JP3108681B2 - Method for producing conductive film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing a conductive film.

[0002]

2. Description of the Related Art Intelligent buildings are typical of modern buildings. As the demand for intelligent buildings has increased, it has become necessary to prevent radio waves from being emitted and shield external radio waves. There has already been proposed an intelligent building in which an opening is formed using an electromagnetic wave shielding member and the entire building has an electromagnetic wave shielding structure, thereby enabling communication within the building by electromagnetic waves. In this intelligent building, the windows and doorways that open the building
The use of glass with mesh or glass with a conductive film attached shields the entire building from electromagnetic waves. It has also been proposed to form a shield film by combining an ITO (indium oxide doped with tin) film and a metal film and use it for a window glass. These devices are also used to prevent malfunctions of electronic devices.

[0003]

In the case of the glass containing the mesh, the visibility is deteriorated when the opening is formed, and it becomes extremely obstructive. Heat ray reflective glass has come to be widely used for both energy saving effect and color design effect of building exterior, but it is difficult to combine glass with mesh with this heat ray reflective glass because there is no fear of heat cracking. Glass attached with a conductive film is inexpensive, but because it is a plastic film, there is a problem that it is easily scratched and deteriorates, resulting in poor transparency. .

[0004] In the combination of an ITO film and a metal film, IT
The O film itself is an extremely rare metal, so it is expensive and has a lower durability than other metal films. The TiN film or the like used as a constituent film of the heat ray reflective glass also has conductivity, but has a high resistance to use as it is. For example, considering TiN, the specific resistance is 2 × 10 ⁻⁴ Ω.
-It was about cm. In this case, assuming a surface resistance of 20 Ω / □ for providing a shielding performance of 20 dB, a thick film of about 1000 ° or more is required, and the visible light transmittance becomes close to 0%.

[0005]

SUMMARY OF THE INVENTION The present invention has the above-mentioned problems.
It has been made to provide a method for manufacturing a conductive film in which the above-mentioned is solved, and one or more kinds of gold among Ti, Zr and Hf are provided .
Group nitrides, boronitrides, carbides or borocarbides
A method for producing a conductive film as a component, wherein Ti, Zr,
One or more metals of Hf, or nitriding of such metals
Of materials, boronitrides, carbides or borocarbides
An arc discharge plasma stream is directed over the material to vaporize the vaporized material.
Conduction on substrate by emitting ion plating method
Provided is a method for manufacturing a conductive film, which comprises forming a conductive film .

In particular, when a conductive film having a specific resistance of 1.5 × 10 ⁻⁴ Ω · cm or less is formed by performing optimal control by an ion plating method using an arc discharge plasma flow, a single-layer film or a dielectric film can be obtained. By combining with a body film, visible light transmittance of 10% or more can be ensured, and electromagnetic shielding glass with good transparency and various adjustments of glass-side reflection color can be produced.

A description will be given below in accordance with an embodiment of the present invention. FIG. 1 is a sectional view of the basic structure of a substrate with a conductive film to which the present invention is applied . The conductive film 1 has a specific resistance of 1.5 × 10 ⁻⁴ Ω.
Cm or less, in this case, 20 Ω /
With a surface resistance of □, there is a shielding performance of about 20 dB,
The film thickness may be about 750 ° or less, and the visible light transmittance can be reduced to 10% or more by the dielectric film 2, for example, a TiO ₂ film. The reflection color can be changed by changing the thickness of the dielectric film 2, for example, TiO ₂ ,
Variations in the reflection color required by heat ray reflection glass and the like are possible, which is a great advantage as commercial value.

FIG. 2 shows a three-layer structure.
To improve the transmittance, and to improve the conductivity of the conductive film 4 and the dielectric film 3;
By changing the film thickness of No. 5, the reflection color can be further changed. Further, as shown in FIG. 3, a desired optical performance can be provided by combining multiple layers.

The conductive films 1 and 4 are made of Ti, Zr, Hf
Among them, a nitride, boronitride, carbide or a film containing borocarbide as a main component is used in view of durability, cost, and the like. Since these materials have different color tones, the reflection color can be further changed. Among these materials, particularly, TiN, ZrN, and HfN have good heat ray reflection performance and also have a function as heat ray reflection glass.

As the dielectric films 2, 3, and 5, for example, Ti
O ₂ , SnO ₂ , ZnO, ZnS, SiO ₂ , Ta ₂ O
_5. Highly durable metal oxides such as ZrO ₂ , chromium oxide, and hafnium oxide can be employed.

If the dielectric film is made of an oxide of a metal contained in the conductive film as in the examples shown in FIGS. 1 and 2, both can be formed from the same metal material as starting materials. It can be manufactured at low cost by a technique such as ionic ion plating.

When the conductive films 1 and 4 are used for an electromagnetic wave shield, they may be appropriately designed so as to obtain a sheet resistance of about 20 Ω / □ or less and a desired visible light transmittance. When used as a reflector, it may be appropriately determined in consideration of heat ray reflection performance, visible light transmittance, and the like. The thicknesses of the dielectric films 2, 3, and 5 may be determined so as to obtain desired transmittance, reflectance, color tone, and the like by utilizing interference with the conductive film.

[0013] As a method for producing a conductive film, T i, Z
An arc discharge plasma flow is directed over an evaporation material comprising at least one of r, Hf, or a nitride, boronitride, carbide, or borocarbide of such metal to evaporate the evaporation material to form N. _2, CH ways of performing ion plating in an atmosphere such as _4.

In the above method, the conductive film-forming material adheres to the substrate through the high energy ion state . In an ion plating method using an arc discharge plasma flow, a high-speed, low-resistance film can be formed over a large area by forming a large-area sheet plasma by deforming the arc discharge plasma flow into a sheet by a magnetic field. FIG. 4 shows an example of such an apparatus.

FIG. 4 shows an arc discharge plasma source 41 having a composite cathode 21, a first intermediate electrode 22 including an annular permanent magnet, and a second intermediate electrode 23 having a second intermediate electrode including an air core coil. Is shown.

In the apparatus shown in FIG. 4, the anode (hearth) 42 is disposed below the plasma source 41, and the high-density plasma flow generated by the arc discharge generated from the plasma source 41 by the air core coil 46. Is drawn out into the vacuum chamber 43. Further, in order to make the extracted plasma into a sheet shape, a pair of permanent magnets 45 are sandwiched between the hearth 42 and the base 47 with the N-pole surfaces facing each other,
The N pole surface or S pole surface of the permanent magnet 45 is
It is arranged so as to be parallel to the two surfaces or the surface of the substrate 47 on which the film is formed, and the plasma is applied to the hearth 42 or
And a sheet plasma 48 is formed.

In FIG. 4, a sheet plasma 48 deformed into a sheet by a pair of permanent magnets 45 has a thickness from the top to the bottom in FIG. 4 and a width in a direction perpendicular to FIG. The sheet plasma 48 is bent at about 90 ° by the magnetic field generated by the permanent magnet 49 placed under the hearth 42, focuses on the hearth 42, evaporates the raw material 50 in the hearth 42, and evaporates the particles into the hearth 42. A film is formed by adhering on the substrate 47 placed above the substrate.

[0018]

In the ion plating method, the sheet plasma used is an arc discharge, so that the density of the plasma is 50 to 10 as compared with the glow discharge type plasma used in the conventional ion plating.
0 times higher, the ionization degree of gas becomes several tens%, ion density,
The electron density and the neutral active species density are extremely high. By converging such a high-density plasma on the vaporized raw material, it becomes possible to extract an extremely large number of particles from the vaporized raw material, which is 3 to 1 compared with the conventional ion plating method.
0 times high-speed film formation can be realized. Further, N ₂ , CH ₄ ,
Many atmospheric gases such as Ar take highly reactive ions or neutral active states, and in addition, vaporized particles pass through a high-density sheet plasma before reaching the substrate, resulting in high reactivity. It becomes a neutral active species. As a result, the reactivity on the substrate is increased, and a conductive film having a low specific resistance can be realized at a higher deposition rate than in the past without heating the substrate.

[0019]

EXAMPLE A glass plate was used as the substrate 47, and was deposited by the following method. First, the degree of vacuum in the vacuum chamber 43 is set to 2 × 10 ⁻⁵ To.
rr, then introduce N ₂ gas to 4.0 × 10
^{At -4} Torr, an arc discharge was performed using the apparatus shown in FIG. 4 with the DC power supply 44 set to 250 A and 70 V.
The distance between the hearth 42 having Ti as a vapor deposition material and the substrate 47 was set to about 60 cm, and the substrate was fixed. Film thickness 55
0 °, specific resistance 1.1 × 10 ⁻⁴ Ω · cm, visible light transmittance 1
A film of 2% (substrate glass 92%) was obtained. This is a film forming speed of 2000 ° / min, which is much faster than a method using an EB (electron beam) gun or the like. As the deposition performed without heating the substrate, a deposition having a considerably low specific resistance was obtained.

Next, the atmosphere gas was changed to O ₂ , a dielectric film made of TiO ₂ was formed on the TiN film by 300 °, and an electromagnetic wave shielding glass was formed. Sheet resistance is 20Ω / □
In a wavelength range of 100 MHz to 1 GHz, about 20 d
B showed the shielding effect. The overall visible light transmittance is 2
At 0%, the appearance was silver.

[0021]

According to the present invention, a conductive film having a low specific resistance is provided.
Can be formed at high speed. The conductive film obtained by the present invention
The electromagnetic shielding glass used can be significantly lower in price and improved in design compared to a double-layered glass sandwiching a metal mesh, which has been conventionally used as an electromagnetic shielding glass, and uses Ag and ITO. Low price,
It can be expected to improve physical, chemical and durability and to provide design. As electromagnetic shielding glass, as its performance,
Each stage has 20 dB, 30 dB, 60 dB, etc., especially for relatively low-level devices whose main target is to prevent malfunctions of electronic devices, such as 20 dB products.
Especially its price is important. By using the method of the present invention, a significantly lower price can be realized, and the durability can be improved. The electrical characteristics of the nitride film vary greatly depending on the film formation conditions, and a low-resistance film can be manufactured by optimizing the electrical characteristics. Since TiN, ZrN, and HfN have high heat ray reflection performance, they also have a great effect as heat ray reflection glass.

With regard to the electromagnetic shielding performance, it is not only used as a window glass, but also used directly as a protective plate to prevent malfunction of electronic equipment, or as a health countermeasure like a window glass of a microwave oven. It is used to prevent electromagnetic waves from being emitted. These applications require durability, especially abrasion resistance and low cost,
It is possible to satisfy the demand sufficiently. If a multilayer film is formed, a film having special optical characteristics becomes possible, and the range of application is extremely wide.

The present invention is not limited to the above embodiment, and various modifications are possible. Although glass is used as the substrate, a resin or other transparent body may be used. Further, heat ray absorbing glass may be used. The window opening can be applied not only to buildings but also to aircraft, automobiles, and the like.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one example (an example of two layers) of an electromagnetic wave shield using a conductive film obtained according to the present invention.

FIG. 2 is a cross-sectional view of one example of an electromagnetic wave shield using a conductive film obtained according to the present invention (in a three-layer example, the conductive film is sandwiched between dielectric films). .

FIG. 3 is a cross-sectional view of one example (an example of a multilayer film) of an electromagnetic wave shield using a conductive film obtained according to the present invention.

Figure 4 is a schematic cross-sectional view of one example of an apparatus for by the arc plasma stream ion plating method using the forming a conductive film.

[Description of Signs] 1: Conductive film 2: Dielectric film 21: Composite cathode 22: First intermediate electrode with built-in annular permanent magnet 23: Second intermediate electrode with built-in air core coil 41: Arc discharge plasma flow source 42: Hearth (Anode) 43: Vacuum chamber 44: DC power supply for plasma generation 45: Permanent magnet 46: Air-core coil 47: Base 48: Sheet plasma 49: Permanent magnet 50: Evaporation raw material 51: Discharge gas inlet 52: Reactant gas inlet mouth

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-58598 (JP, A) JP-A-2-90101 (JP, A) JP-A-2-5308 (JP, A) JP-A-1- 167915 (JP, A) JP-A-63-255366 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05K 9/00

Claims (1)

(57) [Claims] 1. The method of claim 1 wherein at least one metal selected from the group consisting of Ti, Zr and Hf
Mainly nitride, boronitride, carbide or borocarbide
A method for producing a conductive film, wherein Ti, Zr, Hf
One or more metals, or nitrides of such metals,
Boric nitride, conductive you and forming a conductive film on a substrate by an ion plating method for evaporating the evaporation material led to the arc plasma stream onto the evaporation material consisting of carbide or boride carbides Manufacturing method of membrane.