JPH09184905A - Light shielding film, formation of light shielding film and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the abnormal growth of laminated films formed by a plasma CVD apparatus on the film surface of a light shielding film. SOLUTION: The light shielding film 2 constituted by dispersing one kind of particulates among at least metallic particulates and semimetal particulates into an insulator is formed on a substrate 1. The deposition concn. in the film thickness direction of the particulates in the insulator is high on the substrate 1 side and low on the film surface side opposite to the substrate 1. As a result, the particulates do not diffuse into the surface of the light shielding film 2 during the film forming process when the light shielding film 2 is formed by a plasma CVD apparatus on the film surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-shielding film formed by dispersing metal fine particles or semi-metal fine particles in an insulator, a method for forming this light-shielding film, and a liquid crystal display device provided with this light-shielding film. .

[0002]

2. Description of the Related Art Generally, a liquid crystal display device uses a light-shielding film called a black matrix.

This light-shielding film is disclosed, for example, in JP-A-63-64.
As described in Japanese Patent Publication No. 023, the electrodes are arranged in a matrix on the array substrate except the display pixel electrodes. In this case, as the light-shielding film, a black dye is used by blending a polymer with a black dye or two or more dyes having complementary colors.

By the way, since the alignment accuracy of the array substrate on which the switching elements are arranged and the counter substrate having the light-shielding film formed on the color filter is usually 4 to 8 μm, the open / close pattern of the light-shielding film has a front-back alignment accuracy. You must design with a margin of time.

However, by providing a light-shielding film on the array substrate, the alignment accuracy between the array substrate and the counter substrate is 300.
Even for a large substrate of mm square or more, it is about 1/2 or less compared to the conventional one, so that it is possible to suppress a decrease in aperture ratio due to misalignment, and to avoid a reduction in off resistance due to the wraparound of backlight light. Is possible.

As another light-shielding film, a light-shielding film is used as a resist, and a resist in which a dye and a pigment are dispersed in a polymer has been put into practical use.

As another light-shielding film, a metal wiring in the switching element may be used together, or a metal light-shielding film may be provided in the passivation layer. In this case, since a conductive metal is used as the light-shielding film, a problem such as fluctuation of the pixel electrode due to capacitive coupling between the pixel electrode and the signal line, and a passivation layer for avoiding this, for example, are used. It is necessary to provide layers, which complicates the manufacturing process.

Therefore, in recent years, for example, JP-A-61-2
As described in Japanese Patent No. 44068, a light shielding film using an amorphous carbon thin film has been proposed. According to this method, the manufacturing process becomes simple and easy, and the passivation layer can also be used.

[0009]

First, in a light-shielding film obtained by blending a dye or a pigment with a polymer, it is necessary to make the film thickness as thick as about 2 μm or more in order to obtain a sufficient absorbance. Such a thick light-shielding film causes a large step between the display pixel electrode and the light-shielding film,
There is a problem that the electric field applied to the liquid crystal becomes non-uniform and alignment defects and reverse of the liquid crystal appear.

As a countermeasure, there is a method of widening the width of the signal line or the scanning line to shield a part of the display pixel electrode in order to hide the reverse portion, but as a result, the aperture ratio is lowered. There is. That is, the light-shielding film originally provided on the array substrate side to improve the aperture ratio also needs to be covered even if the aperture ratio is sacrificed due to a defect caused by its excessive thickness. .

In a resist made of a polymer in which a dye or a pigment is dispersed, if the concentration of the dye or the pigment is increased as much as possible to improve the light-shielding performance, the pattern performance in photolithography is inferior and the alignment accuracy is lowered. There is also a problem that the scrub cleaning for removing the etching residue may destroy the pattern in terms of manufacturing process.

Further, organic substances generally have a high vapor pressure, and arranging such a light-shielding film in the lower layer of the array substrate is inconvenient when high temperature treatment is required in the subsequent steps. . That is, steam is generated from the lower layer,
There is a problem that the morphology of the upper film is deteriorated.

An amorphous carbon thin film proposed as a light shielding film for shielding an amorphous silicon thin film transistor (a-SiTFT) from light is a kind known as i-carbon. That is, it is a mixture of a diamond-like structure and a graph like structure.

It is known that the physical properties change greatly depending on the film forming conditions. Depending on the conditions, the diamond-like portion has an insulating property and the graphite-like portion has a light-shielding property. It is reported that membranes can be made.

However, this light-shielding film has a large reflection of light,
The liquid crystal display device has a problem that the reflection is large. This is due to the fact that the light-shielding film has a high refractive index, and is a characteristic determined by a substance as diamond has a very high refractive index of about 2.5.

Therefore, in the diamond-like film, the problem of the reflection cannot be solved by the carbon film.

A light-shielding film made of a cermet film using plasma resonance absorption of metal fine particles has been proposed. In this case, in the system in which the metal fine particles are dispersed on the film surface, when the laminated film to be deposited thereon is formed by the plasma CVD apparatus, the laminated film abnormally grows with these metal fine particles as nuclei,
The laminated film has poor flatness, and in some cases, it is almost impossible to form a thin continuous film. In the case of a laminated film having poor flatness, there are disadvantages such as a poor cover coverage of the upper laminated film and a possibility that a thin wiring is easily cut at a step portion, which significantly reduces the manufacturing yield.

The present invention has been made in view of the above problems, and is a light-shielding film capable of suppressing abnormal growth of a laminated film formed by a plasma CVD apparatus on the surface of the light-shielding film. An object of the present invention is to provide a film forming method and a liquid crystal display device having this light shielding film.

[0019]

According to the present invention, there is provided a light-shielding film which is formed on a substrate and in which at least one kind of fine metal particles and semi-fine metal particles is dispersed in an insulator. Since the deposition concentration of the fine particles in the film thickness direction is high on the substrate side and low on the film surface side opposite to the substrate, plasma CVD is performed on the film surface of the light shielding film.
When the film is formed by the apparatus, even if the fine particles diffuse to the film surface of the light shielding film during the film formation process by the plasma CVD apparatus, the fine particles do not reach the film surface of the light shielding film and The abnormal growth of the laminated film formed by the plasma CVD apparatus is suppressed.

By applying different arc powers to the insulator material cathode and the particulate material cathode forming the light-shielding film, the deposition concentration of the particles in the insulator in the film thickness direction is high on the substrate side and A light-shielding film which becomes lower on the opposite film surface side is formed by sputtering. The different arc power includes at least one of a change in the arc power applied to the particulate material cathode from a high level to a low level and a change in the arc power applied to the insulator material cathode from a low level in the sputter deposition process.

In a liquid crystal display device including an array substrate, a counter substrate provided to face the array substrate, and liquid crystal sandwiched between the array substrate and the counter substrate, the array substrate or the counter substrate is provided. The light shielding film is formed on the substrate.

[0022]

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

FIG. 1 is a sectional view of the light-shielding film. Reference numeral 1 is a transparent glass substrate on which a light-shielding film 2 is formed. The light-shielding film 2 is a film of fine particles in an insulator in which fine particles such as bismuth (Bi), which is one type of metal fine particles or semi-metal fine particles, are dispersed in an insulator such as silicon (Si). The deposition concentration in the thickness direction is high on the substrate 1 side and low on the film surface side opposite to the substrate 1.

A method of forming the light shielding film 2 will be described with reference to the perspective view of the film forming apparatus shown in FIG.

For example, the length is 440 mm, the width is 810 mm,
Boron (B) -doped polycrystalline silicon with a thickness of 10 mm is put into a copper backing plate made of indium (In).
A flat plate-shaped insulator material cathode 11 joined by solder is prepared. Also, diameter 10mm, wall thickness 2mm, length 900mm
The metal water-cooled tube (1) is dipped in an indium-bismuth bath for 5 seconds and then dipped in a bismuth bath for 3 minutes to prepare ten pipe-shaped particulate material cathodes 12.

A flat plate-shaped insulator material cathode 11 is arranged above the stage 13 arranged in the film forming chamber of the sputtering apparatus, and, for example, 25 below the insulator material cathode 11.
Ten particulate material cathodes 12 are installed at equal intervals separated by mm. An RF power source is connected to the insulator material cathode 11.
A DC power source is connected to the particulate material cathode 12. A magnet 14 is arranged above the insulator material cathode 11.

Then, a glass substrate 1 having a length of 300 mm, a width of 400 mm, and a thickness of 1.1 mm, for example, Corning product number 7059 is placed on the stage 13 of the film forming chamber of the sputtering apparatus.

After the film formation chamber was kept at room temperature by the sputtering apparatus, the base pressure of the film formation chamber was evacuated to 0.2 Pa, and then nitrogen gas (N2) was flowed at 50 SCCM to adjust the pressure of the film formation chamber to 0.3 Pa. To do. Refrigerant flows in the particulate material cathode 12.

An RF power source of 6 KW is applied to the cathode 11 of the insulator material, and 0.4 K is applied to the cathode 12 of the particulate material.
A DC power source of W is applied to discharge the cathodes 11 and 12 at the same time. As a result, a film in which bismuth fine particles are dispersed in silicon is formed on the substrate 1 on the substrate side (lower layer region).

Approximately 10 minutes after the start of applying the power source, only the DC power source is turned off to stop the discharge of the particulate material cathode 12, and only the insulator material cathode 11 is discharged to form a film for 2 minutes. As a result, a silicon film containing almost no bismuth particles or an extremely small amount of bismuth particles is formed on the bismuth particles and the silicon film already formed on the substrate 1.

The substrate 1 taken out from the film forming chamber is heat-treated at 200 ° C. in a nitrogen gas atmosphere.

In the light-shielding film 2 thus formed, the deposition concentration of bismuth fine particles in silicon in the film thickness direction is
It is formed to be high on the substrate 1 side and almost zero or extremely low on the film surface side opposite to the substrate 1. The depth from the film surface of the film surface side area where the deposition concentration of bismuth particles is low is such that the diffusion of bismuth particles at the longest processing time at the highest process temperature that acts in the manufacturing process of liquid crystal display devices described later It is a depth that does not reach. When the insulator is silicon oxide (SiOx) and the semi-metal fine particles are bismuth, the depth from the film surface of the region on the film surface side where the deposition concentration of bismuth fine particles is low is the highest process that works in the manufacturing process of liquid crystal display devices. It is 1000 Å when the temperature is 230 ° C. and the maximum treatment time is 1 hour.

Then, the thickness of the formed light-shielding film 2 was measured by a contact type step gauge, and a black film having a thickness of 4000 angstrom was obtained.

FIG. 3 shows the measurement results of the transmittance of the light transmission spectrum and the reflectance of the reflection spectrum of the light shielding film 2 in the visible light region. In FIG. 3, the film forming pressure is 0.5 Pa,
For 0.6 Pa and 0.75 Pa, the broken line shows the transmittance and the solid line shows the reflectance. As shown in FIG. 3, although the light absorption power is reduced on the long wavelength side, the light transmission blocking ability is about 1% or less as a whole, and the light blocking ability required for the liquid crystal display device is It shows a sufficient value.

FIG. 4 shows the measurement results of the resistance of the film surface of the light-shielding film 2 with the 2-terminal prober. FIG. 4 shows the current-voltage characteristics at this time, and for example, it has been found that when the electric field strength is 0.1 V / μm, it shows a relatively high value of 6 × 10 ¹⁰ Ωcm or more in terms of deposition resistance. That is, the light-shielding film 2 is a film having a sufficient light-shielding ability and a high specific resistance, and has a characteristic that it can be used on the array substrate side of a liquid crystal display device.

In the sputter film forming process of the light shielding film 2, the arc power supplied to the particulate material cathode 12 is changed from large to small as described above, and the arc power supplied to the insulator material cathode 11 is changed. A similar film can be formed by changing the film size from small to large, and by performing both of them, a similar film can be formed. The change of the arc power from large to small or from small to large may be turned on or off, or may be continuously variable.

Next, a liquid crystal display device using the substrate 1 on which the light shielding film 2 is formed as an array substrate will be described.

FIG. 5 is a sectional view of a liquid crystal display device, in which the light-shielding film (black matrix film) 2 is formed on one main surface of an insulating substrate, for example, a glass substrate 1 having a product number 1737 manufactured by Corning. On the glass substrate 1 including the light shielding film 2, silicon oxide (SiO) or silicon nitride (S
A transparent insulating film 21 such as iN) is formed.

A transparent conductive film of ITO (Indium Tin Oxide) is formed on a portion of the upper surface of the transparent insulating film 21 excluding a part of the light shielding film 2.
22 and a metal film 23 of a molybdenum-tungsten alloy are laminated to form a source electrode 24 and a drain electrode 25 with these two layers, and a display pixel electrode 26 is formed by the transparent conductive film 22 integrated with the source electrode 24. ing.

A semiconductor layer 27 of amorphous silicon is formed so as to be connected to the source electrode 24 and the drain electrode 25.

On the semiconductor layer 27, silicon nitride (Si
N) first silicon nitride film 28, silicon oxide (Si
O) silicon oxide film 29 and second silicon nitride film 30
Are laminated and the gate insulating film 31 is formed by these three layers.

An aluminum (Al) film and a molybdenum (Mo) film are laminated on the second silicon nitride film 30, and a gate electrode 32 is formed by these two layers. With these, a positive staggered thin film transistor 33 is formed. Are formed.

Furthermore, silicon nitride (Si
The insulating protective film 34 of N) is formed, and the array substrate 35 is formed.

On the other hand, ITO is formed on one main surface of an insulating substrate, for example, a glass substrate 36 of product number 1737 manufactured by Corning Incorporated.
A counter electrode 37 formed of a transparent conductive film such as is formed, and a counter substrate 38 is formed.

In addition, polyimide films 39 and 40 are formed on the opposing surfaces of the array substrate 35 and the counter substrate 38, and polarizing plates 41 and 42 are attached to the opposite surfaces of the array substrate 35 and the counter substrate 38. A liquid crystal 43 is sandwiched and sandwiched between.

Next, a method of manufacturing the liquid crystal display device will be described.

As shown in FIG. 2, the light-shielding film 2 is formed on the substrate 1 by the sputtering device. In the formed light-shielding film 2, the deposition concentration of bismuth particles in silicon in the film thickness direction is
It is formed to be high on the substrate 1 side and almost zero or extremely low on the film surface side opposite to the substrate 1. The depth from the film surface of the film surface side area where the deposition concentration of bismuth particles is low is such that the diffusion of bismuth particles at the longest processing time at the highest process temperature that acts in the manufacturing process of liquid crystal display devices described later It is a depth that does not reach. When the insulator is silicon oxide (SiOx) and the semi-metal fine particles are bismuth, the depth from the film surface of the region on the film surface side where the deposition concentration of bismuth fine particles is low is the highest process that works in the manufacturing process of liquid crystal display devices. It is 1000 Å when the temperature is 230 ° C. and the maximum treatment time is 1 hour.

This substrate 1 is subjected to a PEP process, and the light shielding film 2 is etched into a predetermined matrix shape as shown in FIG. That is, jet cleaning is performed first,
Only bismuth is selectively decolorized, silicon is subsequently processed by chemical dry etching (CDE), and as residual treatment, acetic acid / hydrogen peroxide solution wet etching (decolorization), carbon tetrafluoride (CF4) / carbon dioxide gas (O2)
Chemical dry etching and acetic acid / hydrogen peroxide water wet etching (re-bleaching) are performed in order.

The dry etching does not etch the non-bleached portion, but only the decolorized portion. The cross-sectional shape can obtain a taper shape depending on how decolorization occurs, and the decolorized portion is shown in FIGS. 7 to 9.

Subsequently, as shown in FIG. 10, plasma C
A transparent insulating film 21 is formed on the entire surface of the substrate 1 so as to cover the light shielding film 2 with a VD device. It is desirable that the transparent insulating film 21 be a film having excellent step coverage.
A silicon oxide film formed by a plasma CVD apparatus using a mixed gas of EOS (Tetraethylorthosi1icate: Si [OC2H5] 4) and oxygen gas is used. When nitrogen gas or the like is added to the mixed gas, a silicon oxynitride film is formed, and although the step coverage is slightly inferior, a film excellent in water resistance and blocking of impurity ions such as sodium (Na) can be obtained. In practice, a silicon nitride film may be further stacked on these oxide films or oxynitride films by a plasma CVD apparatus. This is to obtain a good quality interface with the a-Si layer in the channel portion.

By the way, the light-shielding film 2 is formed such that the deposition concentration of fine particles of bismuth in silicon in the film thickness direction is high on the substrate 1 side and almost zero or extremely low on the film surface side opposite to the substrate 1. The depth of the region on the film surface side where the deposition concentration of the bismuth fine particles is low from the film surface is
The depth is such that the diffusion of bismuth fine particles does not reach the film surface during the longest processing time at the highest process temperature that acts in the manufacturing process of the liquid crystal display device. Therefore, plasma CVD
Even if fine particles of bismuth diffuse into the film surface of the light shielding film 2 during the process of forming the transparent insulating film 21 by the apparatus, the fine particles of bismuth are formed on the surface of the light shielding film 2 in the initial stage of forming the transparent insulating film 21. Never reaches plasma C
It is possible to sufficiently suppress abnormal growth of the transparent insulating film 21 formed by the VD device. Therefore, the flatness of the transparent insulating film 21 is ensured, and a thin continuous film can be formed.

Then, using a sputtering apparatus, ITO
The transparent conductive film 22 and the metal film 23 of molybdenum-tungsten alloy are laminated and formed by photolithography, and the source electrode 24 integrated with the display pixel electrode 26 is formed.
And the drain electrode 25 is formed.

Then, as shown in FIG.
A semiconductor layer 27 of amorphous silicon, a first silicon nitride film 28, a silicon oxide film 29, and a second silicon nitride film 30 are formed so as to cover 24, the drain electrode 25, and the display pixel electrode 26.
A plasma CVD apparatus is used to sequentially form layers.

Subsequently, as shown in FIG. 12, an aluminum film and a molybdenum film are laminated by a sputtering apparatus, and a gate electrode 32 is formed by etching processing by photolithography.

Further, as shown in FIG. 5, a silicon oxide film 29, a first silicon nitride film 28, a semiconductor layer 27, and a metal film 23.
Is etched by photolithography, and then the entire surface is coated with an insulating protective film 34 such as silicon nitride by a plasma CVD apparatus to form an array substrate 35.

On the other hand, as shown in FIG. 5, a glass substrate
A counter electrode 37 made of ITO is formed on 36, and a counter substrate 38 is formed.

Then, the polyimide films 39 and 40 are formed on the opposed surfaces of the array substrate 35 and the opposed substrate 38, and the polarizing plates 41 and 42 are attached to the opposite surfaces. Also, the array substrate 35
Then, the counter substrate 38 is bonded, and the liquid crystal 43 is sealed between the array substrate 35 and the counter substrate 38 to form a liquid crystal display substrate.

As the light-shielding film, for example, a cermet film in which fine particles of bismuth are dispersed in aluminum nitride may be used. This is obtained by co-sputtering bismuth and aluminum nitride, and a film having a film thickness of 5000 Å, a resistivity of 1E9 Ωcm and an optical density of 3 is obtained. The light shielding film is formed by etching by photolithography, and plasma etching using a Cl-based gas such as HCl is suitable for the etching.

Further, although the liquid crystal display device in which the light shielding film is formed on the array substrate is shown in the above embodiment, the light shielding film of the above embodiment is applied to the liquid crystal display device in which the light shielding film is formed on the counter substrate. Similar effects can be obtained.

The light-shielding film of the present invention can be applied not only to the active matrix type liquid crystal display device but also to an a-Si contact sensor or the like.

[0061]

According to the present invention, by forming a light-shielding film in which the deposition concentration of fine particles in the insulator in the film thickness direction is high on the substrate side and low on the film surface side opposite to the substrate, this light shielding film is formed. It is possible to suppress abnormal growth of the laminated film formed by the plasma CVD apparatus on the film surface of the film, and improve the manufacturing yield.

Further, by using this light-shielding film in a liquid crystal display device, productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a light shielding film showing an embodiment of the present invention.

FIG. 2 is a perspective view of a film forming apparatus according to the same embodiment.

FIG. 3 is a graph showing reflectance and transmittance characteristics of the light shielding film according to the above embodiment.

FIG. 4 is a graph showing resistance characteristics of the light shielding film according to the above embodiment.

FIG. 5 is a cross-sectional view of the liquid crystal display device of the above embodiment.

FIG. 6 is a cross-sectional view showing the manufacturing process of the array substrate according to the embodiment.

FIG. 7 is a cross-sectional view of the light shielding film according to the above embodiment.

FIG. 8 is a cross-sectional view of the light shielding film according to the above embodiment.

FIG. 9 is a cross-sectional view of the light shielding film according to the above embodiment.

FIG. 10 is a cross-sectional view showing the manufacturing process of the array substrate, which is subsequent to FIG. 6 in the embodiment.

FIG. 11 is a cross-sectional view showing the manufacturing process of the array substrate, which is subsequent to FIG. 10 in the embodiment.

FIG. 12 is a cross-sectional view showing the manufacturing process of the array substrate, which is subsequent to FIG. 11 in the embodiment.

[Explanation of symbols]

 1 substrate 2 light shielding film 11 insulator material cathode 12 fine particle material cathode 35 array substrate 38 counter substrate 43 liquid crystal

[Procedure amendment]

[Submission date] March 12, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a light shielding film showing an embodiment of the present invention.

FIG. 2 is a perspective view of a film forming apparatus according to the same embodiment.

FIG. 3 is a graph showing reflectance and transmittance characteristics of the light shielding film according to the above embodiment.

FIG. 4 is a graph showing resistance characteristics of the light shielding film according to the above embodiment.

FIG. 5 is a cross-sectional view of the liquid crystal display device of the above embodiment.

FIG. 6 is a cross-sectional view showing the manufacturing process of the array substrate according to the embodiment.

FIG. 7 is an SEM photograph of the decolorized portion of the light shielding film according to the embodiment.

FIG. 8 is an SEM photograph of the decolorized portion of the light shielding film according to the above embodiment.

FIG. 9 is an SEM photograph of the decolorized portion of the light shielding film according to the above embodiment.

FIG. 10 is a cross-sectional view showing the manufacturing process of the array substrate, which is subsequent to FIG. 6 in the embodiment.

FIG. 11 is a cross-sectional view showing the manufacturing process of the array substrate, which is subsequent to FIG. 10 in the embodiment.

FIG. 12 is a cross-sectional view showing the manufacturing process of the array substrate, which is subsequent to FIG. 11 in the embodiment.

[Explanation of symbols] 1 substrate 2 light-shielding film 11 insulator material cathode 12 fine particle material cathode 35 array substrate 38 counter substrate 43 liquid crystal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomoyuki Sakaguchi 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Stock company Toshiba Yokohama office

Claims (8)

[Claims] 1. A light-shielding film formed on a substrate, in which at least one kind of fine metal particles and semi-metal fine particles is dispersed in an insulator, wherein A light-shielding film, wherein the deposition concentration is high on the substrate side and low on the film surface side opposite to the substrate. 2. The depth from the film surface of the region on the film surface side where the deposition concentration of fine particles is low is such that the diffusion of fine particles does not reach the film surface during the longest processing time at the highest process temperature that acts in the manufacturing process. The light-shielding film according to claim 1, wherein 3. When the insulator is silicon oxide and the semimetal fine particles are bismuth, the depth from the film surface of the region on the film surface side where the deposition concentration of the fine particles is low is 230 ° C. which is the maximum process temperature that acts in the manufacturing process. 3. The light-shielding film according to claim 2, which has a maximum processing time of 1 hour and is 1000 Å. 4. A light-shielding film forming method for forming a light-shielding film in which at least one kind of fine particles of metal fine particles and semi-metal fine particles is dispersed in an insulator on a substrate, the insulator forming the light-shielding film. Different arc powers are applied to the material cathode and the particle material cathode, and the light-shielding film in which the concentration of particles in the insulator in the film thickness direction is high on the substrate side and low on the film surface side opposite to the substrate is formed by sputtering. A method for forming a light-shielding film, comprising: 5. The light-shielding film is sputtered by at least one of a change in the arc power applied to the cathode of the particulate material from a high level to a low level and a change in the arc power applied to the cathode of the insulator material from a low level to a high level in the sputter deposition process. The method for forming a light-shielding film according to claim 4, wherein the film is formed. 6. The light-shielding film forming method according to claim 5, wherein the cathode of the insulating material is a flat plate, and the cathode of the particulate material has a structure in which the particulate material is bonded to the outer periphery of a metal tube through which a coolant flows. 7. An array substrate on which the light-shielding film according to claim 1 is formed, a counter substrate provided so as to face the array substrate, and a liquid crystal sandwiched between the array substrate and the counter substrate. A liquid crystal display device comprising: 8. An array substrate, an opposed substrate provided facing the array substrate and having the light-shielding film according to claim 1, and a liquid crystal sandwiched between the array substrate and the opposed substrate. A liquid crystal display device characterized by being provided.