Metal oxide semiconductor target material, preparation method thereof and thin film transistor

Abstract

The invention relates to the technical field of target material preparation, and provides a metal oxide semiconductor target material, a preparation method thereof and a thin film transistor, and the method comprises the steps: carrying out the calcination and quenching treatment of metal oxide mixed powder, and obtaining metal oxide solid solution powder; mixing and ball-milling the metal oxide solid solution powder, glass powder, an organic auxiliary agent and pure water to obtain slurry; performing spray granulation on the slurry to obtain granulation powder; carrying out molding treatment on the granulation powder to obtain a green body; and degreasing, sintering and annealing the green body to obtain the metal oxide semiconductor target material. According to the method, the metal oxide mixed powder is calcined and quenched, zinc volatilization is inhibited, the content of free zinc is reduced, the metal oxide solid solution powder with high uniformity, stability and compaction is obtained, and the density of the target material is improved. By adding the glass powder, the sintering temperature is reduced, the time is shortened, zinc volatilization is reduced, the density and uniformity of the target material are improved, solid solution or solid phase reaction of Zn is promoted, and the stability of the film is higher; fluorine ions of the glass powder replace part of oxygen ions, so that the conductivity of the target material is enhanced.

Description

Technical Field

[0001] The present application belongs to the technical field of target material preparation, and in particular relates to a metal oxide semiconductor target material, a preparation method thereof, and a thin film transistor. Background Art

[0002] As a key technology in new display industries such as active matrix liquid crystal display (AMLCD) and active matrix light emitting diode (AMOLED), thin film transistor (TFT) has the advantages of high resolution, fast response speed and good stability, making TFT screens widely used in various electronic products. The active layer materials of TFT mainly include amorphous silicon, low temperature polycrystalline silicon and metal oxide semiconductor (MOS). However, the low mobility of amorphous silicon makes it difficult to meet the consumer demand for high-performance liquid crystal displays such as ultra-high definition, high refresh rate and low power consumption; although low temperature polycrystalline silicon has high mobility, the preparation process is complicated, making it difficult to achieve large-scale preparation on large-size and high-generation display panels. In contrast, MOS materials have the characteristics of low cost, large-area preparation, low-temperature growth, etc., and show excellent performance in new display technologies, making them ideal materials for TFT active layers. MOS films in TFT devices are mainly prepared by magnetron sputtering. Therefore, the preparation of MOS targets with excellent performance is the key to preparing high-quality MOS films.

[0003] At present, the commonly used MOS material is IGZO (In-Ga-Zn oxide). Although IGZO has a high mobility, as display technology develops rapidly towards large size, ultra-high definition, ultra-high refresh rate, and low power consumption, higher requirements are placed on mobility. In addition, the existing IGZO material is particularly sensitive to water, oxygen, and light, and is prone to reliability problems after long-term operation, so its stability needs to be improved.

[0004] Therefore, it is necessary to develop a metal oxide semiconductor target material and a preparation method thereof that can achieve both high mobility and high stability. Summary of the invention

[0005] The purpose of the present application is to provide a metal oxide semiconductor target material, a preparation method thereof and a thin film transistor, aiming to solve the problem that the existing MOS target material cannot take into account both high mobility and high stability at the same time.

[0006] In order to achieve the above application purpose, the technical solution adopted in this application is as follows: In a first aspect, the present application provides a method for preparing a metal oxide semiconductor target, comprising the following steps: The metal oxide mixed powder is calcined and quenched to obtain a metal oxide solid solution powder; The metal oxide solid solution powder, glass powder, organic additive and pure water are mixed and ball-milled to obtain a slurry; spraying and granulating the slurry to obtain granulated powder; Processing the granulated powder to obtain a green body; The green body is degreased, sintered and annealed to obtain a metal oxide semiconductor target.

[0007] In a second aspect, the present application provides a metal oxide semiconductor target material, including a metal oxide semiconductor target material prepared by the method for preparing the metal oxide semiconductor target material provided in the present application.

[0008] In a third aspect, the present application provides a thin film transistor, comprising an active layer, wherein the active layer is obtained by sputtering and coating the metal oxide semiconductor target material provided by the present application.

[0009] Compared with the prior art, this application has the following beneficial effects: (1) The mixed metal oxide powder is calcined to allow each metal oxide to form a solid solution and then quenched. On the one hand, the rapid cooling effect can inhibit the volatilization of zinc. On the other hand, the structure of the metal oxide solid solution can be stabilized, phase separation can be reduced, and the position of zinc atoms can be "frozen", reducing their migration and diffusion, thereby reducing the content of free zinc. As a result, a metal oxide solid solution powder with high uniformity, high stability and high tap density is obtained, which helps to improve the density of the target material and maintain the stability of the target coating.

[0010] (2) Since glass powder has a low melting point and good fluidity, adding glass powder and metal oxide solid solution powder for mixed ball milling can, on the one hand, fill the gaps between metal oxide powders in the subsequent sintering process, promote material transfer and reaction, improve the sintering process, and increase the density and uniformity of the target material. It can also reduce the sintering temperature and shorten the sintering time, reduce zinc volatilization, and promote Zn solid solution or solid phase reaction, making the target coating more stable. On the other hand, the fluorine ions in the glass powder replace part of the oxygen ions, introduce additional free electrons, increase the carrier concentration, and thus enhance the conductivity of the target material.

[0011] (3) Annealing is used to eliminate residual stress and defects in the target material, making the composition and organizational structure more uniform, thereby further homogenizing the target material.

[0012] (4) Compared with IGZO, the Sn atomic radius of the prepared MOS target is closer to that of In, which is conducive to the overlap of 5s orbitals of adjacent atoms, thereby increasing the carrier transmission rate and mobility. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0014] Figure 1 is a flow chart of a method for preparing a metal oxide semiconductor target provided in an embodiment of the present application; Figure 2 This is a SEM image of the metal oxide semiconductor target prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0015] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0016] In a first aspect, an embodiment of the present application provides a method for preparing a metal oxide semiconductor target material, such as Figure 1 As shown, the following steps are included: S01: calcining and quenching the metal oxide mixed powder to obtain a metal oxide solid solution powder; S02: mixing metal oxide solid solution powder, glass powder, organic additive and pure water and ball milling to obtain slurry; S03: spray granulating the slurry to obtain granulated powder; S04: forming the granulated powder into a green body; S05: Degreasing, sintering and annealing the green body to obtain a metal oxide semiconductor target.

[0017] The preparation method of the metal oxide semiconductor target provided in the embodiment of the present application is to calcine the metal oxide mixed powder, so that each metal oxide undergoes solid solution and then undergoes quenching treatment. On the one hand, the volatilization of zinc is suppressed by the rapid cooling effect, and on the other hand, the structure of the metal oxide solid solution can be stabilized, the phase separation can be reduced, and the position of the zinc atoms can be "frozen", and the migration and diffusion can be reduced, thereby reducing the content of free zinc, thereby obtaining a metal oxide solid solution powder with high uniformity, high stability and high tap density, which helps to improve the density of the target material and maintain the stability of the target coating. Since the glass powder has a low melting point and good fluidity, the glass powder is added and mixed with the metal oxide solid solution powder for ball milling. On the one hand, the gaps between the metal oxide powders can be filled in the subsequent sintering process, promoting material transfer and reaction, improving the sintering process, and improving the density and uniformity of the target material. It can also reduce the sintering temperature and shorten the sintering time, reduce the volatilization of zinc, and promote the solid solution or solid phase reaction of Zn, so that the stability of the target coating is higher. On the other hand, the fluorine ions in the glass powder replace part of the oxygen ions, introduce additional free electrons, and increase the carrier concentration, thereby enhancing the conductive properties of the target material. Annealing eliminates residual stress and defects in the target material, making the composition and structure more uniform, thereby further homogenizing the target material. Compared with IGZO, the Sn atomic radius of the produced MOS target material is closer to In, which is conducive to the overlap of 5s orbits of adjacent atoms, thereby increasing the carrier transmission rate and mobility.

[0018] In the above step S01, in the embodiment, the metal oxide mixed powder includes indium oxide powder, tin oxide powder and zinc oxide powder in a mass ratio of (40-45): (42-48): (7-18). The step of preparing the metal oxide mixed powder includes: ball milling and mixing the indium oxide powder, tin oxide powder, zinc oxide powder, dispersant and pure water, and then drying to obtain the metal oxide mixed powder. The dispersant can be selected from polyethylene glycol, and the addition amount thereof is 0.5-1% of the total mass of the indium oxide powder, tin oxide powder and zinc oxide powder.

[0019] In an embodiment, the metal oxide mixed powder comprises indium oxide powder, tin oxide powder, zinc oxide powder and gallium oxide powder in a mass ratio of (80-90): (2-4): (3-6): (5-10). The step of preparing the metal oxide mixed powder comprises: ball milling and mixing the indium oxide powder, tin oxide powder, zinc oxide powder, gallium oxide powder, dispersant and pure water, and then drying to obtain the metal oxide mixed powder. The dispersant can be selected from polyethylene glycol, and the addition amount thereof is 0.5-1% of the total mass of the indium oxide powder, tin oxide powder, zinc oxide powder and gallium oxide powder.

[0020] In the embodiment, the calcination temperature is 800~1000℃, and the time is 6~12h; the calcination conditions are beneficial to calcining indium oxide powder, tin oxide powder, zinc oxide powder, etc. to form solid solution powder, and are also beneficial to reducing zinc volatilization and forming free zinc, thereby maintaining the stability of the target material coating and improving the reliability problems that are prone to occur when TFT works for a long time.

[0021] In the embodiments, the quenching treatment can be performed by water quenching, oil quenching or liquid nitrogen, that is, the calcined solid solution powder is added to a medium such as water, oil or liquid nitrogen, or water, oil or liquid nitrogen is added to the calcined solid solution powder to quickly cool the solid solution powder, which can not only effectively reduce the volatilization of zinc, but also stabilize the structure of the metal oxide solid solution powder, thereby "freezing" the position of zinc atoms, reducing their migration and diffusion, reducing free zinc, and also reducing phase separation, maintaining the uniformity and stability of the solid solution powder, and further reducing the content of free zinc, which helps to maintain the stability of the target coating and overcomes the reliability problem that ZnO or IGZO is particularly sensitive to water, oxygen and light, which leads to long-term operation of TFT.

[0022] In the above step S02, the raw materials of the glass powder include silicon dioxide powder, zinc oxide powder and stannous fluoride powder in a mass ratio of (0-5) : (0.5-10) : (85-99.5). Preferably, the raw materials of the glass powder include silicon dioxide powder, zinc oxide powder and stannous fluoride powder in a mass ratio of (1-5) : (0.5-10) : (85-98.5). Stannous fluoride powder is used as a raw material for preparing glass powder, so that the prepared target material contains fluorine, and fluorine ions replace part of oxygen ions, which will introduce additional free electrons, increase the carrier concentration, and thus enhance the conductivity of the target material. Moreover, as a glass former, stannous fluoride powder with a low melting point can give the glass powder a lower melting point and better fluidity, which can not only reduce the sintering temperature and shorten the sintering time, reduce zinc volatilization, but also fill the gaps between metal oxide powders during the sintering process, promote mass transfer, improve the sintering process, and increase the density and uniformity of the target material. It also promotes the solid solution or solid phase reaction of Zn, making the target coating more stable.

[0023] In an embodiment, the step of preparing glass powder includes: mixing silicon dioxide powder, zinc oxide powder and stannous fluoride powder to obtain a mixture; heating the mixture to 800-1100° C. for smelting to obtain glass liquid; quenching, crushing and sieving the glass liquid to obtain glass powder. The quenching may be water quenching, and the crushing may be air flow mill crushing.

[0024] In the embodiment, the particle size of the glass powder is 0.1-0.8 μm, preferably 0.1-0.5 μm.

[0025] In the embodiment, the mass ratio of the metal oxide solid solution powder to the glass powder is (98-99.9): (0.1-2).

[0026] In an embodiment, the organic auxiliary agent may be selected from polyvinyl alcohol and / or polyethylene glycol, and the added amount thereof is 0.5-1% of the total mass of the metal oxide solid solution powder and the glass powder.

[0027] In an embodiment, the solid content of the slurry is 70-90%, preferably 75-85%.

[0028] In the above step S03, in the embodiment, the inlet temperature of the spray granulation is 200-250°C, and the outlet temperature is 80-100°C.

[0029] In the above step S04, in the embodiment, the step of forming treatment comprises: cold isostatic pressing at a pressure of 50-300 MPa, preferably at a pressure of 200-250 MPa.

[0030] In the above step S05, in the embodiment, the degreasing temperature is 300-600° C. and the time is 6-12 hours.

[0031] In the embodiment, the sintering temperature is 1000-1350° C., preferably 1190-1290° C., and the sintering time is 12-36 hours.

[0032] In the embodiment, the annealing temperature is 800-1000° C. and the time is 2-6 hours. Within the annealing temperature and time range, the grains can be better refined, making the produced target material more uniform and dense.

[0033] In an embodiment, the relative density of the metal oxide semiconductor target is ≥98.5%, and the resistivity is ≤10 mΩ·cm.

[0034] A second aspect of an embodiment of the present application provides a metal oxide semiconductor target material, including a metal oxide semiconductor target material prepared by the method for preparing a metal oxide semiconductor target material provided by an embodiment of the present application.

[0035] The metal oxide semiconductor target material provided in the embodiment of the present application is prepared by the preparation method of the metal oxide semiconductor target material provided in the embodiment of the present application, so the target material has the advantages of high density, good uniformity, low resistivity and good stability.

[0036] A third aspect of an embodiment of the present application provides a thin film transistor, comprising an active layer, wherein the active layer is obtained by sputtering and coating the metal oxide semiconductor target material provided by the embodiment of the present application.

[0037] The thin film transistor provided in the embodiment of the present application has an active layer obtained by sputtering and coating the metal oxide semiconductor target material provided in the embodiment of the present application, and has the advantages of low resistivity and high carrier concentration, as well as good stability to water, oxygen, light and heat. Therefore, it is possible to improve performance indicators such as TFT mobility, threshold voltage and current switching ratio, improve reliability problems that are prone to occur when TFT works for a long time, and increase the life of TFT, thereby helping to achieve high resolution, high refresh rate, low power consumption and high definition of the display screen, and improving the stability of the display screen.

[0038] The following describes the invention in conjunction with specific embodiments.

[0039] Example 1 This embodiment provides a method for preparing a metal oxide semiconductor target, comprising the following steps: S11: Indium oxide powder, tin oxide powder, zinc oxide powder, polyethylene glycol and pure water in a mass ratio of 42:45:13 are ball-milled and mixed, and then dried to obtain a metal oxide mixed powder; the amount of polyethylene glycol added is 0.8% of the total mass of the indium oxide powder, tin oxide powder and zinc oxide powder; The metal oxide mixed powder is heated to 900°C, calcined for 8 hours, quenched with water, and dried to obtain a metal oxide solid solution powder; S12: mixing silicon dioxide powder, zinc oxide powder and stannous fluoride powder in a mass ratio of 2:5:93 to obtain a mixture; The mixed material is heated to 950°C for melting to obtain molten glass; The glass liquid is quenched by water, crushed by jet mill and sieved to obtain glass powder with an average particle size of 0.45 μm; S13: mixing and ball-milling the metal oxide solid solution powder, glass powder, polyvinyl alcohol, polyethylene glycol and alcohol to obtain a slurry with a solid content of 80%; The mass ratio of the metal oxide solid solution powder to the glass powder is 99:1, the amount of polyvinyl alcohol added is 0.5% of the total mass of the metal oxide solid solution powder and the glass powder, and the amount of polyethylene glycol added is 0.5% of the total mass of the metal oxide solid solution powder and the glass powder; S14: introducing the slurry into a centrifugal spray granulator, setting the inlet temperature to 220° C. and the outlet temperature to 90° C., and performing spray granulation to obtain granulated powder with a particle size of 45 to 125 μm; S15: the granulated powder is loaded into a stainless steel mold, pre-pressed by a hydraulic press, and then isostatically pressed at a pressure of 250 MPa to obtain a green body; S16: placing the green body in a sintering furnace, first heating it to 400°C for degreasing for 8 hours, then heating it to 1250°C for sintering for 18 hours, cooling it, then heating it to 900°C for annealing for 4 hours, and machining it to obtain a metal oxide semiconductor target.

[0040] Example 2 This embodiment provides a method for preparing a metal oxide semiconductor target, which differs from Embodiment 1 in that step S11 is to mix indium oxide powder, tin oxide powder, zinc oxide powder, gallium oxide powder, polyethylene glycol and pure water in a mass ratio of 86:2.5:3.6:7.9 by ball milling.

[0041] Example 3 This embodiment provides a method for preparing a metal oxide semiconductor target material, which is different from Embodiment 1 in that in step S13, the mass ratio of the metal oxide solid solution powder to the glass powder is 98:2.

[0042] Example 4 This embodiment provides a method for preparing a metal oxide semiconductor target material, which is different from Embodiment 1 in that in step S13, the mass ratio of the metal oxide solid solution powder to the glass powder is 99.9:0.1.

[0043] Comparative Example 1 This comparative example provides a method for preparing a metal oxide semiconductor target material, which is different from Example 1 in that in step S11, the metal oxide mixed powder is heated to 900° C., calcined for 8 hours, and then naturally cooled in the furnace to obtain a metal oxide solid solution powder.

[0044] Comparative Example 2 This comparative example provides a method for preparing a metal oxide semiconductor target material, which differs from Example 1 in that step S11 is omitted (i.e., the mixing, calcination and water quenching of indium oxide powder, tin oxide powder and zinc oxide powder are not performed); and step S13 is to replace the metal oxide solid solution powder with indium oxide powder, tin oxide powder and zinc oxide powder.

[0045] Comparative Example 3 This comparative example provides a method for preparing a metal oxide semiconductor target material, which is different from Example 1 in that in step S12, tin dioxide powder is used instead of stannous fluoride powder.

[0046] Related performance test analysis: 1. The actual density of the metal oxide semiconductor targets prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was tested by the Archimedes density test method. The theoretical density was used as a reference. Relative density = actual density / theoretical density × 100%.

[0047] 2. The resistivity of the metal oxide semiconductor targets prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was tested using a four-probe tester.

[0048] The test results are shown in Table 1 below: Table 1 3. The In, Sn and Zn contents of the metal oxide semiconductor targets prepared in Example 1 and Comparative Examples 1 to 3 were tested by ICP (inductively coupled plasma test); wherein the mass contents of In, Sn and Zn in the metal oxide mixed powder were 34.7:35.4:10.4.

[0049] 4. Using a magnetron sputtering device under the same coating conditions, the metal oxide semiconductor targets prepared in Example 1 and Comparative Examples 1 to 3 were sputtered on a quartz substrate, respectively, and the film thickness was about 50 nm; and then the film was annealed in air at 420° C. for 1 h; The carrier concentration and mobility of the film before and after the weather resistance test were tested using a Hall effect tester; wherein the weather resistance test was as follows: the films corresponding to Example 1 and Comparative Examples 1 to 3 were placed under extreme conditions of a temperature of 80° C. and a humidity of 100% RH for 2 days.

[0050] The test results are shown in Table 2 below: Table 2 It can be seen from Table 1 that the relative density of the targets prepared in Examples 1 to 4 is greater than 99.0% and the resistivity is less than 10 mΩ·cm, indicating that the preparation method of the embodiments of the present application can prepare high-density and low-resistance metal oxide semiconductor targets.

[0051] Moreover, the relative density of the target material prepared in Example 1 is significantly higher than that in Comparative Examples 2 to 3, indicating that in the embodiment of the present application, the metal oxide mixed powder is first calcined to form a solid solution and then quenched, which helps to stabilize the solid solution structure and obtain a highly uniform, stable and highly tapped metal oxide solid solution powder, thereby helping to improve the density of the target material; and the stannous fluoride contained in the glass powder of the present application has a low melting point, so that the glass powder has a lower melting point and better fluidity, so that the gaps between the metal oxide powders can be better filled during the sintering process, material transfer and reaction can be promoted, the sintering process can be improved, and the density of the target material can be further improved.

[0052] The resistivity of the target material prepared in Example 1 is significantly lower than that in Comparative Example 3, indicating that the glass powder prepared in this application uses stannous fluoride as a raw material, and the fluoride ions contained in it can replace part of the oxygen ions, introduce additional free electrons, and increase the carrier concentration, thereby enhancing the conductivity of the target material.

[0053] It can be seen from Table 2 that the In, Sn and Zn contents of the target prepared in Example 1 are close to the mass contents of In, Sn and Zn in the metal oxide mixed powder, while the In, Sn and Zn contents of the targets prepared in Comparative Examples 1-2 deviate greatly from the metal oxide mixed powder, indicating that the present application calcines the metal oxide mixed powder for solid solution and then quenches it to inhibit the volatilization of zinc, so that the In, Sn and Zn contents in the target are close to the raw material ratio; and the glass powder containing stannous fluoride has a low melting point, which can reduce the sintering temperature, shorten the sintering time, and further reduce the volatilization of zinc.

[0054] The carrier concentration and mobility of the thin film corresponding to Example 1 are very different before and after the weathering test, while the carrier concentration and mobility of the thin films corresponding to Comparative Examples 1 and 2 are quite different before and after the weathering test, indicating that the electrical properties of the target coating prepared in the embodiment of the present application are more stable, and the resistance to temperature and water vapor interference is good. This is mainly due to the fact that the present application calcines the metal oxide mixed powder for solid solution and then quenches it, which stabilizes the structure of the metal oxide solid solution and makes the phase more stable. It also "freezes" the position of zinc atoms, reduces zinc migration and diffusion, reduces free zinc, and helps to improve stability. The added glass powder can promote the solid solution or solid phase reaction of Zn, making the target coating more stable.

[0055] from Figure 2 It can be seen from the SEM that the target material prepared in Example 1 has uniform grains, close bonding between grains, and no obvious grain boundaries and pores.

[0056] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a metal oxide semiconductor target, characterized in that: The following steps are involved: The metal oxide mixed powder is calcined and quenched to obtain a metal oxide solid solution powder; The metal oxide solid solution powder, glass powder, organic additive and pure water are mixed and ball-milled to obtain a slurry; spraying and granulating the slurry to obtain granulated powder; Processing the granulated powder to obtain a green body; The green body is degreased, sintered and annealed to obtain a metal oxide semiconductor target.

2. The preparation method according to claim 1, characterized in that The metal oxide mixed powder comprises indium oxide powder, tin oxide powder and zinc oxide powder in a mass ratio of (40-45): (42-48): (7-18); And / or, the step of preparing the metal oxide mixed powder includes: mixing the indium oxide powder, tin oxide powder, zinc oxide powder, dispersant and pure water by ball milling, and then drying to obtain the metal oxide mixed powder.

3. The preparation method according to claim 1, characterized in that: The metal oxide mixed powder comprises indium oxide powder, tin oxide powder, zinc oxide powder and gallium oxide powder in a mass ratio of (80-90): (2-4): (3-6): (5-10); And / or, the step of preparing the metal oxide mixed powder includes: ball-milling the indium oxide powder, tin oxide powder, zinc oxide powder, gallium oxide powder, dispersant and pure water, and then drying to obtain the metal oxide mixed powder.

4. The preparation method according to claim 1, characterized in that: The raw materials of the glass powder include silicon dioxide powder, zinc oxide powder and stannous fluoride powder in a mass ratio of (0-5): (0.5-10): (85-99.5); And / or, the particle size of the glass powder is 0.1-0.8 μm; And / or, the mass ratio of the metal oxide solid solution powder to the glass powder is (98-99.9): (0.1-2).

5. The preparation method according to claim 4, characterized in that: The steps of preparing the glass powder include: mixing the silicon dioxide powder, zinc oxide powder and stannous fluoride powder to obtain a mixture; The mixed material is heated to 800-1100° C. for melting to obtain molten glass; The glass liquid is quenched, crushed and sieved to obtain glass powder.

6. The preparation method according to claim 1, characterized in that: The calcination treatment is carried out at a temperature of 800-1000° C. and for a time of 6-12 hours.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The degreasing temperature is 300-600°C and the time is 6-12h; And / or, the sintering temperature is 1000-1350° C. and the sintering time is 12-36 hours; And / or, the annealing temperature is 800-1000° C. and the time is 2-6 hours.

8. The preparation method according to any one of claims 1 to 6, characterized in that: The relative density of the metal oxide semiconductor target material is ≥98.5%, and the resistivity is ≤10 mΩ·cm.

9. A metal oxide semiconductor target, characterized in that: A metal oxide semiconductor target material prepared by the method for preparing a metal oxide semiconductor target material according to any one of claims 1 to 8.

10. A thin film transistor comprising an active layer, characterized in that: The active layer is obtained by sputtering the metal oxide semiconductor target material according to claim 9.

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