ITZO target material and preparation method thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIANDAO THIN FILM MATERIALS GUANGDONG CO LTD
- Filing Date
- 2026-04-07
- Publication Date
- 2026-06-26
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Abstract
Description
Technical Field
[0001] This application relates to the field of oxide target technology, and in particular to an ITZO target and its preparation method. Background Technology
[0002] Indium tin zinc oxide (ITZO) targets, as multi-element transparent conductive oxide targets, combine high light transmittance and conductivity, have low cost, and have broad application prospects.
[0003] However, existing ITZO sputtering targets still suffer from many technical defects, such as component segregation and insufficient sintering densification, which restrict their industrial application. Therefore, there is an urgent need for an ITZO sputtering target with uniform composition and high density, as well as its preparation technology. Summary of the Invention
[0004] In view of this, the purpose of this application is to provide an ITZO target material and its preparation method to solve the technical problems of uneven composition and low density of existing target materials.
[0005] To achieve the above-mentioned technical objectives, this application provides a method for preparing an ITZO target, comprising the following steps:
[0006] Step S1, to the contents of In 3+ Sn 4+ Zn 2+ A complexing agent is added to the solution to obtain a mixed solution;
[0007] Step S2: The mixed solution is added dropwise to an ammonia solution and aged to obtain the precursor precipitate;
[0008] Step S3: The precursor precipitate is subjected to spray pyrolysis to obtain ITZO powder;
[0009] Step S4: The ITZO powder is subjected to cold isostatic pressing, followed by warm isostatic pressing in an inert atmosphere to obtain the ITZO preform.
[0010] Step S5: Under an air atmosphere, the ITZO preform is subjected to programmed heating and calcination; after calcination, a mixed gas containing inert gas is introduced and programmed cooling is performed to obtain the ITZO target material.
[0011] Furthermore, in step S1, In 3+ Sn 4+ Zn 2+ The molar ratio is (1-2):(1-2):(1-2).
[0012] Furthermore, the molar ratio of the complexing agent to the total amount of metal ions in the mixed solution is (1-1.5):1.
[0013] Furthermore, the complexing agent includes one or more of citric acid, ethylenediaminetetraacetic acid, tartaric acid, and gluconic acid.
[0014] Furthermore, the ammonia solution is prepared by mixing ammonia and water, and the pH value of the ammonia solution is 8-10; and / or, in step S2, the aging time is 8-12 hours.
[0015] Furthermore, in step S3, the pyrolysis temperature of the spray pyrolysis is 800–900°C.
[0016] Further, in step S4, the pressure of cold isostatic pressing is 150-200 MPa; and / or, the temperature of warm isostatic pressing is 80-120°C, the pressure is 200-500 MPa, and the holding time is 3-10 min.
[0017] Furthermore, the programmed temperature rise calcination process includes the following stages:
[0018] In the first stage, the temperature is increased to 550-650℃ in air at a rate of 0.4-0.6℃ / min, and held for 1.5-2.5 hours.
[0019] The second phase, in 10 -4 ~10 -2 Under Pa conditions, the temperature is increased to 1250–1350℃ at a rate of 0.4–0.6℃ / min;
[0020] The third stage, in 10 -4 ~10 -2 Under Pa conditions, the temperature is increased to 1450–1550℃ at a rate of 1.5–2.5℃ / min and held for 7–9 hours.
[0021] Furthermore, the programmed cooling process is as follows: the temperature is reduced to 1300-1400℃ at a rate of 1-2℃ / min, held for 4-5 hours, and then brought to room temperature along with the furnace.
[0022] In summary, this application provides a method for preparing an ITZO target, comprising the following steps: applying an In-containing target... 3+ Sn 4+ Zn 2+ A complexing agent is added to the solution to obtain a mixed solution; the mixed solution is then added dropwise to an ammonia solution and aged to obtain a precursor precipitate; the precursor precipitate is then subjected to spray pyrolysis, cold isostatic pressing, and warm isostatic pressing to obtain an ITZO green blank; the ITZO green blank is then subjected to programmed temperature calcination in an air atmosphere; after calcination, a mixed gas containing inert gas is introduced, and a programmed temperature cooling process is performed to obtain the ITZO target material. This application combines two isostatic pressing processes with dynamic adjustment of the mixed gas composition during programmed temperature cooling to obtain an ITZO target material with uniform composition distribution, high density, and stable crystal structure.
[0023] This application significantly improves the uniformity and density of the target material composition, and the preparation process is simple and efficient, enabling large-scale production. At the same time, using this target material through sputtering, transparent conductive films with high visible light transmittance, excellent electrical properties, and good surface flatness can be prepared, which can fully meet the application requirements of high-end optoelectronic devices. Detailed Implementation
[0024] The technical solutions of this application will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments in this application specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection claimed in this application.
[0025] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0026] Unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0027] In this application, there are no special restrictions on the source of any of the raw materials; they can be purchased on the market or prepared using conventional methods known to those skilled in the art.
[0028] This application provides a method for preparing an ITZO target, comprising the following steps:
[0029] Step S1, to the contents of In 3+ Sn 4+ Zn 2+ A complexing agent is added to the solution to obtain a mixed solution;
[0030] Step S2: The mixed solution is added dropwise to an ammonia solution and aged to obtain the precursor precipitate;
[0031] Step S3: The precursor precipitate is subjected to spray pyrolysis to obtain ITZO powder;
[0032] Step S4: The ITZO powder is subjected to cold isostatic pressing, followed by warm isostatic pressing in an inert atmosphere to obtain the ITZO preform.
[0033] Step S5: Under an air atmosphere, the ITZO preform is subjected to programmed heating and calcination; after calcination, a mixed gas containing inert gas is introduced and programmed cooling is performed to obtain the ITZO target material.
[0034] It should be noted that in a single IZO system, charge carriers are mainly provided by oxygen vacancies. Oxygen vacancies easily form localized energy levels, resulting in strong scattering of charge carriers and hindering conductivity improvement. This application introduces Sn, which provides additional charge carriers, reducing the system's dependence on oxygen vacancies and improving conductivity while stabilizing the amorphous structure of the sputtered film. Furthermore, this application employs a spray pyrolysis process, which integrates drying and calcination. This process utilizes a high-temperature instantaneous reaction to fix the homogeneous ionic mixture in the solution in situ, effectively suppressing component segregation during subsequent processing. If only spray drying is used without high-temperature pyrolysis, only hydroxide precursor precipitate can be obtained, requiring additional calcination, which is more energy-intensive and complex.
[0035] In some embodiments, in step S1, In 3+ Sn 4+ and Zn 2+ The molar ratio is (1-2):(1-2):(1-2). In some specific embodiments, In 3+ Provided by In(NO3)3·4H2O, Sn 4+ Provided by SnCl4·5H2O, Zn 2+ The solution is provided by Zn(CH3COO)2·2H2O; the molar concentrations of In(NO3)3·4H2O, SnCl4·5H2O and Zn(CH3COO)2·2H2O are all 1–3 mol / L.
[0036] In some embodiments, the molar ratio of the complexing agent to the total amount of metal ions in the mixed solution is (1 to 1.5):1.
[0037] In some preferred embodiments, the complexing agent includes one or more of citric acid, ethylenediaminetetraacetic acid, tartaric acid, and gluconic acid.
[0038] It should be noted that the function of the complexing agent is to interact with In 3+ Sn 4+ and Zn 2+This process forms stable complexes, preventing premature precipitation of metal ions, ensuring the homogeneity of the mixed solution, and improving the dispersibility of subsequent precursor precipitation, thereby optimizing the particle size distribution and purity of the ITZO powder. In some specific embodiments, citric acid is used as the main complexing agent, exhibiting a mild complexing effect and completely decomposing during subsequent sintering without residual impurities.
[0039] In some embodiments, the ammonia solution is prepared by mixing ammonia and water, and the pH value of the ammonia solution is 8 to 10.
[0040] In some embodiments, the aging time in step S2 is 8 to 12 hours.
[0041] In some embodiments, in step S3, the pyrolysis temperature of spray pyrolysis is 800–900°C.
[0042] In some embodiments, in step S4, the pressure of cold isostatic pressing is 150-200 MPa; and / or, the temperature of warm isostatic pressing is 80-120°C, the pressure is 200-500 MPa, and the holding time is 3-10 min.
[0043] In some embodiments, the programmed temperature rise calcination treatment includes the following stages: First stage, in an air atmosphere, the temperature is increased to 550–650°C at a rate of 0.4–0.6°C / min, and held for 1.5–2.5 hours; Second stage, at 10… -4 ~10 -2 Under Pa conditions, the temperature was increased to 1250–1350℃ at a rate of 0.4–0.6℃ / min; in the third stage, at 10 -4 ~10 -2 Under Pa conditions, the temperature is increased to 1450–1550℃ at a rate of 1.5–2.5℃ / min and held for 7–9 hours.
[0044] In some embodiments, the programmed cooling process is as follows: the temperature is reduced to 1300-1400°C at a rate of 1-2°C / min, held for 4-5 hours, and then brought to room temperature with the furnace.
[0045] In some preferred embodiments, the inert gas is one or more of argon and nitrogen, and the volume percentage of the inert gas in the gas mixture is more than 95%.
[0046] The applicant further provides the following specific embodiments to describe this application. It should be noted that these embodiments are merely descriptive and do not limit this application in any way.
[0047] Example 1
[0048] This embodiment provides a method for preparing an ITZO target, including the following steps:
[0049] Step S1: Dissolve 10 mol of In(NO3)3·4H2O, 8 mol of SnCl4·5H2O and 10 mol of Zn(CH3COO)2·2H2O in 10 L of deionized water, add 33.6 mol of citric acid as a complexing agent, mix well to obtain a mixed solution;
[0050] Step S2: Add the mixed solution dropwise to an ammonia solution with a pH of 9 to generate a precursor precipitate, and let it stand for aging for another 10 hours.
[0051] Step S3: At 850°C, the aged precursor precipitate is subjected to spray pyrolysis to obtain ITZO powder with an average particle size of 80.3 nm.
[0052] Step S4: The ITZO powder is shaped using a graded isostatic pressing process: first, cold isostatic pressing is performed under a pressure of 200 MPa; then, warm isostatic pressing is performed again under an argon protective atmosphere at a temperature of 120°C and a pressure of 300 MPa. After pressing, the pressure is held for 5 minutes to obtain the shaped ITZO preform.
[0053] Step S5 involves performing programmed heating and cooling treatments on the ITZO green blank. The specific process is as follows: Under air atmosphere, the temperature is increased to 600℃ at a heating rate of 0.5℃ / min and held at this temperature for 2 hours; then the temperature is switched to 10℃. -3 In a vacuum environment of Pa, the temperature was first increased to 1300℃ at a heating rate of 0.5℃ / min, then the heating rate was adjusted to 2℃ / min, and the temperature was continued to rise to 1500℃ and held for 8 hours. In the later stage of sintering, the temperature was reduced to 1350℃, and an Ar / O2 mixed gas (with O2 accounting for 5% by volume) was introduced and held for 4 hours under these conditions. Finally, the temperature was allowed to drop naturally to room temperature to obtain the ITZO target material.
[0054] Example 2
[0055] This embodiment provides a method for preparing an ITZO target, including the following steps:
[0056] Step S1: Dissolve 10 mol of In(NO3)3·4H2O, 8 mol of SnCl4·5H2O and 10 mol of Zn(CH3COO)2·2H2O in 10 L of deionized water, add 33.6 mol of citric acid as a complexing agent, mix well to obtain a mixed solution;
[0057] Step S2: Add the mixed solution dropwise to an ammonia solution with a pH of 9 to generate a precursor precipitate, and let it stand for aging for another 10 hours.
[0058] Step S3: At 800℃, the aged precursor precipitate is subjected to spray pyrolysis to obtain ITZO powder with an average particle size of 106.7 nm.
[0059] Step S4: The ITZO powder is shaped using a graded isostatic pressing process: first, cold isostatic pressing is performed under a pressure of 200 MPa; then, warm isostatic pressing is performed again under an argon protective atmosphere at a temperature of 120°C and a pressure of 300 MPa. After pressing, the pressure is held for 5 minutes to obtain the shaped ITZO preform.
[0060] Step S5 involves performing programmed heating and cooling treatments on the ITZO green blank. The specific process is as follows: Under air atmosphere, the temperature is increased to 600℃ at a heating rate of 0.5℃ / min and held at this temperature for 2 hours; then the temperature is switched to 10℃. -3 In a vacuum environment of Pa, the temperature was first increased to 1300℃ at a heating rate of 0.5℃ / min, then the heating rate was adjusted to 2℃ / min, and the temperature was continued to rise to 1450℃ and held for 8 hours. In the later stage of sintering, the temperature was reduced to 1300℃, and an Ar / O2 mixed gas (with O2 accounting for 5% by volume) was introduced and held for 5 hours under these conditions. Finally, the temperature was allowed to drop naturally to room temperature to obtain the ITZO target material.
[0061] Example 3
[0062] This embodiment provides a method for preparing an ITZO target, including the following steps:
[0063] Step S1: Dissolve 10 mol of In(NO3)3·4H2O, 8 mol of SnCl4·5H2O and 10 mol of Zn(CH3COO)2·2H2O in 10 L of deionized water, add 33.6 mol of citric acid as a complexing agent, mix well to obtain a mixed solution;
[0064] Step S2: Add the mixed solution dropwise to an ammonia solution with a pH of 9 to generate a precursor precipitate, and let it stand for aging for another 10 hours.
[0065] Step S3: At 900℃, the aged precursor precipitate is subjected to spray pyrolysis to obtain ITZO powder with an average particle size of 58.8 nm.
[0066] Step S4: The ITZO powder is shaped using a graded isostatic pressing process: first, cold isostatic pressing is performed under a pressure of 200 MPa; then, warm isostatic pressing is performed again under an argon protective atmosphere at a temperature of 120°C and a pressure of 300 MPa. After pressing, the pressure is held for 5 minutes to obtain the shaped ITZO preform.
[0067] Step S5 involves performing programmed heating and cooling treatments on the ITZO green blank. The specific process is as follows: Under air atmosphere, the temperature is increased to 600℃ at a heating rate of 0.5℃ / min and held at this temperature for 2 hours; then the temperature is switched to 10℃. -3 In a vacuum environment of Pa, the temperature was first increased to 1300℃ at a heating rate of 0.5℃ / min, then the heating rate was adjusted to 2℃ / min, and the temperature was continued to rise to 1550℃ and held for 6 hours. In the later stage of sintering, the temperature was reduced to 1400℃, and an Ar / O2 mixed gas (with O2 accounting for 5% by volume) was introduced and held for 3 hours under these conditions. Finally, the temperature was allowed to drop naturally to room temperature to obtain the ITZO target material.
[0068] Example 4
[0069] This embodiment provides a method for preparing an ITZO target, including the following steps:
[0070] Step S1: Dissolve 10 mol of In(NO3)3·4H2O, 8 mol of SnCl4·5H2O and 10 mol of Zn(CH3COO)2·2H2O in 10 L of deionized water, add 33.6 mol of citric acid as a complexing agent, mix well to obtain a mixed solution;
[0071] Step S2: Add the mixed solution dropwise to an ammonia solution with a pH of 9 to generate a precursor precipitate, and let it stand for aging for another 10 hours.
[0072] Step S3: At 870℃, the aged precursor precipitate is subjected to spray pyrolysis to obtain ITZO powder with an average particle size of 71.4 nm.
[0073] Step S4: The ITZO powder is shaped using a graded isostatic pressing process: first, cold isostatic pressing is performed under a pressure of 200 MPa; then, warm isostatic pressing is performed again under an argon protective atmosphere at a temperature of 120°C and a pressure of 300 MPa. After pressing, the pressure is held for 5 minutes to obtain the shaped ITZO preform.
[0074] Step S5 involves performing programmed heating and cooling treatments on the ITZO green blank. The specific process is as follows: Under air atmosphere, the temperature is increased to 600℃ at a heating rate of 0.5℃ / min and held at this temperature for 2 hours; then the temperature is switched to 10℃. -3 In a vacuum environment of Pa, the temperature was first increased to 1300℃ at a heating rate of 0.5℃ / min, then the heating rate was adjusted to 2℃ / min, and the temperature was continued to rise to 1520℃ and held for 7 hours. In the later stage of sintering, the temperature was reduced to 1370℃, and an Ar / O2 mixed gas (with O2 accounting for 5% by volume) was introduced and held for 4 hours under these conditions. Finally, the temperature was allowed to cool naturally to room temperature to obtain the ITZO target material.
[0075] Comparative Example 1
[0076] This comparative example provides a method for preparing an ITZO target, including the following steps:
[0077] Step S1: Take 5 mol of In2O3, 8 mol of SnO2 and 10 mol of ZnO powder, perform mechanical mixing treatment, and ball mill for 24 h to obtain mixed powder;
[0078] Step S2: The mixed powder is uniaxially pressed under a pressure of 200 MPa to obtain an ITZO preform;
[0079] Step S3: The ITZO preform is sintered in segments. The specific process is as follows: Under an air atmosphere, the temperature is raised to 600℃ at a heating rate of 0.5℃ / min and held for 2 hours; then the temperature is raised to 1300℃ at a heating rate of 0.5℃ / min, and then the heating rate is adjusted to 2℃ / min. The temperature is raised to 1500℃ and held for 10 hours. Finally, the temperature is allowed to cool naturally to room temperature to obtain the ITZO target material.
[0080] Comparative Example 2
[0081] This comparative example provides a method for preparing an ITZO target, including the following steps:
[0082] Step S1: Dissolve 10 mol of In(NO3)3·4H2O, 8 mol of SnCl4·5H2O and 10 mol of Zn(CH3COO)2·2H2O in 10 L of deionized water, add 33.6 mol of citric acid as a complexing agent, mix well to obtain a mixed solution;
[0083] Step S2: Add the mixed solution dropwise to an ammonia solution with a pH of 9 to generate a precursor precipitate, and let it stand for aging for another 10 hours.
[0084] Step S3: At 850°C, the aged precursor precipitate is subjected to spray pyrolysis to obtain ITZO powder with an average particle size of 89.3 nm.
[0085] Step S4: Cold isostatic pressing is performed under a pressure of 200 MPa to obtain the ITZO preform;
[0086] Step S5 involves performing programmed heating and cooling treatments on the ITZO green blank. The specific process is as follows: Under air atmosphere, the temperature is increased to 600℃ at a heating rate of 0.5℃ / min and held at this temperature for 2 hours; then the temperature is switched to 10℃. -3In a vacuum environment of Pa, the temperature was first increased to 1300℃ at a heating rate of 0.5℃ / min, then the heating rate was adjusted to 2℃ / min, and the temperature was continued to rise to 1500℃ and held for 8 hours. In the later stage of sintering, the temperature was reduced to 1350℃, and an Ar / O2 mixed gas (with O2 accounting for 5% by volume) was introduced and held for 4 hours under these conditions. Finally, the temperature was allowed to drop naturally to room temperature to obtain the ITZO target material.
[0087] Comparative Example 3
[0088] This comparative example provides a method for preparing an ITZO target, including the following steps:
[0089] Step S1: Dissolve 10 mol of In(NO3)3·4H2O, 8 mol of SnCl4·5H2O and 10 mol of Zn(CH3COO)2·2H2O in 10 L of deionized water, add 33.6 mol of citric acid as a complexing agent, mix well to obtain a mixed solution;
[0090] Step S2: Add the mixed solution dropwise to an ammonia solution with a pH of 9 to generate a precursor precipitate, and let it stand for aging for another 10 hours.
[0091] Step S3: At 850°C, the aged precursor precipitate is subjected to spray pyrolysis to obtain ITZO powder with an average particle size of 84.5 nm.
[0092] Step S4: The ITZO powder is shaped using a graded isostatic pressing process: first, cold isostatic pressing is performed under a pressure of 200 MPa; then, warm isostatic pressing is performed again under an argon protective atmosphere at a temperature of 120°C and a pressure of 300 MPa. After pressing, the pressure is held for 5 minutes to obtain the shaped ITZO preform.
[0093] Step S5 involves performing programmed heating and cooling treatments on the ITZO green blank. The specific process is as follows: Under air atmosphere, the temperature is increased to 600℃ at a heating rate of 0.5℃ / min and held at this temperature for 2 hours; then the temperature is switched to 10℃. -3 In a vacuum environment of Pa, the temperature was first increased to 1300℃ at a heating rate of 0.5℃ / min, then the heating rate was adjusted to 2℃ / min, and the temperature was continued to be increased to 1500℃ and held for 8 hours. Finally, the temperature was allowed to drop naturally to room temperature to obtain the ITZO target material.
[0094] Comparative Example 4
[0095] This comparative example provides a method for preparing an ITZO target, including the following steps:
[0096] Step S1: Dissolve 10 mol of In(NO3)3·4H2O, 8 mol of SnCl4·5H2O and 10 mol of Zn(CH3COO)2·2H2O in 10 L of deionized water, add 33.6 mol of citric acid as a complexing agent, mix well to obtain a mixed solution;
[0097] Step S2: Add the mixed solution dropwise to an ammonia solution with a pH of 9 to generate a precursor precipitate, and let it stand for aging for another 10 hours.
[0098] Step S3: At 850°C, the aged precursor precipitate is subjected to spray pyrolysis to obtain ITZO powder with an average particle size of 81.8 nm.
[0099] Step S4: The ITZO powder is shaped using a graded isostatic pressing process: first, cold isostatic pressing is performed under a pressure of 200 MPa; then, warm isostatic pressing is performed again under an argon protective atmosphere at a temperature of 120°C and a pressure of 300 MPa. After pressing, the pressure is held for 5 minutes to obtain the shaped ITZO preform.
[0100] Step S5 involves performing programmed heating and cooling treatments on the ITZO green blank. The specific process is as follows: Under air atmosphere, the temperature is increased to 600℃ at a heating rate of 0.5℃ / min and held at this temperature for 2 hours; then the temperature is switched to 10℃. -3 In a vacuum environment of Pa, the temperature was first increased to 1300℃ at a heating rate of 0.5℃ / min, then the heating rate was adjusted to 2℃ / min, and the temperature was increased to 1350℃ and held for 8 hours. In the later stage of sintering, the temperature was reduced to 1300℃, and an Ar / O2 mixed gas (with O2 accounting for 5% by volume) was introduced and held for 4 hours. Finally, the temperature was allowed to cool naturally to room temperature to obtain the ITZO target material.
[0101] To verify the performance of the ITZO targets prepared in the above embodiments and comparative examples, and to clarify the influence of different preparation processes on the targets, the parameter variables in the preparation process were compiled into Table 1, and uniform performance tests were performed on the ITZO targets prepared in each group. The tests used consistent experimental conditions. Each ITZO target to be tested was prepared into a transparent conductive film with a thickness of 100 nm using a magnetron sputtering process. Subsequently, the visible light transmittance and sheet resistance of the film were measured, and the specific test results are shown in Table 2.
[0102] Table 1. Variable parameters in the ITZO sputtering method
[0103]
[0104] Table 2. Performance of ITZO powder particle size, ITZO target material, and transparent conductive film.
[0105]
[0106] Combining the process parameters and performance data in Tables 1 and 2, it can be seen that by adjusting key variables such as spray pyrolysis temperature, molding process, maximum sintering temperature and holding time, cooling temperature and Ar / O2 mixed gas holding time, this application can effectively control the particle size of ITZO powder and significantly improve the density of ITZO target material and the optical and electrical properties of the corresponding transparent conductive film.
[0107] As can be seen from Examples 1-4, the spray pyrolysis temperature has a significant regulatory effect on the powder particle size. With increasing spray pyrolysis temperature, the ITZO powder grains show a refining trend. Example 3 obtained a minimum particle size of 58.8 nm under spray pyrolysis conditions at 900℃, while Example 2 had a relatively larger particle size of 106.7 nm under conditions at 800℃. Furthermore, the preparation methods provided in these examples yield ITZO target materials with a relative density exceeding 99.2%, reaching a maximum of 99.8%. Correspondingly, the visible light transmittance of the transparent conductive film is 88.5%–91.1%, and the sheet resistance is as low as 16.4–21.6 Ω, exhibiting both excellent light transmittance and conductivity.
[0108] Comparative Example 1 did not use the spray pyrolysis process and only used uniaxial pressing molding. The relative density of the target material was only 94.1%, the transmittance of the resulting film decreased to 80.5%, the sheet resistance increased to 60.1Ω, and the overall performance was significantly reduced.
[0109] Comparative Example 2 used only the cold isostatic pressing single molding process without adding a warm isostatic pressing step, and the relative density of the target material was only 96.9%. The film performance was also significantly lower than that of the Example. This shows that the combined cold isostatic pressing and warm isostatic pressing molding process can effectively improve the uniformity of the preform, reduce internal porosity, and thus improve the density of the target material and improve the film performance.
[0110] Comparative Example 3 did not include a high-temperature heat preservation step after cooling, resulting in a target material with a relative density reduced to 98.3%. The film transmittance and sheet resistance were inferior to those of the Example. This demonstrates that the heat preservation treatment during the cooling stage can further promote grain rearrangement and pore closure, which has a positive effect on improving the density of the target material.
[0111] Comparative Example 4 reduced the maximum sintering temperature to 1350℃, resulting in a target material relative density of only 95.6%, decreased film transmittance, and significantly increased sheet resistance. This indicates that a suitable high sintering temperature is a key condition for achieving high densification of the target material.
[0112] Based on the above data, it is evident that this application, through the use of a specific spray pyrolysis regime, a combination of cold isostatic pressing and warm isostatic pressing molding processes, and the synergistic effect of segmented sintering and atmosphere insulation, can stably prepare nanoscale ITZO powder with controllable particle size, obtain high-density ITZO target material, and ultimately enable the prepared transparent conductive film to simultaneously possess high visible light transmittance and low sheet resistance. The overall performance is significantly superior to that of the comparative example lacking key processes or with improper process parameter settings, and can meet the application requirements of high-end transparent conductive films.
[0113] The above are merely preferred embodiments of this application and are not intended to limit this application. Although this application has been described in detail with reference to examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A method for preparing an ITZO target material, characterized in that, Includes the following steps: Step S1, to the contents of In 3+ Sn 4+ Zn 2+ A complexing agent is added to the solution to obtain a mixed solution; Step S2: The mixed solution is added dropwise to an ammonia solution and aged to obtain a precursor precipitate; Step S3: The precursor precipitate is subjected to spray pyrolysis treatment to obtain ITZO powder; Step S4: The ITZO powder is subjected to cold isostatic pressing, followed by warm isostatic pressing in an inert atmosphere to obtain an ITZO preform. Step S5: The ITZO preform is subjected to programmed heating and calcination in an air atmosphere; after calcination, a mixed gas containing inert gas is introduced and programmed cooling is performed to obtain the ITZO target material.
2. The preparation method according to claim 1, characterized in that, In step S1, In 3+ Sn 4+ and Zn 2+ The molar ratio is (1-2):(1-2):(1-2).
3. The preparation method according to claim 2, characterized in that, The molar ratio of the complexing agent to the total amount of metal ions in the mixed solution is (1-1.5):
1.
4. The preparation method according to claim 1 or 3, characterized in that, The complexing agent includes one or more of citric acid, ethylenediaminetetraacetic acid, tartaric acid, and gluconic acid.
5. The preparation method according to claim 1, characterized in that, The ammonia solution is prepared by mixing ammonia and water, and the pH value of the ammonia solution is 8-10; and / or, in step S2, the aging time is 8-12 hours.
6. The preparation method according to claim 1, characterized in that, In step S3, the pyrolysis temperature of the spray pyrolysis is 800-900℃.
7. The preparation method according to claim 1, characterized in that, In step S4, the pressure of the cold isostatic pressing is 150-200 MPa; and / or, the temperature of the warm isostatic pressing is 80-120°C, the pressure is 200-500 MPa, and the holding time is 3-10 min.
8. The preparation method according to claim 1, characterized in that, The programmed heating and calcination process includes the following stages: In the first stage, the temperature is increased to 550-650℃ in air at a rate of 0.4-0.6℃ / min, and held for 1.5-2.5 hours. The second phase, in 10 -4 ~10 -2 Under Pa conditions, the temperature is increased to 1250–1350℃ at a rate of 0.4–0.6℃ / min; The third stage, in 10 -4 ~10 -2 Under Pa conditions, the temperature is increased to 1450–1550℃ at a rate of 1.5–2.5℃ / min and held for 7–9 hours.
9. The preparation method according to claim 1, characterized in that, The cooling process is as follows: the temperature is reduced to 1300-1400℃ at a rate of 1-2℃ / min, held for 4-5 hours, and then brought to room temperature with the furnace.
10. An ITZO sputtering target, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 9.