JP5381724B2 - Method for producing ZnO vapor deposition material - Google Patents

Description

  The present invention relates to a transparent conductive film used for, for example, a solar cell, a liquid crystal display device, an electroluminescence display device, a transparent electrode of a transparent piezoelectric sensor of a touch panel device, an active matrix driving device constituting the display device, and an antistatic conductive film The present invention relates to a method for producing a ZnO vapor deposition material used for forming a conductive film used in coatings, gas sensors, electromagnetic shielding panels, piezoelectric devices, photoelectric conversion devices, light-emitting devices, thin-film secondary batteries, and the like.

  In recent years, a transparent conductive film is indispensable when manufacturing photoelectric conversion devices such as solar cells. An ITO film (indium oxide film doped with tin) is known as a conventional transparent conductive film. The ITO film has the advantages of excellent transparency and low resistance.

  On the other hand, cost reduction is required for solar cells, liquid crystal display devices, and the like. However, since indium is expensive, when an ITO film is used as a transparent conductive film, the solar cell inevitably becomes expensive. In addition, when manufacturing solar cells or the like, amorphous silicon is deposited on the transparent conductive film by plasma CVD. At that time, if the transparent conductive film is an ITO film, There was also a problem that the ITO film deteriorated by the hydrogen plasma.

  In order to eliminate these points, zinc oxide doped with conductive active elements such as Al, B, Si, Ge, Sc, Y, La, Ce, Pr, Nd, Pm, and Sm can be manufactured at a lower cost. It has been proposed to use a system film as a transparent conductive film for solar cells or the like, and a zinc oxide-based vapor deposition material for forming this zinc oxide-based film by vapor deposition is disclosed (for example, see Patent Document 1).

JP 2008-088544 A (Claim 1, specifications [0005] to [0008])

  As shown in FIG. 7, the ZnO vapor deposition material disclosed in Patent Document 1 is obtained by mixing a ZnO powder 1 and an additive powder 2 for improving conductivity to obtain a raw material mixed powder 3, and from this powder, a compact is formed. After obtaining 5, a sintered body 6 to be a ZnO vapor deposition material is produced. Here, when the mixing of the ZnO powder 1 and the additive powder 2 for improving the conductivity is insufficient, the additive 2 may segregate, and the aggregate 4 of the additive powder exists in a small ratio. To do. In the sintered body 6 produced by using the raw material mixed powder 3 having such a non-uniform distribution of the additive powder, the additive is segregated in the sintered structure. There will be a portion 7 that has been removed. When film formation is performed using the sintered body 6 having a non-uniform composition distribution as a deposition material such as electron beam vapor deposition or plasma vapor deposition, the film composition is not constant, making it difficult to control the composition of the film. There is also a problem that the concentration of the additive element in the film is lowered. Furthermore, if the additive segregates, evaporation becomes unstable and splash occurs. When splash occurs, the film structure becomes non-uniform, and the specific resistance of the film increases accordingly.

  An object of the present invention is to provide a method for producing a ZnO vapor deposition material excellent in composition uniformity by suppressing segregation of a rare earth element oxide containing one kind of rare earth element added to a ZnO raw material powder. Another object of the present invention is to provide a method for producing a ZnO vapor deposition material from which a ZnO film having a uniform film composition can be obtained.

  According to a first aspect of the present invention, a composite powder is produced from a ZnO powder having a purity of 98% or more and a rare earth element oxide powder having a purity of 98% or more, and the first granulated powder produced from the composite powder is pelletized. And forming the ZnO vapor-deposited material containing 0.1 to 15% by mass of the rare earth element by molding the green body into a shape, a tablet shape or a plate shape, the rare earth element oxide powder A composite powder having an average particle size of 0.05 to 2 μm by mechanical alloying treatment including mixing and pulverizing the ZnO powder and the rare earth element oxide powder including one element selected from a rare earth element group And a step of producing a first granulated powder from the composite powder.

  According to a second aspect of the present invention, a composite powder is produced from a ZnO powder having a purity of 98% or more and a rare earth element oxide powder having a purity of 98% or more, and the second granulated powder produced from the composite powder is pelletized. And forming the ZnO vapor-deposited material containing 0.1 to 15% by mass of the rare earth element by molding the green body into a shape, a tablet shape or a plate shape, the rare earth element oxide powder A composite powder having an average particle size of 0.05 to 2 μm by mechanical alloying treatment including mixing and pulverizing the ZnO powder and the rare earth element oxide powder including one element selected from a rare earth element group And a step of obtaining a composite calcined body by calcining the composite powder at 800 to 1200 ° C. in an atmosphere of air, nitrogen gas, reducing gas, inert gas or vacuum, and solving the composite calcined body. Crush and compound calcined A step of fabricating the end, characterized in that it comprises a step of preparing a second granulated powder by the composite calcined powder.

  A third aspect of the present invention is the invention based on the first or second aspect, wherein one element selected from the group of rare earth elements is Sc, Y, La, Ce, Pr, Nd, Pm or Sm.

  A fourth aspect of the present invention is an invention based on the first or second aspect, wherein the average particle size of the ZnO powder is 0.1 to 10 μm, and the average particle size of the rare earth element oxide powder is 0. 0.05 to 5 μm.

  A fifth aspect of the present invention is a ZnO film formed by a vacuum film formation method using the ZnO vapor deposition material manufactured by the method of the first to fourth aspects as a target material.

  According to the methods of the first to fourth aspects of the present invention, a composite powder having an average particle size of 0.05 to 2 μm is produced by mechanical alloying treatment in which ZnO powder and rare earth element oxide powder are mixed and pulverized. By producing a ZnO sintered body using, a dispersibility of rare earth elements is improved, segregation is suppressed, and a ZnO vapor deposition material which is a ZnO sintered body having excellent composition uniformity is obtained. That is, the composite powder produced according to the present invention has a very good dispersibility of the rare earth element because ZnO and the rare earth element oxide are compounded at the nanometer level. The dispersibility of the rare earth elements in the aggregate is improved. Furthermore, the ZnO sintered body prepared using the composite calcined powder prepared by calcining and pulverizing this composite powder promotes the formation of a pseudo solid solution of ZnO and rare earth element oxide, so that the composition is uniform. A sintered body with improved properties can be obtained. Further, according to the method of the third aspect of the present invention, there is an effect that the formed ZnO film has good conductivity over a wide temperature range. In particular, Ce can provide high conductivity. When the vapor deposition material according to the fifth aspect of the present invention is used, stable vapor deposition is possible, the film composition is uniform, the film composition change during film formation is small, and the desired conductivity and visible light transmittance ZnO film. Is obtained. This material can be used not only for forming a transparent conductive film but also for forming a conductive film such as a gas sensor, an electromagnetic shielding panel, and a piezoelectric device.

It is a figure which shows each process in 1st and 2nd embodiment of this invention. It is a schematic diagram which shows the microscopic structure of the composite powder in 1st and 2nd embodiment of this invention. It is a schematic diagram which shows the microscopic structure of the 1st granulated powder in the 1st Embodiment of this invention. It is a schematic diagram which shows the microscopic structure of the 2nd granulated powder in the 2nd Embodiment of this invention. It is a schematic diagram which shows the microscopic structure from the 1st granulated powder to a sintered compact in the 1st Embodiment of this invention. It is a schematic diagram which shows the microscopic structure from the 2nd granulated powder to a sintered compact in the 2nd Embodiment of this invention. It is a schematic diagram which shows the microscopic structure from the raw material mixed powder to a ZnO sintered compact in the conventional method.

  Next, an embodiment for carrying out the present invention will be described with reference to the drawings.

A. First Embodiment <Production Process of Composite Powder by Mechanical Alloying Process>
In general, mechanical alloying is called a mechanical mixing method, and is a method in which pulverization and pressure bonding are repeated so that metal powder or ceramic powder is kneaded by the rotational motion of a hard sphere. Examples of the apparatus include a high energy mixing and pulverizing apparatus such as a ball mill, a planetary ball mill, an attritor, and a bead mill. In the case of using metal powder, there are those in which the inside of the apparatus is evacuated to prevent oxidation, those in which hydrogen is filled, and those having a cooling mechanism. By these mixing and pulverizing apparatuses, the mixed powder of metal powder or ceramic powder is finely pulverized to a level of several tens of nanometers. Refinement to this level promotes solid solution formation, compound formation, or amorphization, and can produce alloys and amorphous alloy powders that are thermodynamically impossible with ordinary melting and powder metallurgy methods. . This is thought to be due to the lattice defects introduced by the deformation of strength resulting in the production of metastable materials. Mechanical alloying is well known to be applied to metal powders, but is also applied to nitrides, carbides or oxides. In addition, when a metal powder and a nitride, carbide or oxide powder are mixed, it is also used in a method for producing an alloy powder in which a nitride, carbide or oxide powder is finely dispersed in a metal matrix.

  Next, as a production example of a composite powder by the mechanical alloying process of the present invention, a production process of a composite powder of ZnO powder and rare earth element oxide powder using a planetary ball mill will be described. A planetary ball mill is a device capable of high-energy mixed grinding because a ball mill container rotates on a rotating disk. As shown in FIG. 1, a predetermined amount of ZnO powder 11 having a purity of 98% or more and rare earth element oxide powder 12 having a purity of 98% or more and containing one element selected from a rare earth element group are used in a planetary ball mill apparatus. By filling and operating, mechanical alloying treatment is performed to produce composite powder 13. Preferably, a ZnO powder having a purity of 99.9% or more and a rare earth element oxide powder having a purity of 99.9% or more are used.

  The mixing and pulverization can be carried out by both dry and wet methods, but the wet method is preferable because it has advantages such as less powder adhesion to the container wall surface and balls due to powder aggregation. In the case of wet mixing and grinding, ethanol, n-hexane and the like are preferable as a dispersion medium to be used. Moreover, you may add surfactant, a stearic acid, etc. as a grinding | pulverization additive. The atmosphere in the container is air, but it may be filled with nitrogen or an inert gas.

  The blending ratio of the ZnO powder 11 and the rare earth element oxide powder 12 is such that the total mass of ZnO and the rare earth element oxide is 100% by mass and the rare earth element content is 0.1 to 15% by mass. If the rare earth element is less than the lower limit, the concentration of the rare earth element necessary for improving the conductivity of the film cannot be secured, and if the upper limit is exceeded, basic performance as a ZnO conductive film cannot be obtained. . A preferable rare earth element content is 3 to 6% by mass. The composition of the composite powder 13 produced by mixing and pulverizing the ZnO powder 11 and the rare earth element oxide powder 12 is controlled within the above range, so that the rare earth element content in the ZnO vapor deposition material 16 is reduced to 0.0. It can control to the range of 1-15 mass%.

  The average particle diameter of the raw material ZnO powder 11 is 0.1 to 10 μm, preferably 0.1 to 5 μm. If the amount is less than the lower limit, the powder is agglomerated, and if the upper limit is exceeded, there is a problem that the effect of forming a pseudo solid solution with the rare earth element oxide cannot be obtained sufficiently. More preferably, it is 0.2-2 micrometers. The average particle diameter of the rare earth element oxide powder 12 is 0.05 to 5 μm, preferably 0.1 to 5 μm. If the amount is less than the lower limit, the powder is agglomerated, and if the upper limit is exceeded, there is a problem that the effect of forming a pseudo-solid solution cannot be obtained sufficiently. More preferably, it is 0.1-0.5 micrometer.

  The particle size of the composite powder 13 is controlled by controlling the pot volume, powder input amount, ball amount, ball diameter, disk rotation speed, type of dispersion medium, dispersion medium input amount, operation time, and the like.

In this embodiment, the disk rotation speed is 500 to 1000 rpm. The ball mill container uses a stainless steel cylindrical pot having a volume of 0.2 to 0.5 L. Menor and zirconia containers can also be used. As the ball, a stabilized ZrO ₂ ball having a diameter of 10 to 30 mmφ is used. The smaller the ball diameter, the more finely pulverized, but the amount of contamination due to wear of the ball also increases. A preferable ball diameter is 15 to 20 mmφ. The input amount of the ball is 1/5 to 1/3 of the volume of the ball mill container. When the input raw material is 50 to 100 g, the mixing and grinding time is 0.2 to 1 hour. If it is less than the lower limit value, pulverization is insufficient, and if it exceeds the upper limit value, aggregation due to excessive pulverization and adhesion to the inner wall of the ball or the pot are likely to occur. Preferably it is 0.4 to 0.6 hours.

  The average particle size of the composite powder 13 produced by mixing and grinding under the above conditions is 0.05 to 2 μm. If the amount is less than the lower limit, the powder is agglomerated, and if the upper limit is exceeded, there is a problem that the effect of forming a pseudo solid solution with the rare earth element oxide cannot be obtained sufficiently. Preferably it is 0.1-1 micrometer, More preferably, it is 0.1-0.5 micrometer.

  The average particle size of these powders was determined by laser diffraction / scattering method (microtrack method), using Nikkiso Co., Ltd. (FRA type), using hexametaphosphate Na as a dispersion medium, and measuring time for one second for 30 seconds. Is obtained by averaging the values measured three times.

  When the pulverization proceeds to a level of several tens of nanometers, the spherical ZnO powder 11 and the rare earth element oxide powder 12 are plastically deformed into a flat irregular shape as shown in FIG. Thus, the composite powder 13 having a quasi-lamella structure that does not exhibit such a perfect layer shape is obtained.

<Granulation process of composite powder>
As shown in FIG. 1, the composite powder 13, an organic solvent, and a binder are mixed to prepare a slurry having a concentration of 30 to 75% by mass. A preferable concentration is 40 to 65% by mass. The reason why the concentration of the slurry is limited to 30 to 75% by mass is that when the content exceeds 75% by mass, the slurry is non-aqueous, so there is a problem that stable mixed granulation is difficult. This is because a dense ZnO sintered body having the above cannot be obtained. The average particle size of the composite powder 13 is preferably in the range of 0.05 to 2 μm. When the average particle size of the composite powder is defined within the above range, if the powder is less than the lower limit value, the powder is too fine and agglomerates, so there is a problem that the handling of the powder is worsened. This is because it is difficult to control and a dense pellet cannot be obtained.

It is preferable to use ethanol or propanol as the organic solvent, and polyethylene glycol or polyvinyl butyral is preferable as the binder. It is preferable that the addition amount of a binder is 0.2-5.0 mass%. Further, the wet mixing of the composite powder 13, the binder, and the organic solvent is performed by a wet ball mill or a stirring mill. In the wet ball mill, when ZrO ₂ balls are used, wet mixing is performed for 8 to 24 hours, preferably 20 to 24 hours, using a large number of ZrO ₂ balls having a diameter of 5 to 10 mm. In the stirring mill, wet mixing is performed for 0.5 to 1 hour using a ZrO ₂ ball having a diameter of 1 to 3 mm. Next, the slurry is spray-dried to obtain a first granulated powder 14 (FIG. 3) having an average particle size of 50 to 250 μm, preferably 100 to 200 μm. The spray drying is preferably performed using a spray dryer.

  As shown in FIG. 3, the first granulated powder 14 is composed of a plurality of lamellar structure composite powders 13 formed by plastically deforming and laminating ZnO powder 11 and rare earth element oxide powder 12 into a flat shape. , And combined by a binder.

<Molding process>
As shown in FIG. 1, the first granulated powder 14 is put into a predetermined mold and molded at a predetermined pressure to produce a molded body 15. As the predetermined mold, a uniaxial pressing device or a cold isostatic pressing device (CIP (Cold Isostatic Press) forming device) is used. A tablet machine, a briquette machine, or the like may be used. In uniaxial pressing apparatus, the first granulated powder ^{14 750~2000kg / cm 2 (73.5~196.1MPa)} , uniaxial pressing at a pressure of preferably 1000~1500kg / cm ² (98.1~147.1MPa) In the CIP molding apparatus, the first granulated powder 14 is 1000 to 3000 kg / cm ² (98.0 to 294.2 MPa), preferably 1500 to 2000 kg / cm ² (147.1 to 196.1 MPa). CIP molding with pressure. The reason why the pressure is limited to the above range is to increase the density of the molded body 15 and prevent deformation after sintering, thereby making post-processing unnecessary.

<Sintering process>
As shown in FIG. 1, the molded body 15 is sintered at a predetermined temperature to produce a ZnO sintered body (ZnO vapor deposition material) 16. Sintering is performed in air, inert gas, vacuum or reducing gas atmosphere. A preferable atmosphere is air or a reducing gas atmosphere. Sintering is performed at a sintering temperature of 1000 ° C. or higher. This is because if the sintering temperature is lower than 1000 ° C., sufficient sinterability cannot be obtained. Preferably, it is 2 to 5 hours at 1200 to 1400 ° C. Thereby, a pellet having a relative density of 90% or more is obtained. The above sintering is performed under atmospheric pressure, but when performing pressure sintering such as hot pressing (HP) sintering or hot isostatic pressing (HIP) sintering, an inert gas, It is preferable to carry out in a vacuum or reducing gas atmosphere at a temperature of 1000 ° C. or higher for 1 to 5 hours. Moreover, it is good also as a plate-shaped sintered compact by uniaxial press.

  FIG. 5 is a diagram schematically showing a microscopic structure of the first granulated powder 14, the molded body 15, and the ZnO sintered body 16. As shown in FIG. 5, since the composite powder 13 has a quasi-lamella structure formed by laminating ZnO powder and rare earth element oxide powder in a flat irregular shape, this granulated powder, compact and ZnO sintered body Among them, the rare earth element oxide is uniformly dispersed. Therefore, as shown in FIG. 7, there is no segregated portion of rare earth element oxides as seen in a ZnO sintered body produced using a mixed powder of ZnO powder and rare earth element oxide powder as a raw material. Thus, the ZnO sintered body (ZnO vapor deposition material) 16 excellent in composition uniformity can be obtained.

<Film formation process>
Using the obtained ZnO sintered body (ZnO vapor deposition material) 16 as a vapor deposition source, a ZnO film is formed on the substrate surface by a vacuum film formation method. Examples of the vacuum film forming method for forming the ZnO film include an electron beam evaporation method, a reactive plasma evaporation method, an ion plating method, and a sputtering method.

  When the rare earth additive element is trivalent or tetravalent and is added to the ZnO film, excess carrier electrons are generated relative to the divalent Zn, so that the conductivity of the ZnO film is increased over a wide temperature range. Can be improved.

B. Second Embodiment <Production Step of Composite Powder by Mechanical Alloying Process>
Similarly to the first embodiment, a predetermined amount of ZnO powder 11 having a purity of 98% or more and rare earth element oxide powder 12 having a purity of 98% or more are filled in a planetary ball mill crusher and operated to perform mechanical alloying treatment. To produce the composite powder 13. Preferably, a ZnO powder having a purity of 99.9% or more and a rare earth element oxide powder having a purity of 99.9% or more are used. The details are in accordance with the first embodiment.

<Calcination process of composite powder>
As shown in FIG. 1, the composite powder 13 produced by mechanical alloying is calcined to produce a composite calcined body 17. Calcination is performed in the atmosphere of air, nitrogen gas, reducing gas, inert gas, or vacuum. A preferable atmosphere is air or a reducing gas atmosphere. The calcination temperature is 800 to 1200 ° C. This is because if the calcination temperature is less than 800 ° C., sufficient sinterability cannot be obtained, and if it exceeds 1200 ° C., ZnO evaporates and the composition components change. The preferred calcination time is 2 to 5 hours. As the crucible used for calcination, an alumina-based, magnesia-based, or zirconia-based crucible is used. Preferably magnesia is used. The purpose of calcination is to cause a reaction at the interface between the ZnO particles and the rare earth element oxide particles to form a pseudo solid solution of ZnO and the rare earth element oxide. Thereby, the effect which the dispersibility of the rare earth element with respect to a ZnO matrix improves can be anticipated. In addition, the reactivity can be controlled by the sintering temperature.

<Process of crushing composite calcined body>
As shown in FIG. 1, the composite calcined body 17 obtained by the calcining is mechanically crushed to produce a composite calcined powder 18. As the crusher, a jaw crusher, a roll crusher, a hammer crusher, a disc crusher, a stamp mill, a ball mill, a bead mill, a vibration mill, a jet mill, or the like is used. Preferably, a hammer mark lasher is used. This is because impurities are relatively low and the process is simple. Grind until the average particle size is in the range of 0.05-5 μm, preferably 0.1-5 μm. The reason why the average particle size of the composite calcined powder 18 is controlled within this range is that the powder is agglomerated significantly if it is less than the lower limit, and handling becomes difficult, and if the upper limit is exceeded, the sinterability deteriorates. Especially preferably, it is 0.1-2 micrometers, More preferably, it is 0.2-2 micrometers.

  As shown in FIG. 4, in the composite calcined powder 18, a pseudo solid solution 20 is formed between ZnO and the rare earth element oxide, and the dispersibility of the rare earth element is improved.

<Granulation process of composite calcined powder>
As shown in FIG. 1, a second granulated powder 19 (FIG. 4) is produced from the composite calcined powder 18. The details are based on the granulation step of the composite powder 13 of the first embodiment.

<Molding process>
As shown in FIG. 1, the 2nd granulated powder 19 is shape | molded and the molded object 21 is produced. The details are based on the molding process of the first embodiment.

<Sintering process>
As shown in FIG. 1, the molded body 21 is sintered at a predetermined temperature to produce a ZnO sintered body (ZnO vapor deposition material) 22. Sintering is performed in air, inert gas, vacuum or reducing gas atmosphere. Preferred atmospheres are air, inert gas, vacuum or reducing gas atmosphere. Sintering is performed at a sintering temperature of 1000 ° C. or higher. When the sintering temperature was less than 1000 ° C., sufficient sinterability could not be obtained, so this temperature condition was used. Preferably, it is 2 to 5 hours at 1200 to 1400 ° C. Thereby, a pellet having a relative density of 90% or more is obtained. The above sintering is performed under atmospheric pressure, but when performing pressure sintering such as hot pressing (HP) sintering or hot isostatic pressing (HIP) sintering, an inert gas, It is preferable to carry out in a vacuum or reducing gas atmosphere at a temperature of 1000 ° C. or higher for 1 to 5 hours. Moreover, it is good also as a plate-shaped sintered compact by uniaxial press.

  FIG. 6 is a diagram schematically showing a microscopic structure of the second granulated powder 19, the compact 21, and the ZnO sintered body 22. As shown in FIG. 6, in the composite calcined powder 18, ZnO and rare earth element oxide form a pseudo solid solution 20, and therefore, in this granulated powder, compact and ZnO sintered body, rare earth element oxidation is performed. Things are evenly dispersed. Therefore, as shown in FIG. 7, there is no segregated portion of rare earth element oxides as seen in a ZnO sintered body produced using a mixed powder of ZnO powder and rare earth element oxide powder as a raw material. Thus, the ZnO sintered body (ZnO vapor deposition material) 22 excellent in composition uniformity can be obtained.

<Film formation process>
A ZnO film is produced using the ZnO sintered body (ZnO vapor deposition material) 22 produced according to the second embodiment as an evaporation source. The details are in accordance with the film forming process of the first embodiment.

  Next, examples of the present invention will be described in detail together with comparative examples.

<Example 1>
First, ZnO powder having an average particle size of 2.0 μm and a purity of 99.7% and CeO ₂ powder having an average particle size of 2.5 μm and a purity of 99.5% were weighed by a predetermined amount, and these powders were measured with a planetary ball mill device. By operating this apparatus, a mechanical alloying process for mixing and pulverizing the above powder was performed to produce a composite powder. This mixing and grinding was performed by wet mixing, ethanol was added as a dispersion medium, and a surfactant was added as a grinding additive. The atmosphere in the container was air. The average particle size of the composite powder produced by performing the mechanical alloying treatment was 0.5 μm. Here, regarding the composition of the composite powder, when the total mass of ZnO powder and CeO ₂ powder (rare earth element oxide powder) is 100 mass%, the content ratio of Ce (rare earth element) is 2 mass%. Controlled.

Next, an organic solvent and a binder were added to and mixed with the composite powder to prepare a slurry having a concentration of 50% by mass. Ethanol was used as the organic solvent, and polyvinyl butyral was used as the binder. Moreover, the addition amount of the binder was 0.5 mass%. The wet mixing of the composite powder, the organic solvent and the binder was performed by a stirring mill. The slurry was spray-dried using a spray dryer to obtain a first granulated powder having an average particle size of 200 μm. The first granulated powder was uniaxially pressed at a pressure of 1000 kg / cm ² (98 MPa) using a uniaxial press device (manufactured by Riken Seiki Co., Ltd., model name: CD type) to produce a compact. Furthermore, a ZnO vapor deposition material (ZnO sintered body) was obtained by sintering the molded body in an air atmosphere at a temperature of 1200 ° C. for 5 hours using an air firing furnace. This ZnO vapor deposition body was taken as Example 1.

<Example 2>
As shown in the following Table 1, a ZnO vapor deposition body was produced in the same manner as in Example 1 except that the content ratio of Ce (rare earth element) was 5 mass%. This ZnO vapor deposition body was taken as Example 2.

<Example 3>
As shown in the following Table 1, a ZnO vapor deposition body was produced in the same manner as in Example 1 except that the content ratio of Ce (rare earth element) was 10 mass%. This ZnO vapor deposition body was taken as Example 3.

<Example 4>
As shown in the following Table 1, a ZnO vapor deposition body was produced in the same manner as in Example 1 except that the content ratio of Ce (rare earth element) was 15 mass%. This ZnO vapor deposition body was taken as Example 4.

<Example 5>
First, in the same manner as in Example 1, ZnO powder and CeO ₂ powder are weighed in predetermined amounts, filled in a planetary ball mill device, and subjected to mechanical alloying to obtain a composite having an average particle size of 0.5 μm. A powder was prepared. Here, regarding the composition of the composite powder, when the total mass of ZnO powder and CeO ₂ powder (rare earth element oxide powder) is 100 mass%, the content ratio of Ce (rare earth element) is 2 mass%. Controlled. Next, the composite powder was calcined to produce a composite calcined body. The calcination was performed in the air, the calcination temperature was 1000 ° C., and the calcination time was 3 hours. The composite calcined body was mechanically crushed to produce a composite calcined powder. As a crusher, a Hanmark lasher was used, and a composite calcined powder having an average particle size of 0.4 μm was produced using this crusher. Next, in the same manner as in Example 1, an organic solvent and a binder were added to and mixed with the composite calcined powder to prepare a slurry, and this slurry was spray-dried using a spray dryer to obtain an average particle size. A second granulated powder having a diameter of 200 μm was obtained. Further, in the same manner as in Example 1, the second granulated powder was uniaxially pressed using a uniaxial press device to produce a molded product, and this molded product was sintered using an atmospheric firing furnace. A ZnO vapor deposition body was obtained. This ZnO vapor deposition body was taken as Example 5.

<Example 6>
As shown in the following Table 1, a ZnO vapor deposition body was produced in the same manner as in Example 5 except that the content ratio of Ce (rare earth element) was 5 mass%. This ZnO vapor deposition body was taken as Example 6.

<Example 7>
As shown in the following Table 1, a ZnO vapor deposition body was produced in the same manner as in Example 5 except that the content ratio of Ce (rare earth element) was 10 mass%. This ZnO vapor deposition body was taken as Example 7.

<Example 8>
As shown in the following Table 1, a ZnO vapor deposition body was produced in the same manner as in Example 5 except that the content ratio of Ce (rare earth element) was 15 mass%. This ZnO vapor deposition body was determined as Example 8.

<Example 9>
As shown in Table 1 below, mechanical alloying was performed using ZnO powder with an average particle size of 10.0 μm and CeO ₂ powder with an average particle size of 2.5 μm, with a Ce (rare earth element) content of 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the average particle size of the composite powder after the treatment was 1 μm. This ZnO vapor deposition body was taken as Example 9.

<Example 10>
As shown in the following Table 1, ZnO powder having an average particle diameter of 2.0 μm and CeO ₂ powder having an average particle diameter of 5 μm were used, and the content ratio of Ce (rare earth element) was 5% by mass, and after mechanical alloying treatment A ZnO vapor-deposited material was produced in the same manner as in Example 1 except that the average particle size of the composite powder was 0.8 μm. This ZnO vapor deposition body was taken as Example 10.

<Example 11>
As shown in the following Table 1, ZnO powder having an average particle diameter of 10.0 μm and CeO ₂ powder having an average particle diameter of 5 μm were used, and the content ratio of Ce (rare earth element) was 5 mass%, and after mechanical alloying treatment A ZnO vapor-deposited material was produced in the same manner as in Example 1 except that the average particle size of the composite powder was 1.5 μm. This ZnO vapor deposition body was taken as Example 11.

<Example 12>
As shown in Table 1 below, mechanical alloying was performed using ZnO powder with an average particle size of 10.0 μm and CeO ₂ powder with an average particle size of 2.5 μm, with a Ce (rare earth element) content of 5% by mass. A ZnO vapor deposition body was prepared in the same manner as in Example 5 except that the average particle size of the composite powder after the treatment was 0.5 μm and the average particle size of the composite calcined powder after the pulverization treatment was 0.6 μm. Produced. This ZnO vapor deposition body was taken as Example 12.

<Example 13>
As shown in the following Table 1, ZnO powder having an average particle diameter of 2.0 μm and CeO ₂ powder having an average particle diameter of 5 μm were used, and the content ratio of Ce (rare earth element) was 5% by mass, and after mechanical alloying treatment A ZnO vapor-deposited body was prepared in the same manner as in Example 5 except that the average particle size of the composite powder was 0.5 μm and the average particle size of the composite calcined powder after pulverization was 0.5 μm. . This ZnO vapor deposition body was taken as Example 13.

<Example 14>
As shown in the following Table 1, ZnO powder having an average particle diameter of 10.0 μm and CeO ₂ powder having an average particle diameter of 5 μm were used, and the content ratio of Ce (rare earth element) was 5 mass%, and after mechanical alloying treatment A ZnO vapor-deposited body was prepared in the same manner as in Example 5 except that the average particle size of the composite powder was 0.5 μm and the average particle size of the composite calcined powder after the pulverization treatment was 1 μm. This ZnO vapor deposition body was taken as Example 14.

<Example 15>
As shown in Table 1 below, ZnO powder having an average particle size of 2.0 μm and Sc ₂ O ₃ powder having an average particle size of 2.5 μm were used, and the content ratio of Sc (rare earth element) was 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the average particle size of the composite powder after the alloying treatment was 0.5 μm. This ZnO vapor deposition body was taken as Example 15.

<Example 16>
As shown in the following Table 1, a ZnO powder having an average particle size of 2.0 μm and a Y ₂ O ₃ powder having an average particle size of 2.5 μm were used, and the content ratio of Y (rare earth element) was set to 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the average particle size of the composite powder after the alloying treatment was 0.5 μm. This ZnO vapor deposition body was taken as Example 16.

<Example 17>
As shown in the following Table 1, ZnO powder having an average particle diameter of 2.0 μm and La ₂ O ₃ powder having an average particle diameter of 2.5 μm were used, and the content ratio of La (rare earth element) was set to 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the average particle size of the composite powder after the alloying treatment was 0.5 μm. This ZnO vapor deposition body was taken as Example 17.

<Example 18>
As shown in Table 1 below, ZnO powder having an average particle size of 2.0 μm and Pr ₆ O ₁₁ powder having an average particle size of 2.5 μm were used, and the content ratio of Pr (rare earth element) was set to 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the average particle size of the composite powder after the alloying treatment was 0.5 μm. This ZnO vapor deposition body was taken as Example 18.

<Example 19>
As shown in the following Table 1, a ZnO powder having an average particle diameter of 2.0 μm and an Nd ₂ O ₃ powder having an average particle diameter of 2.5 μm were used, and the content ratio of Nd (rare earth element) was set to 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the average particle size of the composite powder after the alloying treatment was 0.5 μm. This ZnO vapor deposition body was taken as Example 19.

<Example 20>
As shown in the following Table 1, a ZnO powder having an average particle size of 2.0 μm and a Pm ₂ O ₃ powder having an average particle size of 2.5 μm were used, and the content ratio of Pm (rare earth element) was 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the average particle size of the composite powder after the alloying treatment was 0.5 μm. This ZnO vapor deposition body was taken as Example 20.

<Example 21>
As shown in the following Table 1, a ZnO powder having an average particle size of 2.0 μm and an Sm ₂ O ₃ powder having an average particle size of 2.5 μm were used, and the content ratio of Sm (rare earth element) was set to 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the average particle size of the composite powder after the alloying treatment was 0.5 μm. This ZnO vapor deposition body was taken as Example 21.

<Comparative Example 1>
As shown in the following Table 2, a ZnO powder having an average particle diameter of 2.0 μm and a CeO ₂ powder having an average particle diameter of 2.5 μm were used, and the content ratio of Ce (rare earth element) was 5% by mass. A ZnO vapor-deposited body was produced in the same manner as in Example 1 except that the inging process was not performed. This ZnO vapor deposition body was designated as Comparative Example 1.

<Comparative example 2>
As shown in Table 2 below, mechanical alloying was performed using ZnO powder with an average particle size of 2.0 μm and CeO ₂ powder with an average particle size of 2.5 μm, with a Ce (rare earth element) content of 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the average particle size of the composite powder after the treatment was 0.02 μm. This ZnO vapor deposition body was set as Comparative Example 2.

<Comparative Example 3>
As shown in Table 2 below, mechanical alloying was performed using ZnO powder with an average particle size of 2.0 μm and CeO ₂ powder with an average particle size of 2.5 μm, with a Ce (rare earth element) content of 5% by mass. A ZnO vapor deposition body was prepared in the same manner as in Example 5, except that the average particle size of the composite powder after the treatment was 0.02 μm and the average particle size of the composite calcined powder after the pulverization treatment was 0.02 μm. Produced. This ZnO vapor deposition body was designated as Comparative Example 3.

<Comparative Example 4>
As shown in Table 2 below, mechanical alloying was performed using ZnO powder with an average particle size of 2.0 μm and CeO ₂ powder with an average particle size of 2.5 μm, with a Ce (rare earth element) content of 30% by mass. The ZnO vapor-deposited body was treated in the same manner as in Example 5 except that the average particle size of the composite powder after the treatment was 0.5 μm and the average particle size of the composite calcined powder after the pulverization treatment was 0.4 μm. Produced. This ZnO vapor deposition body was designated as Comparative Example 4.

<Comparative Example 5>
As shown in Table 2 below, mechanical alloying was performed using ZnO powder with an average particle size of 2.0 μm and CeO ₂ powder with an average particle size of 2.5 μm, with a Ce (rare earth element) content of 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the average particle size of the composite powder after the treatment was 4 μm. This ZnO vapor deposition body was designated as Comparative Example 5.

<Comparative Example 6>
As shown in Table 2 below, mechanical alloying was performed using ZnO powder with an average particle size of 2.0 μm and CeO ₂ powder with an average particle size of 2.5 μm, with a Ce (rare earth element) content of 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 5 except that the average particle size of the composite powder after the treatment was 4 μm and the average particle size of the composite calcined powder after the pulverization treatment was 3 μm. This ZnO vapor deposition body was designated as Comparative Example 6.

<Comparative Example 7>
As shown in the following Table 2, ZnO powder having an average particle size of 2.0 μm and CeO ₂ powder having an average particle size of 10 μm were used, and the content ratio of Ce (rare earth element) was 5 mass%, and after mechanical alloying treatment A ZnO vapor-deposited body was produced in the same manner as in Example 1 except that the average particle size of the composite powder was 5 μm. This ZnO vapor deposition body was designated as Comparative Example 7.

<Comparative Example 8>
As shown in the following Table 2, ZnO powder having an average particle size of 2.0 μm and CeO ₂ powder having an average particle size of 10 μm were used, and the content ratio of Ce (rare earth element) was 5 mass%, and after mechanical alloying treatment A ZnO vapor-deposited body was prepared in the same manner as in Example 5 except that the average particle size of the composite powder was 5 μm and the average particle size of the composite calcined powder after pulverization was 4 μm. This ZnO vapor deposition body was designated as Comparative Example 8.

<Comparative Example 9>
As shown in Table 2 below, mechanical alloying was performed using ZnO powder with an average particle size of 25.0 μm and CeO ₂ powder with an average particle size of 2.5 μm, with a Ce (rare earth element) content of 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the average particle size of the composite powder after the treatment was 8 μm. This ZnO vapor deposition body was determined as Comparative Example 9.

<Comparative Example 10>
As shown in the following Table 2, ZnO powder having an average particle diameter of 25.0 μm and CeO ₂ powder having an average particle diameter of 10 μm were used, and the content ratio of Ce (rare earth element) was 5 mass%, and after mechanical alloying treatment A ZnO vapor-deposited body was prepared in the same manner as in Example 5 except that the average particle size of the composite powder was 10 μm, and the average particle size of the composite calcined powder after pulverization was 6 μm. This ZnO vapor deposition body was designated as Comparative Example 10.

<Comparative Example 11>
As shown in the following Table 2, ZnO powder having an average particle diameter of 2.0 μm and Sc ₂ O ₃ powder having an average particle diameter of 2.5 μm were used, and the content ratio of Sc (rare earth element) was 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the alloying treatment was not performed. This ZnO vapor deposition body was set as Comparative Example 11.

<Comparative Example 12>
As shown in the following Table 2, a ZnO powder having an average particle diameter of 2.0 μm and a Y ₂ O ₃ powder having an average particle diameter of 2.5 μm were used, and the content ratio of Y (rare earth element) was set to 5 mass%. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the alloying treatment was not performed. This ZnO vapor deposition body was determined as Comparative Example 12.

<Comparative Example 13>
As shown in the following Table 2, ZnO powder having an average particle diameter of 2.0 μm and La ₂ O ₃ powder having an average particle diameter of 2.5 μm were used, and the content ratio of La (rare earth element) was set to 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the alloying treatment was not performed. This ZnO vapor deposition body was determined as Comparative Example 13.

<Comparative example 14>
As shown in the following Table 2, ZnO powder having an average particle diameter of 2.0 μm and Pr ₆ O ₁₁ powder having an average particle diameter of 2.5 μm were used, and the content ratio of Pr (rare earth element) was set to 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the alloying treatment was not performed. This ZnO vapor deposition body was determined as Comparative Example 14.

<Comparative Example 15>
As shown in the following Table 2, a ZnO powder having an average particle size of 2.0 μm and an Nd ₂ O ₃ powder having an average particle size of 2.5 μm were used, and the content ratio of Nd (rare earth element) was set to 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the alloying treatment was not performed. This ZnO vapor deposition body was determined as Comparative Example 15.

<Comparative Example 16>
As shown in the following Table 2, a ZnO powder having an average particle diameter of 2.0 μm and a Pm ₂ O ₃ powder having an average particle diameter of 2.5 μm were used, and the content ratio of Pm (rare earth element) was 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the alloying treatment was not performed. This ZnO vapor deposition body was determined as Comparative Example 16.

<Comparative Example 17>
As shown in the following Table 2, a ZnO powder having an average particle diameter of 2.0 μm and an Sm ₂ O ₃ powder having an average particle diameter of 2.5 μm were used, and the content ratio of Sm (rare earth element) was 5% by mass. A ZnO vapor deposition body was produced in the same manner as in Example 1 except that the alloying treatment was not performed. This ZnO vapor deposition body was determined as Comparative Example 17.

<Comparison test and evaluation>
Using the ZnO vapor deposition materials obtained in Examples 1 to 21 and Comparative Examples 1 to 17, a ZnO film having a predetermined thickness was formed on a glass substrate by an electron beam vapor deposition method. The film formation conditions are as follows: the ultimate vacuum is 1.0 × 10 ⁻⁴ Pa, the oxygen gas partial pressure is 1.0 × 10 ⁻² Pa, the substrate temperature is 200 ° C., and the film formation rate is 0.8. It was 5 nm / second. About the formed ZnO film | membrane, the film thickness, the transmittance | permeability, and the specific resistance were evaluated, respectively. These results are shown in Tables 1 and 2 below.

The film thickness was measured with a Dektak 6M type contact film thickness meter manufactured by ULVAC. The transmittance is measured by using a spectrophotometer U-4000 manufactured by Hitachi, Ltd. as a measuring instrument, and placing the substrate after film formation perpendicular to the measurement light in the visible wavelength range of 380 to 780 nm. did. The specific resistance is determined by a 4-terminal 4-probe method by applying a constant current at a so-called normal temperature at 25 ° C. using a Loresta (HP type, MCP-T410, probe in series 1.5 mm pitch) manufactured by Mitsubishi Chemical Corporation. It was measured. The measurable range of the volume resistance is 1.0 × 10 ^{−6 to} 1.0 × 10 ⁸ Ω · cm.

表１及び表２から明らかなように、実施例２及び１５〜２１と比較例１及び１１〜１７を比較すると、メカニカルアロイング処理を行わずに希土類元素酸化物粉末を変更（８種類）した比較例１及び１１〜１７では、比抵抗が８．５×１０^-4〜１２．４×１０^-4Ωｃｍと大きかったのに対し、メカニカルアロイング処理を行う（処理後の複合粉末の平均粒径０．５μｍ）とともに希土類元素酸化物粉末を変更（８種類）した実施例２及び１５〜２１では、比抵抗が６．１×１０^-4〜９．０×１０^-4Ωｃｍと小さくなった。

As is clear from Tables 1 and 2, when Examples 2 and 15 to 21 and Comparative Examples 1 and 11 to 17 were compared, the rare earth element oxide powder was changed (eight types) without performing mechanical alloying treatment. In Comparative Examples 1 and 11 to 17, the specific resistance was as large as 8.5 × 10 ^{−4 to} 12.4 × 10 ⁻⁴ Ωcm, whereas mechanical alloying treatment was performed (the average grain size of the composite powder after treatment) In Examples 2 and 15 to 21 in which the rare earth element oxide powder was changed (8 types) with a diameter of 0.5 μm), the specific resistance was as small as 6.1 × 10 ^{−4 to} 9.0 × 10 ⁻⁴ Ωcm. .

Comparing Example 2 with Comparative Examples 2 and 5, in Comparative Examples 2 and 5 in which the average particle size of the composite powder after mechanical alloying was 0.02 μm and 4 μm, the specific resistance was 8.6 × 10 ^{−. In} Example 2 where the average particle size of the composite powder after mechanical alloying was 0.5 μm (within a range of 0.05 to 2 μm), whereas it was as large as ⁴ and 9.3 × 10 ⁻⁴ Ωcm The specific resistance was as small as 6.2 × 10 ⁻⁴ Ωcm.

When Examples 5 to 8 and Comparative Example 4 were compared, in Comparative Example 4 where the content of CeO ₂ was too large, 30% by mass, the specific resistance was as large as 70.4 × 10 ⁻⁴ Ωcm, whereas CeO ₂ In Examples 5-8, the specific resistance of 5.8 × 10 ^{−4 to} 7.3 × 10 ⁻⁴ Ωcm was small.

When Example 6 and Comparative Examples 3 and 6 are compared, the average particle size of the composite powder after mechanical alloying is as small as 0.02 μm, and the average particle size of the composite calcined powder after pulverization is as small as 0.02 μm. In Comparative Example 3, the specific resistance is as large as 8.9 × 10 ⁻⁴ Ωcm, and in Comparative Example 6 where the average particle diameter of the composite powder after mechanical alloying is as large as 4 μm, the specific resistance is 9.1 × 10 ^−4. The average particle size of the composite powder after mechanical alloying was 0.5 μm (within a range of 0.05 to 2 μm), whereas the average particle size of the composite calcined powder after pulverization was In Example 6 which was 0.4 μm (in the range of 0.05 to 5 μm), the specific resistance was as small as 6.0 × 10 ⁻⁴ Ωcm.

When Examples 1-4 and Comparative Example 4 are compared, the specific resistance is as large as 58.4 × 10 ⁻⁴ Ωcm, and in Comparative Example 4 where the CeO ₂ powder is as large as 30% by mass, it is 70.4 × 10 ⁻⁴ Ωcm. In Examples 1 to 4, in which CeO ₂ powder was in the range of 0.1 to 15% by mass, the specific resistance was as small as 6.0 × 10 ^{−4 to} 7.4 × 10 ⁻⁴ Ωcm. became.

Comparing Examples 9 to 14 with Comparative Examples 9 and 10, in Comparative Example 9 where the average particle diameter of ZnO powder is as large as 25.0 μm, the specific resistance is as large as 10.7 × 10 ⁻⁴ Ωcm, and the average of ZnO powder In Comparative Example 10 in which the particle diameter was large as 25.0 μm and the average particle diameter of CeO ₂ powder was as large as 10 μm, the specific resistance was as large as 10.3 × 10 ⁻⁴ Ωcm, whereas the average particle diameter of ZnO powder was 0 In Examples 9 to 14 in which the average particle diameter of CeO ₂ powder is in the range of 0.05 to 5 μm in the range of 0.1 to 10.0 μm, the specific resistance is 6.5 × 10 ^{−4 to} 7. It was as small as 1 × 10 ⁻⁴ Ωcm.

11 ZnO powder 12 Rare earth element oxide powder containing one element selected from a rare earth element group 13 Composite powder 14 First granulated powder 15 Molded body 16 ZnO sintered body (ZnO vapor deposition material)
17 Composite calcined body 18 Composite calcined powder 19 Second granulated powder 20 Pseudo solid solution of ZnO and rare earth element oxide 21 Molded body 22 ZnO sintered body (ZnO vapor deposition material)

Claims (5)

A composite powder is prepared from a ZnO powder having a purity of 98% or more and a rare earth element oxide powder having a purity of 98% or more, and the first granulated powder prepared from the composite powder is formed into a pellet, tablet or plate. After that, the molded body is sintered to produce a ZnO vapor deposition material containing 0.1 to 15% by mass of the rare earth element,
The rare earth oxide powder contains one element selected from the group of rare earth elements,
Producing a composite powder having an average particle size of 0.05 to 2 μm by mechanical alloying treatment of mixing and grinding the ZnO powder and the rare earth element oxide powder;
And a step of producing a first granulated powder from the composite powder. A composite powder is produced from a ZnO powder having a purity of 98% or more and a rare earth element oxide powder having a purity of 98% or more, and the second granulated powder produced from the composite powder is formed into a pellet, tablet or plate. After that, the molded body is sintered to produce a ZnO vapor deposition material containing 0.1 to 15% by mass of the rare earth element,
The rare earth oxide powder contains one element selected from the group of rare earth elements,
Producing a composite powder having an average particle size of 0.05 to 2 μm by mechanical alloying treatment of mixing and grinding the ZnO powder and the rare earth element oxide powder;
A step of obtaining a composite calcined body by calcining the composite powder at 800 to 1200 ° C. in an atmosphere of air, nitrogen gas, reducing gas, inert gas or vacuum;
Crushing the composite calcined body to produce a composite calcined powder;
And a step of producing a second granulated powder by the composite calcined powder.   The method for producing a ZnO vapor deposition material according to claim 1 or 2, wherein one element selected from the group of rare earth elements is Sc, Y, La, Ce, Pr, Nd, Pm or Sm.   The method for producing a ZnO vapor deposition material according to claim 1 or 2, wherein the ZnO powder has an average particle size of 0.1 to 10 µm and the rare earth element oxide powder has an average particle size of 0.05 to 5 µm.   A ZnO film formed by a vacuum film-forming method using the ZnO vapor deposition material manufactured by the method according to claim 1 as a target material.

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