TW202126838A - Oxide sputtering target and oxide sputtering target production method - Google Patents

Abstract

An oxide sputtering target comprising, as a metal component, an oxide that contains zirconium, silicon, and indium, wherein the maximum particle size in a zirconium oxide phase (11) is set to 10 [mu]m or less.

Description

Oxide sputtering target and manufacturing method of oxide sputtering target

The present invention relates to an oxide sputtering target made of an oxide containing zirconium, silicon, and indium as metal components, and a method for manufacturing the oxide sputtering target. This case is based on Japanese Special Application No. 2019-217933 filed on December 2, 2019, claiming priority and citing its content here.

Oxide films containing zirconium, silicon, and indium as metal components have high electrical resistance. For example, in display panels such as liquid crystal displays, organic EL displays, and touch panels, they are used to prevent charging of liquid crystal elements or organic EL elements. The misoperation of the shielding layer is used. Here, when the above-mentioned shielding layer is applied to an in-cell type touch panel, the shielding layer is also required to remove noise from the outside while allowing touch signals to reach the sensor part inside the panel. The role. Moreover, in this shielding layer, in order to ensure the visibility of the display panel, it is also required to have high transmittance of visible light.

In addition, an oxide film containing zirconium, silicon, and indium as metal components is also used as a dielectric layer or a protective film of a phase change optical disc used as an information recording medium. Here, Patent Documents 1 to 4 propose an oxide sputtering target to be used when forming an oxide film containing zirconium, silicon, and indium as metal components.

However, it has recently been required to form an oxide film containing zirconium, silicon, and indium as metal components with a large area and high production efficiency. Therefore, it is necessary to cope with the increase in the size of the sputtering target and the increase in output during sputtering film formation. However, in an oxide sputtering target containing zirconium, silicon, and indium as metal components, cracks are likely to occur during sputtering film formation at high output, and sputtering film formation cannot be performed stably. Especially in large sputtering targets, cracks tend to occur easily. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2013-142194 A [Patent Document 2] JP 2007-327103 A [Patent Document 3] JP 2009-062585 A [Patent Document 4] Japanese Patent Application Publication No. 2018-040032

(The problem to be solved by the invention)

The present invention was developed in view of the foregoing circumstances to provide an oxide sputtering that can suppress the occurrence of cracks even in the case of high-output sputtering film formation, and can perform sputtering film formation with stability and high production efficiency. The target and the manufacturing method of this oxide sputtering target are the objective. (Means to solve the problem)

In order to solve the above-mentioned problems, the inventors of the present invention have conducted in-depth studies and confirmed that in an oxide sputtering target containing zirconium, silicon, and indium as metal components, a zirconium oxide phase is present, and this zirconium oxide phase transforms around 1000°C. The volume at this time changed and cracks occurred. In addition, it is known that if the zirconia powder used as the raw material of the oxide sputtering target is pulverized and mixed with indium oxide powder and silicon oxide powder, the particle size of the zirconia powder will be larger than that of the indium oxide powder and silicon oxide powder. The coarse zirconia phase causes the occurrence of cracks.

The present invention was developed based on the above-mentioned knowledge. The oxide sputtering target of one aspect of the present invention is an oxide sputtering target made of an oxide containing zirconium, silicon and indium as metal components, and is characterized by: oxidation The maximum particle size of the zirconium phase is 10 μm or less.

According to the oxide sputtering target according to one aspect of the present invention, since it is an oxide containing zirconium, silicon, and indium as metal components, an oxide film with high electrical resistance and good visible light permeability can be formed. In addition, since the maximum particle size of the zirconia phase is limited to 10 μm or less, during sputtering film formation at high output, even if the zirconia phase changes and the volume changes, the occurrence of cracks is suppressed. In addition, even when the sputtering target is increased in size, the occurrence of cracks during sputtering is suppressed. Therefore, sputtering film formation can be performed stably and with high production efficiency.

Here, in the oxide sputtering target of one aspect of the present invention, when the average particle size of the zirconium oxide phase is D _ZrO and the average particle size of the other oxide phases is D _MO , 0.6≦D _MO /D _ZrO ≦1.8 is ideal. In this case, the difference in particle size between the zirconium oxide phase and other oxide phases is reduced, and the strength of the target can be ensured. Therefore, it is possible to further suppress the occurrence of cracks during sputtering film formation with high output.

In addition, in the oxide sputtering target of one aspect of the present invention, it is preferable that the maximum particle size is 7 μm or less and the average particle size is 4 μm or less in the entire target structure. In this case, since the particle size is uniform and finer in the entire target structure, sputtering film formation can be performed uniformly. In addition, the strength of the target can be ensured, and the occurrence of cracks during sputtering film formation with high output can be further suppressed.

The method for manufacturing an oxide sputtering target in one aspect of the present invention is a method for manufacturing an oxide sputtering target made of an oxide containing zirconium, silicon, and indium as metal components, and is characterized by: Preliminary crushing process, which is to crush the zirconia powder to a maximum particle size of 4μm or less; Sintering raw material powder formation process, which is to obtain sintering raw material powder that mixes zirconium oxide powder, silicon oxide powder and indium oxide powder with a maximum particle size of 4 μm or less; and The sintering process involves heating and firing the obtained sintering raw material powder while introducing oxygen to obtain a sintered body.

According to the manufacturing method of the oxide sputtering target with this configuration, since the zirconia powder is pulverized to a preliminary crushing process with a maximum particle size of 4 μm or less, the maximum particle size of the sintered zirconia phase can be reduced to 10μm or less. Therefore, the occurrence of cracks during sputtering film formation with high output can be suppressed, and an oxide sputtering target that can perform sputtering film formation with stability and high production efficiency can be manufactured.

Here, in the method for producing an oxide sputtering target according to one aspect of the present invention, the average particle diameter of the zirconium oxide powder having a maximum particle diameter of 4 μm or less is d _ZrO , and the average particle diameter of the indium oxide powder is d _InO , and when the average particle size of the silicon oxide powder is set to d _SiO , 0.7≦d _InO /d _ZrO ≦1.6 and 0.7≦d _SiO /d _ZrO ≦1.6 are ideal. In this case, the particle size difference between the zirconium oxide powder and the indium oxide powder and the silicon oxide powder will be reduced, and a high-strength oxide sputtering target can be manufactured.

In addition, in the method for producing an oxide sputtering target according to one aspect of the present invention, in the total sintering raw material powder obtained by mixing zirconium oxide powder, silicon oxide powder, and indium oxide powder, the maximum particle size is 3 μm or less, and the average The particle size is preferably 1 μm or less. In this case, it is possible to manufacture an oxide sputtering target in which the particle size can be made finer and uniform throughout the target structure, and the sputtering film can be formed uniformly. [Effects of the invention]

According to one aspect of the present invention, it is possible to provide an oxide sputtering target capable of suppressing the occurrence of cracks even in the case of high-output sputtering film formation, and capable of performing sputtering film formation with stability and high production efficiency, and the same. Manufacturing method of oxide sputtering target.

Hereinafter, the oxide sputtering target and the manufacturing method of the oxide sputtering target according to the embodiment of the present invention will be described with reference to the drawings. The oxide sputtering target of this embodiment is used to form a phase change suitable as a shielding layer or information recording medium arranged in order to prevent charging in display panels such as liquid crystal display panels, organic EL display panels, and touch panels. It is the oxide film of the dielectric layer or protective film of the type optical disc.

In addition, the shape of the oxide sputtering target of this embodiment is not particularly limited, and it may be a rectangular flat-plate type sputtering target with a rectangular sputtering surface, or a circular plate with a circular sputtering surface. Type sputtering target. Alternatively, it may be a cylindrical sputtering target whose sputtering surface is a cylindrical surface. In addition, the area of the sputtering surface is not particularly limited, but for efficient film formation on a large-area substrate, ^{a large sputtering target with an area of the sputtering surface of 2.0 m 2} or more is preferable.

The oxide sputtering target of this embodiment is composed of an oxide containing zirconium, silicon, and indium as metal components. As shown in FIG. 1, this oxide sputtering target has a zirconium oxide phase 11, an indium oxide phase 12, and a composite oxide phase 13 containing at least a part of the aforementioned metal elements. In this embodiment, the composite oxide phase 13 is a composite oxide of In and Si (for example, In ₂ Si ₂ O ₇ phase).

In addition, in the oxide sputtering target of this embodiment, the maximum particle size of the zirconia phase 11 is 10 μm or less. In this embodiment, the ratio of the average particle size D _{ZrO of the zirconia phase 11 to the average particle size D InO} of the indium oxide phase 12 of the other oxide phase _{D InO} /D _ZrO and the average particle size of the zirconia phase 11 It is _preferable that the ratio D _InSiO /D _ZrO of the average particle diameter D InSiO of the composite oxide phase 13 of the _{diameter D ZrO} and the other oxide phase is in the range of 0.6 or more and 1.8 or less. Furthermore, in this embodiment, it is desirable that the maximum particle size is 7 μm or less and the average particle size is 4 μm or less in the entire target tissue.

The following shows that in the oxide sputtering target of this embodiment, the composition of the oxide, the maximum particle size of the zirconia phase 11, the zirconia phase 11 and other oxide phases (the indium oxide phase 12 and the composite oxide phase The average particle diameter ratio of 13), the maximum particle diameter and the average particle diameter of the entire target tissue are defined for the reasons as described above.

(Oxide composition) The oxide sputtering target of this embodiment is composed of an oxide containing oxides of zirconium, silicon, and indium as metal components. The oxide sputtering target of such a composition can form an oxide film with a very high resistance value and good visible light transmittance. Here, in this embodiment, the total of the metal components is 100 mass%, the content of Zr is within the range of 2 mass% to 27 mass%, and the content of In is within the range of 65 mass% to 95 mass%. It is preferable that the Si content is in the range of 0.5 mass% or more and 15 mass% or less, and the remainder is an unavoidable impurity metal element (unavoidable metal). In addition, the total content of Zr, In, and Si is preferably 95 mass% or more, and more preferably 99 mass% or more. In detail, the oxide sputtering target of this embodiment is made of oxide and unavoidable impurities. The oxide is made of a metal component and oxygen. Zr: 2mass% or more and 27mass% or less, In: 65mass% or more and 95mass% or less, and Si: 0.5mass% or more and 15mass% or less, and the remainder is ideal for unavoidable metals. The inevitable impurities are elements other than oxygen and metal components. The inevitable metal is a metal element other than the above-mentioned elements with a specific content. Hf is chemically similar to Zr, and it is difficult to separate Hf and Zr. _{Therefore, HfO 2} is inevitably contained in the ZrO ₂ powder as an industrial raw material. Therefore, Hf can be cited as an inevitable metal. The Hf content is 0 mass% or more and 0.9 mass% or less. In addition, Fe, Ti, and Na can be cited. As unavoidable metals, the total of these is 0 mass% or more and 0.1 mass% or less.

When the content of Zr is 2 mass% or more, the durability of the oxide film after film formation can be improved, and the hardness can be hardened and scratch resistance can be made. On the other hand, when the content of Zr is 27 mass% or less, the increase in refractive index can be suppressed, and the occurrence of unnecessary reflection can be suppressed, and therefore the decrease in the transmittance of visible light can be suppressed. In addition, the total of the metal components is 100 mass%, and the lower limit of the Zr content is preferably 3 mass% or more, and more preferably 5 mass% or more. The upper limit of the content of Zr is preferably 21 mass% or less, and more preferably 20 mass% or less.

When the In content is 65 mass% or more, the conductivity of the oxide sputtering target can be ensured, and the oxide film can be formed stably by direct current (DC) sputtering. On the other hand, when the content of In is 95 mass% or less, the decrease in the transmittance of short wavelengths can be suppressed, and visibility can be ensured. In addition, the total of the metal components is 100 mass%, and the lower limit of the In content is preferably 75 mass% or more, and more preferably 80 mass% or more. The upper limit of the content of In is preferably 90 mass% or less.

When the Si content is 0.5 mass% or more, the flexibility of the oxide sputtering target can be ensured, and the fracture resistance of the film can be improved. On the other hand, when the Si content is 15 mass% or less, the decrease in conductivity of the film can be suppressed, and the oxide film can be stably formed by direct current (DC) sputtering. In addition, the total of the metal components is 100 mass%, and the lower limit of the Si content is preferably 2 mass% or more, and more preferably 3 mass% or more. The upper limit of the Si content is preferably 12 mass% or less, and more preferably 7 mass% or less.

(Maximum particle size of zirconia phase 11) In this zirconia phase 11, the phase changes and the volume changes at around 1000°C. Therefore, the presence of the coarse zirconia phase 11 may cause a large volume change due to a phase change during sputtering at high output, and there is a possibility of cracking. Therefore, in this embodiment, the maximum particle size of the zirconia phase 11 is limited to 10 μm or less. In addition, in order to further suppress the occurrence of cracks in the oxide sputtering target, the maximum particle size of the zirconia phase 11 is preferably 8 μm or less, and more preferably 7 μm or less.

(The ratio of the average particle size of the zirconia phase 11 to the other oxide phases) In the oxide sputtering target of this embodiment, the zirconia phase 11 and the other oxide phases (the indium oxide phase 12 and the composite oxide phase The difference in particle size of phase 13) can increase the strength of the oxide sputtering target and further suppress the occurrence of cracks. Therefore, in this embodiment, the ratio of the average particle size D _{ZrO of the zirconia phase 11 to the average particle size D InO} of the indium oxide phase 12 of the other oxide phase _{D InO} /D _ZrO and the average of the zirconia phase 11 The ratio D _InSiO /D _{ZrO of the average particle diameter D InSiO} of the composite oxide phase 13 of the particle diameter D _ZrO and other oxide phases is preferably set to be in the range of 0.6 or more and 1.8 or less. In addition, _{the lower limits of D InO} /D _ZrO and D _InSiO /D _ZrO are more preferably 0.63 or more, and more preferably 0.65 or more. On the other hand, _{the upper limit of D InO} /D _ZrO and D _InSiO / D _ZrO is more preferably 1.75 or less, and more preferably 1.7 or less.

(Maximum particle size and average particle size of the entire target tissue) In the oxide sputtering target of this embodiment, by making the particle size finer and uniform in the entire target structure, the sputtering film can be formed uniformly, the strength of the target can be ensured, and the sputtering with high output can be further suppressed. The occurrence of rupture during film formation. Therefore, in the present embodiment, it is preferable that the maximum particle size of the entire target tissue is 7 μm or less, and the average particle size is 4 μm or less. In addition, the maximum particle size in the entire target tissue is more preferably 6.5 μm or less, and more preferably 6 μm or less. In addition, the average particle size of the entire target tissue is more preferably 3 μm or less, and more preferably 2 μm or less.

Next, the method of manufacturing the oxide sputtering target of this embodiment described above will be described with reference to FIG. 2.

(Preliminary grinding process S01) First, zirconia powder (ZrO ₂ powder) is prepared. Here, it is desirable that the zirconia powder has a purity of 99.9 mass% or more after removing inevitable impurities such as _{Fe 2} O ₃ , SiO ₂ , TiO ₂ , and Na _{2 O.} In addition, ZrO _{2 has} a very strong connection with HfO ₂ and even high-purity ZrO ₂ powder contains hafnium oxide (HfO ₂ ) at a maximum of 2.5 mass% among inevitable impurities. Therefore, the purity of _{ZrO 2 is usually measured by measuring the content of impurities other than HfO 2} and calculating by the difference method using the total amount of impurities obtained. The purity of the above-mentioned ZrO ₂ powder is calculated by measuring _{the contents of Fe 2} O ₃ , SiO ₂ , TiO ₂ , and Na ₂ O as impurities, and subtracting the sum of the contents of these compounds from 100 mass%. This zirconia powder (ZrO ₂ powder) is pulverized, and the maximum particle size is set to 4 μm or less. In addition, the pulverization method is not particularly limited, as long as it is appropriately selected from existing pulverization methods.

(Sintering raw material powder formation process S02) Next, silica powder (SiO ₂ powder) and indium oxide powder (In ₂ O ₃ powder) are prepared. Here, it _{is desirable that silicon oxide powder (SiO 2} powder) and indium oxide powder (In ₂ O ₃ powder) each have a purity of 99.9 mass% or more. The silicon oxide powder (SiO ₂ powder) and indium oxide powder (In ₂ O _{3 powder) and zirconia powder (ZrO 2} powder) with a maximum particle size of 4 μm or less by preliminary grinding are weighed to a predetermined composition ratio . A wet pulverizing and mixing device is used to pulverize and mix the weighed raw material powder to form sintering raw material powder (raw material powder for sintering). Here, the solvent can be water or the like. In addition, the drying method of the paste obtained by pulverization and mixing is not particularly limited, and it can be carried out by a normal dryer, spray drying, or the like. From the viewpoint of obtaining a homogeneous mixed powder, spray drying is ideal.

Here, in the sintering raw material powder, the average particle size of the _{zirconia powder (ZrO 2} powder) whose maximum particle size is 4 μm or less in the preliminary grinding process S01 is _{set to d ZrO} , and the indium oxide powder (In ₂ O ₃ powder When the average particle size of) is set to d _InO and the average particle size of silicon oxide powder (SiO ₂ powder) is set to d _SiO , 0.7≦d _InO / d _ZrO ≦1.6 and 0.7≦d _SiO /d _ZrO ≦1.6 are ideal. In addition, the lower limit of the average particle diameter ratio d _InO /d _ZrO and d _SiO /d _ZrO is more preferably 0.7 or more, and more preferably 0.75 or more. In addition, the upper limit of the average particle diameter ratio of d _InO /d _ZrO and d _SiO /d _ZrO is more preferably 1.55 or less, and more preferably 1.5 or less.

In addition, in the entire obtained sintering raw material powder, the maximum particle size is preferably 3 μm or less, and the average particle size is preferably 1 μm or less. In addition, the maximum particle size of the entire sintering raw material powder is more preferably 2.8 μm or less, and more preferably 2.6 μm or less. In addition, the average particle size of the entire sintering raw material powder is more preferably 0.9 μm or less, and more preferably 0.8 μm or less.

(Forming process S03) Next, the obtained sintering raw material powder is filled in a forming mold and pressurized, thereby obtaining a molded body of a predetermined shape. The pressurizing pressure at this time is preferably in the range of 20 MPa or more and 35 MPa or less. In addition, the temperature may be normal temperature, but it is desirable to perform press molding at a temperature in the range of 900°C or more and 950°C or less. Thereby, the neck opening is promoted, and the strength of the molded body is improved.

(Sintering Engineering S04) This compact is put into a sintering device with oxygen introduction function, and the sintered body is obtained by heating and sintering while introducing oxygen. At this time, the amount of oxygen introduced is preferably within the range of 3 L/min or more and 10 L/min or less. In addition, it is desirable that the temperature increase rate is within the range of 50°C/h or more and 200°C/h or less. The firing process S04 is an ideal from the maintenance process and the formal firing process. First, it is desirable to keep the molded body at a temperature of 1200°C or higher and 1400°C or lower for 3 to 5 hours (maintenance process). Next, it is ideal to keep the molded body at a temperature of 1450°C or higher and 1600°C or lower for 5-10 hours (main firing process). In the maintenance process, if the temperature is less than 1200°C, or if the heating time is less than 3 hours, the formation of the composite oxide is insufficient, and there is a risk of cracking in the actual firing process. In the holding process, if the temperature exceeds 1400°C, or if the heating time exceeds 5 hours, there is a possibility that the sintered body may be bent. In the main firing process, if the temperature is less than 1450°C, or if the heating time is less than 5 hours, the density of the sintered body may decrease. In the actual firing process, if the temperature exceeds 1600°C, or if the heating time exceeds 10 hours, there is a risk of excessive grain growth.

(Machining Engineering S05) Next, the above-mentioned sintered body is subjected to mechanical processing such as lathe processing to obtain an oxide sputtering target of a predetermined size.

Through the above-mentioned process, the oxide sputtering target of this embodiment is manufactured.

According to the oxide sputtering target of this embodiment constructed as above, since it is composed of an oxide containing zirconium, silicon, and indium as metal components, an oxide with high resistance and good visible light transmittance can be formed.物膜。 Material film.

In addition, the maximum particle size of the zirconia phase 11 is limited to 10 μm or less. Therefore, even if the zirconia phase 11 undergoes a phase transformation and volume changes, the occurrence of cracks can be suppressed during sputtering with high output. Therefore, sputtering film formation can be performed stably and with high production efficiency.

Also, in this embodiment, the ratio of the average particle size D _{ZrO of the zirconium oxide phase 11 to the average particle size D InO} of the indium oxide phase 12 of the other oxide phase _{D InO} /D _ZrO and the average particle size of the zirconium oxide phase 11 When the average particle size of the composite oxide phase 13 of _{D ZrO and other oxide phases D InSiO} ratio D _InSiO /D _ZrO is in the range of 0.6 to 1.8, the zirconium oxide phase 11 and the other oxide phases The difference in particle size between the indium oxide phase 12 and the composite oxide phase 13 is reduced, and the strength of the target can be ensured. Therefore, it is possible to further suppress the occurrence of cracks during sputtering film formation with high output.

Also, in this embodiment, when the maximum particle size of the entire target tissue is 7 μm or less, and the average particle size is 4 μm or less, since the particle size is uniform and finer throughout the target tissue, it can be uniformly processed. Sputtering film formation. In addition, the strength of the target can be ensured, and the occurrence of cracks during sputtering film formation with high output can be further suppressed.

In addition, according to the method of manufacturing the oxide sputtering target of this embodiment, since the zirconia powder is pulverized to a maximum particle size of 4 μm or less, the preliminary pulverization process S01 is provided, so that the sintered zirconia phase 11 The maximum particle size is below 10μm. Therefore, the occurrence of cracks during sputtering film formation with high output can be suppressed, and an oxide sputtering target that can perform sputtering film formation with stability and high production efficiency can be manufactured.

In addition, in this embodiment, the average particle size of zirconia powder with a maximum particle size of 4 μm or less is set to d _ZrO , the average particle size of indium oxide powder is set to d _InO , and the average particle size of silica powder is set to When it is d _SiO , if it meets the conditions of 0.7≦d _InO /d _ZrO ≦1.6 and 0.7≦d _SiO /d _ZrO ≦1.6, the particle size difference between zirconium oxide powder and indium oxide powder and silicon oxide powder will be small, and high manufacturing can be achieved. Strong oxide sputtering target.

Furthermore, in this embodiment, in the case where the total sintering raw material powder obtained by mixing zirconium oxide powder, silicon oxide powder and indium oxide powder has a maximum particle size of 3 μm or less and an average particle size of 1 μm or less, one type can be produced An oxide sputtering target in which the particle size is refined and uniform in the entire target structure, and can be sputtered and formed uniformly.

As mentioned above, although the embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical requirement of the invention. [Example]

Hereinafter, the results of the confirmation experiment performed to confirm the effectiveness of the present embodiment will be explained.

<Oxide sputtering target> Prepare indium oxide powder (In ₂ O ₃ powder: purity 99.9 mass% or more, average particle size 1μm), silicon oxide powder (SiO ₂ powder: purity 99.8 mass% or more, average particle size 2μm) and Zirconia powder (ZrO ₂ powder: purity 99.9 mass% or more, average particle size 2 μm) was used as the raw material powder. Then, the equivalent was weighed to the mixing ratio shown in Table 1. The purity of the zirconia powder is calculated by measuring _{the content of impurities other than HfO 2 such as Fe 2} O ₃ , SiO ₂ , TiO ₂ , and Na ₂ O, and subtracting the total content of these compounds from 100 mass%. Among zirconia powders, HfO ₂ contains a maximum of 2.5 mass%.

As the preliminary pulverization process, a bead mill device using zirconia balls with a diameter of 0.5 mm as a pulverizing medium was used to wet pulverize the above-mentioned zirconia powder under the conditions shown in Table 1. For the pulverized zirconia powder, the maximum particle diameter and median diameter (D50) are measured by the laser diffraction scattering method. Specifically, 100 mL of an aqueous solution with a concentration of 0.2 mol% of sodium hexametaphosphate was prepared, 10 mg of zirconia powder was added to this aqueous solution, and the laser diffraction scattering method was used (measurement device: manufactured by NIKKISO CO., LTD., Microtrac MT3000) To determine the particle size distribution. Create a cumulative particle size distribution curve from the obtained particle size distribution, and obtain the maximum particle size and the average particle size (median diameter (D50)). The median diameter (D50) referred to here refers to the particle diameter at which the cumulative volume becomes 50%.

As shown in Table 1, use a basket mill device using zirconia balls with a diameter of 2 mm as the pulverizing medium, or a bead mill device using zirconia balls with a diameter of 0.5 mm as the pulverizing medium , 60 minutes, the pulverized zirconia powder, indium oxide powder and silicon oxide powder each raw material powder is wet pulverized and mixed. A dryer is used to dry the obtained paste to obtain sintering raw material powder. In addition, Table 1 shows the maximum particle size and average particle size (median diameter (D50)) of the obtained sintering raw material powder. The measurement method is the same as in the case of zirconia powder.

In addition, the average particle size ratio of the zirconium oxide powder, indium oxide powder, and silicon oxide powder was measured. The measurement results are shown in Table 1. For the sintering raw material powder, an electron probe microanalysis (EPMA) device was used to capture 3 COMPO images (reflected electron composition images) with a magnification of 3000 times, and the zirconia powder, indium oxide powder, and silicon oxide were obtained by image analysis. The average particle diameter of the powder is calculated, and the average particle diameter ratio is calculated. In detail, the approximate diameter of the circle ( ^{D where the area S=πD 2} /4 becomes the particle) is measured as the particle diameter of each particle. The number average of the approximate circle diameters of the particles is calculated and used as the average particle diameter.

Then, in Examples 1 to 6, 10 to 12, and Comparative Example 1 of the present invention, the obtained sintered raw material powder was press-formed to obtain a rectangular flat-shaped molded body. In addition, the size of the forming mold is 165 mm×298 mm. In addition, the pressurizing pressure was set to 98 MPa. In Examples 7 to 9 of the present invention and Comparative Example 2, the obtained sintering raw material powder was subjected to CIP (Cold Isostatic Pressing) to obtain a cylindrical molded body. In addition, the size of the forming mold is set to have an outer diameter of 205 mm, an inner diameter of 165 mm, and a height of 200 mm. In addition, the pressurizing pressure was set to 98 MPa.

Then, the obtained molded body was put into a sintering device having an oxygen introduction function (the internal volume of the device was 27000 cm ³ ), and the oxygen was introduced while heating and sintering. At this time, the amount of oxygen introduced was 6 L/min. In addition, the temperature increase rate was 120°C/h. Then, during the temperature increase of the sintering, the temperature was maintained under the conditions described in the item "Hold" shown in Table 2. Next, main firing was performed under the conditions of the item "main firing" shown in Table 2 to obtain a sintered body.

As described above, the obtained sintered body was subjected to mechanical processing. In Examples 1 to 6, 10 to 12 and Comparative Example 1 of the present invention, a rectangular flat sputtering target of 126 mm×178 mm×thickness 6 mm was obtained. In addition, in Examples 7 to 9 and Comparative Example 2 of the present invention, cylindrical sputtering targets with an outer diameter of 155 mm, an inner diameter of 135 mm, and a height of 150 mm were obtained.

In Comparative Example 3, the obtained sintered raw material powder was filled in a mold with a diameter of 200 mm and punched with a pressure of 15 MPa to produce two disc-shaped molded bodies with a diameter of 200 mm and a thickness of 10 mm. The obtained two pieces of molded body were put into an electric furnace (furnace ^{inner volume 27000 cm 3} ), and oxygen was circulated into the electric furnace at a flow rate of 4 L per minute, and the firing temperature shown in Table 2 was maintained for 7 hours. By this firing, a sintered body is produced. Next, while continuing to circulate oxygen into the electric furnace, the sintered body was cooled to 600°C. Then, the flow of oxygen was stopped, and the furnace was allowed to cool down to room temperature. Next, the sintered body is taken out from the electric furnace. The sintered body obtained as described above was subjected to machining to obtain two disc-shaped sputtering targets having a diameter of 152.4 mm and a thickness of 6 mm.

For the obtained oxide sputtering target, the following items were evaluated. The evaluation results are shown in Table 2.

(Metal component composition) A sample was cut out from the produced oxide sputtering target, pulverized, and pre-treated with acid. Next, the metal components of Zr, Si, and In are analyzed by ICP-AES, and the content of the metal components is calculated from the obtained results. In addition, in the "mixed composition of oxide powder" in Table 1, the _{total amount of ZrO 2} , In ₂ O ₃ , and SiO ₂ is set to 100%, and the amounts of ZrO ₂ , In ₂ O ₃ , and SiO ₂ are described. The "metal composition of the target" in Table 2 is that the total amount of Zr, Si, and In is set to 100%, and the amounts of Zr, Si, and In are described.

(Particle diameter of sintered body) A sample was cut out from the produced oxide sputtering target, and the polishing process was performed by wet polishing. Second, use an electron probe micro analysis (EPMA) device to capture a COMPO image with a magnification of 3000 times (30 μm×40 μm). The photography is performed on 3 pieces. Based on the COMPO image after shooting, the image processing is used. Calculate the maximum particle size and average particle size of the crystal grains of each phase (ZrO ₂ phase, In ₂ O ₃ phase, In ₂ SiO ₇ phase) for the entire 3 pieces, and the maximum particle size and average particle size of the crystal grains of the entire target The average particle diameter ratio is a value obtained by dividing the average particle diameter of the _{In 2} O ₃ phase or the In ₂ Si ₂ O _{7 phase by the average particle diameter of the ZrO 2 phase.} The area of the crystal grains S=πD ² /4 D). The average particle size is the number average of the approximate circle diameter of the crystal grains.

(density) In a rectangular flat sputtering target, the dimensional density was measured for a sample of 10 mm×10 mm cut out from the center. In the cylindrical sputtering target, the dimensional density was measured for a sample of 10 mm×10 mm cut out from the center in the axial direction. The measurement results are shown in Table 2.

(strength) As in the case of density measurement, measurement samples were collected from each sputtering target, and the three-point bending strength was measured in accordance with the JIS R 1601 standard. The evaluation results are shown in Table 2.

(Cracking of sputtering film formation) The sputtering target was welded to a support plate made of oxygen-free copper and installed in a magnetron-type sputtering device (manufactured by ULVAC, SIH-450H). Next, the inside of the sputtering device is evacuated to 5×10 ^-5 Pa or less with a vacuum exhaust device. Next, Ar gas and O ₂ gas were introduced, the sputtering gas pressure was adjusted to 0.67 Pa, and pre-sputtering was performed for 1 hour. Thereby, the processed layer on the surface of the target is removed. The flow ratio of Ar gas to O ₂ gas at this time is 47 to 3, and the electric power is set to DC1200W. Next, under the same sputtering conditions, an oxide film was formed on the glass substrate. Then, the sputtering device was opened to the atmosphere. Then, the sputtering target was taken out from the sputtering device, and its appearance was visually observed to confirm the occurrence of cracks. The results are shown in Table 2.

In Comparative Examples 1 to 3, the preliminary pulverization process was not implemented, and the maximum particle size of the zirconia powder exceeded 4 μm. In these Comparative Examples 1 to 3, _{the maximum particle size of the ZrO 2} phase exceeded 10 μm, and cracks occurred during sputtering film formation.

In contrast, in Examples 1 to 12 of the present invention, the preliminary grinding process was performed, and the maximum particle size of the zirconia powder was 4 μm or less. In the examples 1 to 12 of the present invention, _{the maximum particle size of the ZrO 2} phase is 10 μm or less, and the film does not crack during sputtering film formation, and the film can be formed stably. In addition, in Examples 2-7 and 9-11 of the present invention, the ratio of the average particle size D _{ZrO of the zirconia phase to the average particle size D InO} of the indium oxide phase of the other oxide phase _{D InO} /D _ZrO and the zirconia phase The ratio of the average particle size of D _ZrO to the average particle size of the composite oxide phase D _InSiO of _{other oxide phases D InSiO} /D _ZrO is in the range of 0.6 or more and 1.8 or less, and the maximum particle size of the entire target structure is 7μm or less, the average particle size is 4μm or less. In the examples 2-7, 9-11 of the present invention, the strength of the target will be more improved.

As mentioned above, according to the example of the present invention, it has been confirmed that it is possible to provide an oxide sputtering target capable of suppressing the occurrence of cracks even in the case of high-output sputtering film formation, and capable of performing sputtering film formation with stability and high production efficiency. And the manufacturing method of the oxide sputtering target. [Industrial Utilization Possibility]

The oxide sputtering target of this embodiment is applicable to the production of a shielding layer of a display panel such as a liquid crystal display panel, an organic EL display panel, a touch panel, or the dielectric layer of a phase change optical disc by a sputtering method. Process of oxide film containing zirconium, silicon and indium used in protective film.

11: Zirconia phase 12: Indium oxide phase 13: Complex oxide phase S01: Preparatory crushing project S02: Sintering raw material powder formation process S03: Forming Engineering S04: Sintering Engineering S05: Mechanical Processing Engineering

[Fig. 1] is a photograph of the structure observation of an oxide sputtering target according to an embodiment of the present invention. Fig. 2 is a flowchart showing a method of manufacturing an oxide sputtering target according to an embodiment of the present invention.

11: Zirconia phase

12: Indium oxide phase

13: Complex oxide phase

Claims (6)

An oxide sputtering target is an oxide sputtering target made of oxides containing zirconium, silicon and indium as metal components, and is characterized by: The maximum particle size of the zirconia phase is 10 μm or less. The oxide sputtering target according to claim 1, wherein when the average particle size of the zirconium oxide phase is D _ZrO and the average particle size of the other oxide phases is D _MO , 0.6≦D _MO / D _ZrO ≦1.8. The oxide sputtering target according to claim 1 or 2, wherein the maximum particle size is 7 μm or less and the average particle size is 4 μm or less in the entire target structure. A method for manufacturing an oxide sputtering target is a method for manufacturing an oxide sputtering target made of oxides containing zirconium, silicon and indium as metal components, and is characterized by: Preliminary crushing process, which is to crush the zirconia powder to a maximum particle size of 4μm or less; Sintering raw material powder formation process, which is to obtain sintering raw material powder that mixes zirconium oxide powder, silicon oxide powder and indium oxide powder with a maximum particle size of 4 μm or less; and The sintering process involves heating and firing the obtained sintering raw material powder while introducing oxygen to obtain a sintered body. The method for producing an oxide sputtering target according to claim 4, wherein the average particle size of the zirconia powder is d _ZrO , the average particle size of the indium oxide powder is d _InO , and the average particle size of the silicon oxide powder When the particle size is d _SiO , 0.7≦d _InO /d _ZrO ≦1.6, and 0.7≦d _SiO /d _ZrO ≦1.6 are satisfied. The method for manufacturing an oxide sputtering target according to claim 4 or claim 5, wherein the maximum particle size of the total sintering raw material powder obtained by mixing zirconium oxide powder, silicon oxide powder and indium oxide powder is 3 μm or less, And the average particle size is 1 μm or less.

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