a new color display method and device by reducing the film and coloring it.

Function> The present invention uses tin oxide (S n
O,) Indium oxide, tin oxide, titanium oxide (Ti02), etc. are easily reduced by reduction treatment, and the parts that are reduced and made into thin metal films have good conductivity and absorption of light rays, which are inherent to metals.
We focused on the fact that it exhibits a unique metallic color due to its reflective ability, and that areas that are incompletely deprived of oxygen become colored due to absorption of light due to lattice defects and changes in the refractive index, resulting in a decrease in transparency. Therefore, the method of reducing the transparent conductive film is the key to the present invention.

For example, SnO, which is extremely stable to acids and alkalis, and TiO
It is also known that it can be reduced relatively easily. That is, it can be reduced relatively easily, for example, by reducing flame treatment or wet reduction treatment using chemicals. However, reducing flame treatment is not practical, and wet reduction treatment using chemicals also has the problem of waste liquid treatment that causes pollution, and if the liquid is acidic, there is a concern that metallized parts may be dissolved and removed. In this case, the inventors came up with a treatment using a reducing active gas, that is, a hydrogen plasma treatment.

Its action will be described below.

The parts of the surface of the transparent conductive film other than the parts to be colored and displayed are masked by a known method such as printing a resist material, and the masked parts are removed by irradiating hydrogen plasma generated by an appropriate method. The element resistance in the transparent conductive film in the areas where it is not present is taken away by hydrogen ions in the plasma and hydrogen radicals produced as a by-product during plasma generation.
As it is gradually reduced, it begins to change color as an external change,
It increases in density over time. At this time, the color becomes gray or dark brown, or a bright metallic color, although there are temporal differences depending on the type of transparent conductive film, production conditions, plasma generation conditions, and irradiation conditions. This part had good conductivity and was comparable in resistivity to other parts of the transparent conductive film.

As the irradiation continued for a longer period of time, the colored portion began to fade and eventually became colorless and transparent. At that time, we measured the surface resistance of the faded area and found it to be infinite, and when we measured the thickness, we found that it matched that of the transparent substrate, indicating that there was a difference in level from the surrounding transparent conductive film. That is, the portion metallized by hydrogen plasma is removed from the transparent substrate by sputtering or the like using hydrogen ions.

In other words, when reducing a transparent conductive film using hydrogen plasma, sputtering action reduces the thickness of the film in that area, so even if a colored display is possible, the purpose is to eliminate the difference in level from the surrounding area. I don't like it because it doesn't suit.

The plasma that reduces the transparent conductive film is not limited to hydrogen plasma, but may be plasma of a reducing gas, such as -carbon oxide scum, propane gas, etc. However, the ions produced by turning these gases into plasma,
Radicals generated as a by-product in the plasma have a much larger mass than hydrogen ions, so they can easily spatter the transparent conductive film and reduce the film thickness at the irradiated area, that is, the color display area. This results in a step difference with the transparent conductive film portion. Therefore, in order to reduce the influence on the film thickness of the colored display section, it is most suitable to use hydrogen gas plasma, which has the smallest mass.

For the same reason, the ECR method is the most suitable method for generating plasma, but it goes without saying that any other method may be used to generate hydrogen plasma.

In order to perform the coloring display process efficiently, that is, to reduce the transparent conductive film in a short time, it is necessary to increase the energy of hydrogen ions and the ionic current, but if they are increased too much, as mentioned above, The sputtering effect cannot be ignored. Therefore, it is necessary to find optimal conditions for suppressing the sputtering action as much as possible while maximizing the reducing action, but the optimal conditions vary depending on the type of film and the conditions for forming it.

By applying an electric or magnetic field to ions in a plasma, the energy strength, magnitude of ion current, direction of movement, etc. can be controlled. The ECR plasma generation method generates many neutral particles such as radicals during plasma generation, and the energy of these particles can be kept low, which has the advantage of suppressing sputtering effects. Therefore, in order to suppress the sputtering effect and maximize the reduction effect, the ECR plasma generation method, which has a high ionization rate and can generate low energy plasma, is suitable.

The present invention preferably adopts the ECR plasma method, which has a significantly higher ionization rate than other plasma generation methods, and further improves the device so that the energy of ions extracted from the plasma generation chamber and the ion current density can be controlled over a wide range. This method has the advantage that the optimum processing conditions can be selected for each specification of the transparent conductive substrate in color displaying the transparent conductive film, which is the first aspect of the present invention. There are no particular restrictions on such a colored display area, and for example, it may be used in place of a printed display, or it may be used as various patterns formed on a transparent conductive film as necessary. A pattern is formed.

The transparent conductive film according to the present invention can be exemplified by a conductive film made of metal, metal oxide, etc., and is not particularly limited. An example is a conductive thin film made of tin or the like. There are also no particular limitations on the method of forming the transparent blue light on the substrate, such as sputtering, vapor deposition,
An example is an ion plating method.

The transparent substrate forming the transparent conductive film according to the present invention is not particularly limited, but examples include glass, plastic films, sheets, substrates, and the like.

When a colored pattern of a transparent conductive film is formed according to the present invention, its use is not limited to transparent electrodes of optoelectronic devices such as liquid crystal display elements and electroluminescent devices, and transparent tanti-panel panels, but also for transparent conductive film patterns and transparent electrode patterns. It can be applied to any application that requires the formation of
The performance of these applied products can be improved. Further, as described above, it may be used in place of a printed display, and thus the present invention is not particularly limited in its application and can be applied to any field.

Next, the device will be described.

FIG. 1 is a cross-sectional view showing a specific example of a preferred apparatus for implementing the method of providing a colored display portion in a transparent conductive film, which is the first invention of the present invention, and the present invention is described in the first invention. It is of course possible to use any device within the specified range. The following will explain based on FIG.

The ECR hydrogen plasma generation chamber 1 has a structure capable of maintaining a pressure of, for example, 10 Tor+ order, which is suitable for electron cyclotron resonance. A cooling water jacket 2 is provided on the peripheral wall to prevent temperature rise due to collision of gases in an electron cyclotron resonance state, and an external cooling water supply device (
(not shown). A solenoid coil 3 is disposed outside the plasma generation chamber so as to surround the plasma generation chamber, so that a magnetic field can be applied within the plasma generation chamber. In the second part of the plasma generation chamber 1, there is a microwave introduction window 4 for applying an oscillating electric field in a direction perpendicular to the above-mentioned magnetic field.
is provided, and the outside thereof is connected to a microwave oscillator 6 through a microwave introduction pipe 5. On this occasion,
The window 4 is usually provided with a partition wall made of a suitable material that allows microwaves to pass therethrough, thereby making it possible to maintain the necessary atmospheric pressure.

At this time, instead of the microwave introduction pipe 5, an antenna introduction force type may be used.

A hydrogen gas intake lower is provided at an appropriate location in the plasma generation chamber (in the upper part of the plasma generation chamber in Figure 1), and can be connected to an external hydrogen gas supply device (not shown). . Two or more hydrogen gas intake ports as required.
It is okay to set it in the second place.

Hydrogen ions and radicals generated in the ECR plasma generation chamber are in an extremely high density state, and it is not desirable to reduce the transparent conductive film in this atmosphere due to irradiation control. Therefore, it is desirable to perform the plasma irradiation treatment in the coloring treatment chamber 9 provided adjacent to the ECR plasma generation chamber. Therefore, a plasma extraction section 13 that introduces plasma into the coloring processing chamber 9
is provided in communication with the lower part of the plasma generation chamber, that is, at the border with the coloring processing chamber. Therefore, from the side of the coloring processing chamber 9, the extraction section 13 becomes a plasma intake section 13. The take-out portion 13, ie, the intake portion 13, has a window-like structure in this example.

The coloring processing chamber 9 is equipped with a transparent conductive substrate holding device 11 for gripping a transparent conductive substrate (a transparent substrate on which a transparent conductive film is formed) 10 at a position where plasma is irradiated. It would be convenient to have a device that allows the transparent conductive substrate 10 to be taken in and out without breaking the vacuum state. When the transparent conductive film is formed on a soft substrate, if a transparent conductive substrate holding device is provided with a mechanism for unwinding and winding up the film, it is convenient for continuous processing of long films, and productivity is further improved.

Although the colored display portion of the transparent conductive film may be formed on the entire surface of the transparent conductive film, it is preferably formed on a portion of the transparent conductive film. Although there are no particular limitations on the method of forming a part of the transparent conductive film, it is preferable to use a method of shielding parts of the transparent conductive film other than the colored display area from plasma irradiation. There are no particular restrictions on the method of shielding the parts of the transparent conductive film other than the colored display part from plasma irradiation, but there is a method in which a pattern mask prepared in advance in the shape of the part to be shielded is brought into close contact with the transparent conductive film. Alternatively, the transparent conductive substrate being irradiated with ECR hydrogen plasma can be removed as necessary by printing a resist material on areas other than the colored display area of the transparent conductive film surface and removing the resist material with a chemical solution after coloring. Although it is free to provide an appropriate temperature control device 8 to maintain a predetermined temperature, it is desirable to maintain the temperature at an appropriate temperature depending on the optimum conditions of the coloring process.

Install solenoid coil 1 as necessary around the outer periphery of the coloring treatment chamber.
2 is arranged between the plasma intake part 13 and the transparent conductive substrate 10 to convert the diverging magnetic field generated by the solenoid coil 7 into a mirror magnetic field and reduce the energy of ions diffusing from the plasma intake window 13. do. Instead of the solenoid coil 12, a permanent magnet may be provided near the bottom of the transparent conductive substrate holding device 11.

Further, if necessary, electrodes 14 and 15 are provided in the plasma intake section 13 and the plasma irradiation area of the transparent conductive substrate gripping device 11, respectively, and the electrode 15 on the gripping device side is positive or negative. DC voltage such that the potential is
Alternatively, it is connected to an external power supply device 16 so that alternating current voltage can be applied. If the efficiency of coloring the transparent conductive film is poor due to insufficient energy intensity of ions diffused from the plasma generation chamber or insufficient ion current, applying a negative voltage to the electrode 15 may significantly improve the coloring process. Processing time can be shortened. That is, when a DC voltage or an AC voltage is applied, hydrogen ions are accelerated toward the membrane, reactivating the ions that are to be neutralized. This is because in any case, in addition to increasing the kinetic energy of ions, the number of ions and radicals that reach the transparent conductive film per unit time increases.

In this way, ions can be controlled over a wide range by adjusting the strength of their energy and the direction of their movement by applying electric or magnetic fields. In this respect, ECR hydrogen plasma has an extremely high ionization rate and is easy to control. Therefore, it is easy to select the optimum conditions for plasma generation and irradiation for coloring the transparent conductive film, and the processing efficiency is also good.

Further, the coloring of the transparent conductive film obtained by the reduction treatment can be changed from gray to metallic luster, but the E
When the hydrogen plasma generated in the CR hydrogen plasma generation chamber is used for organometallic chemical vapor deposition (CVD), it is possible to form a metal film, etc. in the reduction treatment area of the transparent conductive film by the plasma CVD method. By simultaneously depositing a thin film of a material while undergoing a reduction treatment, it is possible to achieve multi-colored coloring.

In plasma CVD using ECR hydrogen plasma, a raw material gas such as an organic metal is brought into contact with the transparent conductive film on the transparent conductive substrate 10 through the raw material gas supply pipe 17 and the raw material gas outlet 18 in the coloring processing chamber 9. A thin film can be formed by vapor deposition by causing a decomposition reaction using hydrogen ions or radicals.

Thin 1 thus formed! The thickness of λ is, for example, several 1 nm.
Since it is extremely thin, as shown in the figure below, unlike the configuration of conventional products in which the colored display section appears as a step, there will be no step difference that will cause various problems during practical use.

The plasma generation chamber and the coloring treatment chamber are maintained at an extremely high vacuum level by an external vacuum exhaust device (not shown) provided through an exhaust port 19.

To actually perform the processing, first, the transparent conductive substrate gripping device 1 is
1, place the transparent conductive film side of the transparent conductive substrate 10 at the top (as shown in the drawing), and then apply vacuum through the exhaust port 19 to obtain the required pressure (degree of vacuum).

At this time, the supply amount and vacuum suction amount of these gases are set to such an extent that the required pressure can be maintained even if gas is supplied from the hydrogen sludge intake lower or the raw material gas outlet 18 used as necessary. Hydrogen introduced into the plasma generation chamber 1 is oscillated from a micro oscillator 6, and is introduced into the ECR hydrogen plasma generation chamber 1 through an introduction window of 4, for example 2', 45GH.
It is turned into plasma by the action of the microwave of z and the magnetic field applied in the generation chamber 1 by the solenoid coil 3, enters the coloring process through the extraction window 13, and acts on the transparent conductive film there.

The microwave introduction window 4 and hydrogen scum intake lower in this device may be provided on the inner wall of the ECR hydrogen plasma generation chamber 1, or may be provided inside the ECR hydrogen plasma generation chamber 1, allowing the necessary microwaves and gas to be introduced into the generation chamber. You are free to place it anywhere in the generation chamber as long as it is possible. Furthermore, the plasma extraction section 13 can be freely installed anywhere in the plasma generation chamber 1, and the plasma intake section 13 can also be installed anywhere in the coloring processing chamber 9, and there is no particular restriction as long as the two are configured to communicate with each other.

It should be noted that FIG. 1 is depicted so that the vertical direction of the drawing corresponds to the vertical direction of the actual device.

The specific example shown above is a preferable example of implementing the second invention, and the second invention can also take on all other aspects within its scope.

<Example 1> An indium oxide-tin oxide-based transparent conductive film (ITO film) formed on a transparent glass substrate, an antimony-doped tin oxide-based transparent conductive film (SnO, :Sb film), and a fluorine-doped tin oxide-based transparent conductive film An aluminum mask was placed on each surface of the film (S n Ox : F film), and the film was attached to the transparent conductive substrate holding device of the apparatus shown in Figure 1, and ECR hydrogen plasma was irradiated under the conditions shown in Table 1 to determine the surface resistance and light beam. The transmittance and film thickness values were evaluated and the results shown in Table 2 were obtained.

(hereinafter referred to as efflorescence) Table 1 Coloring treatment Table 2 Measurement results ECR hydrogen plasma irradiation resulted in ITO[,SnO:Sb
A significant decrease in light transmittance was observed for both the film and the SnO+F film. On the other hand, almost no change was observed in the surface resistance value. Although the thickness of the colored display area is reduced numerically, it is small, and the level difference caused by this is negligible compared to the case where coloring material is printed. Under the treatment conditions of this example, Table 1, an ITO transparent conductive film and a SnO transparent conductive film formed on a 100 g thick polyethylene terephthalate (PET) film, a type of organic plastic film, were subjected to ECR hydrogen plasma for 4 minutes. As a result of the treatment, the treated area became a dark gray-black color, and a colored pattern could be formed with high contrast between it and the untreated area.

The ITO transparent conductive film on PET film shown in the above example was used for touch panel switches, and it was confirmed that the film with colored patterns of numbers and letters can be fully used for calculators and indicators. Ta.

<Example 2> A high frequency voltage of 15 kHz and 150 W was applied between the electrode provided in the plasma intake part and the electrode attached to the transparent electric substrate holding stand, and the gas pressure was 2×10 T.

A coloring treatment was performed to form an electrode pattern on the transparent conductive film under the same conditions as in Example 1 except that rr was used, and the results shown in Table 3 were obtained.

(hereinafter referred to as Chinese cabbage) Table 3 Measurement Results The processing time was significantly shortened compared to Example 1, and the effect of applying the plasma extraction voltage as in this example was observed. On the other hand, although the decrease in film thickness value is slightly larger than in Example 1, it is negligible.

<Example 3> In Example 1 and Example 2, EC was applied on the transparent conductive film.
While applying R hydrogen plasma, alkyl compounds such as dimethylzinc, dimethylselenium, trimethylaluminum, trimethylgallium, trimethylindium, tetramethyltin, tetramethyltitanium, and tetramethylgermanium are supplied from the raw material gas supply pipe 17 into the coloring processing chamber. By supplying a raw material gas such as silane and ejecting it from the outlet 18, it is brought into contact with the transparent conductive film, and at the same time, a decomposition reaction is caused in these raw material gases by hydrogen plasma to form a film on the transparent conductive film. It was possible to vary the color of the colored portion of the transparent conductive film. Preferred examples of such raw material gases include organometallic compounds such as the alkyl compounds mentioned above, hydrogen compounds, etc., and any compound that can be expected to have a low energy consumption effect can be freely used.
These appropriate raw material gases may be mixed and used.

Moreover, even though the formation of these thin films is extremely thin.

Since the coloring effect is obtained, the increase in film thickness due to film formation can be ignored.

If this produced film is a metal film, it can also serve as electrode wiring within the scope of the purpose of pattern formation by coloring of the present invention.

Similar film formation was possible by using an alkyl compound combined with an ethyl group instead of an alkyl compound combined with a methyl group as the organic metal compound-based raw material gas.

The colored pattern formation shown in this example was also applicable to a zinc oxide transparent conductive film that is difficult to color by reduction treatment.

<Effects of the Invention> As explained above, the present invention provides a variety of novel transparent electrodes, etc., which do not create a level difference on a transparent conductive film that would be a problem in practice, and which have a colored display that is conductive. This provides a method for realizing display parts, which is not only effective in improving device functions in the field of optoelectronic devices, but also effective in antistatic, infrared shielding, electromagnetic wave shielding, and transparent window materials for housings for electrostatic shielding. It can be adapted even if
Its uses span all fields.

Furthermore, the present invention also provides a preferred apparatus for carrying out the above method, which makes it easier to form highly effective colored displays.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of one embodiment of a preferred apparatus for carrying out the invention. ■, Hydrogen plasma generation chamber 9, Coloring treatment chamber

Claims (7)

[Claims] (1) A transparent conductive film formed on a transparent substrate, which is characterized in that, when a colored display portion is provided on a transparent conductive film, the portion where the display portion is to be formed is colored by being reduced using hydrogen plasma. A method for forming a colored display portion in a film. (2) A method for forming a colored display portion in a transparent conductive film according to claim 1, wherein hydrogen plasma is generated by electron cyclotron resonance. (3) The method for forming a colored display portion in a transparent conductive film according to claim 1 or 2, wherein the colored display portion is a colored pattern. (4) The coloring effect is enhanced by irradiating hydrogen plasma onto the transparent conductive film, bringing the source gas into contact with the transparent conductive film while reducing it, and forming a colored thin film through a decomposition reaction caused by the hydrogen plasma. 3. The method for forming a colored display portion in a transparent conductive film according to 3. (5) The method for forming a colored display portion in a transparent conductive film according to claim 4, wherein the raw material gas is a gas consisting of at least one of a hydrogen compound or an organometallic compound. (6) A cooling jacket provided on a peripheral wall, a solenoid coil for applying a magnetic field provided on the outer periphery of the jacket, and a structure having a microwave introduction window, a hydrogen gas intake port, and a plasma extraction part in the room. a hydrogen plasma generation chamber using the electron cyclotron resonance plasma method, a solenoid coil for applying a mirror magnetic field provided on the outer periphery if necessary, a plasma intake section configured to communicate with the plasma extraction section, and a transparent hydrogen plasma generation chamber provided at the plasma irradiation position. Coloring of a transparent conductive film comprising a conductive substrate gripping device, and if necessary, electrodes provided respectively in the plasma intake section and the plasma irradiation area of the transparent conductive substrate gripping device, and an exhaust port connected to an external vacuum evacuation device. 1. An apparatus for forming a colored display portion in a transparent conductive film, comprising a processing chamber. (7) The gas outlet is provided at a position where the raw material gas containing a predetermined compound can be brought into contact with the transparent conductive film disposed on the transparent conductive substrate holding device. The apparatus for forming a colored display portion in a transparent conductive film according to claim 6.