Indium tin zinc oxide target having high mobility and method of making the same

Abstract

The embodiment of the application discloses indium tin zinc oxide target material with high mobility and a preparation method thereof; the method comprises the following steps: two-step oscillation pressure sintering treatment is performed on spherical granulation prepared by using In2O3 powder, ZnO powder, SnO2 powder and doped metal oxide powder, and the specific steps comprise the following steps: the spherical granulation powder is pre-pressed in a mold under a first pressure; the pre-pressed spherical granulation powder is heated to a first temperature; the first pressure applied to the mold is linearly increased to a second pressure before the temperature reaches the first temperature; first temperature maintaining is performed under the first temperature and the second pressure; oscillation pressure with a frequency of 1-2 Hz and an amplitude of 5-10 MPa is superimposed in the first temperature maintaining stage; the second pressure is maintained to be decreased to a second temperature; second temperature maintaining is performed under the second temperature and the second pressure, and oscillation pressure with the same size and frequency as those in the first temperature maintaining stage is applied; after the second temperature maintaining stage is finished, heating is stopped, the applied oscillation pressure is removed, and the temperature is decreased to 1000 DEG C; and then the furnace is cooled to room temperature.

Description

Technical Field

[0001] This invention belongs to the field of sputtering target technology, specifically relating to indium tin zinc oxide targets with high mobility and their preparation methods. Background Technology

[0002] Amorphous oxide semiconductor thin-film transistors (TFTs) have wide applications in active-matrix displays such as liquid crystal displays (LCDs) and organic light-emitting diodes (OLEDs). In-Ga-Zn-O (IGZO), due to its excellent characteristics such as high mobility, low leakage current, and steep subthreshold swing, has become the first commercially successful TFT product. However, with the increasing demand for ultra-high resolution and frame rates, the typical mobility μFE of IGZO widely used in industry is approximately 10 cm⁻¹. 2 / V·s is no longer sufficient to meet the requirements of new displays, and the field-effect mobility μFE of thin-film transistors needs to be further improved.

[0003] Compared to α-IGZO thin-film transistors, due to In 3+ and Sn 4+ Having similar 5s orbitals, In-Sn-Zn-O (ITZO) thin-film transistors have the potential for high μFE, greater than 20 cm⁻¹. 2 ·V -1 ·s -1 Replacing some of the In with Sn can reduce the manufacturing cost of thin-film transistors. On the other hand, ITZO thin-film transistors have a larger band gap, enabling higher transparency in the visible light range, making them ideal for displays and other optoelectronic applications.

[0004] ITZO targets are typically densified by sintering in a high-temperature environment. Due to prolonged high-temperature holding, abnormal grain growth inevitably occurs, resulting in relatively low density. As a key basic material for transparent conductive oxide thin films, the relative density and grain size of the target material affect the density and chemical state of the film, thereby influencing the mobility and stability of thin-film transistors. However, current technologies still suffer from problems such as low target relative density, large grain size, high sintering temperature, and long sintering time. Summary of the Invention

[0005] In view of this, some embodiments disclose a method for preparing an indium tin zinc oxide target with high mobility, including the following steps:

[0006] S1, In2O3 powder, ZnO powder, SnO2 powder and doped metal oxide powder were prepared into a slurry; the doped metal oxide was an oxide of a low electronegativity metal element with different valence states;

[0007] S2. The slurry is ball-milled;

[0008] S3. The ball-milled slurry is mixed with a binder and spray-granulated to obtain spherical granulated powder;

[0009] S4. Spherical granulated powder is subjected to two-step oscillating pressure sintering treatment to obtain indium tin zinc oxide target material with high mobility;

[0010] The two-step oscillating pressure sintering process includes:

[0011] The spherical granulated powder is pre-compressed in a mold under a first pressure of 5-8 MPa.

[0012] The pre-compressed spherical granulated powder is heated to the first temperature at a heating rate of 5℃ / min; before the temperature reaches the first temperature, the first pressure applied to the mold is linearly increased to the second pressure, with the pressure increasing by 2 to 5 MPa at a time and the rate of increase not exceeding 0.1 MPa / min; the first temperature is 1450 to 1500℃ and the second pressure is 30 to 40 MPa.

[0013] The first heat preservation stage is performed under the first temperature and the second pressure; during the first heat preservation stage, an oscillating pressure with a frequency of 1 to 2 Hz and an amplitude of 5 to 10 MPa is superimposed;

[0014] Maintain the second pressure at 30-40 MPa and cool down to the second temperature at a rate of 5°C / min; the second temperature is 1400-1450°C.

[0015] The second heat preservation stage is performed at a second temperature and a second pressure; wherein, the second heat preservation stage applies an oscillating pressure of the same magnitude and frequency as the first heat preservation stage;

[0016] After the second heat preservation stage, heating is stopped, the external oscillation pressure is removed, the cooling rate is set to 8℃ / min, and the second pressure is maintained until the furnace temperature drops to 1000℃; then the furnace is cooled to room temperature.

[0017] Furthermore, some embodiments disclose methods for preparing indium tin zinc oxide targets with high mobility, wherein the doped metal oxide powder is Pr6O. 11 One of the following: powder, Al2O3 powder, La2O3 powder, HfO2 powder, ZrO2 powder, Nb2O5 powder, V2O5 powder, WO3 powder, or MoO3 powder.

[0018] Some embodiments disclose a method for preparing indium tin zinc oxide targets with high mobility, wherein the mass ratio of In2O3 powder, ZnO powder and SnO2 powder is 20-23:20-27:50-60, the mass ratio of doped metal oxide to total powder is 0.05-5:100, and the total mass content of powder in the slurry is 50-70%.

[0019] Some embodiments disclose a method for preparing indium tin zinc oxide targets with high mobility, wherein the binder is polyvinyl alcohol, and the amount added is 0.5 to 1% of the powder weight.

[0020] Some embodiments disclose a method for preparing indium tin zinc oxide targets with high mobility, wherein the inlet air temperature of spray granulation is 200-300°C, the exhaust air temperature is 80-100°C, and the frequency is 30-50Hz.

[0021] In some embodiments, the preparation method of indium tin zinc oxide target with high mobility is disclosed, wherein the holding time of the first holding stage is set to 5 minutes.

[0022] In some embodiments, the preparation method of indium tin zinc oxide target with high mobility is disclosed, wherein the holding time of the second holding stage is set to 120 min.

[0023] Some embodiments disclose a method for preparing indium tin zinc oxide targets with high mobility, wherein the ball milling conditions include: zirconium oxide balls with diameters of 3, 5, and 10 mm, in a ratio of 1:1:1; ball milling speed of 200–350 rpm; and ball milling time of 24–48 h.

[0024] Some embodiments disclose a method for preparing indium tin zinc oxide targets with high mobility, wherein In2O3 powder, ZnO powder, SnO2 powder, doped metal oxide powder, dispersant, and deionized water are mixed to prepare a slurry, wherein the dispersant is ammonium polyacrylate, and the mass ratio of dispersant to total powder is 0.5 to 1:100.

[0025] On the other hand, some embodiments disclose indium tin zinc oxide targets with high mobility, obtained by the preparation method of indium tin zinc oxide targets with high mobility disclosed in the embodiments of the present invention. The indium tin zinc oxide target is doped with one of the low electronegativity metal elements Pr, Al, La, Hf, Zr, Nb, V, W, and Mo. The relative density of the indium tin zinc oxide target is not less than 99.5%, the grain size is between 2 and 5 μm, and the resistivity is between 3 and 10 mΩ·cm.

[0026] The present invention discloses a method for preparing an indium tin zinc oxide (ITI) target with high mobility. This method involves adding a doped metal oxide to In₂O₃ powder, ZnO powder, and SnO₂ powder, followed by ball milling granulation and a two-step oscillating pressure sintering process to obtain an ITI target with high mobility. This ITI target is doped with one of the low electronegativity metal elements Pr, Al, La, Hf, Zr, Nb, V, W, and Mo. The relative density of this ITI target is not less than 99.5%, the grain size is between 2 and 5 μm, and the resistivity is between 3 and 10 mΩ·cm. It has good application prospects in displays and other optoelectronic applications. Attached Figure Description

[0027] Figure 1 SEM image of the Pr-ITZO sputtering target prepared in Example 2. Detailed Implementation

[0028] The term "embodiment" used herein, as an example, is not necessarily to be construed as superior to or better than other embodiments. Performance testing in these embodiments of the invention, unless otherwise specified, employs conventional testing methods in the art. It should be understood that the terminology used in these embodiments is merely for describing particular implementations and is not intended to limit the scope of the disclosure of these embodiments.

[0029] Unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of this invention pertain; other experimental methods and technical means not specifically noted in the embodiments of this invention refer to experimental methods and technical means commonly used by one of ordinary skill in the art.

[0030] The terms “basic” and “approximately” used in this document are to describe small fluctuations. For example, they can mean 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 expressed in range format in this document are used for convenience and brevity only, and should therefore be flexibly interpreted to include not only the explicitly listed values ​​that define the range, but also all independent values ​​or subranges contained within that range. For example, a numerical range of “1–5%” should be interpreted to include not only the explicitly listed values ​​from 1% to 5%, but also the independent values ​​and subranges within the indicated range. Thus, this numerical range includes independent values ​​such as 2%, 3.5%, and 4%, and subranges such as 1%–3%, 2%–4%, and 3%–5%, etc. This principle also applies to ranges that list only one value. Furthermore, this interpretation applies regardless of the width of the range or the characteristics described.

[0031] In this document, including in the claims, conjunctions such as "comprising," "including," "with," "having," "containing," "involving," and "accommodating" are understood to be open-ended, meaning "including but not limited to." Only the conjunctions "consisting of" and "composed of" are closed conjunctions.

[0032] To better illustrate the content of this invention, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that the invention can be practiced even without certain specific details. In the embodiments, some methods, means, instruments, and devices well-known to those skilled in the art are not described in detail, in order to highlight the main points of the invention.

[0033] Without conflict, the technical features disclosed in the embodiments of the present invention can be combined arbitrarily, and the resulting technical solution belongs to the content disclosed in the embodiments of the present invention.

[0034] In some embodiments, the method for preparing an indium tin zinc oxide target with high mobility includes the steps of:

[0035] Si, In2O3 powder, ZnO powder, SnO2 powder, and doped metal oxide powder are prepared into a slurry; the doped metal oxide is an oxide of a low electronegativity metal element with different valence states; typically, In2O3 powder, ZnO powder, SnO2 powder, and doped metal oxide powder are mixed with a dispersant and water, stirred evenly, and then prepared into a slurry; usually, it is necessary to control the relative proportions of each powder, for example, the mass ratio of In2O3 powder, ZnO powder, and SnO2 powder can be 20-23:20-27:5. The mass ratio of the doped metal oxide powder to the total mass of the three raw material powders can be controlled within a range of 0.05 to 5:100. Generally, the mass of the dispersant needs to be controlled within a certain range, for example, the ratio of the dispersant to the total mass of the three powders can be controlled within a range of 0.5 to 1:100. In some embodiments, the dispersant is ammonium polyacrylate. Furthermore, the total mass of the powder in the slurry needs to be controlled, for example, the total powder mass content in the slurry can be controlled within a range of 50% to 70%.

[0036] Typically, doped metal oxide powders are oxides of low-electronimetric metal elements with different valence states, such as Pr6O. 11 The powder is one of the following: Al2O3 powder, La2O3 powder, HfO2 powder, ZrO2 powder, Nb2O5 powder, V2O5 powder, WO3 powder, or MoO3 powder. By doping with metal oxide powder, the grain size in the indium tin zinc oxide target can be reduced, the distribution can be more uniform, the resistivity of the target can be reduced, and the mobility of the target can be improved.

[0037] S2. The slurry is ball-milled; in some embodiments, the ball milling conditions include: the diameters of the zirconia balls are 3, 5, and 10 mm, the ratio of the number of balls is 1:1:1, the ball milling speed is 200-350 rpm, and the ball milling time is 24-48 h.

[0038] S3. The ball-milled slurry is mixed with a binder and spray-granulated to obtain spherical granulated powder; in some embodiments, the inlet air temperature for spray granulation is 200-300°C, the exhaust air temperature is 80-100°C, and the frequency is 30-50Hz.

[0039] S4. Spherical granulated powder is subjected to two-step oscillating pressure sintering treatment to obtain indium tin zinc oxide target material with high mobility;

[0040] The two-step oscillating pressure sintering process includes:

[0041] The spherical granulated powder is pre-compressed in a mold under a first pressure of 5-8 MPa.

[0042] The pre-compressed spherical granulated powder is heated to the first temperature at a heating rate of 5℃ / min; before the temperature reaches the first temperature, the first pressure applied to the mold is linearly increased to the second pressure, with the pressure increasing by 2 to 5 MPa at a time and the rate of increase not exceeding 0.1 MPa / min; the first temperature is 1450 to 1500℃ and the second pressure is 30 to 40 MPa.

[0043] The first heat preservation stage is performed under the first temperature and the second pressure; during the first heat preservation stage, an oscillating pressure with a frequency of 1 to 2 Hz and an amplitude of 5 to 10 MPa is superimposed; in some embodiments, the heat preservation time of the first heat preservation stage is set to 5 minutes.

[0044] Maintain the second pressure at 30-40 MPa and cool down to the second temperature at a rate of 5°C / min; the second temperature is 1400-1450°C.

[0045] The second heat preservation stage is performed under the second temperature and the second pressure; wherein, the second heat preservation stage applies the same magnitude and frequency of oscillating pressure as the first heat preservation stage, and the heat preservation time of the second heat preservation stage is set to 120 minutes.

[0046] After the second heat preservation stage, heating is stopped, the external oscillation pressure is removed, the cooling rate is set to 8℃ / min, and the second pressure is maintained until the furnace temperature drops to 1000℃; then the furnace is cooled to room temperature to obtain an indium tin zinc target with high mobility.

[0047] In some embodiments, the obtained indium tin zinc oxide target has a relative density of not less than 99.5%, a grain size between 2 and 5 μm, and a resistivity between 3 and 10 mΩ·cm.

[0048] The present invention discloses a method for preparing an indium tin zinc oxide (ITI) target with high mobility. This method involves adding doped metal oxides to In₂O₃ powder, ZnO powder, and SnO₂ powder. The doped metal oxide powders reduce the grain size and make the grain distribution more uniform in the target. After ball milling granulation, a two-step oscillating pressure sintering process is performed to further reduce the grain size, resulting in an ITI target with high mobility. This ITI target has a relative density of not less than 99.5%, a grain size between 2 and 5 μm, and a resistivity between 3 and 10 mΩ·cm, showing promising application prospects in displays and other optoelectronic applications.

[0049] The technical details are further illustrated below with reference to the embodiments.

[0050] Example 1

[0051] The method for preparing the indium tin zinc oxide target with high mobility disclosed in Example 1 includes:

[0052] S1. Add 12g of ammonium polyacrylate to a zirconia ball mill jar containing 720g of deionized water and stir until homogeneous to obtain a dispersant solution. Mix 276g of In2O3 powder, 324g of ZnO powder, and 600g of SnO2 powder and add them to the dispersant solution to form a slurry. In the slurry, the mass ratio of In2O3 powder, ZnO powder, and SnO2 powder is 23:27:50. The solid content of the slurry is 62.5%.

[0053] S2. The slurry is ball-milled. The slurry is poured into a horizontal sand mill and three different diameter zirconia balls of 3, 5 and 10 mm are selected in a ratio of 1:1:1. The ball milling speed is 350 rpm and the ball milling time is 48 hours.

[0054] S3. After ball milling, add 12g of polyvinyl alcohol binder to the slurry and ball mill again for 30min to mix the binder evenly and obtain a mixed slurry. Use a spray granulator to spray dry the obtained mixed slurry to generate a dry mixed spherical granulated powder with good flowability. The inlet air temperature during granulation is 250℃, the outlet air temperature is 100℃, and the frequency is 45Hz.

[0055] S4. Spherical granulated powder is subjected to two-step oscillating pressure sintering treatment to obtain indium tin zinc oxide target material with high mobility;

[0056] The two-step oscillating pressure sintering process includes:

[0057] The spherical granulated powder is pre-compressed in the mold under a first pressure of 5 MPa;

[0058] The pre-compressed spherical granulated powder is heated to a first temperature of 1450℃ at a heating rate of 5℃ / min; before the temperature reaches the first temperature, the first pressure of 5 MPa applied to the mold is linearly increased to a second pressure of 30 MPa, with the pressure increasing by 2 MPa at a time at a rate of 0.1 MPa / min.

[0059] The first heat preservation stage is performed under the first temperature and the second pressure; during the first heat preservation stage, an oscillating pressure with a frequency of 1Hz and an amplitude of 5MPa is superimposed and maintained for 5 minutes;

[0060] After the first heat preservation stage, the second pressure of 30 MPa is maintained, and the temperature is reduced to the second temperature of 1400℃ at a cooling rate of 5℃ / min.

[0061] The second heat preservation stage is performed at the second temperature and the second pressure, and the heat preservation time is 120 minutes; in the second heat preservation stage, the same magnitude and frequency of oscillating pressure as the first heat preservation stage is applied.

[0062] After the second heat preservation stage, heating is stopped, the external oscillation pressure is removed, the cooling rate is set to 8℃ / min, and the second pressure is maintained at 30MPa until the furnace temperature drops to 1000℃; then the furnace is cooled to room temperature.

[0063] The sintered sample was removed, and the relative density of the final ITZO sputtering target sintered body was measured to be 99.70%, the average grain size was 2.76 μm, and the resistivity was 5.67 mΩ·cm.

[0064] Example 2

[0065] Example 2 discloses a method for preparing an indium tin zinc oxide target with high mobility, comprising:

[0066] S1. Add 12g of ammonium polyacrylate to a zirconia ball mill jar containing 720g of deionized water and stir until homogeneous to obtain a dispersant solution. Add 270g of In2O3 powder, 3218g of ZnO powder, 588g of SnO2 powder, and Pr6O... 11 24g of powder was mixed and added to the dispersant solution to form a slurry; in the slurry, the mass ratio of In2O3 powder, ZnO powder and SnO2 powder was 23:27:50; Pr6O 11 The powder accounts for 2% of the total powder mass; the solid content in the slurry is 62.5%.

[0067] S2. The slurry is ball-milled. The slurry is poured into a horizontal sand mill and three different diameter zirconia balls of 3, 5 and 10 mm are selected in a ratio of 1:1:1. The ball milling speed is 350 rpm and the ball milling time is 48 hours.

[0068] S3. After ball milling, add 12g of polyvinyl alcohol binder to the slurry and ball mill again for 30min to mix the binder evenly and obtain a mixed slurry. Use a spray granulator to spray dry the obtained mixed slurry to generate a dry mixed spherical granulated powder with good flowability. The inlet air temperature during granulation is 250℃, the outlet air temperature is 100℃, and the frequency is 45Hz.

[0069] S4. Spherical granulated powder is subjected to two-step oscillating pressure sintering treatment to obtain indium tin zinc oxide target material with high mobility;

[0070] The two-step oscillating pressure sintering process includes:

[0071] The spherical granulated powder is pre-compressed in the mold under a first pressure of 5 MPa;

[0072] The pre-compressed spherical granulated powder is heated to a first temperature of 1450℃ at a heating rate of 5℃ / min; before the temperature reaches the first temperature, the first pressure of 5 MPa applied to the mold is linearly increased to a second pressure of 30 MPa, with the pressure increasing by 2 MPa at a time at a rate of 0.1 MPa / min.

[0073] The first heat preservation stage is performed under the first temperature and the second pressure; during the first heat preservation stage, an oscillating pressure with a frequency of 1Hz and an amplitude of 5MPa is superimposed and maintained for 5 minutes;

[0074] After the first heat preservation stage, the second pressure of 30 MPa is maintained, and the temperature is reduced to the second temperature of 1400℃ at a cooling rate of 5℃ / min.

[0075] The second heat preservation stage is performed at the second temperature and the second pressure, and the heat preservation time is 120 minutes; in the second heat preservation stage, the same magnitude and frequency of oscillating pressure as the first heat preservation stage is applied.

[0076] After the second heat preservation stage, heating is stopped, the external oscillation pressure is removed, the cooling rate is set to 8℃ / min, and the second pressure is maintained at 30MPa until the furnace temperature drops to 1000℃; then the furnace is cooled to room temperature.

[0077] The sintered sample was removed, and the relative density of the final Pr-ITZO sputtering target sintered body was measured to be 99.50%, the average grain size was 2.54 μm, and the resistivity was 5.7 mΩ·cm.

[0078] Figure 1 The SEM image of the Pr-ITZO sputtering target prepared in Example 2 shows that its grain size is small and uniformly distributed, with few voids and high density.

[0079] Example 3

[0080] The preparation method of the indium tin zinc oxide target with high mobility disclosed in Example 3 is carried out with reference to Example 2, wherein: the mass ratio of In2O3, ZnO and SnO2 is 23:27:50; and Pr6O is doped. 11 Its mass accounts for 5% of the total mass of the powder;

[0081] The final Pr-ITZO sputtering target sintered body had a relative density of 99.45%, an average grain size of 2.45 μm, and a resistivity of 5.9 mΩ·cm.

[0082] Example 4

[0083] The preparation method of the indium tin zinc oxide target with high mobility disclosed in Example 4 is carried out with reference to the method disclosed in Example 2, wherein: the mass ratio of In2O3, ZnO and SnO2 is 23:27:50; and the mass of Al2O3 accounts for 1% of the total mass of the powder.

[0084] The final Al-ITZO sputtering target sintered body had a relative density of 99.6%, an average grain size of 2.06 μm, and a resistivity of 4.90 mΩ·cm.

[0085] Example 5

[0086] The preparation method of the indium tin zinc oxide target with high mobility disclosed in Example 5 is carried out with reference to the method disclosed in Example 2, wherein: the mass ratio of In2O3, ZnO and SnO2 is 23:27:50; and the mass of La2O3 accounts for 1% of the total mass of the powder.

[0087] The final La-ITZO sputtering target sintered body had a relative density of 99.60%, an average grain size of 2.43 μm, and a resistivity of 4.69 mΩ·cm.

[0088] Example 6

[0089] The preparation method of the indium tin zinc oxide target with high mobility disclosed in Example 6 is carried out with reference to the method disclosed in Example 2, wherein: the mass ratio of In2O3, ZnO and SnO2 is 23:27:50; and the mass of HfO2 accounts for 1% of the total mass of the powder.

[0090] The final Hf-ITZO sputtering target sintered body had a relative density of 99.65%, an average grain size of 2.41 μm, and a resistivity of 2.40 mΩ·cm.

[0091] Example 7

[0092] The preparation method of the indium tin zinc oxide target with high mobility disclosed in Example 7 is carried out with reference to the method disclosed in Example 2, wherein: the mass ratio of In2O3, ZnO and SnO2 is 23:27:50; and the mass of ZrO2 accounts for 1% of the total mass of the powder.

[0093] The final Zr-ITZO sputtering target sintered body had a relative density of 99.63%, an average grain size of 2.35 μm, and a resistivity of 3.35 mΩ·cm.

[0094] Example 8

[0095] The preparation method of the indium tin zinc oxide target with high mobility disclosed in Example 8 is carried out with reference to the method disclosed in Example 2, wherein the mass ratio of In2O3, ZnO and SnO2 is 23:27:50; and the mass of V2O5 accounts for 1% of the total mass of the powder.

[0096] The final V-ITZO sputtering target sintered body had a relative density of 99.59%, an average grain size of 2.33 μm, and a resistivity of 2.30 mΩ·cm.

[0097] Example 9

[0098] The preparation method of the indium tin zinc oxide target with high mobility disclosed in Example 9 is carried out with reference to the method disclosed in Example 2, wherein the mass ratio of In2O3, ZnO and SnO2 is 23:27:50; and the mass of Nb2O5 accounts for 1% of the total powder mass.

[0099] The final Nb-ITZO sputtering target sintered body had a relative density of 99.61%, an average grain size of 2.30 μm, and a resistivity of 2.32 mΩ·cm.

[0100] Example 10

[0101] The preparation method of the indium tin zinc oxide target with high mobility disclosed in Example 10 is carried out with reference to the method disclosed in Example 2, wherein the mass ratio of In2O3, ZnO and SnO2 is 23:27:50; and the mass of WO3 accounts for 1% of the total mass of the powder.

[0102] The final W-ITZO sputtering target sintered body had a relative density of 99.63%, an average grain size of 2.32 μm, and a resistivity of 2.25 mΩ·cm.

[0103] Example 11

[0104] The preparation method of the indium tin zinc oxide target with high mobility disclosed in Example 11 is carried out with reference to the method disclosed in Example 2, wherein: the mass ratio of In2O3, ZnO and SnO2 is 23:27:50; and the mass of MoO3 accounts for 1% of the total mass of the powder.

[0105] The final Mo-ITZO sputtering target sintered body had a relative density of 99.57%, an average grain size of 2.30 μm, and a resistivity of 2.28 mΩ·cm.

[0106] The results of Examples 1 to 11 show that after doping with low electronegativity metal elements in Examples 2 to 11, the average grain size of the target material is smaller than that in Example 1; and the resistivity of the target material in Examples 4 to 11 decreases continuously with the increase of the valence state of the doped metal element, indicating that metal element doping is indeed effective and is related to the valence state of the doped element.

[0107] The present invention discloses a method for preparing an indium tin zinc oxide (ITI) target with high mobility. This method involves adding a doped metal oxide to In₂O₃ powder, ZnO powder, and SnO₂ powder, followed by ball milling granulation and a two-step oscillating pressure sintering process to obtain an ITI target with high mobility. This ITI target is doped with one of the low electronegativity metal elements Pr, Al, La, Hf, Zr, Nb, V, W, and Mo. The relative density of this ITI target is not less than 99.5%, the grain size is between 2 and 5 μm, and the resistivity is between 3 and 10 mΩ·cm. It has good application prospects in displays and other optoelectronic applications.

[0108] The technical solutions and technical details disclosed in the embodiments of this invention are merely illustrative of the inventive concept of this invention and do not constitute a limitation on the technical solutions of the embodiments of this invention. Any conventional changes, substitutions, or combinations made to the technical details disclosed in the embodiments of this invention have the same inventive concept as this invention and are within the protection scope of the claims of this invention.

Claims

1. A method for preparing an indium tin zinc oxide target with high mobility, characterized in that, Including the following steps: A slurry was prepared from Si, In2O3 powder, ZnO powder, SnO2 powder, and doped metal oxide powder; the doped metal oxide was an oxide of a low electronegativity metal element with different valence states; the doped metal oxide powder was Pr6O 11 The slurry contains one of the following powders: Al2O3 powder, La2O3 powder, HfO2 powder, ZrO2 powder, Nb2O5 powder, V2O5 powder, WO3 powder, or MoO3 powder; the mass ratio of the In2O3 powder, the ZnO powder, and the SnO2 powder is 20–23:20–27:50–60, and the ratio of the doped metal oxide to the total powder mass is 0.05–5:100; the total powder mass content in the slurry is 50–70%. S2. The slurry is ball-milled; S3. The ball-milled slurry is mixed with a binder and spray-granulated to obtain spherical granulated powder; S4. Spherical granulated powder is subjected to two-step oscillating pressure sintering treatment to obtain indium tin zinc oxide target material with high mobility; The two-step oscillating pressure sintering process includes: The spherical granulated powder is pre-compressed in a mold under a first pressure; the first pressure is 5-8 MPa. The pre-compressed spherical granulated powder is heated to a first temperature at a heating rate of 5℃ / min; before the temperature reaches the first temperature, the first pressure applied to the mold is linearly increased to a second pressure, with the pressure increasing by 2 to 5 MPa at a time and the rate of increase not exceeding 0.1 MPa / min; the first temperature is 1450 to 1500℃, and the second pressure is 30 to 40 MPa; The first heat preservation stage is performed under the first temperature and the second pressure; during the first heat preservation stage, an oscillating pressure with a frequency of 1 to 2 Hz and an amplitude of 5 to 10 MPa is superimposed; Maintain the second pressure at 30-40 MPa and cool down to the second temperature at a rate of 5°C / min; the second temperature is 1400-1450°C. The second heat preservation stage is performed at a second temperature and a second pressure; wherein, the second heat preservation stage applies an oscillating pressure of the same magnitude and frequency as the first heat preservation stage; After the second heat preservation stage, heating is stopped, the external oscillation pressure is removed, the cooling rate is set to 8℃ / min, and the second pressure is maintained until the furnace temperature drops to 1000℃; then the furnace is cooled to room temperature.

2. The method for preparing the indium tin zinc oxide target with high mobility according to claim 1, characterized in that, The binder is polyvinyl alcohol, and the amount added is 0.5% to 1% of the powder weight.

3. The method for preparing the indium tin zinc oxide target with high mobility according to claim 1, characterized in that, The inlet air temperature for spray granulation is 200–300℃, the exhaust air temperature is 80–100℃, and the frequency is 30–50Hz.

4. The method for preparing the indium tin zinc oxide target with high mobility according to claim 1, characterized in that, The heat preservation time for the first heat preservation stage is set to 5 minutes.

5. The method for preparing the indium tin zinc oxide target with high mobility according to claim 1, characterized in that, The heat preservation time for the second heat preservation stage is set to 120 minutes.

6. The method for preparing the indium tin zinc oxide target with high mobility according to claim 1, characterized in that, The ball milling conditions included: zirconia balls with diameters of 3, 5, and 10 mm in a ratio of 1:1:1; a ball milling speed of 200–350 rpm; and a ball milling time of 24–48 h.

7. The method for preparing the indium tin zinc oxide target with high mobility according to claim 1, characterized in that, A slurry is prepared by mixing In2O3 powder, ZnO powder, SnO2 powder, doped metal oxide powder, dispersant, and deionized water. The dispersant is ammonium polyacrylate, and the mass ratio of the dispersant to the total powder is 0.5 to 1:

100.

8. An indium tin zinc oxide target with high mobility, characterized in that, The indium tin zinc oxide target is prepared by any one of the following methods according to claims 1-7: the target is doped with one of the low electronegativity metal elements Pr, Al, La, Hf, Zr, Nb, V, W, and Mo; the relative density of the target is not less than 99.5%, the grain size is between 2 and 5 μm, and the resistivity is between 3 and 10 mΩ·cm.

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