KR20060095534A - Conductive material and evaporating target thereof - Google Patents

Abstract

     The present invention relates to a conductive material used as a material for a transparent conductive film, a target for deposition and a transparent conductive film using the same, and more particularly, a conductive sinter for a transparent conductive film having good stability and productivity during film formation in a sputtering method or the like. And a sputtering target made of the sintered compact, a transparent conductive film formed by using the target, and a method for producing a transparent electrode using the same.

Conductive material, evaporation target, transparent conductive film

Description

Conductive Material and Evaporating Target Thereof}

  Figure 1-X-ray diffraction pattern for transparent conductive material

  Fig. 2-Light transmittance for each thickness wavelength

In general, the transparent conductive material is used in the form of a conductive film, such as a plasma display panel (PDP), a liquid crystal display (LCD) device, a light emitting diode device (LED), an organic electroluminescent device (EL) or a solar cell display and a conductive transparent touch panel. .

The transparent conductive film thus formed has high conductivity (eg, resistivity of 1 × 10 ⁻³ Ωcm or less) and high transmittance in the visible light region, so that solar cells, liquid crystal display devices, plasma display panels, conductive transparent touch panels, and other various light receiving devices In addition to being used as electrodes of devices and light emitting devices, it is used as a transparent heating element such as a heat ray reflecting film used in automobile window glass or building window glass, and an antistatic film freezing showcase.

As the transparent conductive thin film, a tin oxide (SnO ₂ ) film doped with antimony or fluorine, a zinc oxide (ZnO) film doped with aluminum or potassium, and an indium oxide (In ₂ O ₃ ) doped with tin are widely used. It is becoming.

In particular, an indium oxide oxide film doped with tin, that is, an In ₂ O ₃ -Sn-based film is called an indium tin oxide (ITO) film and is widely used because a low resistance film can be easily obtained.

In the case of ITO, it has excellent physical properties and has a lot of experience in the process input to date, but since indium oxide (In ₂ O ₃ ) is produced as a by-product from zinc (Zn) mines, supply and demand is unstable and very expensive. As it is expensive, it is necessary to develop a general purpose low cost material.

 In order to reduce the content of indium oxide, a lot of researches have been conducted on zinc oxide-tin oxide compounds or indium oxide-tin oxide-zinc oxide compounds, and zinc oxide (AZO) containing aluminum has high conductivity. Although it is known to have, it has not yet reached the characteristics of ITO in conductivity and transparency.

Accordingly, the present invention has been made to solve the above-mentioned problems of the prior arts, and by using a sintered body of a compound containing zinc oxide, aluminum oxide, gallium oxide and the like in a specific ratio in a transparent conductive material, a film by sputtering or the like It is an object of the present invention to provide a conductive material formed of a sintered body of a metal oxide capable of performing the formation operation stably and with high productivity, a deposition target and a transparent conductive film using the same.

It is also an object of the present invention to provide a transparent conductive film such as a transparent conductive glass and a transparent conductive film having good transparency, conductivity, and electrode workability of the target made of the sintered compact and the target.

According to the present invention for achieving the above object, each component of zinc oxide, aluminum oxide, and gallium oxide is represented by ZnO / (ZnO + Al ₂ O ₃ in terms of the metal atomic ratio thereof. + Ga ₂ O ₃ ) = 0.60 to 0.99, Al ₂ O ₃ / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.01 to 0.30, Ga ₂ O ₃ / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = transparent conductive film, characterized in that it is formed as a sintered body containing the compound in the ratio of 0.001 to 0.10 as the technical gist.

Here, the sintered compact has a specific resistance value of less than 1 Ω · cm, and the sintered compact is ZnO + Al ₂ O ₃ in the denominator term of the sintered compact. Among the group consisting of + trivalent metal oxide indium oxide (In ₂ O ₃ ), + tetravalent metal oxide silicon oxide (SiO ₂ ), and tin oxide (SnO ₂ ) with respect to all metal atoms of the Ga ₂ O ₃ compound At least one or more is added, and the sintered body is preferably used as a sputtering target, an electron beam target, or an ion plating target.

The sintered compact is preferably coated on a glass surface or a transparent resin film surface, has a light transmittance of 75% or more, and a resistivity of 5 mΩ · cm or less.

In the present invention, the zinc compound (ZnO) is mixed with aluminum oxide (Al ₂ O ₃ ) and gallium oxide (Ga ₂ O ₃ ), which are the second element, but the atomic ratio of the second element / (ZnO + second element) is 0.4 or less. It is mixed as much as possible, and it is baked at 800 to 1500 degreeC, and a sintered compact is formed, The electroconductive material formed by coat | covering the surface of a board | substrate using this sintered compact as a target, the vapor deposition target using the same, and a transparent conductive film are technical points.

Here, the third element includes at least one or more of a group consisting of indium oxide (In ₂ O ₃ ), silicon oxide (SiO _{2 )} , tin oxide (SnO _{2 )} , and the sintered body is a sputtering target and an electron beam target. It is preferably used as one of the targets for ion plating, the sintered body is preferably coated on a glass surface or a transparent resin film.

In the present invention, a zinc compound (ZnO) is mixed with aluminum oxide (Al ₂ O ₃ ) and gallium oxide (Ga ₂ O ₃ ), which are the second element, and the atomic ratio of the second element / (ZnO + second element) is 0.4 or less. To prepare a coating solution by mixing so as to prepare a coating solution and to bake at 300 ℃ to 600 ℃ and reducing the conductive material to be made of an oxide containing zinc oxide as the main cationic element, a method of manufacturing a target for deposition using the same and a transparent conductive film Make a point. Here, it is preferable that the said zinc compound is at least 1 sort (s) chosen from the group which used the thing which consists of carboxylate of zinc, an inorganic zinc compound, and zinc alkoxide.

As a result, a transparent conductive film having a light transmittance of 70% or more is formed by depositing with a deposition target made of a conductive material, thereby forming a plasma display panel (PDP), a liquid crystal display (LCD) device, a light emitting diode device (LED), and organic electroluminescence There is an advantage that it can be used for the element (EL) or solar cell display, conductive transparent touch panel.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram showing an X-ray diffraction pattern of a conductive material according to the present invention, and FIG. 2 is a diagram showing transmittance in a transparent conductive film deposited with a deposition target made using a conductive material.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described.

(1) Preparation of Conductive Material

The electroconductive material of this invention is a transparent conductive material used for the film formation of a transparent conductive film, The basic structural component consists of each component of zinc oxide, aluminum oxide, and gallium oxide.

And in each of these components, the composition ratio is an atomic ratio,

ZnO / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.60 to 0.99

Al ₂ O ₃ / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.01 to 0.30

Ga ₂ O ₃ / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.001 to 0.10.

In the present invention, the composition of zinc oxide, aluminum oxide and gallium oxide as its constituents is as described above, since the mixture of zinc oxide and aluminum oxide has high transparency but does not have sufficient conductivity. Small additions of gallium oxide to the mixture result in an improvement in conductivity.

When gallium oxide was added to zinc oxide or gallium oxide, respectively, when the conductivity was measured while changing the temperature of the sintered body, the semiconductor properties of the specific resistance decreased as the temperature increased, but the zinc oxide and gallium oxide on zinc oxide At the same time, when the temperature was increased, the specific resistance of the metal increased as the temperature increased.

The sintered compact of this invention which consists of such a structural component has high electrical conductivity as mentioned above, and has a specific resistance value less than 1 ohm * cm. Therefore, when a film is formed using this sintered compact as a target, such as a sputtering apparatus, stability is high and productivity of a film formation product improves.

In addition, in each of the above components of zinc oxide, aluminum oxide and gallium oxide, indium oxide (In ₂ O ₃ ), which is a + trivalent metal oxide, silicon oxide (SiO ₂ ), which is a + tetravalent metal oxide, and tin oxide (SnO) ₂₎ when compared to one or more of the non-containing bars, hayeotneun form a sintered body which contains from 0.1 to 10 atomic%, the sintered body with respect to the total metal atoms of the metal while some improvement in the transparency and the conductivity is low sintering temperature conductivity Had the property to remain.

Therefore, the transparent conductive film which produced the film | membrane using the sputtering target etc. which consist of this sintered compact will reduce the formation temperature of a film | membrane.

Next, in the method for producing the sintered compact of the present invention, the powder of each metal oxide is uniformly mixed and pulverized by a mixing mill, for example, a wet ball mill, beads mill, ultrasonic wave, or the like. Then, it is good to shape | mold to a desired shape by press molding, and to sinter by baking. Although fine grinding | pulverization is good for the mixed grinding | pulverization of the raw material powder here, what mixed and grind | pulverized so that average particle diameter may be 1 micrometer or less may be used normally. Moreover, baking conditions in this case are 1,200-1,500 degreeC normally, Preferably you may be 10 to 72 hours at 1,250-1,480 degreeC.

(2) Formation of transparent electrode glass and transparent electrode film in this invention

The sintered compact manufactured as mentioned above is used as a target substance, and as a transparent base material used when forming a film, the glass substrate used conventionally, the film and the sheet | seat of the synthetic resin product which have high transparency are used. As such a synthetic resin, polycarbonate resin, poly methyl methacrylate resin, polyester resin, polyether sulfone resin, polyarylate resin and the like are also suitable.

A magnetron sputtering apparatus is suitably used in forming a transparent conductive film by sputtering on a transparent substrate using the target. In addition, as a condition of forming a film by sputtering using this apparatus, the output of the plasma varies depending on the surface area of the target and the film thickness of the transparent conductive film, but the plasma output is usually 1 cm ^{2 of the} target. It is ideal to set the film forming time to 2 to 120 minutes in the range of 0.3 to 4 W per sugar.

On the other hand, also in the case of forming a film using a target of an electron beam device or an ion plating device equipped with the sintered compact, a transparent conductive film can be formed under the same film forming conditions as described above.

The transparent conductive glass and transparent conductive film produced in this way have the transparent conductive film formed on these transparent base materials, are high in light transmittance, and are low in specific resistance. In addition, in the case of performing an etching process for using this transparent conductive film as a transparent electrode, the cross-sectional shape of the boundary portion between the treatment portion and the non-treatment portion by hydrochloric acid, oxalic acid, or the like is smooth, and the treatment portion and the non-treatment portion are clearly distinguished and uniform. A circuit composed of electrode lines having a width and a thickness can be formed.

Therefore, the transparent conductive film in the transparent conductive glass and the transparent conductive film of the present invention not only performs normal etching processing but also the partial electrical resistance in the circuit generated in the case of etching processing of the transparent conductive film having poor electrode workability. A transparent electrode can be obtained without the risk of causing an increase or a decrease or a disconnection path or a circuit break in the insulation.

The transparent conductive glass and the transparent conductive film thus produced are characterized by having at least one transparent conductive film made of a composition of a metal oxide composed of the same composition as the sintered compact used for film formation. Regarding the transparency of the transparent conductive film, the light transmittance of light having a wavelength of 500 nm is 70% or more. Moreover, also regarding the electroconductivity of this transparent conductive film, most have a specific resistance of 1 m (ohm) * cm or less.

As described above, the transparent conductive glass and the transparent conductive film of the present invention can be suitably used as a transparent electrode for ITO in various display devices in which ITO is used. In addition, it is much cheaper than ITO, which can greatly contribute to cost reduction.

Next, although an Example demonstrates this invention still in detail, this invention is not limited in any way by these examples.

<Example>

(1) Preparation of Conductive Sintered Body

As raw materials, powders of zinc oxide, aluminum oxide and gallium oxide,

ZnO / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.956

Al ₂ O ₃ / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.04

Ga ₂ O ₃ / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.004

1st, 2nd, 3rd sintering at 800 ℃

It was carried out for several hours between 1300 ℃ and pulverized.

Subsequently, after assembling the prepared pulverized product, the press was pressed to a diameter of 2 inches and a thickness of 5 mm.

It shape | molded and it baked by pressurization at 1200 degreeC-1300 degreeC for several hours in the kiln.

Through the above process, a conductive sintered body, which is a base material of the transparent conductive film, was formed.

(2) Preparation of Transparent Conductive Glass

By the sintered compact formed in said (1), the target for sputtering of 2 inches in diameter and 5 mm in thickness was manufactured, this was mounted in the RF magnetron sputtering apparatus, and the film | membrane was formed on the glass substrate.

As the sputtering conditions, the sputtering gas uses argon gas, the sputtering pressure of 10 mTorr, the distance between the target and the substrate is 3-5 cm, the substrate temperature of 250 ° C. to 500 ° C., the input power of 50 W to 100 W, and the film formation time of 10 to 60. It was performed as a minute.

The transparent conductive film on the transparent conductive glass thus obtained has a thickness of 1,000 kPa to 9,000 kPa and is crystalline.

The light transmittance of this transparent conductive film was measured by a spectrophotometer with respect to a light having a wavelength of 500 nm, and the result was 85% or more.

On the other hand, the specific resistance of the transparent conductive film measured by the 4-probe method is about 1-5x10 <^{-4> (} ohm) * cm, and is high in electroconductivity.

The analytical evaluation of the transparent conductive film of the obtained electroconductive material and a transparent conductive film was performed, and the result was shown to Table I and FIG. 1, FIG.

Figure 1 shows the X-ray diffraction pattern for the transparent conductive material, as shown in Figure 1, it can be seen that similar to the X-ray diffraction pattern of zinc oxide.

Table 1 shows the surface resistance and the light transmittance, which are electrical properties of the transparent conductive film according to each thickness. In Table 1, ㅁ of the electrical property column represents a rectangular conductive film in which the transparent conductive film was measured.

TABLE 1

As shown in Table 1, when the specific resistance is calculated, it is calculated as specific resistance = thickness x surface resistance, and in the case of a 100 nm thick transparent conductive film, the specific resistance is 100 x 10 ^-9 m x 45 Ω = 4.5 x 10 ^-4 Ωcm It can be seen that it has a specific resistance value of.

The specific resistance in the case of a 200 nm transparent conductive film is 4 × 10 ^-4 Ω · cm, and the specific resistance in the case of a 300 nm transparent conductive film is 2.7 × 10 ⁻⁴ Ω · cm, and the specific resistance in the case of a 600 nm transparent conductive film. Is 3 × 10 ⁻⁴ Ω · cm, and the specific resistance of the 900 nm transparent conductive film is 2.25 × 10 ⁻⁴ Ω · cm, indicating that the conductivity is excellent.

Figure 2 shows the light transmittance according to the wavelength according to each thickness, C3 100 nm, C3 200 nm, C3 300 nm and C3 600 nm shows the thickness of the transparent conductive film as shown in Table 1.

As shown in FIG. 2, the light transmittance in the wavelength range of 400 nm to 700 nm, which is a general visible light region, is 80% or more.

Deposition using a target made using the conductive sintered body of the present invention configured as described above has the effect of forming a transparent conductive film excellent in conductivity and light transmittance.

In addition, the transparent conductive film can also be used for plasma display panels (PDP), liquid crystal display (LCD) devices, light emitting diode devices (LEDs), organic electroluminescent devices (EL) or solar cell displays, conductive transparent touch panels, and the like. .

Claims (14)

Each component of zinc oxide, aluminum oxide, and gallium oxide is, in its metal atomic ratio, ZnO / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.60 to 0.99 Al ₂ O ₃ / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.01 to 0.30 Ga ₂ O ₃ / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.001 to 0.10 A conductive material formed as a sintered body containing a compound at a ratio of. The conductive material according to claim 1, wherein the sintered compact has a specific resistance value of less than 1 Ω · cm. According to claim 1, wherein said sintered body, a denominator, wherein ZnO + Al ₂ O in the sintered body ₃ + Ga ₂ O ₃ compound I metal atoms of indium oxide + 3-valent metal oxide with respect to a (In ₂ O _3), + A conductive material characterized in that at least one or more of the group consisting of silicon oxide (SiO ₂ ) and tin oxide (SnO ₂ ), which are tetravalent metal oxides, is added. The conductive material according to any one of claims 1 to 3, wherein the sintered body is used as a deposition target, an electron beam target, or an ion plating target. The conductive material according to any one of claims 1 to 3, wherein the sintered compact is coated on a glass surface or a transparent resin film surface to form a transparent conductive glass. The zinc compound (ZnO) is mixed with aluminum oxide (Al ₂ O ₃ ) and gallium oxide (Ga ₂ O ₃ ) as the second element, but mixed so that the atomic ratio of the second element / (ZnO + second element) is 0.4 or less. And firing at 800 ° C. to 1500 ° C. to form a sintered body, and using the sintered body as a target to coat the substrate surface. The method of claim 6, wherein the third element is at least one or more of the group consisting of indium oxide (In ₂ O ₃ ), silicon oxide (SiO ₂ ), tin oxide (SnO ₂ ) manufacturing of the conductive material, characterized in that Way. The method of manufacturing a conductive material according to claim 6 or 7, wherein the sintered body is used as one of a sputtering target, an electron beam target, and an ion plating target. The zinc compound (ZnO) is mixed with aluminum oxide (Al ₂ O ₃ ) and gallium oxide (Ga ₂ O ₃ ) as the second element, but mixed so that the atomic ratio of the second element / (ZnO + second element) is 0.4 or less. A method for producing a conductive material, characterized in that the coating solution is prepared, calcined at 300 ° C to 600 ° C, and then reduced to form an oxide containing zinc oxide as the main cation element. The method for producing a conductive material according to claim 9, wherein the zinc compound is at least one member selected from the group consisting of zinc carboxylates, inorganic zinc compounds, and zinc alkoxides. Each component of zinc oxide, aluminum oxide, and gallium oxide is, in its metal atomic ratio, ZnO / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.60 to 0.99 Al ₂ O ₃ / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.01 to 0.30 Ga ₂ O ₃ / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.001 to 0.10 A target for deposition, characterized in that formed into a sintered body containing the compound at a ratio of. Each component of zinc oxide, aluminum oxide, and gallium oxide is, in its metal atomic ratio, ZnO / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.60 to 0.99 Al ₂ O ₃ / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.01 to 0.30 Ga ₂ O ₃ / (ZnO + Al ₂ O ₃ + Ga ₂ O ₃ ) = 0.001 to 0.10 An electronic device comprising a transparent conductive film formed on a substrate using a sintered body containing a compound at a ratio of. The electronic device having a transparent conductive film according to claim 12, wherein the sintered body is coated on a glass surface or a transparent resin film. The method of claim 12, wherein the transparent conductive film has a light transmittance of 75% or more, the specific resistance is  An electronic device having a transparent conductive film, characterized in that 5 mΩ · cm or less.

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