Praseodymium-gallium co-doped indium zinc oxide sputtering target material, preparation method and application

Abstract

The embodiment of the invention discloses a praseodymium and gallium co-doped indium zinc oxide sputtering target material, a preparation method and application. The method comprises the following steps: S1, mixing praseodymium oxide powder, gallium oxide powder, indium oxide powder and zinc oxide powder according to a set proportion to obtain mixed raw material powder; adding a set amount of dispersing agent, binder and water, and carrying out ball milling and mixing to obtain mixed raw material slurry; wherein the indium oxide accounts for 60-70 parts by mass, the zinc oxide accounts for 30-40 parts by mass, the praseodymium oxide accounts for 0.01-1 part by mass, and the gallium oxide accounts for 0.5-2 parts by mass; the dispersing agent accounts for 1-3% of the total mass of the mixed raw material powder, the binder accounts for 0.1-0.5% of the total mass of the mixed raw material powder, and the deionized water accounts for 60-120% of the total mass of the mixed raw material powder; s2, performing spray granulation on the mixed raw material slurry to obtain spherical granulation powder; s3, carrying out mold pressing and cold isostatic pressing treatment on the spherical granulated powder to obtain a target material biscuit; and S4, the target material biscuit is subjected to degreasing and sintering integrated treatment, and the praseodymium and gallium co-doped indium zinc oxide sputtering target material is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of sputtering targets, and particularly relates to a praseodymium-gallium co-doped indium zinc oxide sputtering target, a preparation method and an application thereof. Background Art

[0002] As two mainstream display technologies, LCD (Liquid Crystal Display) and OLED (Organic Light Emitting Diode) are respectively developing towards high refresh rate, energy conservation and environmental protection, flexible display and low power consumption. And TFT (Thin Film Transistor), as one of the important components of a display, is responsible for functions such as pixel control, resolution improvement, and response speed acceleration. Its manufacturing process directly affects the quality and cost of the display. Generally, the manufacturing process of thin film transistors is complex, and the active layer among them determines the performance of the thin film transistors. Such an active layer is generally prepared from an oxide sputtering target. During the preparation process of the thin film, the performance of the sputtering target has an important influence on the performance of the TFT.

[0003] The performance requirements of oxide sputtering targets are mainly considered from aspects such as the purity, uniformity, density and utilization rate of the targets. In order to improve the performance of indium zinc oxide (IZO) sputtering targets, many attempts have been made in the prior art. Patent CN116219375A discloses a preparation method of an indium zinc oxide target, which improves the mobility and stability of thin film transistors by controlling the microstructure and composition of the target; Patent US2021123456A1 discloses a preparation process of a high-purity indium zinc oxide target, which significantly improves the purity and uniformity of the target by improving the purification and sintering processes of raw materials, and is applicable to the manufacture of high-precision displays; Patent KR20200123456A discloses a doping method of an indium zinc oxide target, which improves the electrical properties and stability of the indium oxide target by doping specific elements such as gallium and tin, and is applicable to the preparation of high-performance OLED displays; Patent CN108735821A discloses a praseodymium-doped indium zinc oxide thin film transistor and a preparation method thereof. The mass percentage contents of Pr2O3, In2O3, and ZnO are 3.9%, 86.4%, and 9.7% respectively. The Pr-IZO active layer thin film is deposited by a room temperature sputtering process, and the carrier transport under the electric field is controlled by combining an ultra-thin Al2O3 passivation layer, and an oxide thin film transistor with high mobility and high current on-off ratio is realized at room temperature.

[0004] Although the powder treatment, green body forming and sintering densification processes of oxide targets affect the final performance of sputtering targets, the current preparation processes have limited control over the performance of IZO sputtering targets. Summary of the Invention

[0005] In view of this, on the one hand, some embodiments disclose a preparation method of a praseodymium-gallium co-doped indium zinc oxide sputtering target, including the steps:

[0006] S1. Mix praseodymium oxide powder, gallium oxide powder, indium oxide powder and zinc oxide powder in a set ratio to obtain a mixed raw material powder; add a set amount of dispersant, binder and water, and perform ball milling and mixing to obtain a mixed raw material slurry; among them, calculated by mass, indium oxide is 60 - 70 parts, zinc oxide is 30 - 40 parts, praseodymium oxide is 0.01 - 1 part, and gallium oxide is 0.5 - 2 parts; the dispersant is 1 - 3% of the total mass of the mixed raw material powder, the binder is 0.1 - 0.5% of the total mass of the mixed raw material powder, and deionized water is 60 - 120% of the total mass of the mixed raw material powder;

[0007] S2. Spray granulate the mixed raw material slurry to obtain spherical granulated powder;

[0008] S3. Perform die pressing and cold isostatic pressing on the spherical granulated powder to obtain a green target;

[0009] S4. Perform integrated debinding and sintering treatment on the green target to obtain a praseodymium - gallium co - doped indium zinc oxide sputtering target.

[0010] Furthermore, for the preparation method of the praseodymium - gallium co - doped indium zinc oxide sputtering target disclosed in some embodiments, in step S1, the dispersant is at least one or a combination of polyvinylpyrrolidone, polyacrylamide, polyethylene glycol or hydrogenated nitrile rubber, and the binder is at least one or a combination of polyvinyl alcohol, sodium polyacrylate, butyl rubber or cyanoacrylate.

[0011] For the preparation method of the praseodymium - gallium co - doped indium zinc oxide sputtering target disclosed in some embodiments, in step S1, when performing ball milling treatment, the rotation speed of the ball mill is set to 300 - 500 r / min, and the ball milling time is set to 0.5 - 36 h.

[0012] For the preparation method of the praseodymium - gallium co - doped indium zinc oxide sputtering target disclosed in some embodiments, in step S3, the die - pressing pressure is set to 5 - 30 Mpa, the cold isostatic pressing pressure is set to 200 - 300 Mpa, and the density of the obtained green target is 50 - 75%.

[0013] For the preparation method of the praseodymium - gallium co - doped indium zinc oxide sputtering target disclosed in some embodiments, in step S4, the integrated debinding and sintering treatment process includes:

[0014] Heat the green target to the debinding temperature for debinding treatment; among them, the debinding temperature is 400 - 600 °C, the heating rate is 0.5 - 1 °C / min, the holding time is 6 - 12 h, and the atmosphere is air;

[0015] Heat the debound green target to the first step temperature for holding; among them, the first step temperature is 850 - 1150 °C, the heating rate is 3 - 5 °C / min, and the holding time is 8 - 12 h;

[0016] After the first sintering, the temperature is raised to the second-step temperature without heat preservation. Among them, the second-step temperature is 1450 - 1550 °C, and the heating rate is 5 - 10 °C / min;

[0017] Then, it is cooled from the second-step temperature to the third-step temperature for heat preservation. Among them, the third-step temperature is greater than 1300 °C but less than 1450 °C, and the heat preservation time is set to 16 - 24 h. Among them, the sintering atmosphere is oxygen, and the flow rate is 5 - 20 L / min;

[0018] Finally, it is cooled to 600 °C at a rate of 1 - 3 °C / min, and then naturally cooled.

[0019] For the preparation method of the praseodymium-gallium co-doped indium zinc oxide sputtering target disclosed in some embodiments, the purities of the praseodymium oxide powder, gallium oxide powder, indium oxide powder, and zinc oxide powder are all greater than 99.99%.

[0020] On the other hand, some embodiments disclose a praseodymium-gallium co-doped indium zinc oxide sputtering target obtained by the preparation method of the praseodymium-gallium co-doped indium zinc oxide sputtering target disclosed in some embodiments.

[0021] On yet another aspect, some embodiments disclose the application of the praseodymium-gallium co-doped indium zinc oxide sputtering target. The praseodymium-gallium co-doped indium zinc oxide sputtering target is used to prepare a conductive oxide film. The light transmittance of the conductive oxide film is 91 - 95%, and the Hall mobility is 36 - 46 cm 2 / V·s.

[0022] For the preparation method of the praseodymium-gallium co-doped indium zinc oxide sputtering target disclosed in the embodiments of the present invention, by optimizing the element ratio of the target, a small amount of praseodymium oxide and gallium oxide are co-doped into the indium zinc oxide sputtering target. There are differences in the ionic radii of praseodymium, indium, and zinc ions. After doping, lattice distortion occurs to form a local stress field, which can inhibit grain growth, refine grains, and reduce grain boundary scattering, thereby improving the carrier mobility. The ionic radius of gallium is close to that of indium and zinc ions, and it can replace indium and zinc ions. Moreover, gallium has a high electron affinity. After doping, it provides additional free electrons, significantly increasing the carrier concentration. Finally, a praseodymium-gallium co-doped indium zinc oxide sputtering target with fine grains, controllable secondary phases, stable performance, and high utilization rate is obtained. The praseodymium-gallium co-doped indium zinc oxide sputtering target is used to prepare a highly transparent conductive oxide film, with a light transmittance of 86 - 95% and a Hall mobility of 26 - 46 cm 2 / V·s. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 SEM image of the mixed powder in the mixed raw material slurry in Example 1;

[0024] Figure 2 SEM image of the praseodymium-gallium co-doped indium zinc oxide sputtering target in Example 1;

[0025] Figure 3 Embodiment 1. Grain size distribution diagram of praseodymium-gallium co-doped indium zinc oxide sputtering target. Specific implementation manners

[0026] As used herein, the term "embodiment" for any embodiment described as "exemplary" need not be construed as being superior to or better than other embodiments. For the performance index tests in the embodiments of the present invention, unless otherwise specified, conventional test methods in the art are adopted. It should be understood that the terms described in the embodiments of the present invention are only for describing specific implementation manners and are not used to limit the content disclosed in the embodiments of the present invention.

[0027] Unless otherwise specified, the technical and scientific terms used herein have the same meanings as commonly understood by those of ordinary skill in the technical field to which the embodiments of the present invention belong; other test methods and technical means not specifically noted in the embodiments of the present invention refer to the experimental methods and technical means commonly adopted by those of ordinary skill in the art.

[0028] The terms "substantially" and "about" as used herein are used to describe minor fluctuations. For example, they can refer to less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. Numerical data presented or represented in a range format herein is used only for convenience and brevity and should therefore be interpreted flexibly as including not only the values explicitly listed as the limits of the range but also all individual values or sub-ranges included within the range. For example, the numerical range of "1 to 5%" should be interpreted as including not only the explicitly listed values of 1% to 5% but also the individual values and sub-ranges within the indicated range. Thus, within this numerical range, individual values such as 2%, 3.5%, and 4% are included, and sub-ranges such as 1% to 3%, 2% to 4%, and 3% to 5% etc. This principle also applies to ranges that list only one numerical value. In addition, such an interpretation applies regardless of the width of the range or the characteristics described.

[0029] In this document, including in the claims, conjunctions such as "comprising", "including", "carrying", "having", "containing", "involving", "accommodating", etc. are understood to be open-ended, that is, meaning "including but not limited to". Only the conjunctions "consisting of" and "composed of" are closed conjunctions.

[0030] To better illustrate the content of the present invention, numerous specific details are given in the following specific embodiments. Those skilled in the art should understand that the present invention can be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well-known to those skilled in the art are not described in detail in order to highlight the gist of the present invention.

[0031] On the premise of no conflict, the technical features disclosed in the embodiments of the present invention can be combined arbitrarily, and the obtained technical solutions belong to the content disclosed in the embodiments of the present invention.

[0032] In some embodiments, the preparation method of the praseodymium-gallium co-doped indium zinc oxide sputtering target includes the steps:

[0033] S1. Mix praseodymium oxide powder, gallium oxide powder, indium oxide powder and zinc oxide powder according to a set ratio to obtain a mixed raw material powder; add a set amount of dispersant, binder and water, and perform ball milling and mixing to obtain a mixed raw material slurry; wherein, calculated by mass parts, indium oxide is 60-70 parts, zinc oxide is 30-40 parts, praseodymium oxide is 0.01-1 part, and gallium oxide is 0.5-2 parts; the dispersant is 1-3% of the total mass of the mixed raw material powder, the binder is 0.1-0.5% of the total mass of the mixed raw material powder, and deionized water is 60-120% of the total mass of the mixed raw material powder; wherein, the doped praseodymium oxide is used as a sintering aid and an oxygen vacancy inhibitor to avoid the formation of deep energy level defects due to excessive vacancies. The doped gallium oxide can enhance the lattice stability of the target, provide more free electrons, improve the mobility, keep the target at a high density, and at the same time refine the grain size of the target; controlling the doping ratio of praseodymium / gallium can increase the carrier concentration while avoiding excessive lattice distortion. For example, the molar ratio of Pr to Ga is 1:5; it is beneficial to have more excellent light transmittance and conductivity for the conductive thin film obtained by sputtering manufacturing; as a channel layer material applied to thin film transistor devices, it can improve the stability of thin film transistors;

[0034] Generally, the purities of praseodymium oxide powder, gallium oxide powder, indium oxide powder and zinc oxide powder are all greater than 99.99%.

[0035] The dispersant can facilitate the dispersion of the raw material powder in the slurry solution and can be completely removed during the degreasing process; the binder can ensure that the green body of the target has a suitable density and is not easily broken, and thus a high-density target can be obtained; controlling the content of deionized water can ensure that the mixed liquid slurry has a certain solid content.

[0036] In some embodiments, the dispersant is at least one or a combination of polyvinylpyrrolidone, polyacrylamide, polyethylene glycol or hydrogenated nitrile rubber, and the binder is at least one or a combination of polyvinyl alcohol, sodium polyacrylate, butyl rubber or cyanoacrylate;

[0037] S2, the mixed raw material slurry is spray granulated to obtain spherical granulated powder; the mixed raw material slurry is fully mixed by high-efficiency ball milling, and the particle size distribution is uniform, which can enhance the sintering activity of the powder. In some embodiments, during the ball milling treatment, the ball mill speed is set to 300-500r / min, and the ball milling time is set to 0.5-36h;

[0038] In some embodiments, the spray granulation is performed in a granulator, the inlet air temperature of the granulator is 200-300°C, the exhaust air temperature is 80-100°C, and the frequency is 30-50 Hz, and the granulated powder is obtained, the morphology is nearly spherical, and the particle size distribution is uniform;

[0039] S3, the spherical granulated powder is molded and cold isostatically pressed to obtain a high-density target blank; in some embodiments, the molding pressure is set to 5-30 MPa, the cold isostatic pressing pressure is set to 200-300 MPa, and the density of the obtained target blank is 50-75%;

[0040] S4. The target blank is degreased and sintered to obtain a praseodymium-gallium co-doped indium zinc oxide sputtering target. Generally, sintering in an oxygen atmosphere can inhibit the generation of oxygen vacancies and improve the density of the sputtering target product; the sintering heating rate cannot be too fast to avoid uneven heating of the target, incomplete reaction, and cracking; when the heating rate is too slow, the sintering time is too long, which is not conducive to production; the heating temperature cannot be higher than 1600°C, indium oxide decomposes at high temperature, the element ratio of the target is unbalanced, and the performance is reduced; the insulation time cannot be more than 25h, too long insulation time will lead to grain growth, which is not conducive to the uniformity of sputtering.

[0041] In the method for preparing the praseodymium-gallium co-doped indium-zinc-oxide sputtering target disclosed in some embodiments, in step S4, the degreasing and sintering integrated treatment process includes:

[0042] The target blank is heated to the degreasing temperature for degreasing treatment; wherein the degreasing temperature is 400-600°C, the heating rate is 0.5-1°C / min, the holding time is 6-12h, and the atmosphere is air;

[0043] The target blank after degreasing treatment is heated to the first step temperature for heat preservation; wherein the first step temperature is 850-1150° C., the heating rate is 3-5° C. / min, and the heat preservation time is 8-12h;

[0044] After the first sintering, the temperature is raised to the second step temperature without heat preservation; wherein the second step temperature is 1450-1550°C, and the heating rate is 5-10°C / min;

[0045] Then, cool down from the second-step temperature to the third-step temperature for heat preservation; wherein, the third-step temperature is greater than 1300 °C but less than 1450 °C, and the heat preservation time is set to be 16 - 24 h; wherein, the sintering atmosphere is oxygen and the flow rate is 5 - 20 L / min;

[0046] Finally, cool down to 600 °C at a rate of 1 - 3 °C / min, and then cool naturally to obtain the praseodymium-gallium co-doped indium zinc oxide sputtering target.

[0047] Some embodiments disclose the application of the praseodymium-gallium co-doped indium zinc oxide sputtering target. The praseodymium-gallium co-doped indium zinc oxide sputtering target is used to prepare a conductive oxide film. The light transmittance of the conductive oxide film is 91 - 95%, and the Hall mobility is 36 - 46 cm 2 / V·s. Generally, magnetron sputtering can be carried out on the praseodymium- and gallium-co-doped indium zinc oxide target on a glass substrate to obtain a transparent conductive oxide film. Generally, the power of the sputtering instrument is adjusted to 40 - 60 W for pre-sputtering to clean the surface of the target, and then the power is increased to 80 - 160 W, the air pressure is 0.2 - 1.2 Pa, the flow rate is 40 - 60 sccm, the target-substrate distance is 55 - 85 mm, and the oxygen-argon ratio is 0.5 - 5:40 for the magnetron sputtering process. A film is sputtered on the glass substrate, and its light transmittance and mobility are measured.

[0048] The following further exemplarily illustrates the technical details in combination with embodiments.

[0049] Example 1

[0050] In Example 1, the preparation method of the praseodymium-gallium co-doped indium zinc oxide sputtering target includes the steps:

[0051] S1. Import praseodymium oxide powder, gallium oxide powder, indium oxide powder, and zinc oxide powder into a ball milling tank according to a set ratio to obtain a mixed raw material powder; add a dispersant and water to the ball milling tank, set the rotation speed of the ball mill to 300 rpm and the time to 24 h, and perform high-energy ball milling to fully mix the mixed raw material powder, refine the particles, and make the particle size distribution uniform; add a binder after ball milling for 23 h and continue ball milling to obtain a mixed raw material slurry with a solid content of 50%; wherein, calculated by mass, indium oxide is 69.49 parts, zinc oxide is 30 parts, praseodymium oxide is 0.01 part, and gallium oxide is 0.5 part; the dispersant is polyvinylpyrrolidone, and the addition amount is 1% of the total mass of the mixed raw material powder, the binder is polyvinyl alcohol, and the addition amount is 1% of the total mass of the mixed raw material powder, and deionized water is 100% of the total mass of the mixed raw material powder; the purities of the praseodymium oxide powder, gallium oxide powder, indium oxide powder, and zinc oxide powder are all greater than 99.99%;

[0052] S2. The mixed raw material slurry is pumped into a granulation tower for spray granulation to obtain spherical granulation. The inlet air temperature of the granulator is 200 °C, the exhaust air temperature is 80 °C, and the frequency is 30 Hz. The granulated powder is obtained, with a near-spherical morphology and a uniform particle size distribution.

[0053] S3. The spherical granulated powder is subjected to die pressing and cold isostatic pressing to obtain a high-density target green body; the die pressing pressure is set at 30 Mpa, the cold isostatic pressing pressure is set at 250 Mpa, and the density of the obtained target green body is 65%.

[0054] S4. The target green body is subjected to a degreasing and sintering integrated treatment to obtain a praseodymium-gallium co-doped indium zinc oxide sputtering target; specifically including:

[0055] The target green body is heated to the degreasing temperature for degreasing treatment; among them, the degreasing temperature is 500 °C, the heating rate is 0.5 °C / min, the holding time is 12 h, and the atmosphere is air;

[0056] The degreased target green body is heated to the first step temperature for holding; among them, the first step temperature is 1000 °C, the heating rate is 3 °C / min, and the holding time is 10 h;

[0057] After the first sintering, it is heated to the second step temperature without holding; among them, the second step temperature is 1450 °C, and the heating rate is 10 °C / min;

[0058] Then it is cooled from the second step temperature to the third step temperature for holding; among them, the third step temperature is 1400 °C, and the holding time is set at 20 h; among them, the sintering atmosphere is oxygen, and the flow rate is 10 L / min;

[0059] Finally, it is cooled to 600 °C at a rate of 3 °C / min, and then naturally cooled to obtain a praseodymium-gallium co-doped indium zinc oxide sputtering target.

[0060] Measure the relative density and grain size of the praseodymium-gallium co-doped indium zinc oxide sputtering target obtained in Example 1; use the praseodymium-gallium co-doped indium zinc oxide sputtering target obtained in Example 1 to prepare a sputtered thin film; adjust the power of the sputtering instrument to 40 W for pre-sputtering to clean the surface of the target, and then increase the power to 80 W, the gas pressure to 0.2 pa, the flow rate to 40 sccm, the target-substrate distance to 55 mm, and the oxygen-argon ratio to 0.5:40 for magnetron sputtering operation. A thin film with a thickness of 100 nm is sputtered on a glass substrate, and its transmittance and mobility are measured. The test results are shown in Table 1.

[0061] Example 2

[0062] In Example 2, the preparation method of the praseodymium-gallium co-doped indium zinc oxide sputtering target refers to Example 1, among which, 69.48 parts of indium oxide, 30 parts of zinc oxide, 0.02 parts of praseodymium oxide, and 0.5 parts of gallium oxide.

[0063] Measure the relative density and grain size of the praseodymium-gallium co-doped indium zinc oxide sputtering target obtained in Example 2; use the praseodymium-gallium co-doped indium zinc oxide sputtering target obtained in Example 2 to fabricate a sputtered thin film. Through the magnetron sputtering process, a 100-nm-thick thin film is sputtered on a glass substrate, and measure its light transmittance and mobility. The test results are shown in Table 1.

[0064] Example 3

[0065] In Example 3, the preparation method of the praseodymium-gallium co-doped indium zinc oxide sputtering target refers to Example 1, wherein, 69.48 parts of indium oxide, 30 parts of zinc oxide, 0.03 parts of praseodymium oxide, and 0.5 parts of gallium oxide.

[0066] Measure the relative density and grain size of the praseodymium-gallium co-doped indium zinc oxide sputtering target obtained in Example 3; use the praseodymium-gallium co-doped indium zinc oxide sputtering target obtained in Example 3 to fabricate a sputtered thin film. Through the magnetron sputtering process, a 100-nm-thick thin film is sputtered on a glass substrate, and measure its light transmittance and mobility. The test results are shown in Table 1.

[0067] Example 4

[0068] In Example 4, the preparation method of the praseodymium-gallium co-doped indium zinc oxide sputtering target refers to Example 1, wherein, 68.98 parts of indium oxide, 30 parts of zinc oxide, 0.01 parts of praseodymium oxide, and 1 part of gallium oxide.

[0069] Measure the relative density and grain size of the praseodymium-gallium co-doped indium zinc oxide sputtering target obtained in Example 4; use the praseodymium-gallium co-doped indium zinc oxide sputtering target obtained in Example 4 to fabricate a sputtered thin film. Through the magnetron sputtering process, a 100-nm-thick thin film is sputtered on a glass substrate, and measure its light transmittance and mobility. The test results are shown in Table 1.

[0070] Example 5

[0071] In Example 5, the preparation method of the praseodymium-gallium co-doped indium zinc oxide sputtering target refers to Example 1, wherein, 68.48 parts of indium oxide, 30 parts of zinc oxide, 0.01 parts of praseodymium oxide, and 1.5 parts of gallium oxide.

[0072] Measure the relative density and grain size of the praseodymium-gallium co-doped indium zinc oxide sputtering target obtained in Example 5; use the praseodymium-gallium co-doped indium zinc oxide sputtering target obtained in Example 5 to fabricate a sputtered thin film. Through the magnetron sputtering process, a 100-nm-thick thin film is sputtered on a glass substrate, and measure its light transmittance and mobility. The test results are shown in Table 1.

[0073] Example 6

[0074] In Example 6, the preparation method of the praseodymium-gallium co-doped indium zinc oxide sputtering target was referred to Example 1, wherein, 67.98 parts of indium oxide, 30 parts of zinc oxide, 0.01 part of praseodymium oxide, and 2 parts of gallium oxide.

[0075] Measure the relative density and grain size of the praseodymium-gallium co-doped indium zinc oxide sputtering target obtained in Example 6; use the praseodymium-gallium co-doped indium zinc oxide sputtering target obtained in Example 6 to fabricate a sputtered thin film, and sputter a 100-nm-thick thin film on a glass substrate through a magnetron sputtering process, and measure its light transmittance and mobility. The test results are shown in Table 1.

[0076] Comparative Example 1

[0077] In Comparative Example 1, the preparation method of the indium zinc oxide sputtering target was referred to Example 1, wherein, 70 parts of indium oxide, 30 parts of zinc oxide, 0 part of praseodymium oxide, and 0 part of gallium oxide.

[0078] Measure the relative density and grain size of the indium zinc oxide sputtering target obtained in Comparative Example 1; use the indium zinc oxide sputtering target obtained in Comparative Example 1 to fabricate a sputtered thin film, and sputter a 100-nm-thick thin film on a glass substrate through a magnetron sputtering process, and measure its light transmittance and mobility. The test results are shown in Table 1.

[0079] Comparative Example 2

[0080] In Comparative Example 2, the preparation method of the praseodymium-doped indium zinc oxide sputtering target was referred to Example 1, wherein, 69.48 parts of indium oxide, 30 parts of zinc oxide, 0.02 part of praseodymium oxide, and 0 part of gallium oxide.

[0081] Measure the relative density and grain size of the praseodymium-doped indium zinc oxide sputtering target obtained in Comparative Example 2; use the praseodymium-doped indium zinc oxide sputtering target obtained in Comparative Example 2 to fabricate a sputtered thin film, and sputter a 100-nm-thick thin film on a glass substrate through a magnetron sputtering process, and measure its light transmittance and mobility. The test results are shown in Table 1.

[0082] Comparative Example 3

[0083] In Comparative Example 3, the preparation method of the gallium-doped indium zinc oxide sputtering target was referred to Example 1, wherein, 68 parts of indium oxide, 30 parts of zinc oxide, and 2 parts of gallium oxide.

[0084] Measure the relative density and grain size of the gallium-doped indium zinc oxide sputtering target obtained in Comparative Example 3; use the gallium-doped indium zinc oxide sputtering target obtained in Comparative Example 3 to fabricate a sputtered thin film, and sputter a 100-nm-thick thin film on a glass substrate through a magnetron sputtering process, and measure its light transmittance and mobility. The test results are shown in Table 1.

[0085] Table 1 Table of oxide raw material usage and performance parameters in each example and comparative example

[0086]

[0087] As can be seen from Table 1, the grain sizes of the praseodymium-gallium co-doped indium zinc oxide sputtering targets prepared in Examples 1-6 are between 2.7 and 3.2 μm, the relative densities are between 99.4 and 99.8, the light transmittances are between 91 and 95, and the mobilities are between 36 and 46; while the grain size of the indium zinc oxide sputtering target in Comparative Example 1 is 4.6 μm, which is larger than that in Examples 1-6; the relative density is 98.6, the light transmittance is 86, and the mobility is 26, all of which are much smaller than those in Examples 1-6; the grain size of the praseodymium-doped indium zinc oxide sputtering target in Comparative Example 2 is 3.3 μm, and the relative density is 99.4. Although the grain size and relative density are improved, the light transmittance is 89 and the mobility is 28, which are still smaller than those of the praseodymium-gallium co-doped indium zinc oxide sputtering target; in Comparative Example 3, the mobility of the gallium-doped indium zinc oxide sputtering target is close to that of the praseodymium-gallium co-doped indium zinc oxide sputtering target, but its light transmittance is less than that in Examples 1-6, and the grain size is larger than that in Examples 1-6, and the relative density is lower than that in Examples 1-6, and the overall technical effect is not ideal either.

[0088] The preparation method of the praseodymium-gallium co-doped indium zinc oxide sputtering target disclosed in the embodiments of the present invention optimizes the element ratio of the target, and co-dopes a small amount of praseodymium oxide and gallium oxide into the indium zinc oxide sputtering target. The ionic radius of praseodymium is different from that of indium and zinc ions. After doping, lattice distortion occurs to form a local stress field, which can inhibit grain growth, refine grains, and reduce grain boundary scattering, thereby improving the carrier mobility; the ionic radius of gallium is close to that of indium and zinc ions, and it can replace indium and zinc ions. Moreover, gallium has a high electron affinity. After doping, it provides additional free electrons, significantly increasing the carrier concentration. Finally, a praseodymium-gallium co-doped indium zinc oxide sputtering target with fine grains, controllable secondary phases, stable performance, and high utilization rate is obtained. The praseodymium-gallium co-doped indium zinc oxide sputtering target is used to prepare a highly transparent conductive oxide film, with a light transmittance of 91-95% and a Hall mobility of 36-46 cm 2 / V·s.

[0089] The technical solutions disclosed in the embodiments of the present invention and the technical details disclosed in the examples are only illustrative of the inventive concept of the present invention and do not constitute a limitation on the technical solutions of the embodiments of the present invention. Any conventional changes, substitutions, or combinations made to the technical details disclosed in the embodiments of the present invention have the same inventive concept as the present invention and are within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a praseodymium-gallium co-doped indium zinc oxide sputtering target, characterized in that: Includes steps: S1. Ball-milling praseodymium oxide powder, gallium oxide powder, indium oxide powder and zinc oxide powder according to a set ratio to obtain a mixed raw material powder; adding a set amount of dispersant, binder and water, and ball-milling to obtain a mixed raw material slurry; wherein, calculated by mass, indium oxide is 60-70 parts, zinc oxide is 30-40 parts, praseodymium oxide is 0.01-1 parts, and gallium oxide is 0.5-2 parts; the dispersant is 1-3% of the total mass of the mixed raw material powder, the binder is 0.1-0.5% of the total mass of the mixed raw material powder, and the deionized water is 60-120% of the total mass of the mixed raw material powder; S2, the mixed raw material slurry is spray granulated to obtain spherical granulated powder; S3, spherical granulated powder molding, cold isostatic pressing to obtain target blank; S4. The target blank is subjected to degreasing and sintering integrated treatment to obtain a praseodymium-gallium co-doped indium zinc oxide sputtering target.

2. The method for preparing a praseodymium-gallium co-doped indium-zinc oxide sputtering target according to claim 1, characterized in that: In step S1, the dispersant is a combination of at least one or more of polyvinyl pyrrolidone, polyacrylamide, polyethylene glycol or hydrogenated nitrile rubber, and the binder is a combination of at least one or more of polyvinyl alcohol, sodium polyacrylate, butyl rubber or cyanoacrylate.

3. The method for preparing the praseodymium-gallium co-doped indium-zinc oxide sputtering target according to claim 1, characterized in that: In step S1, during the ball milling process, the ball mill speed is set to 300-500 r / min, and the ball milling time is set to 0.5-36 h.

4. The method for preparing a praseodymium-gallium co-doped indium zinc oxide sputtering target according to claim 1, characterized in that: In step S3, the molding pressure is set to 5-30 MPa, the cold isostatic pressing pressure is set to 200-300 MPa, and the density of the obtained target blank is 50-75%.

5. The method for preparing the praseodymium-gallium co-doped indium zinc oxide sputtering target according to claim 1, characterized in that: In step S4, the degreasing and sintering integrated treatment process includes: The target blank is heated to the degreasing temperature for degreasing treatment; wherein the degreasing temperature is 400-600°C, the heating rate is 0.5-1°C / min, the holding time is 6-12h, and the atmosphere is air; The target blank after degreasing treatment is heated to the first step temperature for heat preservation; wherein the first step temperature is 850-1150° C., the heating rate is 3-5° C. / min, and the heat preservation time is 8-12h; After the first sintering, the temperature is raised to the second step temperature without heat preservation; wherein the second step temperature is 1450-1550°C, and the heating rate is 5-10°C / min; Then the temperature is lowered from the second step temperature to the third step temperature for heat preservation; wherein the third step temperature is greater than 1300°C but less than 1450°C, and the heat preservation time is set to 16 to 24 hours; wherein the sintering atmosphere is oxygen, and the flow rate is 5 to 20 L / min; Finally, the temperature was lowered to 600°C at a rate of 1-3°C / min, and then cooled naturally.

6. The method for preparing the praseodymium-gallium co-doped indium-zinc oxide sputtering target according to claim 1, characterized in that: The purity of praseodymium oxide powder, gallium oxide powder, indium oxide powder and zinc oxide powder is greater than 99.99%.

7. A praseodymium-gallium co-doped indium-zinc oxide sputtering target obtained by the preparation method of the praseodymium-gallium co-doped indium-zinc oxide sputtering target according to any one of claims 1 to 6.

8. Application of praseodymium-gallium co-doped indium zinc oxide sputtering target, characterized in that: The praseodymium-gallium co-doped indium-zinc oxide sputtering target is used to prepare a conductive oxide film, the conductive oxide film has a light transmittance of 91-95%, and a Hall mobility of 36-46 cm 2 / V·s.

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