JPH1060627A - Black thin film having low reflectivity and light shielding property, and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a black thin film having low reflectivity and a light shielding property, capable of being used as the black matrix in the color filter for LCD and formed from a nonchromium vaporization material incapable of generating metallic chromium waste or waste chromium soln. by a dry process and its production method. SOLUTION: This black thin film formed on a substrate is expressed by Ma Ob(1-x) , where M is copper, chromium or iron atom, a=1, b=1 and 0<=x<=1 when M is copper, a=1, b=1 and 0<=x<=1 when M is chromium, and a=3, b=4 and 0<=x<=1 when M is iron. Further, the film has such a gradient composition that the index (x) is gradually increased from the substrate toward the surface in the film thickness direction until x=1 at the outermost surface, a clear interface does not exist between the Ma Ob(1-x) component regions and between the Ma Ob(1-x) component region and the M component region, and the Ma Ob(1-x) component and M component are intermixed in the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a black matrix in a color filter for a liquid crystal display (LCD). The present invention particularly has a low reflectance and an optical density (OD value: Opti
The present invention relates to a thin film having a high cal density and capable of forming a black matrix that divides RGB pixels and the like in a color filter for an LCD and uniforms dimensions and shapes.

[0002]

2. Description of the Related Art Liquid crystal displays are widely used in electronic devices such as televisions and computers, and in instruments such as automobiles. In particular, recently, there has been an increasing demand for colorization of the electronic devices and instruments, and therefore, a multi-color or full-color color LC having a high luminous efficiency.
A color filter which is a display element for D is strongly desired.

At present, in a color filter for LCD, each colored layer is divided by a black matrix in order to improve visibility. The characteristics required for the black matrix include the following items. Optical characteristics: low reflectivity and high light-shielding properties; (i): reflectance: reflectance (% R) ≦ 10%, and (ii): light-shielding properties: optical density (OD value) [= log (1) /
T) (where T represents transmittance)] ≧ 3. Flatness: Flat without any foreign matter or protrusions. Defects: No foreign matter, protrusions, pinholes, and / or film thickness distribution. Heat resistance: heat treatment during LCD manufacturing process (about 200
℃). Dimensional accuracy: the dimensional accuracy of the pixel part is ± 1 with respect to the specified size
μm or less, and the dimension between the outermost pixels on the glass substrate is ± 5 μm or less with respect to a predetermined dimension. Chemical resistance: Insensitive to chemicals used in LCD manufacturing process. Light fastness: No fading due to backlight when used as LCD. Operational stability: No elution of ionic impurities.

As a material for forming such a black matrix, a metal of low reflectivity such as chromium, nichrome and tantalum is mainly used at present, and a carbon-based ink / paint in which carbon particles are dispersed in a resin is used. Sometimes.

Conventionally, as a method for producing a black matrix, in the case of a metal such as chromium, a metal thin film layer (about 0.1 μm) is formed by a vapor deposition method or a sputtering method.
Is formed, a photosensitive resin composition is applied on the metal thin film, and after patterning it by a photolithography method, a pattern of the metal thin film is formed by an etching method, and finally, the pattern remains on the metal thin film pattern. A manufacturing method of peeling / developing the photosensitive resin composition has been adopted. On the other hand, in the case of a carbon-based ink / paint, a resin ink / paint in which carbon particles are dispersed in a base material such as an epoxy resin is formed by applying a printing method, an electrodeposition method, or a pigment dispersion method. Thereby, a black matrix is formed.

However, in the above method, when a black matrix is formed using a metal such as chromium, a problem arises in that the reflectance of the metal thin film is high and the visibility of an LCD image is impaired. In such a case, a waste liquid containing chromium is generated in an etching step for patterning, so that the cost of the waste liquid treatment increases. Further, chromium is not desirable as a metal waste from the viewpoint of environmental destruction.

In order to solve the above problems, it has been proposed to use a metal oxide instead of the metal thin film. However, thin films of metal oxides have the advantage that they hardly reflect and have good contrast,
In order to enhance the light-shielding property, there are disadvantages that the film thickness is larger (about 1 μm) than the metal film (about 0.1 μm) and the film formation time is longer.

On the other hand, when the above-mentioned carbon-based ink is used, since the printing method, the electrodeposition method, or the pigment dispersion method is used, the production cost is low, but the film thickness after patterning is as large as about 2 μm. If the black matrix is thick,
A large step occurs, which may cause poor alignment of the alignment film.

[0009] All of the above-mentioned film forming methods are properly used depending on the purpose. However, with the spread of color LCDs, it is desired that a black matrix as a manufacturing component has a low reflection and a high light shielding property. . Further, there is a demand for forming a non-chromium-based black matrix due to a problem of treatment of waste liquid and metallic chromium generated in the conventional etching process.

[0010]

DISCLOSURE OF THE INVENTION The present invention relates to a black matrix in a color filter for an LCD.
An object of the present invention is to provide a black thin film which can use a non-chromium-based evaporating material which cannot generate chromium metal waste and chromium waste liquid, has low reflectivity and light-shielding properties and is formed by a dry process, and a method for producing the same.

[0011]

The present invention SUMMARY OF THE INVENTION is a black thin film formed on a substrate, the thin film _{(M a O b (1-} x))
(Wherein M represents a copper, chromium, or iron atom; a,
b and x are a = 1, b = 1 and 0 ≦ x ≦ 1 when M is copper, a = 1, b = 1 and 0 ≦ x ≦ 1 when M is chromium, and M When is iron, a = 3, b =
4, and 0 ≦ x ≦ 1. ) Of the composition
_a O b _(1-x) index x in component gradually increases in the thickness direction toward the surface from the substrate, the outermost surface becomes x = 1 M
Has a gradient composition such that only components, as well as M _a O
_{b (1-x)} does not exist clear interface between the component region and between _{M a O b (1-x} ) component area and M component _{region, M a O b (1-} x) and M components The present invention provides a black thin film having low reflectivity and light-shielding property, in which is mixed in the composition.

Further, the present invention provides a method for stabilizing and activating, in an ion plating apparatus, vaporized particle ions generated by ionizing an evaporating material and oxygen plasma generated by discharge, if necessary, in the apparatus. 2. A black thin film having a low reflection property and a light shielding property according to claim 1, wherein a certain amount of an inert gas is introduced in order to cause the reaction, and a metal oxide as a reaction product is vapor-deposited on the substrate. And a method for producing the same.

More specifically, the thin film manufacturing method of the present invention uses a general-purpose vacuum vapor deposition apparatus and sets two parameters to be controlled (output applied to a coil installed in a reaction chamber, oxygen gas introduction amount or oxygen diaphragm gas pressure), by changing either one of them, the composition _{(M a O b (1-} x)) ( in the formula of the oxide evaporation material, M represents copper, chromium, or iron atoms , A, b, and x are a = 1, b = 1, and 0 ≦ x ≦ 1 when M is copper, and a = 1, b = 1, and 0 ≦ x ≦ 1 when M is chromium. and when M is iron, a = 3, b = 4 , and 0 ≦ x is ≦ 1.) is represented by, the said set adult _{M a O b (1-x} ) index in the component x
Gradually increases in the thickness direction from the substrate toward the surface,
Is the top surface has a gradient composition such that only the M component becomes x = 1, and _{M a O b (1-x} ) between component domain and M _a O
_{b (1-x)} does not exist clear interface between the component region and the M component region, a thin film _{M a O b (1-x} ) and M components are mixed in the composition on a substrate It is to be deposited.

Usually, a metal oxide film is a low-reflection film and has a light-transmitting property at the same time. Therefore, a thin film cannot sufficiently exhibit light-shielding properties. Further, the metal film has a light shielding property, but has a high reflectance. Further, when a metal thin film is formed directly on a deposited metal oxide thin film, reflection occurs at an interface between the thin films, and a desired low reflection cannot be obtained. However, in the present invention, in the composition of copper oxide CuO _(1-x) (where 0 ≦ x ≦ 1), the index x gradually increases in the film thickness direction from the substrate toward the surface, The outermost surface has a gradient composition such that x = 1 and only the Cu component exists, and there is no clear interface between the CuO _(1-x) component region and the Cu component region, and CuO ₍₁ By forming a structure in which the _-x) component and the Cu component were mixed, a black film having both the advantages of low reflectivity in the copper oxide film and light shielding properties in the metal film was formed. Thereby, when the thin film of the present invention is applied as a black matrix in a color filter, light incident from the glass substrate side, that is, from the CuO _1-x component region, becomes CuO _1-x
In the component region, light is not absorbed and reflected, but gradually diminishes. In the Cu surface region on the outermost surface, light is shielded, so that almost no light is transmitted. As a result, such a black matrix can prevent light from sneaking from the glass substrate side, thereby protecting a light-sensitive TFT circuit.

As a technique for performing the thin film manufacturing method according to one embodiment of the present invention, the following two types can be considered. One is reactive deposition and the other is reactive ion plating. The former reactive vapor deposition is a technique of heating and evaporating an evaporating material under reduced pressure, simultaneously introducing a reactive gas, and reacting the vaporized material particles with the reactive gas to deposit and grow on a substrate. However, this technology
The reaction rate is low, and it is necessary to increase both the substrate temperature and the reaction gas partial pressure in order to increase the rate to approach the stoichiometric composition. In this case, if the substrate temperature is not increased, the film quality deteriorates because high stress is generated due to the difference in elongation between the film and the substrate after the substrate is cooled. The density of the formed film is reduced due to collision. Therefore, in order to promote a reaction on the substrate surface, particles (for example, argon, oxygen, or the like) of ions or atoms having high energy accelerated by an electric field can be collided. On the other hand, reactive ion plating is performed by applying a DC or AC output to a reaction gas (eg, oxygen, nitrogen, etc.) introduced into the apparatus under a vacuum of 10 ^{−3 to} 10 Pa to form a plasma, thereby evaporating metal or the like. This is a technique for forming a film on a substrate by evaporating or sublimating a material that can be sublimated, or by reacting the evaporated material with a reaction gas that has been turned into plasma. Here, in the latter reactive ion plating, the substrate temperature can be set as low as about room temperature, and the substrate surface is cleaned in a dry process by a plasma such as a reactive gas and / or optionally introduced argon gas. In addition, since the evaporation material is redeposited by sputtering with a gas in which the evaporation material is diffused, there is an advantage that the film quality does not depend on the incident angle of the flux of the evaporation source, and the reaction is promoted by the plasma. At the same time, however, it has the disadvantage that there are many parameters that must be controlled.

In the present invention, as a result of studying to solve the disadvantages of each of the above two types of technologies and to further improve the respective advantages, a film forming method and a thin film obtained by the following method have been described. Obtained.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an exhaust device provided in a chamber (reaction chamber), which is connected to an oil rotary pump and an oil diffusion pump, as well as a leak valve, a gas introduction valve, a coil,
It is an ion plating apparatus equipped with a Pirani vacuum gauge and an ionization vacuum gauge. When a desired metal oxide / metal thin film is to be obtained by reactive vapor deposition, an evaporating material (evaporation) is first placed in an Al ₂ O ₃ -coated tungsten crucible (or an electron gun) in a chamber without using the coil. Source), the pressure is reduced, the evaporating material is heated to evaporate, and at the same time, a reaction gas (oxygen gas) is introduced and a reaction product is deposited and grown on the substrate while performing a gas phase reaction. The composition of the oxide evaporation material _{(M a O b (1-} x)) ( in the formula,
M represents a copper, chromium, or iron atom, and a, b, and x are a = 1, b = 1, and 0 ≦ x when M is copper.
≦ 1, when M is chromium, a = 1, b = 1, and 0 ≦
When x ≦ 1 and M is iron, a = 3, b = 4, and 0 ≦ x ≦ 1. ) Is represented by, the said set adult _{M a O b (1-x} )
Gradually increasing the indices x in component from the substrate in the thickness direction toward the surface, the outermost surface has a gradient composition such that only the M component becomes x = 1, and M _a O b _{( 1-x)} does not exist clear interface between the component region and between M _a O b _(1-x) component area and M component region, M _a O b _(1-x) and M components in composition The desired thin film mixed in the above is achieved by adjusting the amount of oxygen gas introduced during the above reaction.

When the above-mentioned vacuum deposition apparatus is applied to the reactive ion plating method, first, as in the case of the reactive vacuum deposition, an evaporation material is put into a crucible in a chamber,
Further, a DC power supply or a high-frequency power supply (RF Power: 13.56 MHz) is connected to the coil.
Connect. Next, oxygen and an inert gas (for example, argon gas) are introduced into the chamber, and a DC or RF output is adjusted to flow a discharge current to convert oxygen into a plasma [for example, O ⁻ , O ²⁻ , O · (oxygen radical), and e ^- (electron), heating the evaporation material particles evaporated by reacting the oxygen plasma to form a metal oxide film, membranes were placed in the evaporation source upwards A thin film is obtained by depositing on the glass substrate thus formed.

When a thin film is formed by the reactive ion plating method as described above, if the AC voltage for heating the evaporating material is constant (for example, 140 V), as the oxygen gas partial pressure is increased, the evaporating material is removed. It was found that the mean free path was shortened, thereby decreasing the film formation rate. Therefore, the film thickness was controlled so as to obtain a desired film thickness by adjusting the film formation time. Here, the thickness can be directly controlled by using a quartz crystal thickness gauge.

Hereinafter, preferred film forming conditions in the embodiment of the present invention will be described. However, among the following conditions, the film forming pressure varies depending on the exhaust device of the reactor, the film forming time varies depending on the evaporation or sublimation device, and the output applied to generate plasma varies depending on the film forming speed. It is not limited to the following numerical values.

In the case of reactive vacuum deposition, the ultimate vacuum degree: 2.
0 × 10 ⁻² Pa or less, preferably 1.0 × 10 ^{−2 to} 2.0
× 10 ⁻² Pa range and substrate temperature: 25 to 250
° C, preferably in the range of 150 to 200 ° C, oxygen pressure: 1
５5 Pa, preferably 3 Pa, film formation time: 30 to 150
Minutes, preferably 100 minutes, film thickness: 100 to 200 n
m, preferably about 150 nm.

In the case of reactive ion plating (direct current), the ultimate vacuum degree is 2.0 × 10 ⁻² Pa or less, preferably in the range of 1.0 × 10 ^{−2 to} 2.0 × 10 ⁻² Pa. , And substrate temperature: 25 to 250 ° C., preferably room temperature (25
C), oxygen pressure: 1 to 5 Pa, preferably 3 Pa, film formation time: 30 to 150 minutes, preferably 30 minutes, film thickness:
It is between 100 and 200 nm, preferably about 150 nm.

Reactive ion plating (high frequency) ultimate vacuum: 2.0 × 10 ⁻² Pa or less, preferably 1.0 × 10 ⁻² Pa
The range of 10 ^{−2 to} 2.0 × 10 ⁻² Pa, and the substrate temperature:
25 to 250 ° C., preferably room temperature (25 ° C.), oxygen pressure: 1.0 × 10 ^{−2 to} 1.0 × 10 ⁻¹ Pa, preferably 3.0 × 10 ⁻² Pa; The film thickness is 100 to 200 nm, preferably about 150 nm, for 30 minutes, preferably 8 minutes.

The reactive ion plating (high frequency) is performed by a device (manufactured by SYNCHRON, BMC-11) separate from reactive vacuum deposition and reactive ion plating (DC).
00).

In the reactive ion plating which is one embodiment of the method of the present invention, the output applied to generate plasma is constant (4 to 10 W, preferably 6 W for DC output, and 100 W for high frequency output). ~ 1000
W, preferably 400 W) to change the oxygen gas flow rate for introducing the oxygen gas partial pressure (in the case of DC output, 10
0 to 0 SCCM, 50 to 0 SCCM for high frequency output)
Thereby, a metal oxide / metal thin film having a desired film thickness and gradient composition can be obtained by applying reactive ion plating. Under the above conditions, when the oxygen gas introduction amount is 0 SCCM, the argon gas partial pressure is constant (0.5 to 2.0 Pa, preferably 1.0 Pa for DC output, and 1.0 Pa for high frequency output). 1.0 × 10 ^-3 〜
2.0 × 10 ⁻² Pa, preferably 1.3 × 10 ⁻³ Pa) or a constant amount of argon gas (0 to 2 in case of DC output).
0 SCCM, preferably 10 SCCM, in the case of high-frequency output, 0 to 50 SCCM, preferably 15 SCCM) or control the amount of argon introduced using a pressure controller to keep the pressure in the system constant (in the case of DC output) , 0.5-
2.0 Pa, preferably 1.0 Pa, for high-frequency output,
1.0 × 10 ^{-2 to} 2.0 × 10 ^-2 Pa, preferably 1.3
× 10 ^-2 Pa) to stabilize and activate the plasma.

Alternatively, in the reactive ion plating method, the oxygen gas partial pressure is kept constant (in the case of DC output,
5 Pa, preferably 3 Pa, for high frequency output 3.0
× 10 ^{-2 to} 6.0 × 10 ^-2 Pa, preferably 2.7 × 10
^-2 Pa) or a constant amount of oxygen gas introduced (20 to 40 SCCM, preferably 30 SCCM for direct current output, 20 to 60 SCCM, preferably 50 for high frequency output)
SCCM), and the output applied to generate plasma is from high output (5 to 10 W, preferably 6 W for DC output, 100 to 1000 W, preferably 400 W for high frequency output) to low output (DC output). In case of
2 to 1.0 W, preferably 0.4 W, for high frequency output,
5 to 20 W, preferably 10 W) to obtain a metal oxide having a desired film thickness and gradient composition.
Metal thin films can be achieved.

Also in this case, as in the case of the above conditions, a small amount of argon gas is introduced together with oxygen gas in order to stabilize the plasma (partial pressure of argon: DC output,
0.5 to 2.0 Pa, preferably 1.0 Pa, in the case of high-frequency output, 1.0 × 10 ^{−2 to} 2.0 × 10 ⁻² Pa, preferably 1.3 × 10 ⁻² Pa; argon gas amount : 0 to 20 SCCM, preferably 10 SCCM for DC output, 0 to 50 SCCM, preferably 15 S for high frequency output
CCM) is introduced, or the pressure in the system is kept constant by controlling the amount of argon gas introduced using a pressure controller (in the case of DC output, 0.5 to 2.0 Pa, preferably 1.0 Pa,
For high frequency output, 1.0 × 10 ^{-2 to} 2.0 × 10 ^-2 P
a, preferably 1.3 × 10 ⁻³ Pa) to stabilize and activate the plasma. .

Here, as the evaporation material, when a film is formed by applying a vacuum evaporation method, usually, a powder of metal (for example, Cu, Fe, Cr, Al, etc.) or a small piece is used to deposit a metal thin film. Or a metal oxide (eg, CuO, Fe) to deposit a metal oxide thin film.
₃ O ₄ ) powder, small pieces, or pellets must be used. However, in the reactive ion plating method applicable in the present invention, when a metal oxide / metal mixed thin film is formed, Cu, F
Use only small pieces or pellets of e or Cr.

When a black film useful in the present invention is formed, it is optimal to apply an ion plating method and use Cu as an evaporation material.

In the method of the present invention, in order to heat the evaporation material, an AC output (heating voltage up to 240 V) is usually used.
However, an electron gun (EB) may be used instead.
When using an electron gun, the preferred acceleration output of the electron gun is 4
80W (6KV x 80mA)-720W (6KV x 16)
0 mA).

As the substrate used in the film forming method of the present invention, any glass material (for example, non-alkali glass, soda glass, etc.) that can be used for a color filter can be used. It is particularly preferred that they are not contaminated with oils and fats or foreign substances and have no defective parts such as scratches. In the reactive ion plating technique as one embodiment of the film forming method of the present invention, since a film is formed under room temperature conditions, a transparent plastic substrate can also be used. ),
Examples include polyethylene terephthalate (PET) and polyether sulfone (PES).

In the method of the present invention, the gas introduced under the film-forming conditions is 99.99% or more for oxygen and 99.9999 for argon.
% Is preferably used.

As a technique for performing the thin film manufacturing method according to one embodiment of the present invention, there is the following reactive sputtering method in addition to the reactive evaporation method and the reactive ion plating method. It is also possible to produce a black thin film having the above-mentioned gradient composition by the reactive sputtering method and having low reflectivity and light-shielding properties without a clear interface. Hereinafter, an example of the reactive sputtering method will be described.

In the reactive sputtering method, oxygen and argon are turned into plasma and brought into a high energy state.
Accelerated by an electric field, instead of the evaporation source in vacuum deposition or ion plating, a copper target (or
(Chromium target, iron target). At this time, the copper atoms (or chromium atoms and iron atoms) on the target surface are repelled from the target surface by the collision of oxygen and argon ion particles and scattered toward the substrate. At this time, plasma to activated oxygen and copper atoms (or chromium atom, iron atom) with the reaction, are deposited on the substrate with the composition of _{M a O b (1-x} ).

As described above, the method of controlling the bonding ratio between copper atoms (or chromium atoms and iron atoms) and oxygen is based on the output applied to generate plasma, or the amount of oxygen gas and oxygen gas introduced. Is to control the pressure.
By the above method, it is possible to obtain a black thin film having the above-described gradient composition and having low reflectivity and light-shielding properties without a clear interface.

The thin film formed by applying the method of the present invention is L
When it is intended to use as a black matrix for a CD color filter, in order to form a desired pattern on the formed thin film, patterning is performed using a photosensitive resin composition before forming the thin film, and then a lift-off process is performed. Alternatively, after forming a thin film, an etching step is performed by patterning using a photosensitive resin composition.

When a lift-off process is applied to form a black matrix pattern, first, a positive photosensitive resist thin film is formed on a glass substrate, and then the pattern is exposed using a predetermined photomask and developed. Then, a metal oxide / metal thin film having a desired thickness and a gradient composition is formed thereon by the method of the present invention, and then a light source (rear surface) is formed from the surface (back surface) opposite to the surface of the glass substrate on which the thin film is formed. For example, by exposing using an ultra-high pressure mercury lamp) and developing, an unnecessary portion of the metal oxide / metal thin film is peeled together with the resist pattern to form a desired black matrix pattern. The resist used here is
A negative type may be used. In this case, a desired black matrix pattern is formed by dissolving the resist pattern in a developing / stripping solution known to those skilled in the art without exposing after forming the metal oxide / metal thin film. .

In the lift-off step, the fine powder of the black film in the developing / stripping solution can be collected by a filter or the like. Therefore, even when chromium is used as an evaporation source, there is no fear of polluting the environment.

Alternatively, when an etching step is applied to form a black matrix pattern, first, a metal oxide / metal thin film having a desired film thickness and gradient composition is formed on a glass substrate by the method of the present invention. .
Then, after forming a resist pattern thin film using a positive resist on the thin film, the exposed metal oxide / metal thin film is dissolved by an etchant, and then the resist remaining on the pattern is removed using a resist stripper. To form a desired black matrix pattern.

[0041]

The present invention will be described below with reference to examples.
The present invention is not limited to the following examples.

Evaluation method: (1) Film thickness measurement The thickness of the formed thin film was measured using a stylus type film thickness measuring device SV-62.
4 (manufactured by Mitutoyo, resolution: 5 °) (unit: μm).

(2) Evaluation of optical characteristics Double beam type UVPC3101 PC type spectrophotometer (manufactured by Shimadzu Corporation, light source: tungsten bulb in 350 to 3000 nm region, deuterium discharge tube in 200 to 360 nm region, reference mirror: Al vapor deposition mirror ), The absorbance and the reflectance of the formed thin film were measured by setting the reference at the time of the absorbance measurement to air and the incident angle at the time of the reflectance measurement to 5 °.

(3) Scratch test Thin film scratch tester CSR-02 (manufactured by RHESCA)
This was performed using A modified pickup cartridge for record reproduction was used as a scratching needle in the apparatus. The cartridge body of the scratching needle is vibrated at 30 Hz parallel to the sample surface. When the load applied to the needle is increased, the sample breaks and rubs. At that time, the delay of the parallel movement due to the frictional force acting between the needle and the sample surface was recorded as an electric signal. In this electric signal, immediately before the sample was broken, the load at the time of occurrence of disorder or abnormality was defined as a critical load (Wc), and the value was defined as the adhesion strength of the sample.

(4) Crosscut tape test (JIS-K-5)
According to JIS-K-5400, a cross-cut tape test of the formed thin film was performed. The evaluation result is represented by the remaining number (x) with respect to the total number of grids (100) (x / 1
00).

(5) Pencil Scratch Test A thin film formed was subjected to a pencil scratch test according to JIS-K-5400.

(6) X-ray Diffraction Method (XRD) The formed metal oxide / metal thin film is subjected to X-ray diffraction using an X-ray diffractometer RAD-C (manufactured by RIGAKU), and the metal in the thickness direction of the thin film is measured. The change in the oxidation number was investigated.

(7) X-ray photoelectron spectroscopy (XPS) AXIS (S
HIMADZU-KRATOS) was used to measure the binding energy of the outermost surface of the thin film.

Substrate Used and Vacuum Evaporation Apparatus: A slide glass (manufactured by Matsunami, S-1111) was used as the substrate. Before use, the substrate was degreased by ultrasonic cleaning with acetone, dried, and then formed into a film.

The ion plating apparatus used in Examples and Comparative Examples of the present invention (UHV-350 manufactured by SYNCHRON when used by connecting a DC power supply, BMC manufactured by SYNCHRON when used by connecting an AC power supply)
FIG. 1 is a schematic diagram of (-1100 type). In the case of reactive ion plating (DC output), a tungsten crucible coated with Al ₂ O ₃ is placed in a metal bell jar as a reaction chamber, and in the case of reactive ion plating (high frequency output). Has an electron gun instead of a crucible. In the reaction chamber,
A DC power supply (maximum output 100 W) or a high-frequency power supply (maximum output 2.5 kW) is connected and used depending on the case.
The device specifications will be described below by taking a Synchron UHV-350 model as an example. In the chamber, an oil rotary pump (Edw
ards), oil diffusion pump, leak valve, gas introduction valve, copper coil, Pirani vacuum gauge (ULVAC, G
P-2A), ionization gauge (GI-TL, manufactured by ULVAC)
2) is connected. The ultimate vacuum of the oil diffusion pump is
It is 1.0 × 10 ⁻⁴ Pa.

Example 1 In this example, a film was formed by a reactive ion plating method using a DC power supply in the above-mentioned apparatus (UHV-350 type).

An appropriate amount of a small copper piece was placed in a tungsten crucible coated with Al ₂ O ₃ as an evaporating material. The partial pressure of oxygen gas was set to 3 Pa and the partial pressure of argon gas was set to 1 Pa, and the pressure in the system was reduced (about 2 × 10 ⁻² Pa). First, DC output 6W
(200 V × 30 mA), and gradually reduce the current value in 15 minutes to 0.4 W (200 V × 2 mA).
A film was formed at 0.4 W for 15 minutes, and a black thin film having a thickness of about 150 nm as a whole and having a gradient in the copper oxide composition was formed on the substrate.

Example 2 In this example, a high frequency power supply was applied to the above apparatus (BMC-1100 type), and the reaction was performed by a reactive ion plating method. The same evaporating material as in Example 1 was put into an electron gun (JEBG-203UB, manufactured by JEOL Ltd.) and heated to evaporate, the oxygen gas introduction amount was initially 50 SCCM, and the high frequency was obtained for about 6 minutes at a film formation rate of 18 nm / min. Output 400W
To 10 W (film thickness: about 120 n)
m). Thereafter, the film was further formed at a high frequency output of 10 W for 2 minutes (film thickness: about 30 nm), thereby forming a black thin film having an overall film thickness of about 150 nm with a gradient in the copper oxide composition on the substrate. At this time, in order to stabilize and activate the plasma, 1.8 × 1
Argon gas was introduced so that the pressure became 0 ^-2 Pa.

Example 3 With the DC output maintained at 6 W, the oxygen gas partial pressure was increased to 3 Pa.
From 0 to 0 Pa in 15 minutes, and the same method as in Example 1 except that the argon gas partial pressure was set to 1 Pa to stabilize the plasma. An inclined black thin film was formed on the substrate. The thickness of the thin film is about 1 as a whole.
It was 50 nm.

Example 4 Using the same device and evaporation material (copper) as in Example 2,
Reactive ion plating was performed. Initially, the oxygen gas introduction amount was set to 50 SCCM while the high-frequency output was kept constant (400 W). In order to prevent the pressure drop due to the consumption of oxygen due to the reaction and to stabilize the plasma, argon gas was used using a pressure controller. While maintaining the pressure in the system constant (1.3 × 10 ⁻² Pa), the oxygen gas introduction amount was gradually reduced from 50 SCCM to 0 SCCM in 6 minutes to form a film (film thickness: about After that, a 30 nm thick film was formed on the substrate by forming a 30 nm thick copper oxide composition with a gradient in the copper oxide composition while keeping the oxygen gas introduction amount at 0 SCCM.

Example 5 The thin film of the present invention was patterned by a lift-off method.

A positive resist solution (PR-145, manufactured by Nippon Paint Co., Ltd.) is applied to a glass substrate by a spin coating method, and dried at 150 ° C. for 10 minutes. Exposure was performed for 60 seconds using MAP-1200L, output 600 mJ / cm ² (manufactured by Dainippon Screen), and a developing solution (manufactured by Nippon Paint, DE
V-034) for 2 minutes at 40 ° C., followed by washing and drying (10 minutes at 130 ° C.) to form a resist pattern. Approximately 150n black thin film by plating method
m were formed respectively. Thereafter, from the back surface of the substrate (the surface on which the thin film is not formed), back exposure is performed under the same conditions as described above, development is performed, and the black film formed on the resist is peeled off.
Good black matrix (film thickness: 150 nm) by washing with water and drying (at 130 ° C. for 10 minutes)
Was obtained.

Example 6 The thin film of the present invention was patterned by an etching method.

[0059] A black thin film of about 150 nm was formed on a glass substrate in the same manner as described in Examples 1-4.
A resist pattern was formed on the black film in the same manner as described in Example 5 above. Then, the etchant (PM
A good black matrix (thickness: 150 nm) was obtained by immersing in 50 ° C. for 5 minutes and performing etching.

COMPARATIVE EXAMPLE 1 An appropriate amount of a copper piece as an evaporating material was placed in an Al ₂ O ₃ -coated tungsten crucible. Oxygen gas partial pressure 3Pa
The pressure in the system was reduced (approximately 2 × 10 ⁻² Pa) by setting the partial pressure of argon gas to 1 Pa. The DC output was kept constant at 6 W, a film was formed for 30 minutes in oxygen and argon plasma, and a black film made of only copper oxide having a thickness of about 200 nm was formed on the substrate.

COMPARATIVE EXAMPLE 2 An appropriate amount of a copper piece as an evaporating material was placed in an Al ₂ O ₃ -coated tungsten crucible. Argon gas pressure 1
The pressure in the system was reduced to about Pa (about 2 × 10 ⁻² Pa). The DC output was kept constant at 6 W, and a film was formed in argon plasma for 20 minutes to form a film made of only metallic copper with a thickness of about 100 nm on the substrate.

Comparative Example 3 An appropriate amount of a copper piece as an evaporating material was placed in a tungsten crucible coated with Al ₂ O ₃ . Oxygen gas partial pressure 3Pa
The pressure in the system was reduced (about 2 × 10 ^-2 Pa) by setting the pressure of argon gas to 1 Pa. After forming a film for 15 minutes while maintaining a constant DC output of 6 W, a DC output of 0.4 W was further formed for 15 minutes in oxygen and argon plasma, and a black film of copper oxide having a thickness of about 200 nm was formed on the substrate. Formed on top.
In the thin film formed in this comparative example, an interface was present between the copper oxide layer and the copper layer.

Evaluation Results The black thin films formed in Examples 1 to 4 and Comparative Examples 1 to 3 were measured for absorbance and reflectance, scratch test, cross cut tape test, pencil scratch test, and X-ray diffraction method (XRD). And X-ray photoelectron spectroscopy (XPS) were evaluated. The results are summarized in Tables 1 to 3 and FIGS.

Table 1: Measurement of adhesion and luminous intensity of thin film formed in Example 1 Scratch test Cross cut tape test Pencil scratch test [critical load (mN)] 53 93/100 9H or more

Table 2: Optical properties of thin films formed in Examples 1-4 [Thin film composition (CuO _1-x / Cu = 120 nm / 30n)
m)] Average reflectance (visible light region 400 to 800 nm): 8% Maximum (wavelength 800 nm): 10% Minimum (wavelength 550 nm): 5% Average light shielding (OD value) (visible light region 400 to 800 nm): 3 Maximum (wavelength 400 nm): 5 Minimum (wavelength 800 nm): 2

Table 3: Optical properties of thin films formed in Comparative Examples 1 to 3 (however, the reflectance includes 5% of the reflectance of a glass substrate) Comparative Example 1 Comparative Example 2 Comparative Example 3 Thin film composition: CuO _1-x film Cu film CuO / Cu film Thickness: 200 nm 100 nm 150 nm Reflectance: 9.6% ≧ 50% 8.1% OD value: 0.7 3.5 3.1

[0067]

The metal oxide / metal thin film having a gradient composition obtained by the method of the present invention has excellent adhesion (adhesion) to a substrate, is dense, and has a reduced residual stress. In addition, it is useful as a black matrix for an LCD color filter because it has no defects such as foreign matter, protrusions and / or pinholes.

[Brief description of the drawings]

FIG. 1 shows a schematic diagram of a typical ion plating apparatus used in the present invention.

FIG. 2 is an XPS of a black thin film having a gradient in the copper oxide composition formed in Example 3 to which the method of the present invention is applied.
Shows the measurement results.

FIG. 3 shows the absorbance of a black thin film having a gradient in the copper oxide composition formed in Example 3 to which the method of the present invention was applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Evaporation source, 3 ... Coil, 4 ... Pirani vacuum gauge, 5 ... Oil rotary pump, 6 ... Oil diffusion pump, 7 ... Ionization gauge, 10 ... Ion plating apparatus.

Claims (10)

[Claims] 1. A black thin film formed on a substrate,
The thin film has a composition (M _a O _{b (1-x)} ) (where M represents a copper, chromium, or iron atom, and a, b, and x are a = 1, when M is copper, b = 1, and 0 ≦ x ≦ 1, when M is chromium, a = 1, b = 1, and 0 ≦ x ≦ 1, and when M is iron, a = 3, b = 4, and 0 ≦ a x ≦ 1 is represented by.), said set forming a _{M a O b (1-x} ) index in the component x
Gradually increases in the thickness direction from the substrate toward the surface,
Is the top surface has a gradient composition such that only the M component becomes x = 1, and _{M a O b (1-x} ) between component domain and M _a O
_{b (1-x)} does not exist clear interface between the component region and the M component _{region, M a O b (1-} x) component and mixed with that low reflectivity and shading in the composition M components Black thin film with properties. 2. In an ion plating apparatus,
The vaporized particle ions generated by ionizing the vaporized material and the oxygen plasma generated by the discharge are optionally reacted by introducing a certain amount of an inert gas to stabilize and activate the plasma in the apparatus. The method for producing a black thin film having low reflectivity and light shielding properties according to claim 1, wherein the metal oxide and / or metal as a reaction product is deposited on the substrate. 3. The method according to claim 2, wherein the evaporating material is copper, chromium, or iron. 4. The method according to claim 2, wherein the composition of the thin film is controlled by changing an applied output for generating oxygen plasma from a high output to a low output. 5. The thin film composition is controlled by gradually decreasing the amount of introduced oxygen or the partial pressure of oxygen gas without changing the applied output for generating oxygen plasma.
5. The method for producing a black thin film having low reflectivity and light-shielding property described in 1). 6. The low-reflection and light-shielding light according to claim 4, wherein the metal oxide deposited on the substrate is iron oxide (Fe ₃ O ₄ ), chromium oxide (CrO), or copper oxide (CuO). Method for producing black thin film having properties. 7. The method according to claim 2, wherein the black thin film having low reflectivity and light-shielding properties is formed by applying the production method according to any one of claims 2 to 6 repeatedly. Black matrix for color filters. 8. The composition having a composition of (CuO _1-x ) (where 0 ≦ x ≦
It is one. The black thin film having low reflectivity and light-shielding property according to claim 1). 9. When the composition is (Fe ₃ O _{4 (1-x)} ) (where 0 ≦
x ≦ 1. The black thin film having low reflectivity and light-shielding property according to claim 1). 10. The composition (CuO _1-x ) and (Fe ₃ O)
_4. The low-reflective and light-shielding black thin film according to claim 1, which has both _{4 (1-x)} ) (where 0 ≦ x ≦ 1).