Rare earth-doped indium zinc oxide sputter film target and method for producing the same

Abstract

The application discloses a rare earth doped indium zinc oxide sputtering film target and a preparation method thereof. The preparation method comprises the following steps: S1, a certain amount of indium salt solution, zinc salt solution and rare earth salt solution are mixed, and a certain amount of pure water, a stabilizer and an organic solvent are added, and the mixture is stirred to obtain a precursor solution; S2, the precursor solution is spin-coated on a silicon wafer, and the silicon wafer coated with the precursor solution is dried; S3, the dried silicon wafer is annealed at a certain temperature to obtain a rare earth doped indium zinc oxide composite film; wherein the annealing temperature is 200-400 DEG C; and S4, the rare earth doped indium zinc oxide composite film is adhered to a titanium back plate through indium particles to obtain the rare earth doped indium zinc oxide sputtering film target. The preparation method of the rare earth doped indium zinc oxide sputtering film target disclosed in the embodiment of the application has simple preparation process, saves energy consumption, and the formed product has high light transmittance and low resistivity.

Description

Technical Field

[0001] This application belongs to the field of sputtering target technology, specifically relating to rare earth-doped indium zinc oxide sputtering film targets and their preparation methods. Background Technology

[0002] In the current flat panel display (FPD) market, thin-film transistor (TFT) displays hold a dominant position. In TFT fabrication, the channel layer material is crucial to TFT performance. Channel layer materials are generally classified into three categories: amorphous silicon (a-Si), polycrystalline silicon (poly-Si), and metal oxide (MO) semiconductors. With increasing demands for resolution and sharpness in display panels, MO-TFTs are gaining more and more attention due to their higher carrier concentration and high mobility.

[0003] The commonly used deposition method for metal-oxide thin-film transistors (MO-TFTs) is magnetron sputtering deposition of oxide targets. The performance of the oxide target, a key basic material, significantly affects the performance of the sputtered thin film and even the TFT device itself. Therefore, developing novel high-performance oxide targets and finding suitable target element ratios will positively promote the development of flat panel displays.

[0004] However, the preparation of conventional oxide targets is a traditional metallurgical process, which is complex and time-consuming. If the final film performance is uncertain and cannot meet the requirements of device applications, preparing targets with each raw material ratio through conventional processes will not only result in a huge waste of materials, but also increase or decrease time costs, which is not conducive to cost reduction and efficiency improvement. Summary of the Invention

[0005] In view of this, some embodiments disclose a method for preparing a rare earth-doped indium zinc oxide sputtering film target, including the following steps:

[0006] S1. Take a set amount of indium salt solution, zinc salt solution and rare earth salt solution, mix them, and add a set amount of pure water, stabilizer and organic solvent, and stir to obtain precursor solution;

[0007] S2. Spin-coat the precursor solution onto the silicon wafer and dry the silicon wafer coated with the precursor solution.

[0008] S3. The dried silicon wafer is annealed at a set temperature to obtain a rare earth-doped indium zinc oxide composite film; wherein, the annealing temperature is 200-400℃.

[0009] S4. A rare earth-doped indium zinc oxide composite film is adhered to a titanium backing plate by indium particles to obtain a rare earth-doped indium zinc oxide sputtering target.

[0010] Some embodiments disclose a method for preparing rare earth-doped indium zinc oxide sputtering film targets, wherein the molar ratio of rare earth atoms, indium atoms, and zinc atoms in the precursor solution is 0.01–0.1:1:1–3.

[0011] In some embodiments, the method for preparing rare earth-doped indium zinc oxide sputtering film targets is repeated multiple times in step S2.

[0012] Some embodiments disclose a method for preparing a rare earth-doped indium zinc oxide sputtering film target, wherein the indium salt is a nitrate, sulfate, or chloride salt.

[0013] Some embodiments disclose a method for preparing a rare earth-doped indium zinc oxide sputtering film target, wherein the zinc salt is a nitrate, sulfate, or chloride salt.

[0014] Some embodiments disclose a method for preparing a rare earth-doped indium zinc oxide sputtering film target, wherein the rare earth salt is a nitrate, sulfate, or chloride salt.

[0015] Some embodiments disclose a method for preparing a rare earth-doped indium zinc oxide sputtering film target, wherein the rare earth element in the rare earth salt solution is one of lanthanum, praseodymium, neodymium, cerium, terbium, and ytterbium.

[0016] Some embodiments disclose a method for preparing rare earth-doped indium zinc oxide sputtering film targets, in which the stabilizer is monoethanolamine, diethanolamine, or acetylacetone.

[0017] Some embodiments disclose a method for preparing rare earth-doped indium zinc oxide sputtering film targets, in which the organic solvent is 2-methoxyethanol, methoxyethyl acetate, or propylene glycol monomethyl ether acetate.

[0018] Some embodiments disclose a rare earth-doped indium zinc oxide sputtering film target, which is prepared by the above-described method.

[0019] The method for preparing rare-earth-doped indium zinc oxide (IBO) sputtering targets disclosed in this invention controls the phase distribution by adjusting the ratio of rare-earth atoms to indium and zinc atoms in the precursor solution, thus obtaining a rare-earth-doped IBO sputtering target with controllable secondary phase. The spin-coating process of the precursor solution yields a target with uniform and dense size distribution. Annealing at a specific temperature for a certain time inhibits abnormal grain growth, refines the grains, and improves the density of the target, resulting in a rare-earth-doped IBO sputtering target with uniform and refined microstructure. Magnetron sputtering deposition of the target and characterization of the film's transmittance and conductivity reveal a relatively optimal rare-earth-doped IBO formulation, providing a reference for subsequent preparation of rare-earth-doped IBO target materials. The method for preparing rare-earth-doped IBO sputtering targets disclosed in this invention is simple, energy-saving, and produces products with high transmittance and low resistivity. Detailed Implementation

[0020] 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 the embodiments of this application, unless otherwise specified, employs conventional testing methods in the art. It should be understood that the terminology used in this application is merely for describing particular implementations and is not intended to limit the scope of this disclosure.

[0021] 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 this application pertains; other experimental methods and technical means not specifically mentioned in this application refer to experimental methods and technical means commonly used by one of ordinary skill in the art.

[0022] The terms “basic” and “approximately” as used herein are used 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 herein are used for convenience and brevity only, and should therefore be interpreted flexibly 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.

[0023] 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.

[0024] To better illustrate the content of this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented 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 this application.

[0025] Without conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the resulting technical solution belongs to the content disclosed in the embodiments of this application.

[0026] Some embodiments disclose a method for preparing a rare-earth-doped indium zinc oxide sputtering film target, including the following steps:

[0027] S1. Mix predetermined amounts of indium salt solution, zinc salt solution, and rare earth salt solution, and add predetermined amounts of pure water, stabilizer, and organic solvent. Stir to obtain a precursor solution with a metal ion concentration of 0.1M to 0.5M. A magnetic stirrer is typically used to stir the precursor solution at 300 rpm, at room temperature, for 3 to 24 hours, resulting in a transparent precursor solution. Preferably, monoethanolamine is used as the stabilizer, and 2-methoxyethanol is used as the organic solvent, resulting in a precursor solution with a metal ion concentration of 0.4M. Monoethanolamine improves the solubility of the solution, while 2-methoxyethanol better disperses indium ions, zinc ions, and rare earth ions.

[0028] S2. Spin-coat the precursor solution onto the silicon wafer and dry the silicon wafer coated with the precursor solution. Typically, the spin coater speed is 2000-5000 rpm and the spin coating time is 30s to obtain a rare earth-doped indium zinc oxide composite film with a thickness of 300-600nm. Generally, the film thickness can be controlled by controlling the spin coater speed and time. The silicon wafer needs to be pre-treated with oxygen plasma at 80W power for 300s to obtain a clean spin-coated substrate. Typically, the silicon wafer coated with the precursor solution is soft-baked at 50°C for 5min to remove organic solvents, and then placed on a hot plate at 100-200°C for hard-baking for 15-30min to dry, thereby enhancing the strength of the film target.

[0029] S3. The dried silicon wafer is annealed at a set temperature to obtain a rare earth-doped indium zinc oxide composite film with a thickness of 300-600 nm; wherein, the annealing temperature is 200-400℃ to control the grain growth process and obtain uniform and dense grains.

[0030] S4. A rare-earth-doped indium zinc oxide (IBO) composite film is adhered to a titanium backing plate using indium particles to obtain a rare-earth-doped IBO sputtering target. Specifically, the titanium backing plate is heated to 200°C in air, and then some indium particles are placed on the titanium backing plate. After the indium particles melt, the rare-earth-doped IBO composite film is pressed onto the titanium backing plate and allowed to cool naturally to room temperature to obtain the rare-earth-doped IBO sputtering target. The silicon wafer, titanium backing plate, and indium particles are recyclable.

[0031] In some embodiments, the molar ratio of rare earth atoms, indium atoms, and zinc atoms in the precursor solution is 0.01–0.1:1:1–3. The low content of rare earth atoms avoids excessive rare earth elements, inhibiting target densification and preventing poor electrical performance. Typically, the phase distribution can be controlled by adjusting the ratio of rare earth atoms, indium atoms, and zinc atoms in the precursor solution, thereby obtaining a rare earth-doped indium zinc oxide sputtering film target with controllable secondary phase. Rare earth-doped indium zinc oxide sputtering film targets with different ratios of rare earth atoms, indium atoms, and zinc atoms can be prepared, and magnetron sputtering films can be deposited on them. Then, the transmittance and conductivity of films with different ratios of rare earth atoms, indium atoms, and zinc atoms are characterized to determine the relatively optimal rare earth-doped indium zinc oxide ratio, providing a reference for the subsequent preparation of rare earth-doped indium zinc oxide targets.

[0032] In some implementations, step S2 is repeated multiple times. As an optional implementation, step S2 is repeated three times.

[0033] In some embodiments, the indium salt is a nitrate, sulfate, or chloride salt. The purity of the indium salt is greater than 99.99%, with indium nitrate being preferred due to its low pollution and low toxicity.

[0034] In some embodiments, the zinc salt is a nitrate, sulfate, or chloride salt. The zinc salt has a purity greater than 99.99%, with zinc nitrate being the preferred choice due to its low pollution and low toxicity.

[0035] In some embodiments, the rare earth salt is a nitrate, sulfate, or chloride salt. The purity of the rare earth salt is greater than 99.99%, with rare earth nitrates being preferred due to their low pollution and low toxicity.

[0036] In some embodiments, the rare earth element in the rare earth salt solution is one of lanthanum, praseodymium, neodymium, cerium, terbium, and ytterbium.

[0037] In some embodiments, the stabilizer is monoethanolamine, diethanolamine, or acetylacetone. Preferably, monoethanolamine is used as the stabilizer.

[0038] In some embodiments, the organic solvent is 2-methoxyethanol, methoxyethyl acetate, or propylene glycol monomethyl ether acetate. Preferably, the organic solvent is 2-methoxyethanol.

[0039] In some embodiments, the rare earth-doped indium zinc oxide sputtering film target is prepared by the above-described preparation method.

[0040] The technical details are further illustrated below with reference to the embodiments.

[0041] Example 1

[0042] The method for preparing the rare earth-doped indium zinc oxide sputtering film target disclosed in Example 1 includes:

[0043] According to the molar ratio of rare earth atoms, indium atoms, and zinc atoms of 0.01:1:1, indium nitrate solution, zinc nitrate solution, and rare earth nitrate solution were measured and mixed, and a set amount of pure water, monoethanolamine, and 2-methoxyethanol were added. The mixture was stirred at 300 rpm for 3 hours at room temperature using a magnetic stirrer to obtain a precursor solution with a metal ion concentration of 0.4 M.

[0044] A silicon wafer was treated with oxygen plasma at a power of 80W for 300 seconds.

[0045] The precursor solution was spin-coated onto the silicon wafer at a speed of 3000 rpm for 30 seconds using a spin coater, and then the silicon wafer coated with the precursor solution was placed on a hot plate at 150°C and dried for 20 minutes.

[0046] The spin coating and drying were repeated three times, and then annealed at 400℃ for 30 min to obtain a rare earth-doped indium zinc oxide composite film.

[0047] Rare earth-doped indium zinc oxide composite films are attached to a titanium backing plate by indium particles to obtain rare earth-doped indium zinc oxide sputtering targets.

[0048] A rare-earth-doped indium zinc oxide (IBO) sputtering film was deposited using magnetron sputtering. The transmittance and resistivity of the film were tested, yielding a transmittance of 91.32% and a resistivity of 27.60 × 10⁻⁶. -4 Ω*cm.

[0049] Example 2

[0050] The method for preparing the rare earth-doped indium zinc oxide sputtering film target disclosed in Example 2 includes:

[0051] According to the molar ratio of rare earth atoms, indium atoms, and zinc atoms of 0.02:1:1, indium nitrate solution, zinc nitrate solution, and rare earth nitrate solution were measured and mixed, and a set amount of pure water, monoethanolamine, and 2-methoxyethanol were added. The mixture was stirred at 300 rpm for 3 hours at room temperature using a magnetic stirrer to obtain a precursor solution with a metal ion concentration of 0.4 M.

[0052] A silicon wafer was treated with oxygen plasma at a power of 80W for 300 seconds.

[0053] The precursor solution was spin-coated onto the silicon wafer at a speed of 3000 rpm for 30 seconds using a spin coater, and then the silicon wafer coated with the precursor solution was placed on a hot plate at 150°C and dried for 20 minutes.

[0054] The spin coating and drying were repeated three times, and then annealed at 400℃ for 30 min to obtain a rare earth-doped indium zinc oxide composite film.

[0055] Rare earth-doped indium zinc oxide composite films are attached to a titanium backing plate by indium particles to obtain rare earth-doped indium zinc oxide sputtering targets.

[0056] A rare-earth-doped indium zinc oxide (IBO) sputtering film was deposited using magnetron sputtering. The transmittance and resistivity of the film were tested, yielding a transmittance of 92.87% and a resistivity of 13.52 × 10⁻⁶. -4 Ω*cm.

[0057] Example 3

[0058] The method for preparing the rare earth-doped indium zinc oxide sputtering film target disclosed in Example 3 includes:

[0059] According to the molar ratio of rare earth atoms, indium atoms, and zinc atoms of 0.03:1:1, indium nitrate solution, zinc nitrate solution, and rare earth nitrate solution were measured and mixed, and a set amount of pure water, monoethanolamine, and 2-methoxyethanol were added. The mixture was stirred at 300 rpm for 3 hours at room temperature using a magnetic stirrer to obtain a precursor solution with a metal ion concentration of 0.4 M.

[0060] A silicon wafer was treated with oxygen plasma at a power of 80W for 300 seconds.

[0061] The precursor solution was spin-coated onto the silicon wafer at a speed of 3000 rpm for 30 seconds using a spin coater, and then the silicon wafer coated with the precursor solution was placed on a hot plate at 150°C and dried for 20 minutes.

[0062] The spin coating and drying were repeated three times, and then annealed at 400℃ for 30 min to obtain a rare earth-doped indium zinc oxide composite film.

[0063] Rare earth-doped indium zinc oxide composite films are attached to a titanium backing plate by indium particles to obtain rare earth-doped indium zinc oxide sputtering targets.

[0064] A rare-earth-doped indium zinc oxide (IBO) sputtering film was deposited using magnetron sputtering. The transmittance and resistivity of the film were tested, yielding a transmittance of 93.54% and a resistivity of 6.30 × 10⁻⁶. -4 Ω*cm.

[0065] Example 4

[0066] The method for preparing the rare earth-doped indium zinc oxide sputtering film target disclosed in Example 4 includes:

[0067] According to the molar ratio of rare earth atoms, indium atoms, and zinc atoms of 0.05:1:1, indium nitrate solution, zinc nitrate solution, and rare earth nitrate solution were measured and mixed, and a set amount of pure water, monoethanolamine, and 2-methoxyethanol were added. The mixture was stirred at 300 rpm for 3 hours at room temperature using a magnetic stirrer to obtain a precursor solution with a metal ion concentration of 0.4 M.

[0068] A silicon wafer was treated with oxygen plasma at a power of 80W for 300 seconds.

[0069] The precursor solution was spin-coated onto the silicon wafer at a speed of 3000 rpm for 30 seconds using a spin coater, and then the silicon wafer coated with the precursor solution was placed on a hot plate at 150°C and dried for 20 minutes.

[0070] The spin coating and drying were repeated three times, and then annealed at 400℃ for 30 min to obtain a rare earth-doped indium zinc oxide composite film.

[0071] Rare earth-doped indium zinc oxide composite films are attached to a titanium backing plate by indium particles to obtain rare earth-doped indium zinc oxide sputtering targets.

[0072] A rare-earth-doped indium zinc oxide (IBO) sputtering film was deposited using magnetron sputtering. The transmittance and resistivity of the film were tested, yielding a transmittance of 91.56% and a resistivity of 12.84 × 10⁻⁶. -4 Ω*cm.

[0073] Example 5

[0074] The method for preparing the rare earth-doped indium zinc oxide sputtering film target disclosed in Example 5 includes:

[0075] According to the molar ratio of rare earth atoms, indium atoms, and zinc atoms of 0.1:1:1, indium nitrate solution, zinc nitrate solution, and rare earth nitrate solution were measured and mixed, and a set amount of pure water, monoethanolamine, and 2-methoxyethanol were added. The mixture was stirred at 300 rpm for 3 hours at room temperature using a magnetic stirrer to obtain a precursor solution with a metal ion concentration of 0.4 M.

[0076] A silicon wafer was treated with oxygen plasma at a power of 80W for 300 seconds.

[0077] The precursor solution was spin-coated onto the silicon wafer at a speed of 3000 rpm for 30 seconds using a spin coater, and then the silicon wafer coated with the precursor solution was placed on a hot plate at 150°C and dried for 20 minutes.

[0078] The spin coating and drying were repeated three times, and then annealed at 400℃ for 30 min to obtain a rare earth-doped indium zinc oxide composite film.

[0079] Rare earth-doped indium zinc oxide composite films are attached to a titanium backing plate by indium particles to obtain rare earth-doped indium zinc oxide sputtering targets.

[0080] A rare-earth-doped indium zinc oxide (IBO) sputtering film was deposited using magnetron sputtering. The transmittance and resistivity of the film were tested, yielding a transmittance of 89.70% and a resistivity of 22.77 × 10⁻⁶. -4 Ω*cm.

[0081] The rare earth-doped indium zinc oxide sputtering targets prepared in Examples 1 to 5 above were subjected to magnetron sputtering deposition, and the transmittance and resistivity of the thin films were tested. The test results are shown in Table 1.

[0082] Table 1 Performance test results of rare earth-doped indium zinc oxide sputtered target coatings in Examples 1-5

[0083]

[0084] Examples 1-5 used the same indium-zinc atomic ratio but different rare earth atomic ratios. The transmittance and resistivity of the thin films were tested through spin coating, drying, annealing, and magnetron sputtering. Table 1 shows that the rare earth-doped indium zinc oxide sputtered film obtained in Example 3 had a transmittance of 93.54% and a resistivity of 6.30 × 10⁻⁶. -4 Ω*cm, with the best overall performance.

[0085] The method for preparing rare-earth-doped indium zinc oxide (IBO) sputtering targets disclosed in this invention controls the phase distribution by adjusting the ratio of rare-earth atoms to indium and zinc atoms in the precursor solution, thus obtaining a rare-earth-doped IBO sputtering target with controllable secondary phase. The spin-coating process of the precursor solution yields a target with uniform and dense size distribution. Annealing at a specific temperature for a certain time inhibits abnormal grain growth, refines the grains, and improves the density of the target, resulting in a rare-earth-doped IBO sputtering target with uniform and refined microstructure. Magnetron sputtering deposition of the target and characterization of the film's transmittance and conductivity reveal a relatively optimal rare-earth-doped IBO formulation, providing a reference for subsequent preparation of rare-earth-doped IBO target materials. The method for preparing rare-earth-doped IBO sputtering targets disclosed in this invention is simple, energy-saving, and produces products with high transmittance and low resistivity.

[0086] The technical solutions and technical details disclosed in the embodiments of this application are merely illustrative of the inventive concept of this application and do not constitute a limitation on the technical solutions of this application. Any conventional changes, substitutions or combinations made to the technical details disclosed in this application have the same inventive concept as this application and are within the protection scope of the claims of this application.

Claims

1. A method for preparing a rare earth-doped indium zinc oxide sputtering film target, characterized in that, Including the following steps: S1. Mix a predetermined amount of indium salt solution, zinc salt solution, and rare earth salt solution, and add a predetermined amount of pure water, stabilizer, and organic solvent, stirring to obtain a precursor solution; the molar ratio of rare earth atoms, indium atoms, and zinc atoms in the precursor solution is 0.03:1:1; the indium salt is a nitrate, sulfate, or chloride salt; the zinc salt is a nitrate, sulfate, or chloride salt; the rare earth salt is a nitrate, sulfate, or chloride salt; the rare earth element in the rare earth salt solution is one of lanthanum, praseodymium, neodymium, cerium, terbium, and ytterbium; the stabilizer is monoethanolamine, diethanolamine, or acetylacetone; the organic solvent is 2-methoxyethanol, methoxyethyl acetate, or propylene glycol monomethyl ether acetate; S2. Spin-coating the precursor solution onto the silicon wafer and drying the silicon wafer coated with the precursor solution; specifically including: pre-treating the silicon wafer with oxygen plasma at 80W power for 300s; spin-coating the precursor solution onto the silicon wafer at a spin coater speed of 2000-5000rpm for 30s; soft-baking the silicon wafer coated with the precursor solution at 50℃ for 5min to remove organic solvents; and then placing it on a hot plate at 100-200℃ for hard-baking for 15-30min to dry; S3. The dried silicon wafer is annealed at a set temperature to obtain a rare earth-doped indium zinc oxide composite film with a thickness of 300-600 nm; wherein the annealing temperature is 200-400℃. S4. A rare earth-doped indium zinc oxide composite film is adhered to a titanium backing plate by indium particles to obtain a rare earth-doped indium zinc oxide sputtering target. Specifically, the titanium backing plate is heated to 200°C in air, indium particles are placed on the titanium backing plate, and after the indium particles melt, the rare earth-doped indium zinc oxide composite film is pressed onto the titanium backing plate and naturally cooled to room temperature to obtain a rare earth-doped indium zinc oxide sputtering target.

2. The method for preparing a rare earth-doped indium zinc oxide sputtering target according to claim 1, characterized in that, Step S2 is repeated multiple times.

3. A rare earth-doped indium zinc oxide sputtering target, characterized in that, It is prepared by the preparation method described in claim 1 or 2.

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