JP2012132090A - Method for forming electrically conductive transparent zinc oxide-based film, electrically conductive transparent zinc oxide-based film, and elecrically conductive transparent substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming an electrically conductive transparent zinc oxide-based film which combines excellent electroconductivity with excellent chemical durability by an ion plating method.SOLUTION: The method employs an ion plating method to form an electrically conductive transparent zinc oxide-based film and uses a target obtained by processing an oxide sintered compact or an oxide mixture substantially comprising zinc, titanium and oxygen, wherein the atomic ratio Ti/(Zn+Ti) of the titanium to the sum of the zinc and the titanium is greater than 0.02 but does not exceed 0.1.

Description

  The present invention relates to a method for forming a zinc oxide-based transparent conductive film having good conductivity, a zinc oxide-based transparent conductive film formed by the method, and a transparent conductive substrate provided with the film.

  Transparent conductive films that combine electrical conductivity and light transmission have been used as electrodes in solar cells, liquid crystal display elements, and other various light receiving elements, as well as automotive window and heat ray reflective films for buildings, It is used for a wide range of applications such as anti-static films and transparent heating elements for anti-fogging in frozen showcases. In particular, it is known that a transparent conductive film having low resistance and excellent conductivity is suitable for a solar cell, a liquid crystal display element such as a liquid crystal, organic electroluminescence, and inorganic electroluminescence, a touch panel, and the like.

Conventionally, as the transparent conductive film, for example, a tin oxide (SnO ₂ ) -based thin film, a zinc oxide (ZnO) -based thin film, and an indium oxide (In ₂ O ₃ ) -based thin film are known. Specifically, as the tin oxide-based transparent conductive film, those containing antimony as a dopant (ATO) and those containing fluorine as a dopant (FTO) are known, and as a zinc oxide-based transparent conductive film, The one containing aluminum as a dopant (AZO) and the one containing gallium as a dopant (GZO) are known, and the indium oxide-based transparent conductive film includes one containing tin as a dopant (ITO; Indium Tin Oxide). It has been. Among them, the most industrially used is an indium oxide-based transparent conductive film, and in particular, an ITO film is widely used because of its low resistance and excellent conductivity.

However, an indium oxide-based transparent conductive film such as an ITO film is expensive and may be depleted of resources because In (indium), which is an essential raw material, is a rare metal, and has toxicity and is harmful to the environment and the human body. In recent years, there is a demand for an industrially versatile transparent conductive film that can be substituted for an ITO film because it may adversely affect the film. Under such circumstances, zinc oxide-based transparent conductive films that can be manufactured industrially are attracting attention, and research is being conducted to improve their conductive performance. Specifically, attempts have been made to dope ZnO with various dopants in order to increase conductivity, and the optimum doping amount and minimum resistivity have been reported for each of the various dopants (Non-patent Document 1).
According to this report, for example, when TiO ₂ is doped, the optimum doping amount is 2% by mass, and the minimum resistivity at that time is 5.6 × 10 ⁻⁴ Ω · cm. ing. As described above, the zinc oxide-based transparent conductive film has been improved to obtain a low resistance comparable to that of the ITO film at the laboratory level.

  However, the high performance of zinc oxide-based transparent conductive films reported at the laboratory level has been achieved by precise film formation methods such as laser beam ablation and molecular beam epitaxy, and these methods are In terms of film formation speed and film formation area, it was not suitable for industrial mass production.

A direct current magnetron sputtering method is known as a typical method for industrially manufacturing a zinc oxide-based transparent conductive film at a mass production level.
This DC magnetron sputtering method is excellent in terms of film formation speed and film formation area, but on the other hand, the formed zinc oxide-based transparent conductive film has a large resistivity distribution (surface resistivity at the erosion facing portion). Increase). Moreover, in general, the sputtering method has a large film thickness dependency of the specific resistance. For example, when the film thickness is an extremely thin level of about several tens nm to several hundreds nm, there is a problem that a low specific resistance cannot be obtained. .
On the other hand, if the ion plating method is used, a zinc oxide-based transparent conductive film having a low surface resistance can be formed at a high film formation rate (as described in the DC magnetron sputtering method described above) without causing a large resistivity distribution as in the sputtering method. It is known that the film can be formed in a large film-forming area at about 3 to 5 times. Here, the ion plating method means that a vapor deposition material (film forming material) such as a target is irradiated with a plasma beam or an electron beam by a plasma gun or an electron gun to evaporate (emit) the vapor deposition material. In this method, the deposition material is ionized before reaching the substrate, and the energy of the deposition material is controlled using a potential gradient, and then deposited (incident) on the substrate.

Monthly Display, September 1999, p10 “Trends in ZnO-based transparent conductive films”

However, the conventional zinc oxide-based transparent conductive films have the disadvantage of poor chemical durability such as heat resistance, moisture resistance, and chemical resistance (alkali resistance, acid resistance), although excellent in terms of conductivity. . In particular, in the ion plating method, in order to obtain a transparent conductive film by supplementing the oxygen deficient in the film, the film is formed while supplying oxygen into the ion plating apparatus. As a result, the surface resistance of the zinc oxide-based conductive film also increases, and the heat resistance and moisture resistance decrease.
Accordingly, an object of the present invention is to provide a method for forming a zinc oxide-based transparent conductive film having both excellent conductivity and chemical durability by an ion plating method, and a zinc oxide-based transparent conductive film formed by the method. And a transparent conductive substrate provided with the film.

  As a result of intensive studies to solve the above problems, the inventors of the present invention have made it possible to reduce the amount of titanium doped (content) to a low resistance in a film made of titanium-doped zinc oxide obtained by doping titanium oxide with titanium. The chemical durability of zinc oxide-based transparent conductive films can be improved by increasing the amount of dope, which was considered to be optimal for achieving high purity, and adding more titanium, which has better chemical durability than zinc. At that time, it was also predicted that the resistivity of the film would increase if the titanium doping amount deviated from the previously reported optimum value. However, as a result of repeated studies, contrary to this prediction, in the film forming material when forming a zinc oxide based transparent conductive film by the ion plating method so that the doping amount of titanium is larger than the conventional optimum value. The inventors have found that when the atomic ratio of titanium and zinc contained is set in a specific range, it is possible to achieve both the conductivity (low resistance) and chemical durability of the resulting film, and the present invention has been completed.

That is, this invention consists of the following structures.
(1) A method of forming a zinc oxide-based transparent conductive film by an ion plating method, which consists essentially of zinc, titanium and oxygen, and the atomic ratio of titanium to the total of zinc and titanium Ti / (Zn + Ti) A method comprising using a target obtained by processing an oxide sintered body or an oxide mixture having a ratio of 0.02 to 0.1.
(2) The method according to (1), wherein the titanium is titanium derived from low-valent titanium oxide represented by the formula TiO _{2 -X} (X = 0.1-1).
(3) A zinc oxide-based transparent conductive film formed by the method described in (1) or (2) above.
(4) A transparent conductive substrate comprising the zinc oxide-based transparent conductive film according to (3) above on a transparent substrate.
(5) The transparent conductive substrate according to (4), wherein the transparent substrate is a glass plate, a resin film, or a resin sheet.

  According to the present invention, a zinc oxide-based transparent conductive film having excellent conductivity and chemical durability can be formed by an ion plating method. In addition, the transparent conductive film formed in this manner is extremely useful industrially because it has the advantage that it does not require toxic indium, which is a rare metal.

It is the schematic which shows an example of the ion plating apparatus which can be used suitably in this invention.

(Method for forming zinc oxide-based transparent conductive film)
The method for forming a zinc oxide-based transparent conductive film of the present invention uses a specific oxide sintered body or oxide mixture as a film forming material (hereinafter also referred to as “evaporation material”) by an ion plating method. This is a method of forming a film. The film forming material may be a single target formed by processing an oxide sintered body or an oxide mixture containing both zinc and titanium.
First, a specific oxide mixture constituting the film forming material will be described.

(Oxide mixture)
The specific oxide mixture is a mixture formed by mixing raw material powders substantially composed of zinc, titanium, and oxygen and containing zinc and titanium in a specific ratio. Here, “substantially” means that 99% or more of all atoms constituting the oxide mixture are composed of zinc, titanium, or oxygen.
The atomic ratio of titanium and zinc contained in the film forming material used in the method for forming a zinc oxide-based transparent conductive film of the present invention, that is, the atomic ratio Ti / (Zn + Ti) of titanium to the total of zinc and titanium is: It exceeds 0.02 and is 0.1 or less. When the value of Ti / (Zn + Ti) is 0.02 or less, the doping effect of titanium is insufficient, the conductivity of the formed transparent conductive film is lowered, and the chemical durability is not sufficiently improved. On the other hand, when the value of Ti / (Zn + Ti) exceeds 0.1, the impurity scattering factor during film formation increases, the mobility decreases, and the conductivity decreases. Preferably, the atomic ratio of titanium and zinc in the film forming material or in the oxide mixture is Ti / (Zn + Ti) = 0.025 to 0.09, more preferably Ti / (Zn + Ti) = 0. 0.03 to 0.08.

The specific oxide mixture is preferably composed of a zinc oxide phase and a titanium oxide phase. It is important that the titanium oxide is in the state of low-valent titanium oxide described later, including titanium (III) and titanium (II), which have a low valence. Although sintering may be performed, it is important that a composite oxide with the zinc titanate compound phase is not generated.
Here, the zinc titanate compound phase specifically includes ZnTiO ₃ , Zn ₂ TiO ₄ , those in which titanium element is dissolved in these zinc sites, oxygen deficiency introduced, In addition, a non-stoichiometric composition having a Zn / Ti ratio slightly deviated from these compounds is also included.
In addition, the zinc oxide phase specifically includes ZnO, a solution in which a titanium element is dissolved, an oxygen deficiency introduced, or a non-stoichiometric composition due to zinc deficiency. Including things. The zinc oxide phase usually has a wurtzite structure.

It is preferable that the specific oxide mixture is substantially a mixture of crystal phases of zinc oxide and titanium oxide. In addition, the crystal phase of titanium oxide specifically includes TiO ₂ , Ti ₂ O ₃ , and TiO, as well as substances in which other elements such as Zn are dissolved in these crystals.

The specific oxide mixture includes at least one element selected from the group consisting of gallium, aluminum, tin, silicon, germanium, zirconium and hafnium (hereinafter, these may be referred to as “additive elements”). It is preferable to contain. By containing such an additive element, the specific resistance of the formed transparent conductive film is reduced, and the conductivity can be improved.
When the additive element is contained, the total content is preferably 0.05% or less with respect to the total amount of all metal elements constituting the oxide mixture in terms of atomic ratio. When the content of the additive element is larger than the above range, the specific resistance of the film formed using the oxide mixture as a target may increase.
The additive element may be present in the oxide mixture in the form of an oxide, or may be present in a form substituted (solid solution) in the zinc site of the zinc oxide phase. It may be present in a form substituted (solid solution) in the titanium site of the titanium oxide phase.

  The specific oxide mixture may contain other elements such as indium, iridium, ruthenium, and rhenium as impurities in addition to the essential elements zinc and titanium and the additive element. The total content of elements contained as impurities is preferably 0.5% or less with respect to the total amount of all metal elements constituting the oxide mixture in terms of atomic ratio.

  As the raw material powder, as a titanium source, one or more selected from titanium oxide powder, titanium metal powder and the like, and as a zinc source, one or more selected from zinc oxide powder, zinc hydroxide powder, zinc metal powder and the like Can be used in combination. In particular, the raw material powder preferably includes a mixed powder of titanium oxide powder and zinc oxide powder or zinc hydroxide powder. For example, when the raw material powder is a combination of titanium metal powder and zinc oxide powder or a combination of titanium oxide powder and zinc metal powder, titanium and zinc metal particles are present in the oxide mixture. When this film is formed as a film forming material, the metal particles on the surface of the film forming material are melted during film formation and are not released from the film forming material, and the composition of the obtained film and the composition of the film forming material are There is a tendency to vary greatly.

Examples of the titanium oxide powder include titanium oxide (TiO ₂ ) made of tetravalent titanium, titanium oxide (Ti ₂ O ₃ ) made of trivalent titanium, and titanium oxide (TiO) made of divalent titanium. Although it can be used, the low-valent titanium oxide powder not containing TiO ₂ , particularly the film forming material, is obtained by using titanium oxide (Ti ₂ O ₃ ) made of trivalent titanium as a titanium source. In this respect, it is preferable to use Ti ₂ O ₃ powder as the titanium oxide powder. The reason why it is preferable to use Ti ₂ O ₃ as the titanium source is that the crystal structure of Ti ₂ O ₃ is trigonal and the zinc oxide mixed with it is hexagonal wurtzite. This is because they are in agreement, and are easily dissolved in substitution during solid phase sintering. In addition, it is good to use what has a purity of 99 weight% or more as titanium oxide powder.
Low valence titanium oxide includes not only those having an integer valence of TiO (II) and Ti ₂ O ₃ (III), but also Ti ₃ O ₅ , Ti ₄ O ₇ , Ti ₆ O ₁₁ , and Ti ₅ O. ₉ , including Ti ₈ O _{15 and the} like, in the range represented by the formula TiO _2-X (X = 0.1-1).
The structure of the low valence titanium oxide can be confirmed by the results of instrumental analysis such as an X-ray diffraction apparatus (X-ray diffraction, XRD), an X-ray photoelectron spectrometer (X-ray Photoelectron Spectroscopy, XPS).

The low valence titanium oxide represented by the formula TiO _2-X (X = 0.1-1) may be a mixture of low valence titanium oxide. Usually, it can be produced by heating titanium oxide (TiO ₂ ) in a reducing atmosphere such as a hydrogen atmosphere using carbon or the like as a reducing agent. By adjusting the hydrogen concentration, the amount of carbon as a reducing agent, and the heating temperature, the ratio of the low-valent titanium oxide mixture can be controlled.

As the zinc oxide powder, a powder of ZnO or the like having a wurtzite structure is usually used, and a powder obtained by firing this ZnO in advance in a reducing atmosphere and containing oxygen deficiency may be used. In addition, as a zinc oxide powder, it is good to use what has a purity of 99 weight% or more.
The zinc hydroxide may be either amorphous or crystalline.
The average particle size of each compound (powder) used as the raw material powder is preferably 5 μm or less in order to improve the density of the oxide mixture. Further, the BET specific surface area is not particularly limited.

  When using a mixed powder of titanium oxide powder and zinc oxide powder or zinc hydroxide powder as the raw material powder, the mixing ratio of each powder depends on the type of compound (powder) to be used. What is necessary is just to set suitably so that the atomic ratio of titanium and zinc contained may become the ratio whose value of Ti / (Zn + Ti) is the range mentioned above. In addition, each compound (powder) used as the raw material powder may be only one kind or two or more kinds.

The method for forming the raw material powder is not particularly limited, and for example, the raw material powder may be mixed and the obtained mixture may be formed.
The mixing can be performed using a known mixing method such as a ball mill, a vibration mill, an attritor, a dyno mill, a dynamic mill, or the like, and may be performed dry or wet. From the viewpoint of operability at the time of molding, a binder (for example, polyvinyl alcohol, vinyl acetate, etc.), a dispersant, a release agent, and the like may be added to the mixture. In addition, when mixing is performed in a wet manner, the slurry-like mixture obtained before being subjected to molding may be dried. In that case, for example, drying is performed by using a heat dryer, a vacuum dryer, a freeze dryer, or the like. You can use it.
The obtained mixture can be molded, for example, using a uniaxial press, a cold isostatic press (CIP), or the like, and usually applying a pressure of 1 ton / cm ² or more. In molding, the shape may be a shape suitable for an ion plating method to be described later. For example, the shape may be a disk, a square plate, or the like. In addition, after forming, the dimensions can be adjusted by appropriately combining cutting and grinding.

In molding the mixture, in order to increase the mechanical strength of the oxide mixture, the molded body obtained by molding the mixture as described above may be subjected to thermal annealing. For annealing of the obtained molded body, for example, the molded body is allowed to stand in a non-oxidizing atmosphere (vacuum atmosphere, reducing atmosphere (carbon dioxide, hydrogen, ammonia, etc.)) or an oxidizing atmosphere, and the annealing temperature (maximum temperature reached). ) May be 50 to 600 ° C., and the holding time at this heating temperature may be 0.5 to 48 hours. By annealing, the strength of the molded body can be improved. When annealing is performed in an oxidizing atmosphere, it is desirable to perform annealing at 600 ° C. or lower, preferably 400 ° C. or lower in a reducing atmosphere. This is because TiO and Ti ₂ O ₃ are oxidized to TiO ₂ .
When TiO ₂ is used as the titanium oxide powder, thermal annealing may be performed in either an air atmosphere or a reducing atmosphere as long as the annealing temperature is less than 600 ° C.
Even when annealing is performed in any of the above-described atmospheres, the annealing time (that is, the holding time at the annealing temperature) is preferably 1 hour to 15 hours. If the annealing time is less than 1 hour, the mechanical strength is not sufficiently improved.
Annealing can be performed using, for example, an electric furnace, a gas furnace, a reducing furnace, or the like. In addition, the annealing may be performed simultaneously with the above-described forming using hot pressing, hot isostatic pressing (HIP), discharge plasma sintering (SPS), millimeter wave sintering, microwave sintering, or the like. In addition, after annealing, a dimension can also be adjusted by performing combining cutting, grinding, etc. suitably.

The film forming material used in the method for forming a zinc oxide-based transparent conductive film of the present invention may be a target or tablet by processing the specific oxide mixture.
A processing method in particular is not restrict | limited, What is necessary is just to employ | adopt a well-known method suitably. For example, the surface of the oxide mixture may be subjected to surface grinding or the like, and then cut to a predetermined size and then placed at a predetermined position of the ion plating apparatus.

(Oxide sintered body)
In this invention, it can replace with the said specific oxide mixture, and can use the oxide sintered compact obtained by sintering the said molded object.
The atomic ratio Ti / (Zn + Ti) between titanium and zinc in the film forming material or oxide sintered body is more than 0.02 and not more than 0.1, and preferably Ti / (Zn + Ti) is 0.025 to 0.09, more preferably Ti / (Zn + Ti) is 0.03 to 0.08.

The specific oxide sintered body is preferably composed of a zinc oxide phase and a zinc titanate compound phase, or composed of a zinc titanate compound phase. When the zinc titanate compound phase is contained in the oxide sintered body in this way, the strength of the oxide sintered body itself increases, so film formation under severe conditions (high power, etc.) even under film formation conditions There will be no cracks in the material.
Here, the zinc titanate compound phase specifically includes ZnTiO ₃ , Zn ₂ TiO ₄ , those in which titanium element is dissolved in these zinc sites, and oxygen vacancies are introduced. And those having a non-stoichiometric composition in which the Zn / Ti ratio is slightly deviated from these compounds.
It is preferable that the specific oxide sintered body does not substantially contain a crystal phase of titanium oxide.

The specific oxide sintered body is obtained by, for example, mixing and molding a raw material powder containing a titanium source and a zinc source in an oxide mixture in the same manner as described above, and then sintering the obtained molded body. Can be obtained.
For sintering of the obtained molded body, for example, the molded body is allowed to stand in a non-oxidizing atmosphere (vacuum atmosphere, inert atmosphere, reducing atmosphere), and the firing temperature (maximum reached temperature) is set to 600 to 1700 ° C. What is necessary is just to carry out on the conditions which make holding time in this calcination temperature 0.5 to 48 hours. Normally, when an oxide sintered body is sintered in an inert atmosphere, a vacuum atmosphere or a reducing atmosphere, oxygen deficiency is generated, so the specific resistance of the oxide sintered body is low, and the oxide sintered body is sintered in an oxidizing atmosphere. In this case, the specific resistance becomes high.
The firing temperature is preferably 1000 to 1500 ° C., more preferably 1100 to 1300 ° C., and the holding time is preferably 15 hours or more, more preferably 20 hours or more.
Sintering can be performed using, for example, an electric furnace, a gas furnace, a reduction furnace, or the like.
In addition, the sintering may be performed simultaneously with the above-described molding using hot pressing, hot isostatic pressing (HIP), discharge plasma sintering (SPS), millimeter wave sintering, microwave sintering, or the like. In addition, after baking, a dimension can also be adjusted by combining cutting, grinding, etc. suitably.

  In the sintering, for example, the density of the obtained oxide sintered body is preferably 80% or more, more preferably by performing decomposition while preventing the decomposition in a state where the compact is embedded in the ZnO powder. Is preferably 90% high density.

The film forming material used in the method for forming a zinc oxide-based transparent conductive film of the present invention may be a target or tablet by processing the oxide sintered body.
The processing method is not particularly limited, as in the case of processing the oxide mixture described above, and a known method may be adopted as appropriate. For example, after surface grinding or the like is performed on the oxide sintered body, the oxide sintered body is cut to a predetermined size and then placed at a predetermined position of the ion plating apparatus.

(Ion plating method)
The method for forming a zinc oxide-based transparent conductive film of the present invention is to form a film by an ion plating method. In the ion plating method, a film forming material (evaporation material) is disposed on a hearth as an electrode portion disposed in a film forming chamber, and the evaporation material is irradiated with, for example, argon plasma to heat and evaporate. Each particle of the vapor deposition material that has passed through the plasma is deposited on a substrate placed at a position facing the hearth or the like. For specific methods and conditions at that time, the above-described film-forming material is used. There is no particular limitation other than the use, and a known ion plating method and conditions may be appropriately employed.

Hereinafter, an embodiment of an ion plating method will be described with reference to the drawings.
FIG. 1 shows an example of an ion plating apparatus suitable for performing the ion plating method. The ion plating apparatus 10 includes a vacuum vessel 12 that is a film forming chamber, a plasma gun (plasma beam generator) 14 that is a plasma source that supplies a plasma beam PB into the vacuum vessel 12, and a bottom portion in the vacuum vessel 12. An anode member 16 that is disposed and on which the plasma beam PB is incident is provided, and a transport mechanism 18 that appropriately moves a substrate holding member WH that holds a substrate W to be deposited above the anode member 16.
The plasma gun 14 is of a pressure gradient type, and its main body is provided on the side wall of the vacuum vessel 12. By adjusting the power supply to the cathode 14a, the intermediate electrodes 14b and 14c, the electromagnet coil 14d and the steering coil 14e of the plasma gun 14, the intensity and distribution state of the plasma beam PB supplied into the vacuum vessel 12 are controlled.
Reference numeral 20a indicates a carrier gas introduction path made of an inert gas such as Ar, which is the source of the plasma beam PB.
The anode member 16 includes a hearth 16a as a main anode for guiding the plasma beam PB downward, and an annular auxiliary anode 16b disposed around the hearth 16a.

The hearth 16a is controlled to an appropriate positive potential, and sucks the plasma beam PB emitted from the plasma gun 14 downward. In the hearth 16a, a through hole TH is formed at a central portion where the plasma beam PB is incident, and a vapor deposition material 22 is loaded in the through hole TH. The vapor deposition material 22 is a tablet formed into a columnar shape or a rod shape, and is heated and sublimated by an electric current from the plasma beam PB to generate a vapor deposition material. The hearth 16a has a structure for gradually raising the vapor deposition material 22, and the upper end of the vapor deposition material 22 always protrudes from the through hole TH of the hearth 16a by a certain amount.
The auxiliary anode 16b is composed of an annular container disposed concentrically around the hearth 16a, and a permanent magnet 24a and a coil 24b are accommodated in the container. The permanent magnet 24a and the coil 24b are magnetic field control members, and form a cusp-like magnetic field directly above the hearth 16a, whereby the direction of the plasma beam PB incident on the hearth 16a is controlled and corrected.

The transport mechanism 18 has a large number of rollers 18b arranged in the transport path 18a at equal intervals in the horizontal direction to support the substrate holding member WH, and rotates the rollers 18b to move the substrate holding member WH horizontally at a predetermined speed. And a drive device (not shown) to be moved. The substrate W is held by the substrate holding member WH. In this case, the substrate W may be fixedly disposed above the inside of the vacuum vessel 12 without providing the transport mechanism 18 for transporting the substrate W.
The oxygen gas in the oxygen gas container 19 is supplied to the vacuum container 12 while the flow rate is adjusted to a predetermined amount by the mass flow meter 21. Reference numeral 20b indicates a supply path for supplying an atmospheric gas other than oxygen, and reference numeral 20c indicates a supply path for supplying an inert gas such as Ar to the hearth 16a. Reference numeral 20d denotes an exhaust system.

An ion plating method using the ion plating apparatus 10 of FIG. 1 as described above will be described.
First, the vapor deposition material 22 is attached to the through hole TH of the hearth 16a disposed at the lower part of the vacuum vessel 12. On the other hand, the substrate W is disposed at an opposing position above the hearth 16a. Next, a process gas corresponding to the film forming conditions is introduced into the vacuum vessel 12. A DC voltage is applied between the cathode 14a of the plasma gun 14 and the hearth 16a. Then, a discharge is generated between the cathode 14a of the plasma gun 14 and the hearth 16a, thereby generating a plasma beam PB. The plasma beam PB reaches the hearth 16a by being guided by a magnetic field determined by the steering coil 14 and the permanent magnet 24a in the auxiliary anode 16b. At this time, since argon gas is supplied around the vapor deposition material 22, the plasma beam PB is easily attracted to the hearth 16a.

The vapor deposition material 22 exposed to the plasma is gradually heated. When the vapor deposition material 22 is sufficiently heated, the vapor deposition material 22 sublimates and the vapor deposition material evaporates (emits). The vapor deposition material is ionized by the plasma beam PB, adheres (incides) to the substrate W, and is formed into a film. In addition, since the flight direction of the vapor deposition material can be controlled by controlling the magnetic field above the hearth 16a by the permanent magnet 24a and the coil 24b, the plasma activity distribution and the reactivity of the substrate W above the hearth 16a. The film formation speed distribution on the substrate W can be adjusted in accordance with the distribution, and a thin film having a uniform film quality can be obtained over a wide area.
The oxygen partial pressure in the vacuum vessel 12 is not particularly limited, but is preferably adjusted to 0.012 Pa or less. Further, if necessary, a plurality of plasma beams can be prepared, and film formation can be continuously performed in a plurality of partitioned vacuum chambers.

(Zinc oxide based transparent conductive film)
The zinc oxide-based transparent conductive film of the present invention is a transparent conductive film made of titanium-doped zinc oxide formed by the above-described method for forming a zinc oxide-based transparent conductive film. The atomic ratio Ti / (Zn + Ti) of titanium and zinc contained in the zinc oxide-based transparent conductive film is more than 0.02 and not more than 0.1, preferably Ti / (Zn + Ti) is 0.025 to 0.09, More preferably, Ti / (Zn + Ti) is 0.03 to 0.08. As a result, the film can exhibit excellent conductivity due to the doping effect of titanium and also has excellent chemical durability. In this zinc oxide-based transparent conductive film, titanium is substituted and dissolved in zinc sites of a zinc oxide wurtzite crystal structure.

The zinc oxide-based transparent conductive film of the present invention has good transparency and excellent conductivity and chemical durability (heat resistance, moisture resistance, chemical resistance (alkali resistance, acid resistance) as described above. Etc.). Specifically, the zinc oxide-based transparent conductive film of the present invention is the biggest drawback of the conventional zinc oxide-based transparent conductive film (that is, the zinc oxide-based transparent conductive film not containing a specific amount of titanium as in the present invention). Chemical durability is improved without impairing transparency and conductivity. Specifically, although the conventional zinc oxide-based transparent conductive film depends on the film thickness, with respect to heat resistance, the specific resistance increases rapidly when heated in an air atmosphere at 200 ° C. for 30 minutes. When kept in a constant temperature and humidity atmosphere (temperature 60 ° C., relative humidity 90%), it rapidly increased. In addition, the chemical resistance of the conventional zinc oxide-based transparent conductive film disappears completely after 10 minutes when immersed in a 3% hydrochloric acid aqueous solution at 40 ° C. or a 3% sodium hydroxide solution at 40 ° C., for example. It was.
The film thickness of the zinc oxide-based transparent conductive film of the present invention may be appropriately set depending on the application and is not particularly limited, but is preferably 50 to 600 nm, more preferably 100 to 500 nm. If the film thickness is less than 50 nm, sufficient specific resistance may not be ensured. On the other hand, if the film thickness exceeds 600 nm, the film may be colored.

(Transparent conductive substrate)
The transparent conductive substrate of the present invention comprises a zinc oxide-based transparent conductive film formed on a transparent base material by the method for forming a transparent conductive film described above.
The transparent substrate is not particularly limited as long as the transparent substrate can maintain the shape under film forming conditions by the ion plating method. For example, inorganic materials such as various glasses, thermoplastic resins and thermosetting resins (for example, epoxy resin, polymethyl methacrylate, polycarbonate, polystyrene, polyethylene sulfide, polyethersulfone, polyolefin, polyethylene terephthalate, polyethylene naphthalate, triacetyl cellulose) Plate-like material, sheet-like material, film-like material, etc. formed of a resin such as a plastic such as polyimide), and in particular, any of a glass plate, a resin film and a resin sheet Is preferred. Since the ion plating method is a film forming method that can obtain a film having better crystallinity at a lower temperature than the sputtering method, it can also be formed on a resin film or a resin sheet. The visible light transmittance of the transparent substrate is usually 90% or more, preferably 95% or more.

In addition, when using a resin film or a resin sheet as the transparent substrate, in order to disperse and uniformize damage caused by film formation by the ion plating method, an industrially performed roll-to-roll film formation method, It is preferable to form a film in a state where tensile stress is applied while controlling the unwinding speed and the winding speed. Furthermore, the resin film or the resin sheet may be formed in a heated state in advance, or the resin film or the resin sheet may be cooled during the film formation. It is also effective to increase the speed of transporting the resin film or resin sheet (for example, at 1.0 m / min or more) in order to reduce the time for damage caused by film formation by the ion plating method. In this case, for example, film formation is possible even when the distance between the target resin film or resin sheet and the target is short, which is advantageous as an industrial process.
The transparent substrate may be formed with any of a single layer or multiple layers of an insulating layer, a semiconductor layer, a gas barrier layer, and a protective layer as necessary.
Examples of the insulating layer include a silicon oxide film and a silicon nitride oxide film.
As a semiconductor layer, a thin film transistor (TFT) etc. are mentioned, for example, and it is mainly formed in a glass substrate.
Examples of the gas barrier layer include a silicon oxide film, a silicon nitride oxide film, and a magnesium aluminum oxide film, and the gas barrier layer is formed on a resin plate or a resin film as a water vapor barrier film.
A protective layer is for protecting the surface of a base material from a damage | wound and an impact, and various coating layers, such as Si type | system | group, Ti type | system | group, and an acrylic resin type | system | group, are mentioned.

The specific resistance of the zinc oxide-based transparent conductive substrate of the present invention is usually 2 × 10 ⁻³ Ω · cm or less, preferably 8 × 10 ⁻⁴ Ω · cm or less. The surface resistance (sheet resistance) varies depending on the application, but is usually 5 to 10,000 Ω / □, preferably 10 to 300 Ω / □. In addition, specific resistance and surface resistance can be measured by the method mentioned later in an Example, for example.
The transmittance of the zinc oxide-based transparent conductive substrate of the present invention is usually 85% or more, preferably 90% or more in the visible light region. The total light transmittance is preferably 80% or more, more preferably 85% or more, and the haze value is preferably 10% or less, more preferably 5% or less. The transmittance can be measured by, for example, a method described later in the examples.

  The thickness of the zinc oxide-based transparent conductive film in the transparent conductive substrate of the present invention is preferably 50 to 600 nm. In this film thickness range, although it varies depending on the application, it is possible to obtain a continuous film in which flexibility is maintained. Furthermore, the film thickness of the transparent conductive film of the present invention is desirably 100 to 500 nm depending on the application.

In the transparent conductive substrate of the present invention, if necessary, as an outermost layer, any resin that functions as a protective film, an antireflection film, a filter, etc., functions of adjusting the viewing angle of liquid crystal, preventing fogging, etc. Alternatively, one layer or two or more layers of inorganic compounds can be stacked.
The transparent conductive substrate of the present invention has good transparency as described above, and excellent conductivity and chemical durability (heat resistance, moisture resistance, chemical resistance (alkali resistance) as described above. For example, transparent electrodes such as liquid crystal displays, plasma displays, inorganic EL (electroluminescence) displays, organic EL displays, and electronic paper, solar cell photoelectric conversion element windows, etc. It can be used in combination with other metal films / metal oxide films as electrodes, electrodes of input devices such as transparent touch panels, electromagnetic shielding films of electromagnetic shields, transparent radio wave absorbers, ultraviolet absorbers, and transparent semiconductor devices.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by this Example.
In addition, evaluation of the obtained transparent conductive substrate was performed by the following method.
<Resistivity>
The specific resistance was measured by a four-terminal four-probe method using a resistivity meter (“LORESTA-GP, MCP-T610” manufactured by Mitsubishi Chemical Corporation). Specifically, four needle-shaped electrodes are placed on a straight line on the sample, a constant current is passed between the outer two probes, a constant current is passed between the inner two probes, and the inner two probes are The resulting potential difference was measured to determine the resistance.
<Surface resistance>
The surface resistance (Ω / □) was calculated by dividing the specific resistance (Ω · cm) by the film thickness (cm).
<Transmissivity>
The transmittance was measured using an ultraviolet visible near infrared spectrophotometer (“V-670” manufactured by JASCO Corporation).
<Moisture resistance>
The transparent conductive substrate was subjected to a moisture resistance test in which the transparent conductive substrate was held in an atmosphere at a temperature of 60 ° C. and a relative humidity of 90% for 1000 hours, and then the surface resistance was measured. It can be said that the surface resistance after the moisture resistance test is excellent in moisture resistance when the surface resistance before the moisture resistance test is twice or less.
<Heat resistance>
The transparent conductive substrate was subjected to a heat resistance test in which the transparent conductive substrate was held in the atmosphere at a temperature of 200 ° C. for 5 hours, and then the surface resistance was measured. When the surface resistance after the heat test is 1.5 times or less than the surface resistance before the heat test, it can be said that the heat resistance is excellent.
<Alkali resistance>
The transparent conductive substrate was immersed in a 3% NaOH aqueous solution (40 ° C.) for 10 minutes, and the presence or absence of a change in film quality on the substrate before and after immersion was confirmed visually.
<Acid resistance>
The transparent conductive substrate was immersed in a 3% aqueous HCl solution (40 ° C.) for 10 minutes, and the presence or absence of a change in film quality on the substrate before and after immersion was confirmed visually.

Example 1
Zinc oxide powder (ZnO; manufactured by Wako Pure Chemical Industries, Ltd., special grade) and titanium oxide powder (Ti ₂ O ₃ ; manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%) are used as raw material powders. Mixing was performed at a Zn: Ti atomic ratio of 96: 4 to obtain a mixture of raw material powders. Next, the obtained mixture was put in a mold and molded by a uniaxial press at a molding pressure of 500 kg / cm ² to obtain a disk-shaped molded body having a diameter of 30 mm and a thickness of 5 mm. This compact was annealed at 500 ° C. for 3 hours under an argon atmosphere at normal pressure (100 Pa) to obtain an oxide mixture (1).
When the obtained oxide mixture (1) was analyzed with an energy dispersive X-ray fluorescence apparatus (“EDX-700L” manufactured by Shimadzu Corporation), the atomic ratio of Zn and Ti was Zn: Ti = 96. : 4 (Ti / (Zn + Ti) = 0.04).
Next, a tablet is produced by processing the obtained oxide mixture (1) into a disk shape of 20 mmφ, and a transparent conductive film is formed by ion plating using this to form a transparent conductive substrate. Obtained.
That is, using an ion plating apparatus (“SUPLaDUO” manufactured by Chugai Furnace Co., Ltd.), ion plating is performed under the following conditions, and the film thickness is formed on a transparent substrate (a non-alkali glass substrate having a thickness of 0.7 mm). A 200 nm transparent conductive film was formed.
Preheating temperature of substrate before film formation: 250 ° C.
Pressure during film formation: 0.3 Pa
Atmospheric gas conditions during film formation: Argon = 160 sccm, Oxygen = 2 sccm
Discharge current during film formation: 100 A
Deposition time: 200 seconds

  The composition (Zn: Ti) in the formed transparent conductive film is quantitatively analyzed using a calibration curve by a fluorescent X-ray method using a wavelength dispersion type fluorescent X-ray apparatus (“XRF-1700WS” manufactured by Shimadzu Corporation). As a result, Zn: Ti (atomic ratio) was 96: 4. The transparent conductive film is subjected to X-ray diffraction using an attachment for thin film measurement using an X-ray diffractometer ("RINT2000" manufactured by Rigaku Corporation) and an energy dispersive X-ray microanalyzer (TEM-). EDX) was used to investigate the doping state of titanium into zinc, and further the crystal structure was examined using a field emission electron microscope (FE-SEM). Was found to be substituted and dissolved in zinc.

The specific resistance of the transparent conductive film on the obtained transparent conductive substrate was 7.3 × 10 ⁻⁴ Ω · cm, and the surface resistance was 36.5 Ω / □. The specific resistance distribution on the transparent substrate was uniform in the plane.
The transmittance of the obtained transparent conductive substrate was an average of 90% in the visible region (380 nm to 780 nm) and an average of 65% in the infrared region (780 nm to 2700 nm). In addition, the transmittance | permeability in the visible region (380 nm-780 nm) of the glass substrate before film-forming was an average of 94%, and the transmittance | permeability in an infrared region (780 nm-2700 nm) was an average of 94%.
When the moisture resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the moisture resistance test was 1.6 times the surface resistance before the moisture resistance test, and the moisture resistance was excellent. Moreover, when the heat resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the heat test was 1.3 times the surface resistance before the heat test, and the heat resistance was excellent.
When the alkali resistance of the obtained transparent conductive substrate was evaluated, it was found that there was no change in film quality before and after immersion, and the alkali resistance was excellent. Moreover, when the acid resistance of the obtained transparent conductive substrate was evaluated, it was found that after immersion, the film thickness was thin and dissolved, but the film quality did not change before and after immersion, and the acid resistance was excellent. It was.
From the above, the film on the obtained transparent conductive substrate is a transparent conductive film that is transparent and has low resistance, and also has chemical durability (heat resistance, moisture resistance, alkali resistance, acid resistance). It is clear that there is.

(Comparative Example 1)
Zinc oxide powder (ZnO; manufactured by Wako Pure Chemical Industries, Ltd., special grade) and titanium oxide powder (Ti ₂ O ₃ ; manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%) are used as raw material powders. A mixture of raw material powders was obtained by mixing at a ratio where the atomic ratio of Zn: Ti was 99: 1. Next, the obtained mixture was put in a mold and molded by a uniaxial press at a molding pressure of 500 kg / cm ² to obtain a disk-shaped molded body having a diameter of 30 mm and a thickness of 5 mm. This molded body was annealed at 400 ° C. for 3 hours in an argon atmosphere at normal pressure (100 Pa) to obtain an oxide mixture (C1).
When the obtained oxide mixture (C1) was analyzed with an energy dispersive X-ray fluorescence apparatus (“EDX-700L” manufactured by Shimadzu Corporation), the atomic ratio of Zn and Ti was Zn: Ti = 99. : 1 (Ti / (Zn + Ti) = 0.01).
Next, by processing the obtained oxide mixture (C1) into a disk shape of 20 mmφ, a tablet is prepared, and a transparent conductive film is formed by ion plating using the tablet, thereby forming a transparent conductive substrate. Obtained.
That is, using an ion plating apparatus (“SUPLaDUO” manufactured by Chugai Furnace Co., Ltd.), ion plating is performed under the following conditions, and the film thickness is formed on a transparent substrate (a non-alkali glass substrate having a thickness of 0.7 mm). A 150 nm transparent conductive film was formed.
Preheating temperature of substrate before film formation: 250 ° C.
Pressure during film formation: 0.3 Pa
Atmospheric gas conditions during film formation: Argon = 160 sccm, Oxygen = 2 sccm
Discharge current during film formation: 100 A
Deposition time: 150 seconds

  The composition (Zn: Ti) in the formed transparent conductive film is quantitatively analyzed using a calibration curve by a fluorescent X-ray method using a wavelength dispersion type fluorescent X-ray apparatus (“XRF-1700WS” manufactured by Shimadzu Corporation). As a result, Zn: Ti (atomic ratio) was 99: 1. The transparent conductive film is subjected to X-ray diffraction using an attachment for thin film measurement using an X-ray diffractometer ("RINT2000" manufactured by Rigaku Corporation) and an energy dispersive X-ray microanalyzer (TEM-). EDX) was used to investigate the doping state of titanium into zinc, and further the crystal structure was examined using a field emission electron microscope (FE-SEM). Was found to be substituted and dissolved in zinc.

The specific resistance of the transparent conductive film on the obtained transparent conductive substrate was 7.0 × 10 ⁻³ Ω · cm, and the surface resistance was 467 Ω / □. The specific resistance distribution on the transparent substrate was uniform in the plane.
The transmittance of the obtained transparent conductive substrate was an average of 91% in the visible region (380 nm to 780 nm) and an average of 70% in the infrared region (780 nm to 2700 nm). In addition, the transmittance | permeability in the visible region (380 nm-780 nm) of the glass substrate before film-forming was an average of 94%, and the transmittance | permeability in an infrared region (780 nm-2700 nm) was an average of 94%.
When the moisture resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the moisture resistance test was 3.1 times the surface resistance before the moisture resistance test, and the moisture resistance was poor. Moreover, when the heat resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the heat test was 3.0 times the surface resistance before the heat test, which is inferior in heat resistance.
When the alkali resistance of the obtained transparent conductive substrate was evaluated, the film was completely dissolved and disappeared after immersion. Moreover, when the acid resistance of the obtained transparent conductive substrate was evaluated, the film was completely dissolved and disappeared.
From the above, the film on the transparent conductive substrate obtained is a transparent conductive film that is transparent but has high resistance and inferior chemical durability (heat resistance, moisture resistance, alkali resistance, acid resistance). It is clear that there is.

(Example 2)
By processing the oxide mixture (1) obtained in the same manner as in Example 1 into a disk shape of 20 mmφ, a tablet was prepared, and a transparent conductive film was formed by ion plating using this, A transparent conductive substrate was obtained.
That is, using an ion plating apparatus (“SUPLaDUO” manufactured by Chugai Furnace Co., Ltd.), ion plating is performed under the following conditions, and the film thickness is formed on a transparent substrate (a non-alkali glass substrate having a thickness of 0.7 mm). A 50 nm transparent conductive film was formed.
Preheating temperature of substrate before film formation: 250 ° C.
Pressure during film formation: 0.3 Pa
Atmospheric gas conditions during film formation: Argon = 160 sccm, Oxygen = 2 sccm
Discharge current during film formation: 100 A
Deposition time: 50 seconds

  The composition (Zn: Ti) in the formed transparent conductive film is quantitatively analyzed using a calibration curve by a fluorescent X-ray method using a wavelength dispersion type fluorescent X-ray apparatus (“XRF-1700WS” manufactured by Shimadzu Corporation). As a result, Zn: Ti (atomic ratio) was 96: 4. The transparent conductive film is subjected to X-ray diffraction using an attachment for thin film measurement using an X-ray diffractometer ("RINT2000" manufactured by Rigaku Corporation) and an energy dispersive X-ray microanalyzer (TEM-). EDX) was used to investigate the doping state of titanium into zinc, and further the crystal structure was examined using a field emission electron microscope (FE-SEM). Was found to be substituted and dissolved in zinc.

The specific resistance of the transparent conductive film on the obtained transparent conductive substrate was 8.0 × 10 ⁻⁴ Ω · cm, and the surface resistance was 160Ω / □. The specific resistance distribution on the transparent substrate was uniform in the plane.
The transmittance of the obtained transparent conductive substrate was an average of 91% in the visible region (380 nm to 780 nm) and an average of 70% in the infrared region (780 nm to 2700 nm). In addition, the transmittance | permeability in the visible region (380 nm-780 nm) of the glass substrate before film-forming was an average of 94%, and the transmittance | permeability in an infrared region (780 nm-2700 nm) was an average of 94%.
When the moisture resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the moisture resistance test was 1.8 times the surface resistance before the moisture resistance test, and the moisture resistance was excellent. Moreover, when the heat resistance of the obtained transparent conductive substrate was evaluated, the surface resistance after the heat test was 1.5 times the surface resistance before the heat test, and it was found that the heat resistance was excellent.
When the alkali resistance of the obtained transparent conductive substrate was evaluated, it was found that there was no change in film quality before and after immersion, and the alkali resistance was excellent. Moreover, when the acid resistance of the obtained transparent conductive substrate was evaluated, it was found that after immersion, the film thickness was thin and dissolved, but the film quality did not change before and after immersion, and the acid resistance was excellent. It was.
From the above, the film on the transparent conductive substrate obtained is transparent and low resistance even when the film thickness is 100 nm or less, and has chemical durability (heat resistance, moisture resistance, alkali resistance, acid resistance). It is clear that this is a transparent conductive film having both properties.

Example 3
By processing the oxide mixture (1) obtained in the same manner as in Example 1 into a disk shape of 20 mmφ, a tablet was prepared, and a transparent conductive film was formed by ion plating using this, A transparent conductive substrate was obtained. That is, using an ion plating apparatus (“SUPLaDUO” manufactured by Chugai Furnace Co., Ltd.), ion plating was performed under the following conditions, and a transparent substrate (heat-resistant transparent with a thickness of 0.3 mm showing heat resistance at 200 ° C. or higher) A transparent conductive film having a thickness of 200 nm was formed on the (resin film).
Preheating temperature of substrate before film formation: 200 ° C.
Pressure during film formation: 0.3 Pa
Atmospheric gas conditions during film formation: Argon = 160 sccm, Oxygen = 2 sccm
Discharge current during film formation: 100 A
Deposition time: 200 seconds

  The composition (Zn: Ti) in the formed transparent conductive film is quantitatively analyzed using a calibration curve by a fluorescent X-ray method using a wavelength dispersion type fluorescent X-ray apparatus (“XRF-1700WS” manufactured by Shimadzu Corporation). As a result, Zn: Ti (atomic ratio) was 96: 4. The transparent conductive film is subjected to X-ray diffraction using an attachment for thin film measurement using an X-ray diffractometer ("RINT2000" manufactured by Rigaku Corporation) and an energy dispersive X-ray microanalyzer (TEM-). EDX) was used to investigate the doping state of titanium into zinc, and further the crystal structure was examined using a field emission electron microscope (FE-SEM). Was found to be substituted and dissolved in zinc.

The specific resistance of the transparent conductive film on the obtained transparent conductive substrate was 8.5 × 10 ⁻⁴ Ω · cm, and the surface resistance was 42.5 Ω / □. The specific resistance distribution on the transparent substrate was uniform in the plane.
The transmittance of the obtained transparent conductive substrate was an average of 85% in the visible region (380 nm to 780 nm) and an average of 65% in the infrared region (780 nm to 2700 nm). In addition, the transmittance | permeability in the visible region (380 nm-780 nm) of the heat-resistant transparent resin film before film-forming was 90% on average, and the transmittance | permeability in the infrared region (780 nm-2700 nm) was 90% on average.
When the moisture resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the moisture resistance test was 1.8 times the surface resistance before the moisture resistance test, and the moisture resistance was excellent. Moreover, when the heat resistance of the obtained transparent conductive substrate was evaluated, the surface resistance after the heat test was 1.5 times the surface resistance before the heat test, and it was found that the heat resistance was excellent.
When the alkali resistance of the obtained transparent conductive substrate was evaluated, it was found that there was no change in film quality before and after immersion, and the alkali resistance was excellent. Moreover, when the acid resistance of the obtained transparent conductive substrate was evaluated, it was found that after immersion, the film thickness was thin and dissolved, but the film quality did not change before and after immersion, and the acid resistance was excellent. It was.
From the above, the film on the obtained transparent conductive substrate is transparent and low resistance even when the substrate is a heat resistant film, and has chemical durability (heat resistance, moisture resistance, alkali resistance, acid resistance). It is clear that this is a transparent conductive film having both properties.

(Comparative Example 2)
97.7 parts by weight of zinc oxide powder having an average particle diameter of 1 μm and 2.3 parts by weight of aluminum oxide powder having an average particle diameter of 0.2 μm are placed in a polyethylene pot and mixed for 72 hours using a dry ball mill. A raw material powder mixture was obtained. The obtained mixture was put into a mold and pressed at a molding pressure of 300 kg / cm ² to obtain a molded body.
The compact was subjected to densification treatment with CIP at a pressure of 3 ton / cm ² and then sintered under the following conditions to obtain an oxide sintered body (C2) of aluminum-doped zinc oxide.
Sintering temperature: 1500 ° C
Temperature rising rate: 50 ° C./hour Holding time: 5 hours Sintering atmosphere: in air

When the obtained oxide sintered body (C2) was analyzed by X-ray diffraction, it was a two-phase mixed structure of ZnO and ZnAl ₂ O ₄ .
Next, the obtained oxide sintered body (C2) was processed into a shape of 4 inches φ and 6 mmt, and bonded to an oxygen-free copper backing plate using indium solder to prepare a target.
And using this target, the film-forming by sputtering method was performed on condition of the following, the transparent conductive film with a film thickness of 300 nm was formed on the transparent base material (quartz glass substrate), and the transparent conductive substrate was obtained. The Al content in the formed film was 2.3% by weight.
Equipment: dc magnetron sputtering equipment Magnetic field strength: 1000 Gauss (horizontal component directly above the target)
Substrate temperature: 200 ° C
Ultimate vacuum: 5 · 10 ^-5 Pa
Sputtering gas: Ar
Sputtering gas pressure: 0.5 Pa
DC power: 300W
The specific resistance of the transparent conductive film on the obtained transparent conductive substrate was 7.6 × 10 ⁻⁴ Ω · cm, and the surface resistance was 25.3 Ω / □.
The transmittance of the transparent conductive substrate obtained was an average of 88% in the visible region (380 nm to 780 nm) and an average of 55% in the infrared region (780 nm to 2700 nm).
When the moisture resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the moisture resistance test was 3.2 times the surface resistance before the moisture resistance test, and the moisture resistance was poor. Moreover, when the heat resistance of the obtained transparent conductive substrate was evaluated, the surface resistance after the heat test was 7.0 times the surface resistance before the heat test, and it was found that the heat resistance was poor.
When the alkali resistance of the obtained transparent conductive substrate was evaluated, the film was completely dissolved and disappeared after immersion. Moreover, when the acid resistance of the obtained transparent conductive substrate was evaluated, the film was completely dissolved and disappeared.
From the above, the film on the obtained transparent conductive substrate is a transparent conductive film which is transparent and has low resistance but inferior in chemical durability (heat resistance, moisture resistance, alkali resistance, acid resistance). Is clear.

Example 4
Zinc oxide powder (ZnO; manufactured by Wako Pure Chemical Industries, Ltd., special grade) and titanium oxide powder (Ti ₂ O ₃ ; manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%) are used as raw material powders. Mixing was performed at a Zn: Ti atomic ratio of 96: 4 to obtain a mixture of raw material powders. Next, the obtained mixture was put in a mold and molded by a uniaxial press at a molding pressure of 500 kg / cm ² to obtain a disk-shaped molded body having a diameter of 30 mm and a thickness of 5 mm. This molded body was sintered at 800 ° C. for 4 hours under an argon atmosphere of normal pressure (1.01325 · 10 ² kPa) to obtain an oxide sintered body (4).
When the obtained oxide sintered body (4) was analyzed with an energy dispersive fluorescent X-ray apparatus (“EDX-700L” manufactured by Shimadzu Corporation), the atomic ratio of Zn and Ti was Zn: Ti = It was 96: 4 (Ti / (Zn + Ti) = 0.04). When the crystal structure of this oxide sintered body (4) was examined with an X-ray diffractometer (“RINT2000” manufactured by Rigaku Corporation), crystals of zinc oxide (ZnO) and zinc titanate (Zn ₂ TiO ₄ ) were obtained. It was a phase mixture and no titanium oxide was present.

Next, by processing the obtained oxide sintered body (4) into a disk shape of 20 mmφ, a tablet is produced, and a transparent conductive film is formed by ion plating using this, and a transparent conductive substrate is formed. Got.
That is, using an ion plating apparatus (“SUPLaDUO” manufactured by Chugai Furnace Co., Ltd.), ion plating is performed under the following conditions, and the film thickness is formed on a transparent substrate (a non-alkali glass substrate having a thickness of 0.7 mm). A 200 nm transparent conductive film was formed.
Preheating temperature of substrate before film formation: 250 ° C.
Pressure during film formation: 0.3 Pa
Atmospheric gas conditions during film formation: Argon = 160 sccm, Oxygen = 2 sccm
Discharge current during film formation: 100 A
Deposition time: 200 seconds

The composition (Zn: Ti) in the formed transparent conductive film is quantitatively analyzed using a calibration curve by a fluorescent X-ray method using a wavelength dispersion type fluorescent X-ray apparatus (“XRF-1700WS” manufactured by Shimadzu Corporation). As a result, Zn: Ti (atomic ratio) was 96: 4. The transparent conductive film is subjected to X-ray diffraction using an attachment for thin film measurement using an X-ray diffractometer ("RINT2000" manufactured by Rigaku Corporation) and an energy dispersive X-ray microanalyzer (TEM-). EDX) was used to investigate the doping state of titanium into zinc, and further the crystal structure was examined using a field emission electron microscope (FE-SEM). Was found to be substituted and dissolved in zinc.
The specific resistance of the transparent conductive film on the obtained transparent conductive substrate was 7.8 × 10 ⁻⁴ Ω · cm, and the surface resistance was 39.0 Ω / □. The specific resistance distribution on the transparent substrate was uniform in the plane.
The transmittance of the obtained transparent conductive substrate was an average of 90% in the visible region (380 nm to 780 nm) and an average of 65% in the infrared region (780 nm to 2700 nm). In addition, the transmittance | permeability in the visible region (380 nm-780 nm) of the glass substrate before film-forming was an average of 94%, and the transmittance | permeability in an infrared region (780 nm-2700 nm) was an average of 94%.
When the moisture resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the moisture resistance test was 1.5 times the surface resistance before the moisture resistance test, and the moisture resistance was excellent. Moreover, when the heat resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the heat test was 1.3 times the surface resistance before the heat test, and the heat resistance was excellent.
When the alkali resistance of the obtained transparent conductive substrate was evaluated, it was found that there was no change in film quality before and after immersion, and the alkali resistance was excellent. Moreover, when the acid resistance of the obtained transparent conductive substrate was evaluated, it was found that after immersion, the film thickness was thin and dissolved, but the film quality did not change before and after immersion, and the acid resistance was excellent. It was.
From the above, the film on the obtained transparent conductive substrate is a transparent conductive film that is transparent and has low resistance, and also has chemical durability (heat resistance, moisture resistance, alkali resistance, acid resistance). It is clear that there is.

(Example 5)
Zinc oxide powder (ZnO; manufactured by Wako Pure Chemical Industries, Ltd., special grade) and titanium oxide powder (Ti ₂ O ₃ ; manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%) are used as raw material powders. Mixing was performed at a Zn: Ti atomic ratio of 96: 4 to obtain a mixture of raw material powders. After the mixing operation, the mixed powder obtained by removing the balls and ethanol is put into a mold (die) made of graphite, and vacuum-pressed at a pressure of 40 MPa with a punch made of graphite, followed by heat treatment at 1000 ° C. for 4 hours. To obtain a disk-shaped oxide sintered body (5).
When the obtained oxide sintered body (5) was analyzed with an energy dispersive fluorescent X-ray apparatus (“EDX-700L” manufactured by Shimadzu Corporation), the atomic ratio of Zn and Ti was Zn: Ti = It was 96: 4 (Ti / (Zn + Ti) = 0.04). When the crystal structure of the oxide sintered body (5) was examined with an X-ray diffractometer (“RINT2000” manufactured by Rigaku Corporation), crystals of zinc oxide (ZnO) and zinc titanate (Zn ₂ TiO ₄ ) were obtained. It was a phase mixture and no titanium oxide was present.

Next, by processing the obtained oxide sintered body (5) into a disk shape of 20 mmφ, a tablet is prepared, and a transparent conductive film is formed by ion plating using the tablet. Got. That is, using an ion plating apparatus (“SUPLaDUO” manufactured by Chugai Furnace Co., Ltd.), ion plating is performed under the following conditions, and the film thickness is formed on a transparent substrate (a non-alkali glass substrate having a thickness of 0.7 mm). A 200 nm transparent conductive film was formed.
Preheating temperature of substrate before film formation: 250 ° C.
Pressure during film formation: 0.3 Pa
Atmospheric gas conditions during film formation: Argon = 160 sccm, Oxygen = 2 sccm
Discharge current during film formation: 100 A
Deposition time: 200 seconds

The composition (Zn: Ti) in the formed transparent conductive film is quantitatively analyzed using a calibration curve by a fluorescent X-ray method using a wavelength dispersion type fluorescent X-ray apparatus (“XRF-1700WS” manufactured by Shimadzu Corporation). As a result, Zn: Ti (atomic ratio) was 96: 4. The transparent conductive film is subjected to X-ray diffraction using an attachment for thin film measurement using an X-ray diffractometer ("RINT2000" manufactured by Rigaku Corporation) and an energy dispersive X-ray microanalyzer (TEM-). EDX) was used to investigate the doping state of titanium into zinc, and further the crystal structure was examined using a field emission electron microscope (FE-SEM). Was found to be substituted and dissolved in zinc.
The specific resistance of the transparent conductive film on the obtained transparent conductive substrate was 7.3 × 10 ⁻⁴ Ω · cm, and the surface resistance was 36.5 Ω / □. The specific resistance distribution on the transparent substrate was uniform in the plane.
The transmittance of the obtained transparent conductive substrate was an average of 90% in the visible region (380 nm to 780 nm) and an average of 65% in the infrared region (780 nm to 2700 nm). In addition, the transmittance | permeability in the visible region (380 nm-780 nm) of the glass substrate before film-forming was an average of 94%, and the transmittance | permeability in an infrared region (780 nm-2700 nm) was an average of 94%.
When the moisture resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the moisture resistance test was 1.6 times the surface resistance before the moisture resistance test, and the moisture resistance was excellent. Moreover, when the heat resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the heat test was 1.3 times the surface resistance before the heat test, and the heat resistance was excellent.
When the alkali resistance of the obtained transparent conductive substrate was evaluated, it was found that there was no change in film quality before and after immersion, and the alkali resistance was excellent. Moreover, when the acid resistance of the obtained transparent conductive substrate was evaluated, it was found that after immersion, the film thickness was thin and dissolved, but the film quality did not change before and after immersion, and the acid resistance was excellent. It was.
From the above, the film on the obtained transparent conductive substrate is a transparent conductive film that is transparent and has low resistance, and also has chemical durability (heat resistance, moisture resistance, alkali resistance, acid resistance). It is clear that there is.

(Example 6)
Zinc oxide powder (ZnO; manufactured by Wako Pure Chemical Industries, Ltd., special grade) and titanium oxide powder (TiO; manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%) are used as raw material powders, and these are Zn: Ti Were mixed at a ratio of 97: 3 to obtain a mixture of raw material powders. After the mixing operation, the mixed powder obtained by removing the balls and ethanol is put into a mold (die) made of graphite, and vacuum-pressed at a pressure of 40 MPa with a punch made of graphite, followed by heat treatment at 1000 ° C. for 4 hours. To obtain a disk-shaped sintered body. Further, the sintered body was sintered at 800 ° C. for 4 hours under an argon atmosphere to obtain an oxide sintered body (6).
When the obtained oxide sintered body (6) was analyzed with an energy dispersive fluorescent X-ray apparatus (“EDX-700L” manufactured by Shimadzu Corporation), the atomic ratio of Zn and Ti was Zn: Ti = 97: 3 (Ti / (Zn + Ti) = 0.03). When the crystal structure of the oxide sintered body (6) was examined with an X-ray diffractometer (“RINT2000” manufactured by Rigaku Corporation), crystals of zinc oxide (ZnO) and zinc titanate (Zn ₂ TiO ₄ ) were obtained. It was a phase mixture and no titanium oxide was present.

Next, by processing the obtained oxide sintered body (6) into a disk shape of 20 mmφ, a tablet is produced, and a transparent conductive film is formed by ion plating using this, and a transparent conductive substrate is formed. Got.
That is, using an ion plating apparatus (“SUPLaDUO” manufactured by Chugai Furnace Co., Ltd.), ion plating is performed under the following conditions, and the film thickness is formed on a transparent substrate (a non-alkali glass substrate having a thickness of 0.7 mm). A 200 nm transparent conductive film was formed.
Preheating temperature of substrate before film formation: 250 ° C.
Pressure during film formation: 0.3 Pa
Atmospheric gas conditions during film formation: Argon = 160 sccm, Oxygen = 2 sccm
Discharge current during film formation: 100 A
Deposition time: 200 seconds

The composition (Zn: Ti) in the formed transparent conductive film is quantitatively analyzed using a calibration curve by a fluorescent X-ray method using a wavelength dispersion type fluorescent X-ray apparatus (“XRF-1700WS” manufactured by Shimadzu Corporation). As a result, Zn: Ti (atomic ratio) was 97: 3. The transparent conductive film is subjected to X-ray diffraction using an attachment for thin film measurement using an X-ray diffractometer ("RINT2000" manufactured by Rigaku Corporation) and an energy dispersive X-ray microanalyzer (TEM-). EDX) was used to investigate the doping state of titanium into zinc, and further the crystal structure was examined using a field emission electron microscope (FE-SEM). Was found to be substituted and dissolved in zinc.
The specific resistance of the transparent conductive film on the obtained transparent conductive substrate was 6.0 × 10 ⁻⁴ Ω · cm, and the surface resistance was 30.0Ω / □. The specific resistance distribution on the transparent substrate was uniform in the plane.
The transmittance of the obtained transparent conductive substrate was an average of 90% in the visible region (380 nm to 780 nm) and an average of 65% in the infrared region (780 nm to 2700 nm). In addition, the transmittance | permeability in the visible region (380 nm-780 nm) of the glass substrate before film-forming was an average of 94%, and the transmittance | permeability in an infrared region (780 nm-2700 nm) was an average of 94%.
When the moisture resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the moisture resistance test was 1.6 times the surface resistance before the moisture resistance test, and the moisture resistance was excellent. Moreover, when the heat resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the heat test was 1.3 times the surface resistance before the heat test, and the heat resistance was excellent.
When the alkali resistance of the obtained transparent conductive substrate was evaluated, it was found that there was no change in film quality before and after immersion, and the alkali resistance was excellent. Moreover, when the acid resistance of the obtained transparent conductive substrate was evaluated, it was found that after immersion, the film thickness was thin and dissolved, but the film quality did not change before and after immersion, and the acid resistance was excellent. It was.
From the above, the film on the obtained transparent conductive substrate is a transparent conductive film that is transparent and has low resistance, and also has chemical durability (heat resistance, moisture resistance, alkali resistance, acid resistance). It is clear that there is.

(Example 7)
Zinc oxide powder (ZnO; manufactured by Wako Pure Chemical Industries, Ltd., special grade) and titanium oxide powder (TiO; manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%) are used as raw material powders, and these are Zn: Ti Were mixed at a ratio of 97: 3 to obtain a mixture of raw material powders. Next, the obtained mixture was put in a mold and molded by a uniaxial press at a molding pressure of 500 kg / cm ² to obtain a disk-shaped molded body having a diameter of 30 mm and a thickness of 5 mm. This molded body was sintered at 1000 ° C. for 4 hours under an argon atmosphere at normal pressure (1.01325 × 10 ² kPa) to obtain an oxide sintered body (7).
When the obtained oxide sintered body (7) was analyzed with an energy dispersive fluorescent X-ray apparatus (“EDX-700L” manufactured by Shimadzu Corporation), the atomic ratio of Zn and Ti was Zn: Ti = 97: 3 (Ti / (Zn + Ti) = 0.03). When the crystal structure of the oxide sintered body (7) was examined with an X-ray diffractometer (“RINT2000” manufactured by Rigaku Corporation), crystals of zinc oxide (ZnO) and zinc titanate (Zn ₂ TiO ₄ ) were obtained. It was a phase mixture and no titanium oxide was present.

Next, by processing the obtained oxide sintered body (7) into a disk shape of 20 mmφ, a tablet is produced, and a transparent conductive film is formed by ion plating using this, and a transparent conductive substrate is formed. Got.
That is, using an ion plating apparatus (“SUPLaDUO” manufactured by Chugai Furnace Co., Ltd.), ion plating is performed under the following conditions, and the film thickness is formed on a transparent substrate (a non-alkali glass substrate having a thickness of 0.7 mm). A 200 nm transparent conductive film was formed.
Preheating temperature of substrate before film formation: 250 ° C.
Pressure during film formation: 0.3 Pa
Atmospheric gas conditions during film formation: Argon = 160 sccm, Oxygen = 2 sccm
Discharge current during film formation: 100 A
Deposition time: 200 seconds

The composition (Zn: Ti) in the formed transparent conductive film is quantitatively analyzed using a calibration curve by a fluorescent X-ray method using a wavelength dispersion type fluorescent X-ray apparatus (“XRF-1700WS” manufactured by Shimadzu Corporation). As a result, Zn: Ti (atomic ratio) was 95: 5. The transparent conductive film is subjected to X-ray diffraction using an attachment for thin film measurement using an X-ray diffractometer ("RINT2000" manufactured by Rigaku Corporation) and an energy dispersive X-ray microanalyzer (TEM-). EDX) was used to investigate the doping state of titanium into zinc, and further the crystal structure was examined using a field emission electron microscope (FE-SEM). Was found to be substituted and dissolved in zinc.
The specific resistance of the transparent conductive film on the obtained transparent conductive substrate was 6.0 × 10 ⁻⁴ Ω · cm, and the surface resistance was 30.0Ω / □. The specific resistance distribution on the transparent substrate was uniform in the plane.
The transmittance of the obtained transparent conductive substrate was an average of 90% in the visible region (380 nm to 780 nm) and an average of 65% in the infrared region (780 nm to 2700 nm). In addition, the transmittance | permeability in the visible region (380 nm-780 nm) of the glass substrate before film-forming was an average of 94%, and the transmittance | permeability in an infrared region (780 nm-2700 nm) was an average of 94%.
When the moisture resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the moisture resistance test was 1.6 times the surface resistance before the moisture resistance test, and the moisture resistance was excellent. Moreover, when the heat resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the heat test was 1.3 times the surface resistance before the heat test, and the heat resistance was excellent.
When the alkali resistance of the obtained transparent conductive substrate was evaluated, it was found that there was no change in film quality before and after immersion, and the alkali resistance was excellent. Moreover, when the acid resistance of the obtained transparent conductive substrate was evaluated, it was found that after immersion, the film thickness was thin and dissolved, but the film quality did not change before and after immersion, and the acid resistance was excellent. It was.
From the above, the film on the obtained transparent conductive substrate is a transparent conductive film that is transparent and has low resistance, and also has chemical durability (heat resistance, moisture resistance, alkali resistance, acid resistance). It is clear that there is.

(Comparative Example 3)
Zinc oxide powder (ZnO; manufactured by Wako Pure Chemical Industries, Ltd., special grade) and titanium oxide powder (TiO; manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%) are used as raw material powders, and these are Zn: Ti Were mixed at a ratio of 98.5: 1.5 to obtain a raw material powder mixture. Next, the obtained mixture was put in a mold and molded by a uniaxial press at a molding pressure of 500 kg / cm ² to obtain a disk-shaped molded body having a diameter of 30 mm and a thickness of 5 mm. This molded body was sintered at 1000 ° C. for 4 hours under an argon atmosphere at normal pressure (1.01325 × 10 ² kPa) to obtain an oxide sintered body (C3).
When the obtained oxide sintered body (C3) was analyzed with an energy dispersive X-ray fluorescence apparatus (“EDX-700L” manufactured by Shimadzu Corporation), the atomic ratio of Zn and Ti was Zn: Ti = It was 98.5: 1.5 (Ti / (Zn + Ti) = 0.015). When the crystal structure of the oxide sintered body (C3) was examined with an X-ray diffractometer (“RINT2000” manufactured by Rigaku Corporation), crystals of zinc oxide (ZnO) and zinc titanate (Zn ₂ TiO ₄ ) were obtained. It was a phase mixture and no titanium oxide was present.

Next, the obtained oxide sintered body (C3) is processed into a disk shape of 20 mmφ to produce a tablet, and a transparent conductive film is formed by ion plating using the tablet, thereby forming a transparent conductive substrate. Got.
That is, using an ion plating apparatus (“SUPLaDUO” manufactured by Chugai Furnace Co., Ltd.), ion plating is performed under the following conditions, and the film thickness is formed on a transparent substrate (a non-alkali glass substrate having a thickness of 0.7 mm). A 200 nm transparent conductive film was formed.
Preheating temperature of substrate before film formation: 250 ° C.
Pressure during film formation: 0.3 Pa
Atmospheric gas conditions during film formation: Argon = 160 sccm, Oxygen = 2 sccm
Discharge current during film formation: 100 A
Deposition time: 200 seconds

The composition (Zn: Ti) in the formed transparent conductive film is quantitatively analyzed using a calibration curve by a fluorescent X-ray method using a wavelength dispersion type fluorescent X-ray apparatus (“XRF-1700WS” manufactured by Shimadzu Corporation). As a result, Zn: Ti (atomic ratio) was 98.5: 1.5. The transparent conductive film is subjected to X-ray diffraction using an attachment for thin film measurement using an X-ray diffractometer ("RINT2000" manufactured by Rigaku Corporation) and an energy dispersive X-ray microanalyzer (TEM-). EDX) was used to investigate the doping state of titanium into zinc, and further the crystal structure was examined using a field emission electron microscope (FE-SEM). Was found to be substituted and dissolved in zinc.
The specific resistance of the transparent conductive film on the obtained transparent conductive substrate was 1.2 × 10 ⁻³ Ω · cm, and the surface resistance was 60.0Ω / □. The specific resistance distribution on the transparent substrate was uniform in the plane.
The transmittance of the obtained transparent conductive substrate was 90% on average in the visible region (380 nm to 780 nm), and 70% on average in the infrared region (780 nm to 2700 nm). In addition, the transmittance | permeability in the visible region (380 nm-780 nm) of the glass substrate before film-forming was an average of 94%, and the transmittance | permeability in an infrared region (780 nm-2700 nm) was an average of 94%.
When the moisture resistance of the obtained transparent conductive substrate was evaluated, the surface resistance after the moisture resistance test was 2.6 times the surface resistance before the moisture resistance test, and it was found that the moisture resistance was inferior. Moreover, when the heat resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the heat test was 2.0 times the surface resistance before the heat test, and the heat resistance was poor.
When the alkali resistance of the obtained transparent conductive substrate was evaluated, the film was completely dissolved and disappeared after immersion. Moreover, when the acid resistance of the obtained transparent conductive substrate was evaluated, the film was completely dissolved and disappeared.
From the above, the obtained film on the transparent conductive substrate is transparent and low resistance, but is a transparent conductive film inferior in chemical durability (heat resistance, moisture resistance, alkali resistance, acid resistance). Is clear.

(Comparative Example 4)
Zinc oxide powder (ZnO; manufactured by Wako Pure Chemical Industries, Ltd., special grade) and titanium oxide powder (TiO; manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%) are used as raw material powders, and these are Zn: Ti Were mixed at a ratio of 88:12 to obtain a mixture of raw material powders. Next, the obtained mixture was put in a mold and molded by a uniaxial press at a molding pressure of 500 kg / cm ² to obtain a disk-shaped molded body having a diameter of 30 mm and a thickness of 5 mm. This compact was sintered at 1000 ° C. for 4 hours in an argon atmosphere at normal pressure (1.01325 × 10 ² kPa) to obtain an oxide sintered body (C4).
When the obtained oxide sintered body (C4) was analyzed with an energy dispersive fluorescent X-ray apparatus (“EDX-700L” manufactured by Shimadzu Corporation), the atomic ratio of Zn and Ti was Zn: Ti = 88:12 (Ti / (Zn + Ti) = 0.12). When the crystal structure of this oxide sintered body (C4) was examined with an X-ray diffractometer (“RINT2000” manufactured by Rigaku Corporation), crystals of zinc oxide (ZnO) and zinc titanate (Zn ₂ TiO ₄ ) were obtained. It was a phase mixture and no titanium oxide was present.

Next, the obtained oxide sintered body (C4) is processed into a disk shape of 20 mmφ to produce a tablet, and a transparent conductive film is formed by ion plating using the tablet, thereby forming a transparent conductive substrate. Got.
That is, using an ion plating apparatus (“SUPLaDUO” manufactured by Chugai Furnace Co., Ltd.), ion plating is performed under the following conditions, and the film thickness is formed on a transparent substrate (a non-alkali glass substrate having a thickness of 0.7 mm). A 200 nm transparent conductive film was formed.
Preheating temperature of substrate before film formation: 250 ° C.
Pressure during film formation: 0.3 Pa
Atmospheric gas conditions during film formation: Argon = 160 sccm, Oxygen = 2 sccm
Discharge current during film formation: 100 A
Deposition time: 200 seconds

The composition (Zn: Ti) in the formed transparent conductive film is quantitatively analyzed using a calibration curve by a fluorescent X-ray method using a wavelength dispersion type fluorescent X-ray apparatus (“XRF-1700WS” manufactured by Shimadzu Corporation). As a result, Zn: Ti (atomic ratio) was 88:12. The transparent conductive film is subjected to X-ray diffraction using an attachment for thin film measurement using an X-ray diffractometer ("RINT2000" manufactured by Rigaku Corporation) and an energy dispersive X-ray microanalyzer (TEM-). EDX) was used to investigate the doping state of titanium into zinc, and further the crystal structure was examined using a field emission electron microscope (FE-SEM). Was found to be substituted and dissolved in zinc, but the crystallinity was lowered.
The specific resistance of the transparent conductive film on the obtained transparent conductive substrate was 2.4 × 10 ⁻² Ω · cm, and the surface resistance was 1200.0Ω / □. The specific resistance distribution on the transparent substrate was uniform in the plane.
The transmittance of the obtained transparent conductive substrate was 90% on average in the visible region (380 nm to 780 nm) and 73% on average in the infrared region (780 nm to 2700 nm). In addition, the transmittance | permeability in the visible region (380 nm-780 nm) of the glass substrate before film-forming was an average of 94%, and the transmittance | permeability in an infrared region (780 nm-2700 nm) was an average of 94%.
When the moisture resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the moisture resistance test was 1.1 times the surface resistance before the moisture resistance test, and the moisture resistance was excellent. Moreover, when the heat resistance of the obtained transparent conductive substrate was evaluated, it was found that the surface resistance after the heat test was 1.1 times the surface resistance before the heat test, and the heat resistance was excellent.
When the alkali resistance of the obtained transparent conductive substrate was evaluated, it was found that there was no change in film quality before and after immersion, and the alkali resistance was excellent. Moreover, when the acid resistance of the obtained transparent conductive substrate was evaluated, it was found that after immersion, the film thickness was thin and dissolved, but the film quality did not change before and after immersion, and the acid resistance was excellent. It was.
From the above, the film on the transparent conductive substrate obtained is a transparent conductive film that is transparent and also has chemical durability (heat resistance, moisture resistance, alkali resistance, acid resistance). It is clear that it is a resistance.

(Example 8)
Zinc oxide powder (ZnO; manufactured by Wako Pure Chemical Industries, Ltd., special grade) and titanium oxide powder (Ti ₂ O ₃ (III); manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%) are used as raw material powders. These were mixed at a Zn: Ti atomic ratio of 93: 7 to obtain a raw material powder mixture. After the mixing operation, the mixed powder obtained by removing the balls and ethanol is put into a mold (die) made of graphite, and vacuum-pressed at a pressure of 40 MPa with a punch made of graphite, followed by heat treatment at 1000 ° C. for 4 hours. To obtain a disk-shaped oxide sintered body (8). (hot press)
When the obtained oxide sintered body (8) was analyzed with an energy dispersive X-ray fluorescence apparatus (“EDX-700L” manufactured by Shimadzu Corporation), the atomic ratio of Zn and Ti was Zn: Ti = 93: 7 (Ti / (Zn + Ti) = 0.07). When the crystal structure of this oxide sintered body (8) was examined with an X-ray diffractometer (“RINT2000” manufactured by Rigaku Corporation), crystals of zinc oxide (ZnO) and zinc titanate (Zn ₂ TiO ₄ ) were obtained. It was a phase mixture and no titanium oxide was present.

Next, the obtained oxide sintered body (8) is processed into a disk shape of 20 mmφ to produce a tablet, and a transparent conductive film is formed by ion plating using this to form a transparent conductive substrate. Got. That is, using an ion plating apparatus (“SUPLaDUO” manufactured by Chugai Furnace Co., Ltd.), ion plating is performed under the following conditions, and the film thickness is formed on a transparent substrate (a non-alkali glass substrate having a thickness of 0.7 mm). A 200 nm transparent conductive film was formed.
Preheating temperature of substrate before film formation: 250 ° C.
Pressure during film formation: 0.3 Pa
Atmospheric gas conditions during film formation: Argon = 160 sccm, Oxygen = 2 sccm
Discharge current during film formation: 100 A
Deposition time: 200 seconds

The composition (Zn: Ti) in the formed transparent conductive film is quantitatively analyzed using a calibration curve by a fluorescent X-ray method using a wavelength dispersion type fluorescent X-ray apparatus (“XRF-1700WS” manufactured by Shimadzu Corporation). As a result, Zn: Ti (atomic ratio) was 93: 7. The transparent conductive film is subjected to X-ray diffraction using an attachment for thin film measurement using an X-ray diffractometer ("RINT2000" manufactured by Rigaku Corporation) and an energy dispersive X-ray microanalyzer (TEM-). EDX) was used to investigate the doping state of titanium into zinc, and further the crystal structure was examined using a field emission electron microscope (FE-SEM). Was found to be substituted and dissolved in zinc.
The specific resistance of the transparent conductive film on the obtained transparent conductive substrate was 1.1 × 10 ⁻³ Ω · cm, and the surface resistance was 55.0Ω / □. The specific resistance distribution on the transparent substrate was uniform in the plane.
The transmittance of the obtained transparent conductive substrate was an average of 90% in the visible region (380 nm to 780 nm) and an average of 67% in the infrared region (780 nm to 2700 nm). In addition, the transmittance | permeability in the visible region (380 nm-780 nm) of the glass substrate before film-forming was an average of 94%, and the transmittance | permeability in an infrared region (780 nm-2700 nm) was an average of 94%.
When the moisture resistance of the obtained transparent conductive substrate was evaluated, the surface resistance after the moisture resistance test was 1.4 times the surface resistance before the moisture resistance test, and it was found that the moisture resistance was excellent. Moreover, when the heat resistance of the obtained transparent conductive substrate was evaluated, the surface resistance after the heat test was 1.2 times the surface resistance before the heat test, and it was found that the heat resistance was excellent.
When the alkali resistance of the obtained transparent conductive substrate was evaluated, it was found that there was no change in film quality before and after immersion, and the alkali resistance was excellent. Moreover, when the acid resistance of the obtained transparent conductive substrate was evaluated, it was found that after immersion, the film thickness was thin and dissolved, but the film quality did not change before and after immersion, and the acid resistance was excellent. It was.
From the above, the film on the obtained transparent conductive substrate is a transparent conductive film that is transparent and has low resistance, and also has chemical durability (heat resistance, moisture resistance, alkali resistance, acid resistance). It is clear that there is.

Example 9
Zinc oxide powder (ZnO; manufactured by Wako Pure Chemical Industries, Ltd., special grade) and titanium oxide powder (TiO (II); manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%) are used as raw material powders. Mixing was performed at a ratio of the Zn: Ti atomic ratio of 93: 7 to obtain a mixture of raw material powders. After the mixing operation, the mixed powder obtained by removing the balls and ethanol is put into a mold (die) made of graphite, and vacuum-pressed at a pressure of 40 MPa with a punch made of graphite, followed by heat treatment at 1000 ° C. for 4 hours. To obtain a disk-shaped oxide sintered body (9). (Hot press sintering)
When the obtained oxide sintered body (9) was analyzed with an energy dispersive fluorescent X-ray apparatus (“EDX-700L” manufactured by Shimadzu Corporation), the atomic ratio of Zn and Ti was Zn: Ti = 93: 7 (Ti / (Zn + Ti) = 0.07). When the crystal structure of the oxide sintered body (9) was examined with an X-ray diffractometer (“RINT2000” manufactured by Rigaku Corporation), crystals of zinc oxide (ZnO) and zinc titanate (Zn ₂ TiO ₄ ) were obtained. It was a phase mixture and no titanium oxide was present.

Next, the obtained oxide sintered body (9) is processed into a disk shape of 20 mmφ to produce a tablet, and a transparent conductive film is formed by ion plating using the tablet, thereby forming a transparent conductive substrate. Got. That is, using an ion plating apparatus (“SUPLaDUO” manufactured by Chugai Furnace Co., Ltd.), ion plating is performed under the following conditions, and the film thickness is formed on a transparent substrate (a non-alkali glass substrate having a thickness of 0.7 mm). A 200 nm transparent conductive film was formed.
Preheating temperature of substrate before film formation: 250 ° C.
Pressure during film formation: 0.3 Pa
Atmospheric gas conditions during film formation: Argon = 160 sccm, Oxygen = 2 sccm
Discharge current during film formation: 100 A
Deposition time: 200 seconds

The composition (Zn: Ti) in the formed transparent conductive film is quantitatively analyzed using a calibration curve by a fluorescent X-ray method using a wavelength dispersion type fluorescent X-ray apparatus (“XRF-1700WS” manufactured by Shimadzu Corporation). As a result, Zn: Ti (atomic ratio) was 93: 7. The transparent conductive film is subjected to X-ray diffraction using an attachment for thin film measurement using an X-ray diffractometer ("RINT2000" manufactured by Rigaku Corporation) and an energy dispersive X-ray microanalyzer (TEM-). EDX) was used to investigate the doping state of titanium into zinc, and further the crystal structure was examined using a field emission electron microscope (FE-SEM). Was found to be substituted and dissolved in zinc.
The specific resistance of the transparent conductive film on the obtained transparent conductive substrate was 9.4 × 10 ⁻⁴ Ω · cm, and the surface resistance was 47.0 Ω / □. The specific resistance distribution on the transparent substrate was uniform in the plane.
The transmittance of the obtained transparent conductive substrate was an average of 90% in the visible region (380 nm to 780 nm) and an average of 67% in the infrared region (780 nm to 2700 nm). In addition, the transmittance | permeability in the visible region (380 nm-780 nm) of the glass substrate before film-forming was an average of 94%, and the transmittance | permeability in an infrared region (780 nm-2700 nm) was an average of 94%.
When the moisture resistance of the obtained transparent conductive substrate was evaluated, the surface resistance after the moisture resistance test was 1.4 times the surface resistance before the moisture resistance test, and it was found that the moisture resistance was excellent. Moreover, when the heat resistance of the obtained transparent conductive substrate was evaluated, the surface resistance after the heat test was 1.2 times the surface resistance before the heat test, and it was found that the heat resistance was excellent.
When the alkali resistance of the obtained transparent conductive substrate was evaluated, it was found that there was no change in film quality before and after immersion, and the alkali resistance was excellent. Moreover, when the acid resistance of the obtained transparent conductive substrate was evaluated, it was found that after immersion, the film thickness was thin and dissolved, but the film quality did not change before and after immersion, and the acid resistance was excellent. It was.
From the above, the film on the obtained transparent conductive substrate is a transparent conductive film that is transparent and has low resistance, and also has chemical durability (heat resistance, moisture resistance, alkali resistance, acid resistance). It is clear that there is.

DESCRIPTION OF SYMBOLS 10 Ion plating apparatus 12 Vacuum vessel PB Plasma beam 14 Plasma gun (plasma beam generator)
14a Plasma gun cathode 14b, 14c Intermediate electrode 14d Electromagnetic coil 14e Steering coil 16 Anode member 16a Hearth as main anode 16b Annular auxiliary anode W Substrate WH Substrate holding member 18 Transport mechanism 18a Transport path 18b Roller 19 Oxygen gas container 20a Ar 20 b Supply path for supplying an atmospheric gas other than oxygen 20 c Supply path for supplying an inert gas such as Ar to Hearth 20 d Exhaust system TH Through hole 21 Mass flow meter 22 Vapor deposition material 24a Permanent magnet 24b Coil

Claims (5)

  A method of forming a zinc oxide-based transparent conductive film by an ion plating method, which is substantially composed of zinc, titanium, and oxygen, and the atomic ratio Ti / (Zn + Ti) of titanium to the total of zinc and titanium is 0. A method comprising using a target obtained by processing an oxide sintered body or an oxide mixture that exceeds 02 and is 0.1 or less. The method according to claim 1, wherein the titanium is titanium derived from low-valent titanium oxide represented by a formula TiO _2−X (X = 0.1-1).   A zinc oxide-based transparent conductive film formed by the method according to claim 1.   A transparent conductive substrate comprising the zinc oxide-based transparent conductive film according to claim 3 on a transparent substrate.   The transparent conductive substrate according to claim 4, wherein the transparent substrate is a glass plate, a resin film, or a resin sheet.

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