A high-density oxide target and a method for manufacturing the same

Abstract

The application belongs to the technical field of new materials, and discloses a preparation method of high-density oxide target material, which comprises the following steps: mixing a first oxide precursor powder and a second oxide precursor powder, then performing die forming and sintering to obtain the target material; the first oxide precursor powder and the second oxide precursor powder both contain not less than 97wt% of indium oxide; the weight of the first oxide precursor powder is equivalent to 80% to 90% of the total weight of the first oxide precursor powder and the second oxide precursor powder; the particle size of the first oxide precursor powder is 20 to 30 microns; and the particle size of the second oxide precursor powder is 45 to 73 microns. The method can effectively improve the relative density, reduce the resistivity and improve the forming effect of the target material with high indium oxide content by using a small amount of large-particle-size precursor powder and a large amount of small-particle-size precursor powder. Meanwhile, the application also provides the high-density oxide target material.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new materials, in particular to a high-density oxide target material and a preparation method thereof. BACKGROUND

[0002] Indium oxide is a kind of n-type semiconductor material with high conductivity, high transmittance (visible light band), wide band gap, high mechanical hardness and good stability. On this basis, doping can further improve the conductivity of the thin film material, that is, the indium oxide-based TCO thin film. The doping elements are various, such as tin, tungsten, titanium, zirconium, manganese and the like. However, the quality of the indium oxide-based thin film depends largely on the quality of the indium oxide-based target material. At present, the sintering of the target material usually needs to be sintered at high temperature for a long time, which will cause problems such as coarse grains, uneven element distribution and high energy consumption. Therefore, to realize the preparation of high-quality target material with low energy consumption, it is necessary to reduce the sintering temperature by improving the green density, so as to avoid the occurrence of adverse problems.

[0003] The preparation process of the indium oxide-based target material is divided into three procedures: powder preparation, green body forming and sintering. These three procedures are the key factors affecting the quality of the target material. The fine and uniform powder is beneficial to improve the sintering activity, so the powder with small particle diameter and good dispersibility is usually used in the preparation process of the target material. Secondly, in the forming process of the powder, the larger the particle diameter, the greater the friction force, which leads to the stress attenuation of the compacted target material, resulting in problems such as uneven accumulation of particles and low density in the green body, which will ultimately affect the sintering performance of the target material.

[0004] The low-density green body particles are loosely accumulated, and the particles are more likely to rotate during sintering, so the densification rate is high, but the density of the sintered body is still lower than that of the sintered body of the high-density green body. Although the high green density sample has a low densification rate, it is easier to obtain high density and small grain size at a lower temperature. Therefore, high green density is beneficial to obtain high-density indium oxide-based target material. It is necessary to ensure the packing density and uniformity of the particles in the forming process. Uneven accumulation leads to shrinkage difference in the sintering process of the target material, resulting in pores in the target material and reducing the density of the target material.

[0005] The most commonly used forming method of the green body is the combination of die pressing and cold isostatic pressing forming method. The simplest method to increase the green density is to increase the stress of the green body, which will cause large internal stress in the green body and produce cracks during sintering. The process of green body forming is the process of particle accumulation. The size grading of powder particles is widely used in water conservancy, geology and powder metallurgy fields. In the preparation of ceramics, the accumulation theory is often used for the design of porous ceramics, and the theory is also used to control the size of ceramic grains. The traditional single particle method is difficult to achieve high density, and the highest theoretical density of uniform spherical particles with single size is 0.74.

[0006] In order to seek higher green body bulk density and subsequent sintered target density, the applicant previously filed a patent application CN116143500B Ingotmolybdenum praseodymium oxide target and preparation method thereof, which discloses Pr6O 11 The mass ratio of the powder, the MoO3 powder and the In2O3 powder is 10-23:5-17:60-80; the coarse powder particle size is 90-115 μm, and the fine powder particle size is 10-35 μm; when the coarse powder particle size is 90-100 μm and the coarse powder particle size is not 100 μm, the ratio of the fine powder to the coarse powder is 1:6-9; when the coarse powder particle size is 100-105 μm and the coarse powder particle size is not 105 μm, the ratio of the fine powder to the coarse powder is 1:9-12; when the coarse powder particle size is 105-115 μm, the ratio of the fine powder to the coarse powder is 1:12-16. The result is that the true density is 6.2 or more, and the forming rate is 80% or more.

[0007] In another previous application CN116219375B Ingot zinc oxide target and preparation method thereof of the applicant, it is recorded that part of the indium oxide is prepared into small particles, and part of the indium oxide is prepared into large particles; the atomic ratio of the large particle size indium oxide to the small particle size indium oxide is 3:7-1:9; the particle size D50 of the large particle size indium oxide is 1-2 μm, and the particle size D90 is 1-1.8 μm; the particle size D50 of the small particle size indium oxide is 0.1-0.3 μm, and the particle size D90 is 0.1-0.2 μm; then the large particles, the small particles and zinc oxide are slurried and spray granulated.

[0008] The result is that the relative density is 98% or more, and the resistivity is 135 or less;

[0009] From the above description, it can be seen that for the indium oxide target, adjusting the powder particle size or adjusting the raw material particle size can optimize the density and other related properties.

[0010] We hope to further improve the density of the indium oxide target and reduce the damage of the target.

[0011] The technical problem solved by the present application is how to further improve the relative density of the indium oxide target and improve the forming effect. SUMMARY

[0012] The purpose of the present application is to provide a preparation method of a high-density oxide target. The method of the present application is for a target with high indium oxide content, and a small amount of large particle size precursor powder and a large amount of small particle size precursor powder are used, which can effectively improve the relative density of the target of this type, reduce the resistivity and improve the forming effect.

[0013] Meanwhile, the present application also provides the high-density oxide target.

[0014] To achieve the above object, the application discloses the following:

[0015] A preparation method of a high-density oxide target material, comprising the following steps: mixing a first oxide precursor powder and a second oxide precursor powder, and then performing die forming and sintering to obtain the target material.

[0016] The first oxide precursor powder and the second oxide precursor powder each contain not less than 97wt% of indium oxide.

[0017] The weight of the first oxide precursor powder is equivalent to 80% to 90% of the total weight of the first oxide precursor powder and the second oxide precursor powder.

[0018] The particle size of the first oxide precursor powder is 20 to 30 microns, and the particle size of the second oxide precursor powder is 45 to 73 microns.

[0019] The application can effectively solve the problems of more pores and loose particle accumulation when the large particle powder occupies a dominant position, and the prepared high-density green body can also gradually reduce the pores of the target material and reduce the diameter of the pores, so that the compactness of the oxide target material is gradually improved.

[0020] The application further finds that the method is particularly effective for the target material with high indium oxide content.

[0021] In the above preparation method of the high-density oxide target material, the first oxide precursor powder and the second oxide precursor powder each contain not less than 98wt% of indium oxide.

[0022] In the above preparation method of the high-density oxide target material, the first oxide precursor powder and the second oxide precursor powder further contain one or more combinations of cerium oxide, titanium oxide, tantalum oxide, molybdenum oxide, praseodymium oxide and zinc oxide.

[0023] In the above preparation method of the high-density oxide target material, the first oxide precursor powder and the second oxide precursor powder contain 97.5wt% to 99.7wt% of indium oxide.

[0024] More preferably, the first oxide precursor powder and the second oxide precursor powder each contain indium oxide powder, cerium oxide powder, titanium oxide powder and tantalum oxide powder, and the weight ratio of each powder is 97.5 to 99.7: 0.1 to 1: 0.1 to 1: 0.1 to 0.5.

[0025] In the preparation method of the high-density oxide target material, the preparation method of the first oxide precursor powder and the second oxide precursor powder is as follows: mixing an oxide, a dispersant and a binder to prepare a slurry with a solid content of 30wt%-95wt%, and then performing sand milling and spray granulation to obtain powders with corresponding particle sizes.

[0026] In the sand milling process for preparing the first oxide precursor powder, the milling balls used are a mixture of three specifications of 0.3mm, 0.4-0.6mm and 0.8-1.0mm milling balls; the weight ratio of the 0.3mm milling balls, the 0.4-0.6mm milling balls and the 0.8-1.0mm milling balls is 4-7:1-4:1-4.

[0027] In the sand milling process for preparing the second oxide precursor powder, the milling balls used are 0.8mm-1.0mm milling balls.

[0028] In the preparation method of the high-density oxide target material, in the sand milling operation, the rotation speed of the sand mill is 800-1600rpm, and the grinding time is 2-12h.

[0029] In the spray granulation operation, the air outlet temperature is 60-75℃, and the frequency of the atomizer is 80-160Hz.

[0030] In the preparation method of the high-density oxide target material, the dispersant in the slurry accounts for 0.1wt%-5wt% of the weight of the slurry; and the binder accounts for 5wt%-20wt% of the weight of the slurry.

[0031] In the preparation method of the high-density oxide target material, the die molding operation includes die molding treatment and cold isostatic pressing treatment performed in sequence, the pressure during die molding is 85-95Mpa, and the pressure maintaining time is 100-140s; the pressure during cold isostatic pressing is 300-400Mpa, and the pressure maintaining time is 100-140s.

[0032] In the preparation method of the high-density oxide target material, the sintering operation includes degreasing treatment and sintering treatment.

[0033] The temperature of the degreasing treatment is 400℃-600℃.

[0034] The sintering treatment is performed under aerobic conditions after the degreasing treatment, the sintering temperature is 1100-1500℃, the heating rate is 0.1-0.5 / min, and the holding time is 8-12h.

[0035] In addition, the application further discloses a high-density oxide target material prepared by the method.

[0036] The application has at least the following beneficial effects:

[0037] The present application controls the proportion of different particle sizes, controls the large particle size and the small particle size, and prepares a high-density green body, thereby improving the density and performance of the target material. DETAILED DESCRIPTION

[0038] The present application will be described in detail below with reference to the embodiments thereof, and it should be noted that, in the description of the present application, if specific conditions are not indicated in the embodiments, conventional conditions or conditions recommended by the manufacturers are used. If the reagents or instruments used are not indicated by the manufacturers, they are all conventional products that can be purchased on the market.

[0039] Example 1

[0040] A preparation process of a high-density oxide target material is prepared by the following steps:

[0041] Step 1: Take 99.1 kg of indium oxide, 0.2 kg of cerium oxide, 0.5 kg of titanium oxide, 0.2 kg of tantalum oxide, 8.1 kg of dispersant polyvinylpyrrolidone, and 3.1 kg of binder polyethylene glycol each twice for standby;

[0042] Step 2: The raw materials weighed in step 1 are dispersed for 30 min at a speed of 100 rpm and ground for 4 h at a speed of 1100 rpm to obtain slurry one with a solid content of 45%. The zirconium balls with a weight ratio of 5:3:2 of 0.3 mm, 0.4-0.6 mm, 0.8-1.0 mm are used for grinding; the volume ratio of zirconium balls to slurry is 0.18;

[0043] Step 3: The slurry one obtained in step 2 is granulated by spraying, then mixed and sieved to obtain mixed oxide target precursor powder one with an average particle diameter of d. The air outlet temperature is 75°C, and the frequency of the atomizer is 120 Hz; d = 20.71 nm;

[0044] Step 4: The raw materials weighed in step 1 are dispersed for 30 min at a speed of 100 rpm and ground for 4 h at a speed of 1100 rpm to obtain slurry two with a solid content of 45%. The zirconium balls with a weight ratio of 5:3:2 of 0.3 mm, 0.4-0.6 mm, 0.8-1.0 mm are used for grinding; the volume ratio of zirconium balls to slurry is 0.18;

[0045] Step 5: The slurry two obtained in step 4 is granulated by spraying, then mixed and sieved to obtain mixed oxide target precursor powder two with an average particle diameter of D. The air outlet temperature is 75°C, and the frequency of the atomizer is 120 Hz; D = 50.02 nm;

[0046] Step 6: The oxide target precursor powder one and two are size graded, molded, and cold isostatic pressed to obtain a target blank containing metal oxide. The pressure during molding of the target is 90 MPa, and the pressure holding time is 120 s; the pressure during cold isostatic pressing is 350 MPa, and the pressure holding time is 120 s. The mass ratio of the oxide target precursor powder one and two is 80:20;

[0047] Step 7: The obtained compact is heat treated, and the temperature is controlled at 400℃ for debinding treatment (the holding time is 5 hours, and the heating rate is 0.1℃ / min). Then, the temperature is increased to perform sintering in oxygen to obtain an indium oxide-based target (the sintering temperature is 1400℃, the heating rate is 0.3℃ / min, and the holding time is 8h), and the density and resistivity of the target are detected.

[0048] Example 2

[0049] A preparation process of a high-density oxide target, which is basically the same as that of Example 1, except that the mass ratio of the oxide target precursor powder one and two in Step 6 is 85:15.

[0050] Example 3

[0051] A preparation process of a high-density oxide target, which is basically the same as that of Example 1, except that the mass ratio of the oxide target precursor powder one and two in Step 6 is 90:10.

[0052] Example 4

[0053] A preparation process of a high-density oxide target, which is basically the same as that of Example 1, except that the average particle size of the oxide target precursor powder one and two is 23.65μm and 57.13μm, respectively.

[0054] Example 5

[0055] A preparation process of a high-density oxide target, which is basically the same as that of Example 1, except that the average particle size of the oxide target precursor powder one and two is 21.87μm and 52.83μm, respectively.

[0056] Example 6

[0057] A preparation process of a high-density oxide target, which is basically the same as that of Example 1, except that the average particle size of the oxide target precursor powder one and two is 29.41μm and 71.04μm, respectively.

[0058] Example 7

[0059] A preparation process of a high-density oxide target, which is obtained by the following steps:

[0060] Step 1: Take 97.5 kg of indium oxide, 1 kg of cerium oxide, 1 kg of titanium oxide, 0.5 kg of tantalum oxide, 8.1 kg of dispersant polyvinylpyrrolidone, and 3.1 kg of binder polyethylene glycol, each two portions, and place them aside for use;

[0061] Step 2: Disperse and grind the powders, dispersants, and additives obtained in Step 1 for 30 min at a speed of 100 rpm and for 4 h at a speed of 1100 rpm to obtain slurry one with a solid content of 45%.

[0062] The grinding is performed using zirconium balls with diameters of 0.3 mm, 0.4-0.6 mm, and 0.8-1.0 mm in a weight ratio of 5:3:2, and the volume ratio of the zirconium balls to the slurry is 0.18.

[0063] Step 3: Spray granulate the slurry one obtained in Step 2, then mix and sieve to obtain mixed oxide target precursor powder one with a particle diameter of d. The air outlet temperature is 75°C, and the atomizer frequency is 120 Hz; d = 30.51 nm.

[0064] Step 4: Disperse and grind the powders, dispersants, and additives obtained in Step 1 for 30 min at a speed of 100 rpm and for 4 h at a speed of 1100 rpm to obtain slurry two with a solid content of 45%.

[0065] The grinding is performed using zirconium balls with diameters of 0.8-1.0 mm, and the volume ratio of the zirconium balls to the slurry is 0.18.

[0066] Step 5: Spray granulate the slurry two obtained in Step 4, then mix and sieve to obtain mixed oxide target precursor powder two with a particle diameter of D. The air outlet temperature is 75°C, and the atomizer frequency is 120 Hz; D = 73.70 nm.

[0067] Step 6: Size-grade the oxide target precursor powders one and two, then perform die pressing and cold isostatic pressing to obtain a target blank containing metal oxides. The pressure during die pressing is 90 MPa, and the pressure holding time is 120 s; the pressure during cold isostatic pressing is 350 MPa, and the pressure holding time is 120 s. The mass ratio of the oxide target precursor powders one and two is 80:20.

[0068] Step 7: Perform heat treatment on the obtained compact, control the temperature at 400, perform debinding treatment (heat preservation time of 5 hours, and heating rate of 0.1°C / min), then cool to room temperature, introduce oxygen, and increase the temperature to perform sintering to obtain an indium oxide-based target (sintering temperature of 1400°C, heating rate of 0.3°C / min, and heat preservation time of 8 h), and detect the target density and resistivity.

[0069] Example 8

[0070] A preparation process of high-density oxide target material is prepared by the following steps:

[0071] Step 1: Take 99.7 kg of indium oxide, 0.1 kg of cerium oxide, 0.1 kg of titanium oxide, 0.1 kg of tantalum oxide, 8.1 kg of dispersant polyvinyl pyrrolidone, and 3.1 kg of binder polyethylene glycol each two parts for standby;

[0072] Step 2: The powders weighed in step 1 and the dispersant and additive are dispersed for 30 min at a speed of 100 rpm and ground for 4 h at a speed of 1100 rpm to obtain slurry one with a solid content of 45%.

[0073] Among them, 0.3 mm, 0.4-0.6 mm, 0.8-1.0 mm zirconium balls with a weight ratio of 5:3:2 are used for grinding; the volume ratio of zirconium balls to slurry is 0.18;

[0074] Step 3: The slurry one obtained in step 2 is spray granulated, then mixed and sieved to obtain mixed oxide target precursor powder one with a particle diameter of d. Among them, the air outlet temperature is 75℃, and the atomizer frequency is 120Hz; d=31.58;

[0075] Step 4: The powders weighed in step 1 and the dispersant and additive are dispersed for 30 min at a speed of 100 rpm and ground for 4 h at a speed of 1100 rpm to obtain slurry two with a solid content of 45%.

[0076] Among them, 0.8-1.0 mm zirconium balls are used for grinding; the volume ratio of zirconium balls to slurry is 0.18;

[0077] Step 5: The slurry two obtained in step 4 is spray granulated, then mixed and sieved to obtain mixed oxide target precursor powder two with a particle diameter of D. Among them, the air outlet temperature is 75℃, and the atomizer frequency is 120Hz; D=76.28nm;

[0078] Step 6: The oxide target precursor powders one and two are size graded and molded, and then cold isostatic pressed to obtain a target blank containing metal oxides. The pressure during target molding is 90Mpa, and the pressure holding time is 120s; the pressure during cold isostatic pressing is 350Mpa, and the pressure holding time is 120s. The mass ratio of the oxide target precursor powders one and two is 80:20;

[0079] Step 7: The obtained green compact is subjected to heat treatment, and the temperature is controlled at 400°C for debinding treatment (the holding time is 5 hours, and the heating rate is 0.1°C / min). After cooling to room temperature, oxygen is introduced, and the temperature is increased for sintering to obtain an indium oxide-based target material (the sintering temperature is 1400°C, the heating rate is 0.3°C / min, and the holding time is 8 hours), and the density and resistivity of the target material are detected.

[0080] Comparative Example 1

[0081] The procedure is basically the same as that in Example 1, except that the mass ratio of the oxide target precursor powders one and two in Step 6 is 50:50.

[0082] Comparative Example 2

[0083] The procedure is basically the same as that in Example 1, except that the mass ratio of the oxide target precursor powders one and two in Step 6 is 60:40.

[0084] Comparative Example 3

[0085] The procedure is basically the same as that in Example 1, except that the mass ratio of the oxide target precursor powders one and two in Step 6 is 70:30.

[0086] Comparative Example 4

[0087] The procedure is basically the same as that in Example 1, except that the size of the oxide target precursor powders one and two in Step 6 is 23-25 μm.

[0088] Comparative Example 5

[0089] The procedure is basically the same as that in Example 1, except that the size of the oxide target precursor powders one and two in Step 6 is 56-59 μm.

[0090] Performance detection

[0091] The detection items include relative density and resistivity.

[0092] The detection results are shown in Table 1 below.

[0093] Table 1 Detection results

[0094]

[0095]

[0096] Result analysis:

[0097] In the range of the experimental parameters, the ratio of different sizes of the precursor particles is adjusted, and the small size particles are incorporated into the large size particles, which effectively solves the problem of more pores and loose particle accumulation when the large size particles are dominant, and the preparation of high density green body also makes the target holes gradually decrease, and the diameter of the holes is also decreasing, which gradually improves the compactness of the oxide target. Comparative examples 1, 2 and 3 show that the size is not graded according to the set binary particle octahedral gap filling and stacking model, so that the problems of uneven particle accumulation and low density in the green body occur, which ultimately affects the sintering performance of the target; Comparative examples 4 and 5 show the influence of powder particle size grading on the sintering density of the target, and the larger particles form more pores during the sintering process, which increases the porosity; while the small particles help to reduce the formation of pores and improve the density of the target, but too many small particles will affect the filling of the particle gap, thereby leading to a decrease in density.

[0098] It will be obvious to a person skilled in the art that the application is not limited to the details of the above-described exemplary embodiments but can be implemented in other embodiments without departing from the scope of the application. The embodiments are to be considered in all respects as illustrative and not restrictive, and the scope of the application is defined by the appended claims rather than by the foregoing description, and it is intended to include all changes and modifications that fall within the meaning and scope of the equivalent elements of the claims.

Claims

1. A method for preparing a high-density oxide target, characterized in that: Mixing the first oxide precursor powder and the second oxide precursor powder, performing compression molding, and sintering to obtain a target material; The first oxide precursor powder and the second oxide precursor powder both contain no less than 97 wt % of indium oxide; The weight of the first oxide precursor powder is equivalent to 80% to 90% of the total weight of the first oxide precursor powder and the second oxide precursor powder; The particle size of the first oxide precursor powder is 20 to 30 μm; the particle size of the second oxide precursor powder is 45 to 73 μm.

2. The method for preparing a high-density oxide target according to claim 1, wherein: The first oxide precursor powder and the second oxide precursor powder both contain no less than 98 wt % of indium oxide.

3. The method for preparing a high-density oxide target according to claim 1, wherein: The first oxide precursor powder and the second oxide precursor powder further contain one or more combinations of cerium oxide, titanium oxide, tantalum oxide, molybdenum oxide, praseodymium oxide, and zinc oxide.

4. The method for preparing a high-density oxide target according to claim 3, wherein: The first oxide precursor powder and the second oxide precursor powder contain 97.5 wt % to 99.7 wt % of indium oxide.

5. The method for preparing a high-density oxide target according to claim 1, wherein: The preparation methods of the first oxide precursor powder and the second oxide precursor powder are both: mixing oxide, dispersant and binder to prepare a slurry with a solid content of 30wt% to 95wt%, and then sand grinding and spray granulation to obtain powder of corresponding particle size.

6. The method for preparing a high-density oxide target according to claim 5, wherein: In the sand milling process for preparing the first oxide precursor powder, the grinding balls used are a mixture of grinding balls of three sizes: 0.3 mm, 0.4-0.6 mm, and 0.8-1.0 mm; the weight ratio of the 0.3 mm grinding balls, the 0.4-0.6 mm grinding balls, and the 0.8-1.0 mm grinding balls is 4-7:1-4:1-4; In the sand milling process of preparing the second oxide precursor powder, the grinding balls used are 0.8 mm to 1.0 mm grinding balls.

7. The method for preparing a high-density oxide target according to claim 5, wherein: During the sand grinding operation, the speed of the sand grinder is 800 to 1600 rpm, and the grinding time is 2 to 12 hours; During the spray granulation operation, the air outlet temperature is 60-75°C and the atomizer frequency is 80-160Hz.

8. The method for preparing a high-density oxide target according to claim 5, wherein: In the slurry, the dispersant accounts for 0.1 wt% to 5 wt% of the slurry weight; the binder accounts for 5 wt% to 20 wt% of the slurry weight.

9. The method for preparing a high-density oxide target according to any one of claims 1 to 8, characterized in that: The compression molding operation includes compression molding and cold isostatic pressing, wherein the pressure during compression molding is 85-95 MPa and the pressure is maintained for 100-140 seconds; the pressure during cold isostatic pressing is 300-400 MPa and the pressure is maintained for 100-140 seconds; The sintering operation includes a degreasing process and a sintering process; The temperature of degreasing treatment is 400℃~600℃; After degreasing, sintering is carried out under oxygen conditions, with a sintering temperature of 1100-1500° C., a heating rate of 0.1-0.5 / min, and a holding time of 8-12 hours.

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