A rare earth doped indium tin zinc oxide sputtering target and a method for producing the same

Abstract

The application relates to a rare earth doped indium tin zinc oxide sputtering target material and a preparation method thereof, which comprises indium oxide, tin oxide, zinc oxide and rare earth oxide, and the rare earth element in the rare earth oxide is selected from at least one of praseodymium, neodymium and lanthanum. 11 The preparation method comprises the following steps: (1) raw material preparation: weighing indium oxide powder, tin oxide powder, zinc oxide powder and rare earth oxide powder (at least one of Pr6O 11 , Nd2O3 or La2O3) according to the above atomic ratio; (2) ball milling: pre-ball milling of the rare earth oxide, and then multiple times of ball milling by sequentially adding the oxides from small to large in mass; (3) spray granulation; (4) compression molding; (5) high-temperature sintering: three-stage sintering is adopted, which is beneficial to obtaining the target material with smaller grain size. The application introduces specific types and proportions of rare earth elements by optimizing the process, synchronously improves the density of the target material, refines the grain and reduces the resistivity under the premise of maintaining the high mobility advantage of the ITZO, so that the prepared TFT device has high mobility and high stability.

Description

Technical Field

[0001] This invention belongs to the field of oxide semiconductor sputtering technology, specifically relating to a rare earth-doped indium tin zinc oxide (RE-ITZO) sputtering target and its preparation method. Background Technology

[0002] With the rapid development of ultra-high-definition displays, flexible displays, and transparent electronic devices, the demand for high-performance thin-film transistors (TFTs) is becoming increasingly urgent. Oxide semiconductor TFTs, represented by amorphous indium gallium zinc oxide (IGZO), have become one of the core technologies in the flat panel display field due to their advantages such as high mobility, good large-area uniformity, and low-temperature fabrication compatibility. However, the mobility of traditional IGZO TFTs is typically only 10 cm⁻¹. 2 The current speed of around / V·s is no longer sufficient to meet the stringent requirements of high mobility for 8K ultra-high-definition displays and high refresh rates above 120 Hz; and from a technical perspective, the core of the industry lies in overcoming the inherent contradiction that "high mobility" and "high stability" are difficult to achieve simultaneously.

[0003] Indium tin zinc oxide (ITZO), as a novel oxide semiconductor material, has been widely used in the field of optoelectronic thin-film transistors due to its excellent electrical properties and optical transmittance. Compared with IGZO, ITZO has a higher intrinsic electron mobility, showing great potential in TFT channel layer materials. However, the fabrication of ITZO targets still faces technical challenges such as insufficient density, large grain size, and high resistivity, which affect the quality of sputtered films and the stability of TFT devices.

[0004] To improve the performance of ITZO, existing technologies mainly employ elemental doping strategies. For example, patent CN113735567A discloses a method for preparing an oxide planar target containing praseodymium oxide, indium oxide, gallium oxide, and zinc oxide; patent CN113831141A discloses a method for preparing an oxide rotating target containing praseodymium oxide, gallium oxide, zinc oxide, and indium oxide. However, these technical solutions primarily target IZO or IGZO systems and do not address rare-earth doping optimization for ITZO systems.

[0005] Current research indicates that rare earth element (RE) doping is an effective means of improving the performance of oxide targets. Rare earth elements possess a unique 4f electronic structure with high density of states, and doping can effectively control the carrier concentration within the target, improving the resistivity of oxide targets and devices. For example, Pr-doped IZO (PrIZO) targets can achieve grain refinement through a doping-induced grain boundary pinning strategy, producing high-performance ceramic targets under optimized sintering time and holding temperature. Studies show that PrIZO and NdIZO targets exhibit higher density, finer grain size, and better conductivity. However, there is currently a lack of technical solutions for systematically optimizing the ITZO system with rare earth element doping, particularly for simultaneously achieving high target density, fine grain size, and excellent electrical performance through rare earth doping, thereby improving the stability of TFT devices.

[0006] Therefore, developing a rare-earth-doped ITZO sputtering target that simultaneously improves the target density, refines the grain size, and optimizes electrical properties through the introduction of rare-earth elements is of great significance for obtaining high-performance ITZO thin films and stable TFT devices. Summary of the Invention

[0007] The purpose of this invention is to overcome the technical defects of existing ITZO targets, such as insufficient density, large grain size, and high resistivity, and to provide a rare earth-doped indium tin zinc oxide (RE-ITZO) sputtering target and its preparation method. This invention introduces specific types and proportions of rare earth elements (selected from at least one of praseodymium (Pr), neodymium (Nd), and lanthanum (La)) through process optimization. Utilizing the unique electronic structure and doping-induced grain boundary pinning effect of rare earth elements, while maintaining the high mobility advantage of ITZO, the density of the target material is simultaneously improved, the grain size is refined, and the resistivity is reduced. This results in a novel oxide semiconductor target material that combines high density, fine grain size, and excellent electrical properties, enabling the fabricated TFT devices to have both high mobility and high stability.

[0008] The technical solution to the above technical problem is: a rare earth-doped indium tin zinc oxide sputtering target, comprising indium oxide, tin oxide, zinc oxide and rare earth oxides; wherein the rare earth element in the rare earth oxide is selected from at least one of praseodymium, neodymium and lanthanum; Based on the atomic ratio of metallic elements, the atomic proportions of each component are as follows: The indium atomic content is 40–80 at.%. The tin atom content is 5-15 at.%. The zinc atomic content is 10–40 at.%. The atomic content of rare earth elements ranges from 0.5% to 5.0 at.%. Furthermore, the atomic ratio of rare earth elements to tin is 1:2 to 1:30.

[0009] Preferably, the atomic content of indium is 60-76 at.%, the atomic content of tin is 8-12 at.%, the atomic content of zinc is 14-28 at.%, the atomic content of rare earth elements is 1.0-3.0 at.%, and the atomic ratio of rare earth elements to tin is 1:5-1:15.

[0010] Preferably, based on the atomic ratio of metal elements, In:Sn:Zn:RE = (65-72):(9-11):(16-25):(1.0-2.0).

[0011] Preferably, the target material has a relative density ≥99.0%, an average grain size ≤4.0 μm, and a resistivity ≤4.0 mΩ·cm.

[0012] Another technical solution of the present invention is: the preparation method of the above-mentioned rare earth-doped indium tin zinc oxide sputtering target includes the following steps: (1) Raw material preparation: Weigh indium oxide powder, tin oxide powder, zinc oxide powder and rare earth oxide powder according to the above atomic ratio. The rare earth oxide is Pr6O 11 At least one of Nd2O3 or La2O3; (2) Ball milling: Rare earth oxides are added to deionized water and dispersant and pre-milled for 0.5-3 hours; then, oxides are added in order of increasing mass, and each material is ball-milled for 0.5-2 hours before adding another material; after all materials are added, ball milling continues for 2-6 hours until the particle size D90 in the slurry is ≤0.8μm, and then the binder is added and ball-milled for 0.5-2 hours to obtain a uniformly dispersed rare earth-doped ITZO slurry. The solid content of the slurry is controlled at 45-60 wt.%. (3) Spray granulation: The slurry obtained in step (2) is spray dried and granulated to obtain rare earth doped ITZO granulated powder with an average particle size D50 of 30-60 μm; (4) Press molding: The granulated powder obtained in step (3) is loaded into the mold, pressed, and then transferred to cold isostatic pressing to obtain a target blank with the required size. The relative density of the blank is controlled to be 55-65%. (5) High-temperature sintering: The green blank obtained in step (4) is placed in a sintering furnace and sintered in the following three stages under an oxygen atmosphere or an oxygen-containing atmosphere: (i) Heat the powder from room temperature to 600-700℃ at a heating rate of 0.5-2℃ / min and hold for 2-5 hours to remove the binder and residual moisture from the granulated powder. (ii) Then raise the temperature to 1350-1500℃ at a heating rate of 1-3℃ / min, hold for 0.5-4 hours, and carry out rapid degassing and densification sintering; (iii) The temperature is then reduced by 50-100℃ at a cooling rate of 2-8℃ / min, and held for 8-20 hours to carry out final densification and control of grain size. Finally, the material was cooled to room temperature at a cooling rate of 2–5 °C / min to obtain rare earth-doped ITZO target material.

[0013] Furthermore, in step (1), the purity of all powders used is ≥99.9%, and the specific surface area (BET) is as follows: for indium oxide powder, the BET is 8-15 m². 2 / g, BET of tin oxide powder is 5-10 m 2 / g, BET of zinc oxide powder is 25-45 m 2 / g, the BET of rare earth oxide powder is 2-6 m 2 / g.

[0014] Furthermore, in step (2), the dispersant is triethanolamine, and the amount added accounts for 0.3 to 2.0 wt.% of the total mass of the powder, and the binder is PVA, and the amount added accounts for 0.5 to 3.0 wt.% of the total mass of the powder.

[0015] Furthermore, in step (3), the inlet air temperature is set to 200-240℃ and the outlet air temperature is set to 80-120℃ during spray drying granulation.

[0016] Furthermore, in step (4), the cold isostatic pressure is 200-400 MPa, and the holding time is 5-15 min.

[0017] Furthermore, in step (5), the oxygen partial pressure during the sintering process is controlled at 50–100 vol.% O2.

[0018] The rare earth-doped indium tin zinc oxide sputtering target prepared by this invention is used to deposit the target into a semiconductor thin film by magnetron sputtering process, which is then used as the channel layer or active layer of a thin film transistor (TFT).

[0019] Specifically, radio frequency magnetron sputtering is employed, using a mixture of Ar and O2 as the working gas, with an O2 partial pressure of 0.2–5% and a sputtering power density of 2–6 W / cm³. 2 The sputtering pressure was 0.2–1.0 Pa, and the film was deposited at room temperature. The deposited film was then annealed at 250–400 °C for 0.5–2 hours.

[0020] The RE-ITZO thin film prepared by this method has an amorphous structure, a surface roughness Ra ≤ 1.2 nm, and an average transmittance ≥ 88% in the visible light region. TFT devices fabricated using this thin film as the channel layer exhibit a field-effect mobility ≥ 16.4 cm⁻¹. 2 / V·s, on / off ratio ≥ 106 Subthreshold swing ≤ 0.5V / dec, stability NBIS ≤ 3.5V.

[0021] Compared with the prior art, the present invention has the following significant advantages: 1. A systematic scheme for rare earth element (Pr / Nd / La) doped ITZO targets was proposed for the first time.

[0022] This invention overcomes the limitations of existing technologies where rare earth doping is mainly concentrated in IZO or IGZO systems. For the first time, it systematically introduces rare earth elements (praseodymium (Pr), neodymium (Nd), and lanthanum (La)) into ITZO targets. Through the grain boundary pinning effect induced by rare earth doping and a grain refinement strategy, it solves the technical problems of insufficient density and large grain size in ITZO targets. Research shows that rare earth element doping can form a RE-In-O second phase (such as PrInO3) during sintering. These nanoparticles pinnate at the In2O3 grain boundaries, effectively hindering grain growth and achieving significant grain refinement.

[0023] 2. Precise component design enables synergistic optimization of target material performance.

[0024] This invention, through extensive experimental optimization, determined the optimal atomic ratio range for In, Sn, Zn, and RE, particularly limiting the atomic ratio of rare earth elements to tin to 1:2 to 1:30. This ratio design ensures the synergistic effect of the two types of dopants in the ITZO lattice: Sn 4+ Replace In 3+ Position, maintaining excellent In5s orbital overlap and electron transport channels; rare earth ions (such as Pr 3+ (Radius 0.99 Å) and In 3+ The difference in ionic radii (0.80 Å) leads to local lattice distortion, achieving grain refinement through a dual effect of solid solution strengthening and grain boundary pinning. Experiments show that the density of Pr-doped ITZO targets can exceed 99.0%, and the average grain size can be controlled within 4 μm.

[0025] 3. Pre-ball milling and oxides are added in order of increasing mass during multiple ball milling processes to make the mixture more uniform.

[0026] This invention innovates and optimizes the ball milling process, making the material mix more uniform, providing uniform powder particles for subsequent granulation and forming, promoting better target material structure uniformity, which is beneficial for subsequent control of target material grain size, and better film uniformity, resulting in better TFT device performance.

[0027] 4. Three-stage sintering is beneficial for obtaining target materials with smaller grain sizes.

[0028] First, raise the temperature to 600-700℃ at an appropriate heating rate to effectively degrease the grains. Then, raise the temperature to the target temperature at a faster heating rate. Finally, quickly cool the temperature to a lower temperature and hold it for a long time to inhibit excessive grain growth and achieve full densification.

[0029] 5. Excellent target material performance.

[0030] The rare-earth-doped ITZO target prepared by this invention has a relative density of over 99.0%, an average grain size as low as below 4.0 μm, and a resistivity as low as below 4.0 mΩ·cm. All performance indicators are significantly superior to those of undoped ITZO target. The high density and small grain size not only effectively suppress nodulation and arcing during sputtering, but also greatly improve the uniformity of the thin film.

[0031] 6. Thin-film transistors have excellent overall performance.

[0032] The TFT device fabricated using the rare-earth-doped ITZO thin film of this invention as the channel layer has a field-effect mobility ≥ 16.4 cm⁻¹. 2 / V·s, achieving excellent stability while maintaining high mobility. Studies have shown that doping with rare earth elements (such as Pr) can effectively suppress oxygen vacancies in ITZO films, reduce carrier concentration, and thus significantly improve the stability of TFT devices under negative bias photo-irradiation stress (NBIS).

[0033] 7. The preparation process is controllable and easy to mass-produce.

[0034] The preparation method of this invention adopts a conventional process route of ball milling-spray granulation-cold isostatic pressing-high temperature sintering, which has good process compatibility with existing ITZO / IZO target production lines. Through precise control of various process parameters (such as powder BET value, ball milling time, slurry solid content, sintering temperature, and oxygen partial pressure), the uniform distribution of rare earth elements is ensured, significantly improving the yield and facilitating industrial mass production. The three-step sintering method further suppresses excessive grain growth, ensuring the uniformity of the target microstructure. Attached Figure Description

[0035] Figure 1 This is a physical image of the Pr-ITZO target material prepared in Example 1 of the present invention.

[0036] Figure 2 Metallographic image of the Pr-ITZO target material prepared in Example 1 of this invention.

[0037] Figure 3 The image shows the metallographic structure of the ITZO target material prepared in Comparative Example 1 of this invention. Detailed Implementation

[0038] To better illustrate the objectives, technical solutions, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0039] Example 1 (Pr doping) According to the metal atomic ratio In:Sn:Zn:Pr = 72:10:17:1, weigh out indium oxide powder (In2O3), tin oxide powder (SnO2), zinc oxide powder (ZnO), and praseodymium oxide powder (Pr6O). 11 The purity of the powders is ≥99.9%, and the BET values ​​of each powder are as follows: In₂O₃ 10.5 m 2 / g、SnO2 6.5 m 2 / g、ZnO 28 m 2 / g、Pr6O 11 3.2 m 2 / g.

[0040] The weighed rare earth oxide praseodymium oxide powder (Pr6O) 11 Deionized water and a dispersant, including 1.5 wt.% of the total powder mass, were added. The mixture was pre-ball-milled for 2 hours, then the oxides were added sequentially from smallest to largest mass (i.e., ZnO, SnO2, In2O3). Each new material was ball-milled for 1 hour before adding the next. After all materials were added, the mixture was ball-milled for another 4 hours until the particle size D90 in the slurry reached 0.6 μm. Then, 1.2 wt.% of a binder, PVA, was added, and the mixture was ball-milled for 1 hour to obtain a uniformly dispersed rare-earth-doped ITZO slurry. The solid content of the slurry was controlled at 50 wt.%. Pre-ball milling of the rare-earth oxides ensured effective and uniform mixing with other materials. The other materials were added sequentially from smallest to largest mass, with each addition requiring thorough ball milling to ensure complete mixing and dispersion, guaranteeing a uniform mixture of multiple oxides.

[0041] The slurry obtained above was spray-dried and granulated. The inlet air temperature was set to 200-240℃ and the outlet air temperature to 110℃, resulting in rare earth-doped ITZO granulated powder with an average particle size D50 of 40 μm.

[0042] The granulated powder obtained above was loaded into a mold, pressed, and then transferred to cold isostatic pressing (CIP). The molding pressure was 240 MPa, and the holding time was 8 minutes, resulting in a target blank with the required dimensions. The relative density of the blank was controlled at 60%.

[0043] The resulting green blank was placed in a sintering furnace and sintered in a three-stage process under an oxygen atmosphere or an oxygen-containing atmosphere. The sintering process was as follows: (i) heating from room temperature to 650℃ at a heating rate of 1℃ / min and holding for 3 hours to remove organic binders and residual moisture from the granulated powder; (ii) heating to 1450℃ at a heating rate of 1.5℃ / min and holding for 2 hours for rapid venting and densification sintering; (iii) cooling to 1380℃ at a cooling rate of 3℃ / min and holding for 15 hours for final densification and grain size control. The oxygen partial pressure during the sintering process was controlled at 70–80 vol.% O2. A high oxygen partial pressure environment is beneficial for suppressing the generation of oxygen vacancies during the sintering process and ensuring that rare earth elements maintain their optimal valence state. The three-step sintering method first raised the temperature to the target temperature at a relatively fast heating rate, and then rapidly cooled to a lower temperature and held for a long time to suppress excessive grain growth and achieve sufficient densification.

[0044] Finally, the material was cooled to room temperature at a cooling rate of 2℃ / min to obtain rare earth-doped ITZO target material.

[0045] The sintered target material is cut, ground, and polished to achieve the required size and surface roughness (Ra≤ 1.2 μm) for sputtering.

[0046] The properties of the obtained target material are as follows: relative density 99.3% (Archimedes displacement method), average grain size 3 μm (SEM observation), and resistivity 1.16 mΩ·cm (four-probe method). Thin film deposition and TFT fabrication:

[0047] The target material prepared in Example 1 was used to deposit a Pr-ITZO thin film using radio frequency magnetron sputtering. Background vacuum degree ≤ 5 × 10⁻⁶ -4 Pa, working gas pressure 0.5 Pa, Ar:O2 flow ratio 95:5, sputtering power density 4 W / cm³ 2 The substrate temperature was room temperature. The film thickness was approximately 30 nm. After deposition, it was annealed in air at 300°C for 1 hour. Using the fabricated film as the channel layer, a TFT device was fabricated using a bottom-gate top-contact structure.

[0048] Thin film properties: Average transmittance in the visible light region is 90.2%.

[0049] Device performance testing: Field-effect mobility 18.8 cm⁻¹ 2 / V·s (saturation region extraction), threshold voltage 0.5V, on / off ratio 3.2×10 6 The subthreshold swing is 0.33 V / dec. In the NBIS test (4000 nits white light illumination, gate bias -20 V, duration 3600 s), the threshold voltage drift ΔVth = 2.75 V. Examples 2-6, Comparative Examples 1 and 2

[0050] The preparation method is the same as in Example 1, except that the raw material components are different. The raw material components of each example and comparative examples 1 and 2 are shown in Table 1.

[0051] Table 1

[0052] In each embodiment and Comparative Examples 1-2, the corresponding indium oxide powder (In2O3), tin oxide powder (SnO2), zinc oxide powder (ZnO), and praseodymium oxide powder (Pr6O3) ​​were weighed according to their atomic ratios. 11 Neodymium oxide powder (Nd2O3) and lanthanum oxide powder (La2O3). Comparative Example 3

[0053] The raw material ratio is the same as that in Example 1, except that: (1) all the weighed oxide materials are mixed with dispersant and binder by wet ball milling until the particle size D90 in the slurry is ≤0.8μm; (2) a two-stage sintering process is adopted, first heating from room temperature to 650℃ at a heating rate of 1℃ / min and holding for 3 hours, and then heating to 1450℃ at a heating rate of 1.5℃ / min and holding for 2 hours.

[0054] The performance of the target materials prepared in the embodiments and comparative examples of this invention is shown in Table 2.

[0055] Table 2

[0056] As shown in the table, Pr doping (Example 1) exhibits the best overall performance in terms of density, grain refinement, and NBIS stability; the average grain size is 3 μm, the NBIS is relatively stable (ΔVth 2.75 V), and the mobility is also high (18.8 cm⁻¹). 2 / V·s). Doping with Nd or La, or with any two rare earth elements among Pr, Nd, and La (Examples 2-6), can also yield targets with high density (≥99.0%) and fine grains (≤3.0 μm), and the mobility and stability are improved compared with Comparative Example 1 (undoped with rare earth elements).

[0057] In Comparative Example 2, the atomic ratio of rare earth elements to tin was 1:1, which is greater than 1:2 to 1:30. The prepared target material showed lower relative density, higher resistivity, and reduced stability of TFT devices.

[0058] In Comparative Example 3, the ball milling and sintering processes were changed, and the prepared target material also showed a lower relative density and reduced stability of the TFT device.

Claims

1. A rare earth-doped indium tin zinc oxide sputtering target, characterized in that: It includes indium oxide, tin oxide, zinc oxide, and rare earth oxides; the rare earth element in the rare earth oxide is selected from at least one of praseodymium, neodymium, and lanthanum; Based on the atomic ratio of metallic elements, the atomic proportions of each component are as follows: The indium atomic content is 40–80 at.%. The tin atom content is 5-15 at.%. The zinc atomic content is 10–40 at.%. The atomic content of rare earth elements ranges from 0.5% to 5.0 at.%. Furthermore, the atomic ratio of rare earth elements to tin is 1:2 to 1:

30.

2. The rare earth-doped indium tin zinc oxide sputtering target according to claim 1, characterized in that: The atomic content of indium is 60–76 at.%, the atomic content of tin is 8–12 at.%, the atomic content of zinc is 14–28 at.%, the atomic content of rare earth elements is 1.0–3.0 at.%, and the atomic ratio of rare earth elements to tin is 1:5–1:

15.

3. The rare earth-doped indium tin zinc oxide sputtering target according to claim 1, characterized in that: Based on the atomic ratio of metal elements, In:Sn:Zn:RE = (65~72):(9~11):(16~25):(1.0~2.0).

4. A rare earth-doped indium tin zinc oxide sputtering target as described in any one of claims 1-3, characterized in that: The target material has a relative density ≥99.0%, an average grain size ≤4.0 μm, and a resistivity ≤4.0 mΩ·cm.

5. The method for preparing a rare earth-doped indium tin zinc oxide sputtering target as described in any one of claims 1-3, characterized in that: Includes the following steps: (1) Raw material preparation: Weigh indium oxide powder, tin oxide powder, zinc oxide powder and rare earth oxide powder according to the above atomic ratio. The rare earth oxide is Pr6O 11 At least one of Nd2O3 or La2O3; (2) Ball milling: Rare earth oxides are added to deionized water and dispersant and pre-milled for 0.5-3 hours; then, oxides are added in order of increasing mass, and each material is ball-milled for 0.5-2 hours before adding another material; after all materials are added, ball milling continues for 2-6 hours until the particle size D90 in the slurry is ≤0.8μm, and then the binder is added and ball-milled for 0.5-2 hours to obtain a uniformly dispersed rare earth-doped ITZO slurry. The solid content of the slurry is controlled at 45-60 wt.%. (3) Spray granulation: The slurry obtained in step (2) is spray dried and granulated to obtain rare earth doped ITZO granulated powder with an average particle size D50 of 30-60 μm; (4) Press molding: The granulated powder obtained in step (3) is loaded into the mold, pressed, and then transferred to cold isostatic pressing to obtain a target blank with the required size. The relative density of the blank is controlled to be 55-65%. (5) High-temperature sintering: The green blank obtained in step (4) is placed in a sintering furnace and sintered in the following three stages under an oxygen atmosphere or an oxygen-containing atmosphere: (i) Heat the powder from room temperature to 600-700℃ at a heating rate of 0.5-2℃ / min and hold for 2-5 hours to remove the binder and residual moisture from the granulated powder. (ii) Then raise the temperature to 1350-1500℃ at a heating rate of 1-3℃ / min, hold for 0.5-4 hours, and carry out rapid degassing and densification sintering; (iii) The temperature is then reduced by 50-100℃ at a cooling rate of 2-8℃ / min, and held for 8-20 hours to carry out final densification and control of grain size. Finally, the material was cooled to room temperature at a cooling rate of 2–5 °C / min to obtain rare earth-doped ITZO target material.

6. The method for preparing a rare earth-doped indium tin zinc oxide sputtering target as described in claim 5, characterized in that: In step (1), the purity of all powders used is ≥99.9%, and the specific surface area (BET) is as follows: for indium oxide powder, the BET is 8-15 m². 2 / g, BET of tin oxide powder is 5-10 m 2 / g, BET of zinc oxide powder is 25-45 m 2 / g, the BET of rare earth oxide powder is 2-6m 2 / g.

7. The method for preparing a rare earth-doped indium tin zinc oxide sputtering target as described in claim 5, characterized in that: In step (2), the dispersant is triethanolamine, and the amount added accounts for 0.3 to 2.0 wt.% of the total mass of the powder, and the binder is PVA, and the amount added accounts for 0.5 to 3.0 wt.% of the total mass of the powder.

8. The method for preparing a rare earth-doped indium tin zinc oxide sputtering target as described in claim 5, characterized in that: In step (3), the inlet air temperature is set to 200-240℃ and the outlet air temperature is set to 80-120℃ during spray drying granulation.

9. The method for preparing a rare earth-doped indium tin zinc oxide sputtering target as described in claim 5, characterized in that: In step (4), the cold isostatic pressure is 200-400 MPa and the holding time is 5-15 min.

10. The method for preparing a rare earth-doped indium tin zinc oxide sputtering target as described in claim 5, characterized in that: In step (5), the oxygen partial pressure during the sintering process is controlled at 50-100 vol.% O2.

Images