JPS5934655B2 - Manufacturing method of transparent conductive film - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a transparent conductive film.

Currently, transparent conductive films formed on transparent substrates such as glass and plastic are being used in many fields, not only in electronic engineering fields such as electro-optical elements and heating elements, but also as drip-proof or anti-fog glass. .

Conventionally, various methods have been proposed as methods for obtaining the above-mentioned transparent conductive film.

Specifically, a method of spraying an aqueous solution of tin halide onto a heated glass plate, a method of forming a thin film by vapor depositing tin oxide, a method of vapor depositing titanium and then performing forced oxidation to obtain a titanium oxide film with an appropriate resistance value. Examples include a method of vapor depositing gold to obtain a gold vapor-deposited thin film, and a method of vapor depositing indium oxide to obtain a thin film.

However, it is difficult to obtain a uniform conductive film using methods such as spraying, and even in vacuum deposition, the materials are expensive, the vapor pressure is low, the deposition conditions are unstable, the process is complicated, etc. It has been difficult to perform vapor deposition uniformly and with good reproducibility in terms of both transparency and conductivity.

Further, since the reflectance of a gold conductive film having good conductivity is too high, it is insufficient as a transparent conductive film unless antireflection treatment is further applied. In addition, materials that have been forcibly oxidized, such as titanium oxide, have various practical drawbacks, such as a tendency for conductivity to become somewhat unstable. The present inventors kept these difficulties in mind, and as a result of intensive research, they reduced Ξ molybdenum oxide to conductive molybdenum pentoxide by the reducing action of silicon oxide during the vapor deposition process, thereby forming conductive molybdenum oxide.
By forming a silicon oxide-based transparent conductive film, it is possible to easily produce a transparent conductive film with a uniform layer thickness that has high transparency and stable conductivity. It was discovered that a transparent conductive film having any desired conductivity could be easily obtained by changing the ratio of the amount of silicon deposited, and the present invention was completed based on this knowledge.

That is, the gist of the present invention is to vapor-deposit molybdenum trioxide on a silicon oxide film provided on a substrate, and at the same time as the vapor deposition, reduce the molybdenum trioxide to molybdenum pentoxide by the reducing action of silicon oxide, thereby converting the molybdenum trioxide into conductive molybdenum oxide. - A method for producing a transparent conductive film characterized by forming a silicon oxide-based transparent conductive film.

Hereinafter, the present invention will be explained in detail. 5 Molybdenum trioxide is vapor-deposited on the silicon oxide film provided on the substrate, and at the same time as the vapor deposition, the molybdenum trioxide is reduced to molybdenum pentoxide by the reduction action of silicon oxide, and a conductive molybdenum oxide silicon monoxide-based transparent conductive material is created. Forms a film.

In the manufacturing method of the present invention, various materials such as glass, plastic, cloth, and paper can be used as the substrate.

Next, in the production method of the present invention, silicon oxide is a compound of silicon and oxygen, and the ratio of silicon to oxygen can be up to 0 to 2.

In the present invention, it is sufficient that the silicon oxide as a whole has reducibility before forming the transparent conductive film, so a mixture of various silicon and oxygen ratios may be used. However, it can be said that it is preferable for the ratio of silicon to oxygen to be constant from the viewpoint of adjusting the electrical conductivity. Next, as a method for forming a silicon oxide film on the substrate, vacuum heating vapor deposition such as resistance heating, electron beam heating, induction heating or thermal radiation heating, or sputtering can be applied. Next, in the manufacturing method of the present invention, the thickness of the silicon oxide film varies depending on the desired conductivity, but can be up to 5000λ.

Next, the amount of molybdenum trioxide deposited on the silicon oxide film is 10
It is possible to set the film thickness according to the desired conductivity up to about 2,000 people. Next, as a method for vapor depositing molybdenum trioxide, vacuum heating vapor deposition such as resistance heating, electron beam heating, induction heating or thermal radiation heating, or sputtering can be applied.

According to the production method of the present invention, molybdenum trioxide is reduced by silicon oxide and changes to molybdenum pentoxide,
It is thought that a portion of the oxide contains intermediate compounds of pentavalent and hexavalent oxides of molybdenum.

The transparent conductive film obtained by the production method of the present invention has high transparency, exhibits stable conductivity, and has little reflected light.

Silicon oxide and molybdenum trioxide, which are the materials used to manufacture the transparent conductive film according to the manufacturing method of the present invention, are both inexpensive and easily available. It is easy to deposit, and a uniform layer can be obtained. Furthermore, according to the manufacturing method of the present invention, a transparent conductive film having any desired conductivity can be easily obtained by varying the amounts of molybdenum trioxide and silicon oxide deposited. Furthermore, according to the manufacturing method of the present invention, since vapor deposition can be carried out while the substrate is at room temperature, a transparent conductive film can be formed on a substrate that cannot withstand high temperatures, such as plastic. It is. The transparent conductive film obtained by the production method of the present invention can be applied to a wide variety of fields such as electro-optical elements, heat generating elements, drip-proof and anti-fog glass.

As detailed above, according to the manufacturing method of the present invention, a transparent conductive film with high transparency, stable conductivity, little reflected light, and uniform layer thickness can be produced using easily available materials. Not only can it be easily formed, but also a transparent conductive film of arbitrary conductivity can be obtained. Furthermore, according to the production method of the present invention, vapor deposition can be carried out while the substrate is at room temperature.
A transparent conductive film can also be formed on a substrate that cannot withstand high temperatures. Next, the present invention will be further specifically explained by showing examples.

Example Silicon oxide was deposited on a glass substrate by sputtering (1 x 10-2 T0rr) to a thickness of 300 mm, and then molybdenum trioxide was successively deposited by sputtering (1 x
A conductive molybdenum oxide silicon monoxide based transparent conductive film was obtained by vapor deposition to a thickness of 500 mm at a temperature of 10-2T0rr).

Claims (1)

[Claims] 1 Molybdenum trioxide is vapor-deposited on the silicon oxide film provided on the substrate, and at the same time as the vapor deposition, the molybdenum trioxide is reduced to molybdenum pentoxide by the reduction action of silicon oxide, and a transparent conductive molybdenum oxide-silicon oxide system is created. A method for producing a transparent conductive film, characterized by forming a film.