A high-density high-uniformity zinc-aluminum oxide target material and a method for preparing the same

Abstract

The application belongs to the technical field of target materials, and discloses a high-density and high-uniformity zinc-aluminum oxide target material and a preparation method thereof. The high-density and high-uniformity zinc-aluminum oxide target material is obtained by mixing small-particle-size zinc-aluminum oxide powder and large-particle-size zinc-aluminum oxide powder to obtain mixed powder, and then by sequentially performing die pressing, cold isostatic pressing, defatting heat treatment and sintering. The small-particle-size zinc-aluminum oxide powder accounts for 30-50% of the mass of the mixed powder, the particle size of the small-particle-size zinc-aluminum oxide powder is 0.3-0.8 μm, the particle size of the large-particle-size zinc-aluminum oxide powder is 1-1.5 μm, and the difference between the particle sizes of the large-particle-size zinc-aluminum oxide powder and the small-particle-size zinc-aluminum oxide powder is less than 0.8 μm. The small-particle-size zinc-aluminum oxide powder and the large-particle-size zinc-aluminum oxide powder with specific particle sizes are mixed to prepare the zinc-aluminum oxide powder, which can effectively improve the sintering density of the target material, improve the metallographic uniformity and bending strength of the target material, and balance the comprehensive performance of the target material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of target materials, in particular to a high-density and high-uniformity zinc aluminum oxide target material. BACKGROUND

[0002] The target material is a basic consumable material in the process of magnetron sputtering, and the quality of the target material plays a crucial role in determining the performance of the thin film. The target material is widely used in various fields, including optical target material, display thin film target material, semiconductor target material, recording medium target material, superconducting target material, etc. Among them, the semiconductor target material, display target material and recording medium target material are the three most widely used target materials.

[0003] In order to improve the thin film preparation rate and ensure the growth quality of the thin film, the sputtering target material must meet certain index requirements. In recent years, with the rapid development of liquid crystal display, active organic light-emitting diode display and flexible display, the importance of thin film transistor (TFT) as a core component is self-evident. Among them, the TFT based on oxide semiconductor has attracted widespread attention due to its high mobility, good electrical uniformity, high visible light transmittance, low preparation temperature and low cost.

[0004] Zinc aluminum oxide target material is one of the oxide semiconductor raw materials used to prepare thin film transistors. Due to its low price, easy availability of raw materials and stable performance, it can be used as a target material to replace ITO and applied in the field of TCO thin films. The density and uniformity of zinc aluminum oxide target material are important factors affecting the performance of the thin film, the bending strength affects the large size and mass production of the target material.

[0005] Currently, the existing technology for preparing zinc aluminum oxide target material includes D1: Chinese patent 202010451973.2 discloses a zinc aluminum oxide target material and a preparation method thereof. The invention uses zinc salt and aluminum salt as raw materials to prepare zinc aluminum oxide powder by co-precipitation method. The zinc aluminum oxide powder is pre-sintered, crushed, pressed into shape and secondarily sintered to obtain a zinc aluminum oxide target material. By optimizing the secondary sintering curve, the organic matter in the target material can be effectively removed, and the relative density of the prepared target material is not less than 98%, the carbon content is not higher than 105ppm, and the resistivity is less than 9x10 –2 Ω·cm.

[0006] The above-mentioned patent technology prepares zinc aluminum oxide powder by co-precipitation method and then prepares zinc aluminum oxide target material. The target material obtained has high relative density and low resistivity, and is a target material with excellent performance. However, the particle size of the zinc aluminum oxide powder prepared by co-precipitation method is not uniform, which leads to low metallographic uniformity of the zinc aluminum oxide target material, and it is not able to meet the current high-speed development of semiconductor demand.

[0007] Therefore, D2: Chinese patent 202110417139.6 provides a preparation method of zinc aluminum oxide target material, comprising the steps of: (1) preparing zinc oxide, aluminum oxide, dispersant, binder and water into a mixed slurry and defoaming; and controlling the average particle size and particle size uniformity of zinc oxide and aluminum oxide in the slurry; (2) the mixed slurry obtained in step (1) is spray granulated, mixed, and the average particle size and particle size uniformity of the zinc aluminum oxide powder are controlled; (3) the zinc aluminum oxide powder obtained in step (2) is pressure formed to obtain a zinc aluminum oxide target blank; (4) the zinc aluminum oxide target blank obtained in step (3) is sintered at 1300-1500 DEG C.

[0008] The preparation method of the above-mentioned patent zinc aluminum oxide target material prepares zinc oxide, aluminum oxide and dispersant, binder into a slurry, and sprays and presses the target blank, and by controlling the particle size and uniformity of the zinc aluminum oxide powder and zinc oxide, the quality of the zinc aluminum oxide target material is significantly improved, and the composition uniformity of the zinc aluminum oxide target material is improved; but the powder particle size used is very fine.

[0009] The above-mentioned patent effectively solves the problem of insufficient composition uniformity of zinc aluminum oxide target material, but does not solve the problem of uniformity of target metallographic structure. The uniformity of target metallographic structure is actually the uniformity of target grain, and since the zinc aluminum oxide powder particle size used in the above-mentioned patent is too small, it will lead to uneven grain growth at the edge and middle part of the target, poor grain uniformity, and poor bending strength of the target, thereby causing problems when the target is used for sputtering production of thin film.

[0010] Therefore, it is necessary to develop a preparation method capable of improving the density, metallographic structure uniformity and bending strength of zinc aluminum oxide target material, and to prepare zinc aluminum oxide target material with good comprehensive performance. SUMMARY

[0011] One of the purposes of the present application is to provide a high-density and high-uniformity zinc aluminum oxide target material to solve the problem that the density, uniformity and bending strength of the zinc aluminum oxide target material in the prior art are not balanced and cannot meet the current sputtering thin film performance requirements.

[0012] Another purpose of the present application is to provide a preparation method of high-density and high-uniformity zinc aluminum oxide target material, which can prepare zinc aluminum oxide target material with high density, high uniformity and high bending strength, and has excellent comprehensive performance, fully meeting the current market demand.

[0013] To achieve the above object, the present application provides a high-density and high-uniformity zinc-aluminum oxide target material, which is obtained by mixing small-particle-size zinc-aluminum oxide powder and large-particle-size zinc-aluminum oxide powder to obtain mixed powder, and then sequentially performing die pressing, cold isostatic pressing, debinding heat treatment and sintering; wherein the small-particle-size zinc-aluminum oxide powder accounts for 30%-50% of the mass of the mixed powder, the particle size of the small-particle-size zinc-aluminum oxide powder is 0.3-0.8 μm, the particle size of the large-particle-size zinc-aluminum oxide powder is 1-1.5 μm, and the difference between the particle sizes of the large-particle-size zinc-aluminum oxide powder and the small-particle-size zinc-aluminum oxide powder is less than 0.8 μm.

[0014] Further, the small-particle-size zinc-aluminum oxide powder is obtained by dry ball milling of large-particle-size zinc-aluminum oxide powder.

[0015] The present application also provides a preparation method of the high-density and high-uniformity zinc-aluminum oxide target material, which comprises the following steps:

[0016] Step 1: uniformly mixing and dispersing zinc oxide powder, pure water and dispersant, and then performing wet grinding to obtain slurry one;

[0017] Step 2: uniformly mixing and dispersing aluminum oxide powder, pure water and dispersant in the slurry one, and then performing wet grinding to obtain slurry two;

[0018] Step 3: uniformly mixing and dispersing binder in the slurry two, and then performing wet grinding to obtain slurry three;

[0019] Step 4: sequentially performing spray granulation, mixing and screening on the slurry three to obtain large-particle-size zinc-aluminum oxide powder;

[0020] Step 5: taking part of the large-particle-size zinc-aluminum oxide powder to obtain small-particle-size zinc-aluminum oxide powder by dry ball milling;

[0021] Step 6: mixing the remaining large-particle-size zinc-aluminum oxide powder with the small-particle-size zinc-aluminum oxide powder obtained in Step 5 to obtain mixed powder;

[0022] Step 7: sequentially performing die pressing and cold isostatic pressing on the mixed powder to obtain a zinc-aluminum oxide target blank;

[0023] Step 8: performing debinding heat treatment on the zinc-aluminum oxide target blank by heating it to 400-600 ℃ at a heating rate of 0.1-0.5 ℃ / min and then maintaining the temperature for 3-8 h;

[0024] Step 9: performing sintering on the zinc-aluminum oxide target blank after the debinding heat treatment in Step 8 by heating it to 1200-1600 ℃ at a heating rate of 0.5-3 ℃ / min and then maintaining the temperature for 10-15 h to obtain the high-density and high-uniformity zinc-aluminum oxide target material.

[0025] Further, the specific operation of the step 1 is: adding zinc oxide powder, pure water and dispersant into a slurry barrel to mix and disperse at a speed of 60-200 rpm / min for 20-40 min, and then punching into a sand mill to wet grind at a grinding speed of 1200-1800 r / min for 10-22 h to obtain slurry one, wherein the dispersant accounts for 1-5% of the total mass of the added zinc oxide powder, pure water and dispersant, and the solid content of the slurry one is 60-70%.

[0026] Further, the specific operation of the step 2 is: adding aluminum oxide powder, pure water and dispersant into the slurry one to mix and disperse at a speed of 60-200 rpm / min for 20-40 min, and then punching into a sand mill to wet grind at a grinding speed of 1200-1800 r / min for 8-15 h to obtain slurry two, wherein the dispersant accounts for 1-15% of the total mass of the added aluminum oxide powder, pure water and dispersant, and the solid content of the slurry two is 60-70%.

[0027] Preferably, the dispersant is one of polyvinylpyrrolidone, sodium dodecyl benzene sulfonate and sodium hexadecyl benzene sulfonate.

[0028] Further, the specific operation of the step 3 is: adding a binder into the slurry two to mix and disperse at a speed of 60-200 rpm / min for 20-40 min, and then punching into a sand mill to wet grind at a grinding speed of 1200-1800 r / min for 2-4 h to obtain slurry three, wherein the binder accounts for 5-15% of the total mass of the aluminum oxide powder, zinc oxide powder and binder.

[0029] Preferably, the binder is a mixed agent of polyvinyl alcohol and polyethylene glycol, polyvinyl alcohol or polyvinyl butyral.

[0030] Preferably, the mass ratio of the zinc oxide powder and the aluminum oxide powder is 97-98:2-3.

[0031] More preferably, the mass ratio of the zinc oxide powder and the aluminum oxide powder can be selected as 97:3 or 98:2.

[0032] Further, the mixing time in the step 6 is 10-12 h.

[0033] Beneficial effects

[0034] Compared with the prior art, the present application has at least the following advantages:

[0035] (1) The present application adopts small particle size zinc oxide aluminum powder of a specific particle size mixed with large particle size zinc oxide aluminum powder to prepare zinc oxide aluminum powder, which can effectively improve the sintering density of the target material, improve the metallographic uniformity and bending strength of the target material, and balance the comprehensive performance of the target material.

[0036] (2) The small particle size zinc aluminum oxide powder and the large particle size zinc aluminum oxide powder used in the application have little difference in particle size, which can further improve the metallographic structure uniformity and bending strength of the target material;

[0037] (3) The application discloses a high-density high-uniformity zinc aluminum oxide target material, and the ratio of the small particle size zinc aluminum oxide powder to the large particle size zinc aluminum oxide powder is in a reasonable range, so that the relative density, the metallographic structure uniformity and the bending strength of the target material are effectively improved, and the case that the comprehensive performance of the target material is significantly reduced due to too much or too little small particle size zinc aluminum oxide powder does not occur. DETAILED DESCRIPTION

[0038] The application will be further described below in conjunction with the embodiments, but does not constitute any limitation on the application, and any limited modification made within the scope of the claims of the application is still within the scope of the claims of the application.

[0039] In order to describe the technical content of the application in detail, the following further describes the embodiments.

[0040] In the following examples and comparative examples, the spray granulation, mixing, screening, molding and cold isostatic pressing processes are all conventional technical means in the field of target material preparation, and those skilled in the art can perform them through conventional technical means. In the examples and comparative examples of the application, the molding process is as follows: the mixed powder is loaded into a 50-300mm mold, and then the mold is placed in a hydraulic machine to perform hydraulic pressure at a pressure of 15-80Mpa. After demolding, the target blank semi-finished product is obtained. The cold isostatic pressing process is as follows: the target blank semi-finished product obtained by molding is placed in a soft bag film, the sealed bag is placed in a cold isostatic pressing machine and soaked in a liquid pressure medium, and then high-pressure liquid injected by a high-pressure pump is used for pressing, and the pressure is 380MPa, so as to obtain the target blank.

[0041] Example 1

[0042] A zinc aluminum oxide target material is prepared by the following steps:

[0043] Step 1: weigh the zinc oxide powder and the aluminum oxide powder, and the mass ratio of the zinc oxide powder to the aluminum oxide powder is 97.5:2.5;

[0044] Step 2: add the zinc oxide powder, pure water and polyvinylpyrrolidone into a slurry barrel to mix and disperse at a speed of 100rpm / min for 30min, and then punch into a sand mill to wet grind at a grinding speed of 1500r / min for 12h to obtain slurry one, wherein the polyvinylpyrrolidone accounts for 4% of the total mass of the zinc oxide powder, pure water and polyvinylpyrrolidone added, and the solid content of the slurry one is 65%;

[0045] Step 3: Add alumina powder, pure water and polyvinylpyrrolidone into slurry one, mix and disperse at 100 rpm / min for 30 min, then put into a sand mill to wet grind at a grinding speed of 1500 r / min for 8 h to obtain slurry two, wherein the polyvinylpyrrolidone accounts for 4% of the total mass of the added alumina powder, pure water and polyvinylpyrrolidone, and the solid content of the slurry two is 62%;

[0046] Step 4: Add a binder to slurry two, mix and disperse at 100 rpm / min for 30 min, then put into a sand mill to wet grind at a grinding speed of 1500 r / min for 2 h to obtain slurry three, wherein the binder accounts for 10% of the total mass of the alumina powder, zinc oxide powder and binder;

[0047] Step 5: Spray granulation, mixing and screening are sequentially performed on the slurry three to obtain large-particle-size zinc-aluminum oxide powder with an average particle size of 1.2 μm, wherein the outlet air temperature is 75°C and the frequency of the atomizer is 120 Hz;

[0048] Step 6: Take out 50% of the large-particle-size zinc-aluminum oxide powder to perform dry ball milling to obtain small-particle-size zinc-aluminum oxide powder with an average particle size of 0.6 μm;

[0049] Step 7: Mix the remaining 50% of the large-particle-size zinc-aluminum oxide powder with the small-particle-size zinc-aluminum oxide powder obtained in step 5 to obtain a mixed powder;

[0050] Step 8: Perform die pressing and cold isostatic pressing sequentially on the mixed powder to obtain a zinc-aluminum oxide target blank;

[0051] Step 9: Perform a debinding heat treatment on the zinc-aluminum oxide target blank by heating it to 500°C at a heating rate of 0.5°C / min and then maintaining the temperature for 8 h;

[0052] Step 10: Perform a sintering treatment on the zinc-aluminum oxide target blank after the debinding heat treatment in step 8 by heating it to 1200°C at a heating rate of 1°C / min and then maintaining the temperature for 12 h to obtain the high-density high-uniformity zinc-aluminum oxide target material.

[0053] Example 2

[0054] A zinc-aluminum oxide target material is prepared by the following steps:

[0055] Step 1: Weigh the zinc oxide powder and the alumina powder, wherein the mass ratio of the zinc oxide powder to the alumina powder is 97.5:2.5;

[0056] Step 2: zinc oxide powder, pure water and polyvinylpyrrolidone were added into a slurry barrel and mixed and dispersed at a rotation speed of 100 rpm / min for 30 min, and then fed into a sand mill for wet grinding at a grinding rotation speed of 1500 r / min for 12 h to obtain slurry one, wherein the polyvinylpyrrolidone accounts for 4% of the total mass of the zinc oxide powder, pure water and polyvinylpyrrolidone added, and the solid content of the slurry one is 65%;

[0057] Step 3: aluminum oxide powder, pure water and polyvinylpyrrolidone were added into the slurry one and mixed and dispersed at a rotation speed of 100 rpm / min for 30 min, and then fed into a sand mill for wet grinding at a grinding rotation speed of 1500 r / min for 8 h to obtain slurry two, wherein the polyvinylpyrrolidone accounts for 4% of the total mass of the aluminum oxide powder, pure water and polyvinylpyrrolidone added, and the solid content of the slurry two is 62%;

[0058] Step 4: a binder was added into the slurry two and mixed and dispersed at a rotation speed of 100 rpm / min for 30 min, and then fed into a sand mill for wet grinding at a grinding rotation speed of 1500 r / min for 2 h to obtain slurry three, wherein the binder accounts for 10% of the total mass of the aluminum oxide powder, zinc oxide powder and binder;

[0059] Step 5: the slurry three was sequentially subjected to spray granulation, mixing and screening to obtain large-particle-size zinc aluminum oxide powder with an average particle size of 1 μm, wherein the air outlet temperature was 75℃ and the frequency of the atomizer was 120 Hz;

[0060] Step 6: 30% of the large-particle-size zinc aluminum oxide powder was taken out and subjected to dry ball milling to obtain small-particle-size zinc aluminum oxide powder with an average particle size of 0.3 μm;

[0061] Step 7: the remaining 70% of the large-particle-size zinc aluminum oxide powder was mixed with the small-particle-size zinc aluminum oxide powder obtained in step 5 to obtain a mixed powder;

[0062] Step 8: the mixed powder was sequentially subjected to die pressing and cold isostatic pressing to obtain a zinc aluminum oxide target blank;

[0063] Step 9: the zinc aluminum oxide target blank was heated to 500℃ at a heating rate of 0.5℃ / min and then kept for 8 h for debinding heat treatment;

[0064] Step 10: the zinc aluminum oxide target blank after debinding heat treatment in step 8 was heated to 1200℃ at a heating rate of 1℃ / min and then kept for 12 h for sintering to obtain the high-density high-uniformity zinc aluminum oxide target material.

[0065] Example 3

[0066] A zinc aluminum oxide target material was prepared by the following steps:

[0067] Step 1: weigh the zinc oxide powder and the aluminum oxide powder, wherein the mass ratio of the zinc oxide powder to the aluminum oxide powder is 97.5:2.5;

[0068] Step 2: add the zinc oxide powder, pure water and polyvinylpyrrolidone into a slurry barrel to mix and disperse at a rotation speed of 100 rpm / min for 30 min, and then punch into a sand mill to wet grind at a grinding rotation speed of 1500 r / min for 12 h to obtain slurry one, wherein the polyvinylpyrrolidone accounts for 4% of the total mass of the zinc oxide powder, pure water and polyvinylpyrrolidone added, and the solid content of the slurry one is 65%;

[0069] Step 3: add the aluminum oxide powder, pure water and polyvinylpyrrolidone into the slurry one to mix and disperse at a rotation speed of 100 rpm / min for 30 min, and then punch into a sand mill to wet grind at a grinding rotation speed of 1500 r / min for 8 h to obtain slurry two, wherein the polyvinylpyrrolidone accounts for 4% of the total mass of the aluminum oxide powder, pure water and polyvinylpyrrolidone added, and the solid content of the slurry two is 62%;

[0070] Step 4: add the binder into the slurry two to mix and disperse at a rotation speed of 100 rpm / min for 30 min, and then punch into a sand mill to wet grind at a grinding rotation speed of 1500 r / min for 2 h to obtain slurry three, wherein the binder accounts for 10% of the total mass of the aluminum oxide powder, zinc oxide powder and binder;

[0071] Step 5: the slurry three is sequentially subjected to spray granulation, mixing and screening to obtain large-particle-size zinc aluminum oxide powder with an average particle size of 1.5 μm, wherein the air outlet temperature is 75°C and the frequency of the atomizer is 120 Hz;

[0072] Step 6: take out 40% of the large-particle-size zinc aluminum oxide powder to perform dry ball milling to obtain small-particle-size zinc aluminum oxide powder with an average particle size of 0.8 μm;

[0073] Step 7: mix the remaining 60% of the large-particle-size zinc aluminum oxide powder with the small-particle-size zinc aluminum oxide powder obtained in step 5 to obtain a mixed powder;

[0074] Step 8: sequentially perform die pressing and cold isostatic pressing on the mixed powder to obtain a zinc aluminum oxide target blank;

[0075] Step 9: heat the zinc aluminum oxide target blank to 500°C at a heating rate of 0.5°C / min, and then perform a debinding heat treatment for 8 h;

[0076] Step 10: heat the zinc aluminum oxide target blank after the debinding heat treatment in step 8 to 1200°C at a heating rate of 1°C / min, and then perform a sintering for 12 h to obtain the high-density high-uniformity zinc aluminum oxide target material.

[0077] Comparative Example 1

[0078] The same as Example 1 except that step 6 and step 7 were cancelled and the large particle size aluminum zinc oxide powder with an average particle size of 1.2 μm obtained in step 5 was directly subjected to the subsequent steps of die pressing and cold isostatic pressing to obtain the aluminum zinc oxide target blank.

[0079] Comparative Example 2

[0080] The same as Example 1 except that the large particle size aluminum zinc oxide powder obtained in step 5 was 2 μm.

[0081] Comparative Example 3

[0082] The same as Example 1 except that the small particle size aluminum zinc oxide powder obtained in step 6 was 0.2 μm.

[0083] Comparative Example 4

[0084] The same as Example 1 except that step 6 was changed to dry ball milling all the large particle size aluminum zinc oxide powder to obtain small particle size aluminum zinc oxide powder with an average particle size of 0.6 μm and step 7 was cancelled accordingly.

[0085] Comparative Example 5

[0086] The same as Example 1 except that the large particle size aluminum zinc oxide powder obtained in step 5 was 2 μm and the small particle size aluminum zinc oxide powder obtained in step 6 was 1.5 μm.

[0087] Comparative Example 6

[0088] The same as Example 2 except that step 6 was changed to dry ball milling 10% of the large particle size aluminum zinc oxide powder to obtain small particle size aluminum zinc oxide powder with an average particle size of 0.3 μm.

[0089] Comparative Example 7

[0090] The same as Example 2 except that step 6 was changed to dry ball milling 70% of the large particle size aluminum zinc oxide powder to obtain small particle size aluminum zinc oxide powder with an average particle size of 0.3 μm.

[0091] Performance Test

[0092] Test Method:

[0093] The relative density of the target was measured by Archimedes drainage method;

[0094] The uniformity of the metallographic structure of the target was obtained by scanning electron microscope observation;

[0095] The target bending strength is measured by a universal testing machine.

[0096] The zinc aluminum oxide target prepared from Examples 1-3 and Comparative Examples 1-5 is subjected to performance testing by using the above testing methods, and the results are shown in Table 1.

[0097] Table 1 Performance testing results of the zinc aluminum oxide target prepared from Examples 1-3 and Comparative Examples 1-5

[0098]

[0099]

[0100] According to the results in Table 1, it can be seen that:

[0101] According to the comparison of the results of Example 1, Example 2 and Example 3, it can be seen that the particle size selection and ratio of the small particle size zinc aluminum oxide powder and the large particle size zinc aluminum oxide powder have a relatively obvious influence on the performance of the target, and the small particle size zinc aluminum oxide powder and the large particle size zinc aluminum oxide powder with specific particle size and specific ratio used in the present application can significantly improve the relative density, the metallographic structure uniformity and the bending strength of the target.

[0102] According to the comparison of the results of the embodiment 1 and the comparative examples 1, 4, it can be seen that the present application can significantly improve the relative density and the bending strength of the target material, and effectively improve the uniformity of the metallographic structure of the target material, by using the small particle size aluminum zinc oxide powder and the large particle size aluminum zinc oxide powder to prepare the aluminum zinc oxide powder. Although the comparative example 1 uses the large particle size aluminum zinc oxide powder with a uniform particle size of 1.2 μm to prepare the aluminum zinc oxide target material, the relative density and the bending strength of the target material are poorer than those of the embodiment 1, because the overall particle size of the powder is too large, the sintering temperature is not easy to reach quickly at the periphery in the sintering process, and the oxygen and impurities in the interior are relatively easy to remove, so the uniformity of the metallographic structure is good. However, because the particle size of the powder is too large, the activity of the powder is low, so the relative density is low. At the same time, the bending strength of the target material prepared by using the large particle size aluminum zinc oxide powder in the comparative example 1 is obviously improved compared with the comparative example 4, but the improvement of the bending strength is not significant compared with the embodiment 1 of the present application, which uses the small particle size aluminum zinc oxide powder and the large particle size aluminum zinc oxide powder to prepare the aluminum zinc oxide target material. This may be because the small particle size aluminum zinc oxide powder of the present application is uniformly distributed, and the sintering temperature is quickly reached and formed in the sintering process, and then the large particle size aluminum zinc oxide powder is slowly sintered and formed, thereby guiding the formation and growth of the internal sintering neck in the sintering process, and improving the bending strength of the target material. The comparative example 4 uses the small particle size aluminum zinc oxide powder with a uniform particle size of 0.6 μm to prepare the aluminum zinc oxide powder target material, and the relative density of the target material is better than that of the comparative example 1. However, because the particle size of the powder is too small, the sintering temperature is quickly reached at the periphery in the sintering process, so the high-density shell is quickly formed at the periphery of the blank, which makes it difficult to remove the oxygen and other impurities in the interior and hinders the formation and growth of the internal sintering neck, resulting in a significant decrease in the uniformity of the metallographic structure and the bending strength of the target material.

[0103] According to the comparison of the results of the embodiment 1 and the comparative examples 2, 3, it can be seen that the particle size difference between the small particle size aluminum zinc oxide powder and the large particle size aluminum zinc oxide powder is too large, which will seriously affect the comprehensive performance of the target material, mainly in the uniformity of the metallographic structure and the bending strength of the target material, and the relative density of the target material is obviously reduced.

[0104] According to the comparison of the results of the embodiment 1 and the comparative example 5, it can be seen that reducing the particle size difference between the small particle size aluminum zinc oxide powder and the large particle size aluminum zinc oxide powder can effectively improve the uniformity of the metallographic structure of the target material. However, when the particle size of the small particle size aluminum zinc oxide powder and the large particle size aluminum zinc oxide powder used is not within the range of the present application, the relative density and the bending strength of the target material prepared are significantly reduced, which shows that the present application can significantly and balancedly improve the comprehensive performance of the target material by using the small particle size aluminum zinc oxide powder and the large particle size aluminum zinc oxide powder with specific particle sizes and specific proportions to prepare the aluminum zinc oxide target material.

[0105] According to the comparison of the results of Example 1 and Comparative Example 6, Comparative Example 7, when the ratio of the small particle size aluminum zinc oxide powder and the large particle size aluminum zinc oxide powder is not within the scope of the present application, the synergistic effect of the small particle size aluminum zinc oxide powder and the large particle size aluminum zinc oxide powder is too small, and thus the relative density, the uniformity of the microstructure, and the bending strength of the target material prepared thereby are close to the performance of a single particle size.

[0106] The examples presented herein are merely selected embodiments according to a combination of all possible embodiments. The appended claims should not be limited by the embodiments described as illustrating the present application. Some numerical ranges recited in the claims include sub-ranges within their scope, and the ranges in these sub-ranges are also intended to be covered.

Claims

1. A high-density and high-uniformity zinc oxide aluminum target, characterized in that: The mixed powder is obtained by mixing small-particle zinc-aluminum oxide powder and large-particle zinc-aluminum oxide powder, and then subjected to molding, cold isostatic pressing, degreasing heat treatment, and sintering in sequence; the small-particle zinc-aluminum oxide powder accounts for 30%-50% of the mass of the mixed powder, the particle size of the small-particle zinc-aluminum oxide powder is 0.3-0.8 μm, the particle size of the large-particle zinc-aluminum oxide powder is 1-1.5 μm, and the difference in particle size between the large-particle zinc-aluminum oxide powder and the small-particle zinc-aluminum oxide powder is less than 0.8 μm; the small-particle zinc-aluminum oxide powder is obtained by dry ball milling the large-particle zinc-aluminum oxide powder.

2. A method for preparing a high-density and high-uniformity zinc oxide aluminum target according to claim 1, characterized in that: The steps include: Step 1: zinc oxide powder, pure water and a dispersant are mixed and dispersed uniformly, and then wet-grinded to obtain slurry 1; Step 2: Add alumina powder, pure water and dispersant to slurry 1, mix and disperse evenly, and then perform wet grinding to obtain slurry 2; Step 3: Add a binder to the slurry 2 and mix and disperse evenly, and then perform wet grinding to obtain slurry 3; Step 4: spray granulation, mixing and sieving the slurry three in sequence to obtain large-particle zinc aluminum oxide powder; Step 5: taking out a portion of the large-particle zinc oxide aluminum powder and performing dry ball milling to obtain a small-particle zinc oxide aluminum powder; Step 6: mixing the remaining large-particle zinc oxide aluminum powder with the small-particle zinc oxide aluminum powder obtained in step 5 to obtain a mixed powder; Step 7: The mixed powder is subjected to molding and cold isostatic pressing in sequence to obtain a zinc oxide aluminum target embryo; Step 8: Heat the zinc oxide aluminum target embryo to 400-600°C at a heating rate of 0.1-0.5°C / min and then keep it at that temperature for 3-8 hours for degreasing heat treatment; Step 9: The zinc oxide aluminum target embryo after the degreasing heat treatment in step 8 is heated to 1200-1600° C. at a heating rate of 0.5-3° C. / min, and then kept warm for 10-15 hours for sintering to obtain the high-density and high-uniformity zinc oxide aluminum target material.

3. The method for preparing a high-density and high-uniformity zinc oxide aluminum target according to claim 2, characterized in that: The specific operation of step 1 is: adding zinc oxide powder, pure water and dispersant into a slurry barrel and mixing and dispersing at a speed of 60-200 rpm / min for 20-40 minutes, then putting into a sand mill and wet grinding at a grinding speed of 1200-1800 r / min for 10-22 hours to obtain slurry 1, wherein the dispersant accounts for 1-5% of the total mass of the added zinc oxide powder, pure water and dispersant, and the solid content of slurry 1 is 60-70%.

4. The method for preparing a high-density and high-uniformity zinc oxide aluminum target according to claim 2, wherein: The specific operation of step 2 is: adding alumina powder, pure water and dispersant to slurry one and mixing and dispersing at a speed of 60-200 rpm / min for 20-40 minutes, then putting it into a sand mill and wet grinding it at a grinding speed of 1200-1800 r / min for 8-15 hours to obtain slurry two, wherein the dispersant accounts for 1-15% of the total mass of the added alumina powder, pure water and dispersant, and the solid content of slurry two is 60-70%.

5. The method for preparing a high-density and high-uniformity zinc oxide aluminum target according to claim 3 or 4, characterized in that: The dispersant is one of polyvinyl pyrrolidone, sodium dodecylbenzenesulfonate and sodium hexadecylbenzenesulfonate.

6. The method for preparing a high-density and high-uniformity zinc oxide aluminum target according to claim 2, characterized in that: The specific operation of step 3 is: adding a binder to slurry 2 and mixing and dispersing at a speed of 60-200 rpm / min for 20-40 minutes, then putting it into a sand mill and wet grinding it at a grinding speed of 1200-1800 r / min for 2-4 hours to obtain slurry 3, wherein the binder accounts for 5-15% of the total mass of the aluminum oxide powder, zinc oxide powder and binder.

7. The method for preparing a high-density and high-uniformity zinc oxide aluminum target according to claim 6, characterized in that: The binder is a mixture of polyvinyl alcohol and polyethylene glycol, polyvinyl alcohol or polyvinyl butyral.

8. The method for preparing a high-density and high-uniformity zinc oxide aluminum target according to claim 2, characterized in that: The mass ratio of the zinc oxide powder to the aluminum oxide powder is 97-98:2-3.

9. The method for preparing a high-density and high-uniformity zinc oxide aluminum target according to claim 2, characterized in that: The mixing time in step 6 is 10-12 hours.

Images