Indium gallium tin oxide sputtering target and method for manufacturing the same

Abstract

The application provides a preparation method of a low-resistivity indium gallium tin oxide (IGTO) sputtering target, and belongs to the technical field of photoelectric device materials. In the application, indium oxide powder, gallium oxide powder and tin oxide powder are added into a ball mill tank according to a certain indium gallium tin atomic ratio (70:15:15, 70:10:20, 70:20:10), deionized water, a dispersing agent and a binder are added, and high-solid-content and low-viscosity IGTO slurry is prepared by using high-energy ball milling technology; high-density and microstructure-uniform IGTO target green bodies are prepared by using pressure injection molding forming technology or granulation-molding-cold isostatic pressing forming technology; and high-density, low-resistivity and fine-grained IGTO target sintered bodies are prepared by using pressure-free debinding and sintering integrated technology. Experimental results of the embodiments show that the relative density of the indium gallium tin oxide sputtering target prepared by the preparation method is 98.2-99.8%.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic device materials technology, and in particular to an indium gallium tin oxide sputtering target and its preparation method. Background Technology

[0002] Transparent conductive oxide (TCO) films are a class of special functional materials with excellent optical and electrical properties, widely used in electronic screens, touch screen panels, light-emitting diodes (LEDs), and solar cells. These materials are easy to manufacture and can be prepared using techniques such as chemical vapor deposition, magnetron sputtering, and spray pyrolysis. Currently, the most commonly used TCOs are tin-doped indium oxide (indium tin oxide or ITO) and indium gallium zinc oxide (IGZO) systems.

[0003] Compared with tin-doped indium oxide (ITO) and aluminum-doped zinc oxide (AZO) material systems, indium gallium tin oxide (IGTO) thin films prepared by indium gallium tin oxide material system have higher carrier mobility. Therefore, their excellent optoelectronic performance can be further improved without increasing the carrier concentration (maintaining high transmittance).

[0004] Indium gallium tin oxide (IGTO) films can also be used as channel layer materials in thin-film transistor (TFT) devices. Compared to indium gallium zinc oxide (IGZO) films, indium gallium tin oxide (IGTO) films contain more In... 3+ and Sn 4+ The ions have the same electronic structure, which allows Sn to enhance the percolation conduction path in the oxide film through extensive overlap of adjacent large 5s orbitals, thereby enabling higher field-effect mobility at lower annealing temperatures.

[0005] Currently, magnetron sputtering is the main method used to prepare indium gallium tin oxide (IGTO) thin films. The density and grain size of the sputtering target are important factors affecting sputtering stability and film properties.

[0006] Therefore, improving the density of IGTO targets and controlling their grain size has become the primary technical problem to be solved in this field. Summary of the Invention

[0007] The purpose of this invention is to provide a low resistivity indium gallium tin oxide (IGTO) sputtering target and its preparation method to solve the problems mentioned in the background art. The indium gallium tin oxide (IGTO) sputtering target prepared by the preparation method proposed in this invention has high-density fine grains.

[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0009] A method for preparing a low resistivity indium gallium tin oxide sputtering target includes the following steps:

[0010] S1. Indium oxide, gallium oxide, tin oxide, deionized water, dispersant and binder are mixed according to stoichiometric ratio to obtain indium gallium tin oxide slurry;

[0011] S2. The indium gallium tin oxide (IGTO) slurry obtained in S1 is subjected to pressure injection molding, and after drying, an indium gallium tin oxide (IGTO) sputtering target blank is obtained.

[0012] S3. The indium gallium tin oxide (IGTO) sputtering target blank obtained in S2 is processed using a degreasing-pressureless sintering integrated technology to obtain an indium gallium tin oxide (IGTO) sputtering target.

[0013] Preferably, the number of indium atoms in the indium gallium tin oxide (IGTO) paste obtained in S1 is 70% of the total number of indium, gallium, and tin atoms;

[0014] Preferably, the number of gallium atoms in the indium gallium tin oxide (IGTO) paste obtained in S1 is 10 to 20% of the total number of indium, gallium, and tin atoms.

[0015] Preferably, the mass of the dispersant in S1 is 0.5 to 1.8% of the total mass of indium oxide, gallium oxide, and tin oxide.

[0016] Preferably, the mass of the binder in S1 is 0.3% to 2.5% of the total mass of indium oxide, gallium oxide, and tin oxide.

[0017] Preferably, the indium gallium tin oxide (IGTO) slurry obtained in S1 has a solid content greater than 75% and a viscosity less than 100 mPa·s.

[0018] Preferably, the pressure grouting forming in S2 specifically includes the following:

[0019] Before pressure injection molding, the indium gallium tin oxide (IGTO) slurry is subjected to vacuum degassing treatment; the mold material used for pressure injection molding is gypsum; the pressure for pressure injection molding is 0.1 to 0.4 MPa.

[0020] Preferably, the drying operation in S2 is carried out in a constant temperature and humidity chamber, specifically including the following:

[0021] The oven temperature is 30–35℃; the ambient humidity is 50–60%RH; the drying time is 48–72 hours; and the quality of the sputtering target blank remains constant.

[0022] Preferably, the degreasing treatment temperature in S3 is 650-800°C, and the holding time for the degreasing treatment is 12-24 hours.

[0023] Preferably, the pressureless sintering process described in S3 specifically includes the following:

[0024] The sintering atmosphere is oxygen; the heating rate is 3℃ / min; the holding temperature is 1400~1600℃; and the cooling rate is 1-5℃ / min.

[0025] Indium gallium tin oxide (IGTO) sputtering target prepared using the above method.

[0026] Compared with existing technologies, this invention provides a method and system for generating modular and efficient integrated grids for numerical reactors, which has the following advantages:

[0027] This invention provides an indium gallium tin oxide (IGTO) sputtering target and its preparation method. Indium oxide powder, gallium oxide powder, and tin oxide powder are added to a ball mill jar at specific indium-gallium-tin atomic ratios (70:15:15, 70:10:20, 70:20:10), along with deionized water, a dispersant, and a binder. A high-solids-content, low-viscosity IGTO slurry is prepared using high-energy ball milling technology. A high-density IGTO sputtering target blank is obtained using pressure casting technology. The dispersant and binder are removed using a degreasing process, followed by sintering in a pressureless flow atmosphere, resulting in a target with a uniform microstructure and high density. Experimental results from the examples show that the indium gallium tin oxide sputtering target prepared by the method provided by this invention has a relative density of 98.2%–99.8%, significantly superior to existing commercially available preparation methods. Attached Figure Description

[0028] Figure 1 This is an overall flowchart of a method for preparing an indium gallium tin oxide sputtering target proposed in this invention;

[0029] Figure 2 The diagram shows the phase composition and microstructure of the IGTO sputtering target prepared in Example 1 of this invention.

[0030] Figure 3 The diagram shows the phase composition and microstructure of the IGTO sputtering target prepared in Example 2 of this invention.

[0031] Figure 4 This is a diagram showing the phase composition and microstructure of the IGTO sputtering target prepared in Example 3 of the present invention. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0033] This invention provides an indium gallium tin oxide sputtering target and its preparation method, comprising the following steps:

[0034] (1) In stoichiometric ratio, indium oxide, gallium oxide, tin oxide, deionized water, dispersant and binder are mixed to obtain IGTO slurry;

[0035] (2) The IGTO slurry obtained in step (1) is subjected to pressure injection molding and dried to obtain an IGTO sputtering target blank;

[0036] (3) The IGTO sputtering target blank obtained in step (2) is subjected to degreasing treatment and pressureless flow atmosphere sintering in sequence to obtain indium gallium tin oxide sputtering target.

[0037] Unless otherwise specified, the present invention does not have any special limitation on the source of the components, and commercially available products well known to those skilled in the art can be used.

[0038] In this invention, indium oxide, gallium oxide, tin oxide, deionized water, dispersant and binder are mixed in stoichiometric proportions to obtain IGTO slurry;

[0039] In this invention, the indium oxide, gallium oxide and tin oxide are preferably nanoparticles: the particle size of the indium oxide, gallium oxide and tin oxide is preferably 100-300 nm, more preferably 150-250 nm.

[0040] The present invention does not impose any particular limitation on the mixing operation of indium oxide, gallium oxide, and tin oxide; any powder mixing technique well known to those skilled in the art that can achieve uniform mixing is acceptable. In this invention, the mixing of indium oxide, gallium oxide, and tin oxide is preferably carried out in a high-efficiency mixer, an air jet mill, or a ball mill.

[0041] This invention mixes indium oxide, gallium oxide, tin oxide, deionized water, dispersant and binder to obtain IGTO slurry.

[0042] In this invention, the dispersant is preferably ammonium polyacrylate or a polycarboxylic acid dispersant. The mass of the dispersant is preferably 0.8–1.6% of the total mass of indium oxide, gallium oxide, and tin oxide, more preferably 1.0–1.4%, and most preferably 1.2%. By controlling the mass of the dispersant within the above range, this invention ensures that the oxide powder is fully and uniformly dispersed in the slurry, which is beneficial for obtaining an IGTO sputtering target with a uniform phase distribution.

[0043] In this invention, the binder is preferably polyvinyl alcohol or gum arabic. The mass of the binder is preferably 0.3–1.0% of the total mass of indium oxide, gallium oxide, and tin oxide, more preferably 0.4–0.9%, and most preferably 0.5–0.8%. By controlling the mass of the binder within the above range, this invention ensures that the slurry has a suitable viscosity and that the resulting IGTO sputtering target preform has a suitable density, thereby improving the density of the target.

[0044] In this invention, the water content is preferably 16-20% of the total mass of indium oxide, gallium oxide, and tin oxide, more preferably 17-19%, and most preferably 18%. By controlling the amount of water within the above range, this invention ensures that the slurry has a suitable solid content, promotes the full and uniform dispersion of oxide powder in the slurry, and is beneficial to obtaining an IGTO sputtering target with a uniform phase distribution.

[0045] In this invention, the solid content of the IGTO slurry is preferably greater than 75%, more preferably less than 80%. The viscosity of the IGTO slurry is preferably less than 100 mPa·s, more preferably greater than 50 mPa·s. By controlling the viscosity and solid content of the IGTO slurry within the above ranges, this invention facilitates the full and uniform dispersion of the oxide powder in the slurry, while also ensuring the slurry has a suitable viscosity, which is beneficial for obtaining an IGTO sputtering target with uniform phase distribution and high density.

[0046] In this invention, the mixing of indium oxide, gallium oxide, tin oxide, deionized water, dispersant, and binder is preferably ball milling. Ball milling, through which indium oxide, gallium oxide, and tin oxide are uniformly mixed, is beneficial for obtaining IGTO sputtering targets with uniform phase distribution.

[0047] In this invention, the addition of a dispersant causes a change in the pH value of the slurry. Preferably, this invention uses a nanoparticle size potentiometer to detect the zeta potential value of the slurry as pH changes, ensuring the slurry is in an optimal dispersion state.

[0048] After obtaining the IGTO slurry, the present invention performs pressure injection molding on the IGTO slurry to obtain an IGTO sputtering target blank.

[0049] In this invention, the pressure for pressure injection molding is preferably 0.1–0.4 MPa. The mold used for pressure injection molding is preferably made of gypsum material. This invention utilizes pressure injection molding to prepare large-sized target blanks, and is simple to operate and cost-effective.

[0050] Preferably, the IGTO slurry is subjected to vacuum degassing treatment before pressure injection molding; the vacuum pressure of the vacuum degassing treatment is preferably below 0.1 Pa. In this invention, the vacuum degassing treatment can remove gas from the slurry, which is beneficial for obtaining a high-density IGTO sputtering target preform.

[0051] After pressure grouting is completed, the product obtained by pressure grouting is preferably dried to obtain an IGTO sputtering target preform. Drying removes residual moisture.

[0052] In this invention, the drying temperature is preferably 30-35°C; the ambient humidity for low-temperature drying is preferably 50-60%RH; and the low-temperature drying time is preferably 48-72 hours.

[0053] In this invention, the drying is preferably carried out in a constant temperature and humidity chamber.

[0054] In this invention, the relative density of the IGTO sputtering target preform is preferably 60% or higher.

[0055] After obtaining the IGTO sputtering target blank, the present invention performs degreasing treatment and pressureless flow atmosphere sintering on the IGTO sputtering target blank to obtain indium gallium tin oxide sputtering target.

[0056] In this invention, the degreasing treatment temperature is preferably 650–800°C; the holding time for the degreasing treatment is preferably 12–24 h; and the rate of heating to the degreasing treatment temperature is preferably 0.5–1.5°C / min. This invention, through degreasing treatment, can remove binders and dispersants from IGTO preforms.

[0057] In this invention, after the degreasing process is completed, no cooling is performed, and sintering is carried out directly in a pressureless flowing atmosphere.

[0058] In this invention, the pressureless flow atmosphere sintering preferably includes:

[0059] The preferred sintering atmosphere is oxygen; the preferred heating rate is 6℃ / min; the preferred holding temperature is 1400~1600℃, more preferably 1450~1550℃; and the preferred cooling method is furnace cooling.

[0060] After sintering in a pressureless flowing atmosphere, an indium gallium tin oxide sputtering target is obtained.

[0061] This invention uses a pressure injection molding method to prepare target blanks with large dimensions, and the operation is simple and cost-effective.

[0062] This invention provides an indium gallium tin oxide (IGaT) sputtering target prepared by the method described above. The IGaT sputtering target provided by this invention has a uniform microstructure and high density.

[0063] In this invention, the indium gallium tin oxide sputtering target has a relative density of 98.2-99.8% and a bulk resistivity of 0.2-0.6 mΩ·cm.

[0064] Based on the above, specific examples are as follows.

[0065] Example 1

[0066] Nanoscale indium oxide powder, gallium oxide powder, and tin oxide powder were weighed according to an atomic ratio of indium:gallium:tin = 70:15:15 at.%, with a total powder mass of 800g, including 580.84g of indium oxide powder, 84.03g of gallium oxide powder, and 135.13g of tin oxide powder. 200g of deionized water (25% of the total powder mass), 9.6g of ammonium polyacrylate (NH4PAA) (1.2% of the total powder mass), and 6.4g of polyvinyl alcohol (NH4PAA) (0.8% of the total powder mass) were added to the mixed powder to obtain an IGTO slurry with a solid content of 79.06% and a viscosity of 90mPa·s.

[0067] The prepared slurry was dispersed by ball milling at 300 rpm for 72 hours. The IGTO slurry after sand milling was then vacuum defoamed to prevent the formation of large air bubbles. IGTO sputtering target preforms were then prepared using a pressure injection molding process with an injection pressure of 0.3 MPa and a holding time of 3 hours. The preforms were then removed and placed in a constant temperature and humidity oven for drying at 35°C and 60% RH for 48 hours until the quality of the preforms remained constant. Finally, IGTO sputtering target preforms with a relative density of 60% were obtained.

[0068] The IGTO sputtering target blank was degreased at a heating rate of 1℃ / min to a degreasing temperature of 700℃ for 18 hours. The degreased IGTO sputtering target blank was then directly sintered in a pressureless flowing atmosphere at a heating rate of 6℃ / min to 1500℃ for 10 hours. After furnace heating was completed, the sintered target body was cooled with the furnace, yielding In2O3 and Ga2In6Sn2O phases. 16 Uniformly distributed IGTO sputtering target, phase composition and microstructure as follows Figure 1 As shown.

[0069] The density and resistivity of the IGTO sputtering target prepared in this embodiment were tested according to Archimedes' principle and a four-probe instrument, and the relative density was 99.1% and the bulk resistivity was 0.5 mΩ·cm.

[0070] Example 2

[0071] Nanoscale indium oxide powder, gallium oxide powder, and tin oxide powder were weighed according to an atomic ratio of indium:gallium:tin = 70:10:20 at.%, with a total powder mass of 800g, including 568.73g of indium oxide powder, 54.85g of gallium oxide powder, and 176.41g of tin oxide powder. 200g of deionized water (25% of the total powder mass), 9.6g of ammonium polyacrylate (NH4PAA) (1.2% of the total powder mass), and 6.4g of polyvinyl alcohol (NH4PAA) (0.8% of the total powder mass) were added to the mixed powder to obtain an IGTO slurry with a solid content of 79.06% and a viscosity of 90mPa·s.

[0072] The prepared slurry was dispersed by ball milling at 300 rpm for 72 hours. The IGTO slurry after sand milling was then vacuum defoamed to prevent the formation of large air bubbles. IGTO sputtering target preforms were then prepared using a pressure injection molding process with an injection pressure of 0.3 MPa and a holding time of 3 hours. The preforms were then removed and placed in a constant temperature and humidity oven for drying at 35°C and 60% RH for 48 hours until the quality of the preforms remained constant. Finally, IGTO sputtering target preforms with a relative density of 60% were obtained.

[0073] The IGTO sputtering target blank was degreased at a heating rate of 1℃ / min to a degreasing temperature of 700℃ for 18 hours. The degreased IGTO sputtering target blank was then directly sintered in a pressureless flowing atmosphere at a heating rate of 6℃ / min to 1500℃ for 10 hours. After furnace heating was completed, the sintered target body was cooled with the furnace, yielding In₂O₃ and Ga phases. 1.6 In 6.4 Sn2O 16 Uniformly distributed IGTO sputtering target, phase composition and microstructure as follows Figure 2 As shown.

[0074] The density and resistivity of the IGTO sputtering target prepared in this embodiment were tested according to Archimedes' principle and a four-probe instrument, and the relative density was 98.2% and the bulk resistivity was 0.4 mΩ·cm.

[0075] Example 3

[0076] Nanoscale indium oxide powder, gallium oxide powder, and tin oxide powder were weighed according to an atomic ratio of indium:gallium:tin = 70:20:10 at.%, with a total powder mass of 800g, including 593.48g of indium oxide powder, 114.48g of gallium oxide powder, and 92.04g of tin oxide powder. 200g of deionized water (25% of the total powder mass), 9.6g of ammonium polyacrylate (NH4PAA) (1.2% of the total powder mass), and 6.4g of polyvinyl alcohol (NH4PAA) (0.8% of the total powder mass) were added to the mixed powder to obtain an IGTO slurry with a solid content of 79.06% and a viscosity of 90mPa·s.

[0077] The prepared slurry was dispersed by ball milling at 300 rpm for 72 hours. The IGTO slurry after sand milling was then vacuum defoamed to prevent the formation of large air bubbles. IGTO sputtering target preforms were then prepared using a pressure injection molding process with an injection pressure of 0.3 MPa and a holding time of 3 hours. The preforms were then removed and placed in a constant temperature and humidity oven for drying at 35°C and 60% RH for 48 hours until the quality of the preforms remained constant. Finally, IGTO sputtering target preforms with a relative density of 60% were obtained.

[0078] The IGTO sputtering target blank was degreased at a heating rate of 1℃ / min to a degreasing temperature of 700℃ for 18 hours. The degreased IGTO sputtering target blank was then directly sintered in a pressureless flowing atmosphere at a heating rate of 6℃ / min to 1500℃ for 10 hours. After furnace heating was completed, the sintered target body was cooled with the furnace, yielding In₂O₃ and Ga phases. 1.6 In 6.4 Sn2O 16 The phase composition and microstructure of the IGTO sputtering target with uniform GaInO3 distribution are as follows: Figure 3 As shown.

[0079] The density and resistivity of the IGTO sputtering target prepared in this embodiment were tested according to Archimedes' principle and a four-probe instrument, and the relative density was 99.8% and the bulk resistivity was 0.4 mΩ·cm.

[0080] As can be seen from the above embodiments, the preparation method provided by the present invention is simple to operate, saves costs, and produces IGTO sputtering targets with uniform structure, high density and low resistivity.

[0081] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a low-resistivity indium gallium tin oxide sputtering target, characterized in that, Includes the following steps: S1. Indium oxide, gallium oxide, tin oxide, deionized water, dispersant, and binder are mixed in stoichiometric proportions to obtain an indium gallium tin oxide slurry; the number of indium atoms in the indium gallium tin oxide slurry obtained in S1 is 70% of the total number of indium, gallium, and tin atoms; The number of gallium atoms in the indium gallium tin oxide paste obtained in S1 is 10-20% of the total number of indium, gallium, and tin atoms; S2. The indium gallium tin oxide slurry obtained in S1 is pressure-cast into shape, and after drying, an indium gallium tin oxide sputtering target blank is obtained. S3. The indium gallium tin oxide sputtering target blank obtained in S2 is processed using a degreasing-pressureless sintering integrated technology to obtain an indium gallium tin oxide sputtering target; the indium gallium tin oxide sputtering target has a relative density of 98.2-99.8% and a volume resistivity of 0.2-0.6 mΩ·cm.

2. The method for preparing a low resistivity indium gallium tin oxide sputtering target according to claim 1, characterized in that, The mass of the dispersant in S1 is 0.5 to 1.8% of the total mass of indium oxide, gallium oxide, and tin oxide.

3. The method for preparing a low resistivity indium gallium tin oxide sputtering target according to claim 1, characterized in that, The mass of the binder mentioned in S1 is 0.3 to 2.5% of the total mass of indium oxide, gallium oxide, and tin oxide.

4. The method for preparing a low resistivity indium gallium tin oxide sputtering target according to claim 1, characterized in that, The indium gallium tin oxide slurry obtained in S1 has a solid content greater than 75% and a viscosity less than 100 mPa·s.

5. The method for preparing a low resistivity indium gallium tin oxide sputtering target according to claim 1, characterized in that, The pressure grouting molding described in S2 specifically includes the following: Before pressure injection molding, the indium gallium tin oxide slurry is subjected to vacuum degassing treatment; the mold material used for pressure injection molding is gypsum; the pressure for pressure injection molding is 0.1~0.4 MPa.

6. The method for preparing a low resistivity indium gallium tin oxide sputtering target according to claim 1, characterized in that, The drying process in S2 is carried out in a constant temperature and humidity chamber, and includes the following: The oven temperature is 30~35 ℃; the ambient humidity is 50~60%RH; the drying time is 48~72 h; and the quality of the sputtered target blank remains constant.

7. The method for preparing a low resistivity indium gallium tin oxide sputtering target according to claim 1, characterized in that, The degreasing treatment temperature described in S3 is 650~800 ℃, and the holding time for the degreasing treatment is 12~24 h.

8. The method for preparing a low resistivity indium gallium tin oxide sputtering target according to claim 1, characterized in that, The pressureless sintering process described in S3 specifically includes the following: The sintering atmosphere is oxygen; the heating rate is 3 ℃ / min; the holding temperature is 1400~1600 ℃; and the cooling rate is 1-5 ℃ / min.

9. An indium gallium tin oxide sputtering target prepared by the preparation method according to any one of claims 1 to 8.

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