High-purity indium cerium tantalum holmium oxide target material and method for manufacturing the same

Abstract

The application relates to the technical field of target production, and discloses a preparation method of high-purity indium cerium tantalum holmium oxide target material, which comprises the following steps: step 1: soluble metal salts of indium, cerium, tantalum and holmium are weighed according to a molar ratio of In:Ce:Ta:Ho=90-94:0.8-1.2:4-6:1.2-2.8, and are dissolved in deionized water; step 2: a precipitant urea is added to the mixture in step 1 and is mixed; step 3: the mixture in step 2 is placed in a sealed container and is heated at 190-200 DEG C, and after heating is completed, a precursor powder is separated; and step 4: the precursor powder is calcined and shaped to obtain the indium cerium tantalum holmium oxide target material. The content of indium in the target material is relatively low, the use of cerium, tantalum and holmium is beneficial to control of high conductivity, and the purity of the target material can be effectively maintained through a wet precipitation process, which is also an important factor for improvement of the conductivity. In addition, the application also discloses the target material.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of target materials, in particular to a high-purity indium cerium tantalum holmium oxide target material and a preparation method thereof. BACKGROUND

[0002] A target material is a basic consumable material in a magnetron sputtering process, and the quality of the target material plays a crucial role in determining the performance of a thin film. Target materials are widely used in various fields, including optical target materials, display thin film target materials, semiconductor field target materials, recording medium target materials, superconducting target materials, etc. Among them, semiconductor field target materials, display target materials and recording medium target materials are the three most widely used target materials. In order to improve the thin film preparation rate and ensure the growth quality of the thin film, the sputtering target material needs to meet certain index requirements. In recent years, liquid crystal display, active organic light-emitting diode display and flexible display technologies have developed rapidly, and the importance of thin film transistors (TFT) as core components is self-evident. Among them, TFT based on oxide semiconductors has attracted widespread attention due to its high mobility, good electrical uniformity, high visible light transmittance, low preparation temperature and low cost. In the prior art, indium tin oxide (ITO) film with excellent light transmittance and conductivity is the mainstream of TFT. However, ITO film has poor moisture resistance and has the disadvantage of increased resistance value due to moisture. In order to improve the above-mentioned shortcomings, oxide indium cerium titanium tantalum semiconductors are being researched in the technical field, which have high mobility and large band gap, can meet the display requirements of large size, high resolution and high aperture ratio, and have great application potential.

[0003] CN115893988A discloses a kind of solar cell evaporation target material and its preparation method, which discloses the following contents:

[0004] A kind of solar cell evaporation target material. The evaporation target material includes the following components: indium oxide (In2O3) 98.5-99.5wt%, doped oxide 0.5-1.5wt%, the doped oxide is 2-4 kinds of cerium oxide (CeO2), tungsten oxide (WO3), molybdenum oxide (MoO3), holmium oxide (Ho2O3), yttrium oxide (Y2O3), zirconium oxide (ZrO2), gallium oxide (Ga2O3).

[0005] Its embodiment records that its electron mobility generally reaches 120cm2 / V.s; infrared transmittance reaches 98%; according to the relative density of target material label, it is 40-75%;

[0006] From its preparation method, it can be seen that it uses ball milling method for dispersion mixing.

[0007] In the process of studying the ball milling method, we found that some defects of the ball milling method are unacceptable in the product:

[0008] 1. Impurities are uncontrollable, the grinding process needs to use zirconium balls for grinding, in order to reduce the particle size, the grinding time is longer, the zirconium content is higher, which leads to more impurities in the target material; at the same time, the ball milling process does not have high requirements for the sealing of the processing environment, so as to further cause more impurities;

[0009] 2. The mixing uniformity cannot be further improved.

[0010] The problem to be solved by the present application is: how to provide a high-purity and high-conductivity indium oxide target material. SUMMARY

[0011] The purpose of the present application is to provide an improved preparation method of a high-purity indium oxide cerium tantalum holmium target material, which has a relatively low content of indium, and the use of cerium tantalum holmium is beneficial to control a higher electrical conductivity, and at the same time, the purity of the target material can be effectively maintained through a wet precipitation process, which is also an important factor for improving the electrical conductivity.

[0012] As above, the present application also discloses the target material.

[0013] To achieve the above-mentioned purpose, the present application discloses a preparation method of a high-purity indium oxide cerium tantalum holmium target material, comprising the following steps:

[0014] Step 1: soluble metal salts of indium, cerium, tantalum and holmium are weighed according to the molar ratio In:Ce:Ta:Ho=90-94:0.8-1.2:4-6:1.2-2.8, and dissolved in deionized water;

[0015] Step 2: a precipitating agent urea is added to the mixture of step 1 and mixed;

[0016] Step 3: the mixture of step 2 is placed in a sealed container and heated at 190-200℃, and after heating, a precursor powder is obtained;

[0017] Step 4: the precursor powder is calcined and formed to obtain an indium oxide cerium tantalum holmium target material.

[0018] In the above preparation method of a high-purity indium oxide cerium tantalum holmium target material, the urea is added to the mixture of step 1 in the form of a urea solution, the addition amount of the urea solution is 8-12% of the mass of the solution of step 1; the concentration of the urea solution is 3 mol / L.

[0019] In the preparation method of the high-purity indium cerium tantalum holmium oxide target material, the soluble metal salt and the deionized water are mixed for 30-60 minutes in the step 1; and the mixing time of the mixture and the urea is 10-30 minutes in the step 2.

[0020] In the preparation method of the high-purity indium cerium tantalum holmium oxide target material, the specific operation of the step 3 is as follows:

[0021] The mixture of the step 2 is heated in a closed container at 190-200 DEG C for 10-12 hours, and after the heating is completed, the precipitate in the solution is separated and washed and dried after the solution is cooled.

[0022] In the preparation method of the high-purity indium cerium tantalum holmium oxide target material, the temperature of the calcination in the step 4 is 550-900 DEG C.

[0023] In the preparation method of the high-purity indium cerium tantalum holmium oxide target material, the forming operation in the step 4 is as follows:

[0024] After the calcined powder is subjected to dry pressing and cold isostatic pressing, a target blank is obtained, and the target blank is subjected to heat treatment and degreasing; then after being cooled to room temperature, oxygen is introduced, and the temperature is increased to a sintering temperature for sintering, so that the indium cerium tantalum holmium oxide target material is obtained; and the sintering temperature is 1100-1500 DEG C.

[0025] In the preparation method of the high-purity indium cerium tantalum holmium oxide target material, the heating rate during sintering is 0.1-0.5 DEG C / min, and the holding time is 8-12 hours.

[0026] In the preparation method of the high-purity indium cerium tantalum holmium oxide target material, the soluble metal salt of indium, cerium, tantalum and holmium is nitrate of indium, cerium, tantalum and holmium.

[0027] In the preparation method of the high-purity indium cerium tantalum holmium oxide target material, the weight ratio of the soluble metal salt and the deionized water is 1:1.5-1.7.

[0028] Meanwhile, the application also discloses an indium cerium tantalum holmium oxide target material prepared by the method.

[0029] The application has the following beneficial effects:

[0030] In the application, the target material is prepared according to the molar ratio In:Ce:Ta:Ho=90-94:0.8-1.2:4-6:1.2-2.8, the density of the target material prepared by the ratio is good, and the conductivity is relatively high.

[0031] The preparation method used in the application is a hydrothermal precipitation method. Compared with the original grinding process, the impurity content of the method used in the application will be greatly reduced. The reasons are as follows: 1. The grinding process needs to use zirconium balls for grinding. In order to reduce the particle size, the grinding time is long, and the zirconium content is high, which leads to more impurities in the target material. However, the method does not use zirconium balls for grinding, but the particle size of the obtained powder is similar to that of grinding, and the impurity content is low. 2. The reaction in the application is carried out in a closed container, and impurities are difficult to enter.

[0032] The reaction is carried out in a reaction kettle, and a high-pressure high-heat condition is provided. Compared with the ordinary precipitation method, the reaction of the method is more thorough, the yield is high, and if there are difficult-to-dissolve substances in the reactants, the method can also be used for dissolution.

[0033] The solvent used for precipitation in the application is urea. Compared with other sodium hydroxide or ammonia, urea becomes alkaline only at high temperature, so that the precipitation reaction starts. However, sodium hydroxide or ammonia will cause the precipitation reaction to start when it is dropped into the solution. At this time, the solution has not been fully dissolved and mixed, and the product obtained is easy to be a single oxide, not a mixture of oxides. Urea becomes alkaline only at high temperature, and there is almost no reaction after it is dropped into the solution in the early stage, so that the components of the product obtained by precipitation are more uniform. DETAILED DESCRIPTION

[0034] In the description of the application, it should be noted that the specific conditions are not specified in the examples. The conventional conditions or manufacturer's recommended conditions are used. The reagents or instruments used are not specified by the manufacturer. They are all conventional products that can be purchased on the market.

[0035] The application will be described clearly and completely by combining the examples of the application. Obviously, the described examples are only a part of the examples of the application, not all the examples. Based on the examples in the application, all other examples obtained by those skilled in the art without creative labor belong to the scope of protection of the application.

[0036] Example 1

[0037] 1. The respective metal salts are weighed according to the molar ratio In:Ce:Ta:Ho=90:1.2:6:2.8, wherein the metal salts are nitrate salts.

[0038] 2. The weighed In, Ce, Ta and Ho metal salts are dissolved in deionized water, and a mixed solution is obtained after magnetic stirring for 60 min.

[0039] The total amount of metal salt and the weight ratio of deionized water are 1:1.5;

[0040] 3. After adding 10% urea solution to the stirred solution, the concentration of the urea solution was 3.0 mol / L. Stirring was continued for 30 min.

[0041] 4. The solution obtained in step (3) was added to a high-temperature and high-pressure reaction kettle, and after heating at 195°C for 12 h, the product was centrifuged after the reaction kettle was cooled to room temperature, washed with deionized water, and dried in an oven for 24 h to obtain a precursor powder. The yield of the precursor powder was 82.97%.

[0042] 5. The obtained precursor powder was calcined at 450-550°C in an air atmosphere to obtain an indium cerium tantalum holmium oxide mixed powder. The Malvern result of the powder was D90=0.431 μm.

[0043] 6. The indium cerium tantalum holmium oxide mixed powder obtained in step (5) was subjected to dry pressing and cold isostatic pressing to obtain a target blank;

[0044] The process parameters for dry pressing were as follows: the indium cerium tantalum holmium oxide mixed powder was loaded into a 50-300 mm mold, and then the mold was placed in a hydraulic machine for hydraulic pressing at a pressure of 15-80 MPa. After demolding, an indium cerium tantalum holmium oxide target blank was obtained.

[0045] The process parameters for cold isostatic pressing were as follows: the obtained indium cerium tantalum holmium oxide target blank was placed in a soft bag film, the material of which was generally a PE plastic bag. The sealed bag was placed in a cold isostatic pressing machine and soaked in a liquid pressure medium. The blank was pressed by a high-pressure liquid injected by a high-pressure pump, and the pressure was 360 MPa-400 MPa. An indium cerium tantalum holmium oxide target blank was obtained.

[0046] The obtained target blank was placed in a sintering furnace and sintered by increasing the sintering temperature in an oxygen atmosphere to obtain an indium cerium tantalum holmium oxide target material (the sintering temperature was 1500°C, the heating rate was 0.5 / min, and the holding time was 8 h). The density of the target material was 99.21%, the electrical conductivity was 928 s / m, and the total impurity content was 41 ppm.

[0047] Example 2

[0048] 1. The respective metal salts were weighed according to the molar ratio In:Ce:Ta:Ho=94:0.8:4:1.2, and the metal salts were nitrate salts.

[0049] 2. The weighed In, Ce, Ta, and Ho metal salts were dissolved in deionized water, and a mixed solution was obtained after magnetic stirring for 60 min.

[0050] The total amount of metal salt and the weight ratio of deionized water were 1:1.5;

[0051] 3. After adding 10% urea solution to the stirred solution, the concentration of the urea solution was 3.0 mol / L. Stirring was continued for 30 min.

[0052] 4. The solution obtained in step (3) was added to a high-pressure reaction kettle, and after heating at 195°C for 12 h, the product was centrifuged after the reaction kettle was cooled to room temperature, washed with deionized water, and dried in an oven for 24 h to obtain a precursor powder. The yield of the precursor powder was 83.03%.

[0053] 5. The obtained precursor powder was calcined at 450-550°C to obtain an indium cerium tantalum holmium oxide mixed powder. The Malvern result of the powder was D90=0.517 μm.

[0054] 6. 6. The indium cerium tantalum holmium oxide mixed powder obtained in step (5) was subjected to dry pressing and cold isostatic pressing to obtain a target blank;

[0055] The process parameters for dry pressing were as follows: the indium cerium tantalum holmium oxide mixed powder was loaded into a 50-300 mm mold, and then the mold was placed in a hydraulic machine for hydraulic pressing at a pressure of 15-80 MPa. After demolding, an indium cerium tantalum holmium oxide target blank was obtained.

[0056] The process parameters for cold isostatic pressing were as follows: the obtained indium cerium tantalum holmium oxide target blank was placed in a soft bag film, the material of which was generally a PE plastic bag. The sealed bag was placed in a cold isostatic pressing machine and soaked in a liquid pressure medium. The high-pressure liquid was injected by a high-pressure pump for pressing at a pressure of 360 MPa-400 MPa to obtain an indium cerium tantalum holmium oxide target blank.

[0057] The obtained target blank was placed in a sintering furnace and sintered by increasing the sintering temperature to obtain an indium cerium tantalum holmium oxide target material (sintering temperature was 1500°C, heating rate was 0.5 / min, and holding time was 8 h). The density of the target material was 99.17%, the electrical conductivity was 916 s / m, and the total impurity content was 38 ppm.

[0058] Example 3

[0059] 1. The respective metal salts were weighed according to the molar ratio In:Ce:Ta:Ho=92:1:5:2, and the metal salts were nitrate salts.

[0060] 2. The weighed In, Ce, Ta, and Ho metal salts were dissolved in deionized water, and a mixed solution was obtained after magnetic stirring for 60 min.

[0061] The total amount of metal salt and the weight ratio of deionized water were 1:1.5;

[0062] 3. After adding 10% urea solution to the stirred solution, the concentration of the urea solution was 3.0 mol / L. Stirring was continued for 30 min.

[0063] 4. The solution obtained in step (3) was added to a high-pressure reaction kettle, and after heating at 195°C for 12 h, the product was centrifuged after the reaction kettle was cooled to room temperature, washed with deionized water, and dried in an oven for 24 h to obtain a precursor powder. The yield of the precursor powder was 82.91%.

[0064] 5. The obtained precursor powder was calcined at 450-550°C to obtain an indium cerium tantalum holmium oxide mixed powder. The Malvern result of the powder was D90 = 0.462 μm.

[0065] 6 6. The indium cerium tantalum holmium oxide mixed powder obtained in step (5) was subjected to dry pressing and cold isostatic pressing to obtain a target blank;

[0066] The process parameters for dry pressing were as follows: the indium cerium tantalum holmium oxide mixed powder was loaded into a 50-300 mm mold, and then the mold was placed in a hydraulic machine for hydraulic pressing at a pressure of 15-80 MPa. After demolding, an indium cerium tantalum holmium oxide target blank was obtained.

[0067] The process parameters for cold isostatic pressing were as follows: the obtained indium cerium tantalum holmium oxide target blank was placed in a soft bag film, the material of which was generally a PE plastic bag. The sealed bag was placed in a cold isostatic pressing machine and soaked in a liquid pressure medium. The blank was pressed by a high-pressure liquid injected by a high-pressure pump, and the pressure was 360 MPa-400 MPa. An indium cerium tantalum holmium oxide target blank was obtained.

[0068] The obtained target blank was placed in a sintering furnace and sintered by increasing the sintering temperature in an oxygen atmosphere. An indium cerium tantalum holmium oxide target material was obtained (the sintering temperature was 1500°C, the heating rate was 0.5 / min, and the holding time was 8 h). The density of the target material was 99.25%, the electrical conductivity was 984 s / m, and the total impurity content was 35 ppm.

[0069] Comparative Example 1

[0070] 1. The respective metal salts were weighed according to the molar ratio In:Ce:Ta:Ho = 90:2:6:2, and the metal salts were nitrate salts.

[0071] 2. The weighed In, Ce, Ta, and Ho metal salts were dissolved in deionized water, and a mixed solution was obtained after magnetic stirring for 60 min.

[0072] The total amount of metal salt and the weight ratio of deionized water were 1:1.5;

[0073] 3. After adding urea solution with 10% of the solution mass to the stirred solution, the concentration of the urea solution is 3.0 mol / L. Continue to stir for 30 min.

[0074] 4. After adding the solution obtained in step (3) into a high-pressure reaction kettle and heating at 195°C for 12 h, the product is centrifuged after the reaction kettle is cooled to room temperature, washed with deionized water, and dried in an oven for 24 h to obtain a precursor powder. The yield of the precursor powder is measured to be 83.05%.

[0075] 5. The obtained precursor powder is calcined at 450-550°C to obtain an indium cerium tantalum holmium oxide mixed powder. The powder Malvern result D90 is measured to be 0.528 μm.

[0076] 6. The indium cerium tantalum holmium oxide mixed powder obtained in step (5) is subjected to dry pressing and cold isostatic pressing to obtain a target blank.

[0077] The process parameters of dry pressing are as follows: the indium cerium tantalum holmium oxide mixed powder is loaded into a 50-300 mm mold, and then the mold is placed in a hydraulic machine for hydraulic pressing at a pressure of 15-80 MPa. After demolding, an indium cerium tantalum holmium oxide target blank is obtained.

[0078] The process parameters of cold isostatic pressing are as follows: the obtained indium cerium tantalum holmium oxide target blank is placed in a soft bag film, and the material is generally a PE plastic bag. The sealed bag is placed in a cold isostatic pressing machine and soaked in a liquid pressure medium. The high-pressure liquid is injected by a high-pressure pump for pressing at a pressure of 360 MPa-400 MPa to obtain an indium cerium tantalum holmium oxide target blank.

[0079] The obtained target blank is placed in a sintering furnace and sintered by increasing the sintering temperature to obtain an indium cerium tantalum holmium oxide target material (the sintering temperature is 1500°C, the heating rate is 0.5 / min, and the holding time is 8 h). The target material density is 98.28%, the conductivity is 532 s / m, and the total impurity content is 38 ppm.

[0080] Comparative Example 2

[0081] The procedure of Comparative Example 1 is basically the same, except that the materials are weighed according to the molar ratio In:Ce:Ta:Ho = 90:1.5:5.8:2.7.

[0082] The powder Malvern result D90 is measured to be 0.512 μm.

[0083] The target material density is 98.34%, the conductivity is 615 s / m, and the total impurity content is 41 ppm.

[0084] Comparative Example 3

[0085] Comparative Example 3 was prepared according to the same procedure as Comparative Example 1 except that the molar ratio of In:Ce:Ta:Ho was 90:1:7:2.

[0086] The measured Malvern powder was D90=0.429 μm

[0087] The measured target density was 98.98%, the conductivity was 606 / s / m, and the total impurity content was 44 ppm.

[0088] Comparative Example 4

[0089] Comparative Example 4 was prepared according to the same procedure as Comparative Example 1 except that the molar ratio of In:Ce:Ta:Ho was 90:1:6:3.

[0090] The measured Malvern powder was D90=0.429 μm

[0091] The measured target density was 98.98%, the conductivity was 606 / s / m, and the total impurity content was 44 ppm.

[0092] Comparative Example 5

[0093] Comparative Example 5 was prepared according to the same procedure as Comparative Example 1 except that the molar ratio of In:Ce:Ta:Ho was 85:3:8:4.

[0094] The measured Malvern powder was D90=0.429 μm

[0095] The measured target density was 98.98%, the conductivity was 606 / s / m, and the total impurity content was 44 ppm.

[0096] Comparative Example 6

[0097] 1. The oxides of the corresponding elements were weighed according to the molar ratio of In:Ce:Ta:Ho=92:1:5:2 for use;

[0098] 2. 1500 g of pure water and a polyvinylpyrrolidone dispersant were added to the slurry barrel. The polyvinylpyrrolidone dispersant accounted for 5% of the total mass of the cerium oxide, tantalum oxide powder and holmium oxide powder.

[0099] 3. The weighed cerium oxide, tantalum oxide powder and holmium oxide powder in step (1) were added to the solution in step (2) to obtain a slurry one by pre-dispersing. The pre-dispersing time was 30 min, the pre-dispersing speed was 100 rpm, and the solid content in the slurry was 50%.

[0100] 4. The slurry one obtained in step (3) was pumped into a sand mill by a pneumatic diaphragm pump for grinding to obtain a slurry two. The grinding speed was 1200 rpm, and the grinding time was 6 h;

[0101] 5. Add the weighed indium oxide powder in step (1) and 500 g of polyvinylpyrrolidone dispersant and 3500 g of pure water into slurry two and stir to pre-disperse to obtain slurry three. The mass of the polyvinylpyrrolidone dispersant accounts for 5% of the total mass of the indium oxide, cerium oxide, tantalum oxide and holmium oxide powders. The dispersion rotation speed is 100 rpm, the dispersion time is 40 min, and the solid content in the slurry is 67%.

[0102] 6. The slurry three obtained in step (5) is pumped into a sand mill with a pneumatic diaphragm pump for grinding to obtain slurry four. The grinding rotation speed is 1200 rpm, and the grinding time is 10 h.

[0103] 7. Add a binder to the slurry four obtained in step (6) for pre-dispersion, the pre-dispersion time is 30 min, and the dispersion rotation speed is 100 rpm. The obtained slurry is pumped into a sand mill with a pneumatic diaphragm pump for grinding to obtain slurry five. The grinding time is 2 h, and the grinding rotation speed is 1200 rpm. The binder accounts for 10% of the total mass of the added powders and the binder.

[0104] 8. The slurry five obtained in step (7) is pumped into a co-current spray drying tower for spray granulation, followed by mixing and sieving to obtain the precursor of the indium cerium tantalum holmium oxide target material. The Malvern measurement of the powder is D90 = 0.415 μm. The air outlet temperature is 75°C, and the atomizer frequency is 120 Hz.

[0105] 9. The indium cerium tantalum holmium oxide target precursor obtained in step (8) is subjected to dry pressing and cold isostatic pressing to obtain an indium cerium tantalum holmium oxide target blank.

[0106] 10. The indium cerium tantalum holmium oxide target blank obtained in step (9) is subjected to heat treatment, the temperature is controlled at 500°C for degreasing treatment (heat preservation time is 2 hours, and the heating rate is 0.1°C / min). Then, after cooling to room temperature, oxygen is introduced, and the sintering temperature is increased for sintering to obtain an indium cerium tantalum holmium oxide target material (the sintering temperature is 1400°C, the heating rate is 0.2°C / min, and the heat preservation time is 8 h), thereby obtaining an indium cerium tantalum holmium oxide target material.

[0107] The target material has a density of 98.96%, an electrical conductivity of 831 s / m, and a total impurity content of 217 ppm.

[0108] Comparative Example 7

[0109] Comparative Example 7 is prepared according to the same procedure as Comparative Example 5 except that the molar ratio of In:Ce:Ta:Ho = 94:0.8:4:1.2.

[0110] The Malvern measurement of the powder is D90 = 0.412 μm

[0111] The measured target density is 99.01%, the conductivity is 807 s / m, and the total impurity content is 289 ppm.

[0112] Comparative Example 8

[0113] Comparative Example 8 is prepared according to the molar ratio of In:Ce:Ho = 96:1.2:2.8, and other conditions are the same as those in Comparative Example 1.

[0114] The measured Malvern powder is D90 = 0.463 μm

[0115] The measured target density is 98.17%, the conductivity is 297 s / m, and the total impurity content is 42 ppm.

[0116] Result analysis:

[0117] 1. It can be seen from the comparison between Example 1 and Comparative Example 1 that when the amount of Ce is significantly increased, the effect on the target density and the conductivity is negative. The possible reason is that the decrease in the target density reduces the conductivity, and the excessive use of Ce has a negative effect on the conductivity. This phenomenon is further verified in Comparative Example 2, in which the target density is slightly improved and the conductivity is further improved as the amount of Ce decreases.

[0118] 2. It can be found from the further comparison between Example 1 and Comparative Examples 3 and 4 that the excessive use of Ta and Ho also leads to a decrease in the relative density of the target and the conductivity. In this regard, it can be considered that Ce, Ta, and Ho must be in a relatively appropriate proportion in order to further improve the relative density of the target and the conductivity.

[0119] 3. It can be seen from Example 1 and Comparative Example 5 that the further increase in the amount of Ce, Ta, and Ho leads to a further decrease in the target density and a significant decrease in the conductivity.

[0120] 4. It can be found from the comparison between Examples 2 and 3 and Comparative Examples 6 and 7 that the use of the grinding method leads to a significant increase in impurities and the relative density is not improved synchronously. The possible reason is that the grinding method is less uniform than the solution method. At the same time, the decrease in the target density does not weaken the conductivity, and the possible reason is that impurities can increase the conductivity.

[0121] 5. It can be seen from the comparison between Example 1 and Comparative Example 8 that in the absence of Ta, the target density and the conductivity are significantly deteriorated.

[0122] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present application should be equivalent replacement manners and should be included in the protection scope of the present application.

Claims

1. A method for preparing a high-purity indium cerium tantalum holmium oxide target, characterized in that, The method comprises the following steps: Step 1: soluble metal salts of indium, cerium, tantalum and holmium are weighed according to a molar ratio of In:Ce:Ta:Ho=90-94:0.8-1.2:4-6:1.2-2.8, and dissolved in deionized water; Step 2: a precipitant urea is added to the mixture in step 1 and mixed; Step 3: the mixture in step 2 is placed in a closed container and heated at 190-200℃, and after heating, a precursor powder is separated; Step 4: the precursor powder is calcined, and after the calcined powder is subjected to dry pressing and cold isostatic pressing, a target blank is obtained, and the target blank is subjected to heat treatment and degreasing; then after cooling to room temperature, oxygen is introduced, and the temperature is raised to a sintering temperature for sintering, so that an indium-cerium-tantalum-holmium oxide target material is obtained; the sintering temperature is 1100-1500℃.

2. The method of producing a high-purity indium cerium tantalum holmium oxide target according to claim 1, characterized by, The urea is added to the mixture in step 1 in the form of a urea solution, and the addition amount of the urea solution is 8-12% of the mass of the solution in step 1; the concentration of the urea solution is 3 mol / L.

3. The method of claim 1, wherein the high purity indium cerium tantalum holmium oxide target is prepared by the steps of: In step 1, the soluble metal salts and the deionized water are mixed for 30-60 min; in step 2, the mixture and the urea are mixed for 10-30 min. ​ 4. The method for preparing high-purity indium cerium tantalum holmium target material according to claim 1, characterized in that, The specific operation of step 3 is as follows: The mixture in step 2 is placed in a closed container and heated at 190-200℃, and the heating time is 10-12 h; after heating, the precipitate in the solution is separated and washed and dried after the solution is cooled.

5. The method for preparing high-purity indium cerium tantalum holmium oxide target material according to claim 1, characterized in that, The calcination temperature in step 4 is 550-900℃.

6. The method of claim 1, wherein the high purity indium cerium tantalum holmium oxide target is prepared by the steps of: The heating rate during sintering is 0.1-0.5 / min, and the holding time is 8-12 h. ​ 7. The method for preparing high-purity indium cerium tantalum holmium target material according to claim 1, characterized in that, The soluble metal salts of indium, cerium, tantalum and holmium are nitrate salts of indium, cerium, tantalum and holmium.

8. The method for preparing high-purity indium cerium tantalum holmium oxide target material according to claim 1, characterized in that, The weight ratio of the soluble metal salts to the deionized water is 1:1.5-1.

7.

9. An indium cerium tantalum holmium oxide target material, characterized by, The method is prepared by any one of claims 1-8.