High-conductivity high-density tin oxide-based target material, and preparation method and application thereof

Abstract

The application discloses a high-conductivity high-density tin oxide-based target material and a preparation method and application thereof. The preparation raw material of the high-conductivity high-density tin oxide-based target material comprises metal oxides, and the metal oxides comprise, in terms of mass fractions, 96.0-99.8 parts of tin oxide, 0.01-2.0 parts of a first oxide and 0.1-0.6 parts of a second oxide; wherein the first oxide is selected from at least one of RuO2 and ReO3; and the second oxide is selected from at least one of ZnO, CuO, PbO2 and MnO2. The tin oxide-based target material prepared by using the raw material component has a relative density of more than 97.85%, excellent conductive performance and high light transmittance, and compared with a target material that is not doped or only doped with a traditional high-valence oxide (such as Ta2O5 and Nb2O5), the conductive performance and the density are both significantly improved, and the target material has a good application prospect.

Description

Technical Field

[0001] This invention relates to the field of metal target technology, and in particular to a high-conductivity, high-density tin oxide-based target, its preparation method, and its application. Background Technology

[0002] Transparent conductive oxide (TCO) thin films are essential core functional materials in display panels, solar cells, and optical coatings, and are typically prepared using physical vapor deposition methods such as magnetron sputtering and reactive plasma deposition. Indium oxide (ITO)-based targets have long held a dominant position due to their superior overall performance; however, their high cost and the scarcity of indium resources severely restrict the sustainable development of related industries. Therefore, developing non-indium TCO targets to replace ITO has become a pressing technical challenge for the industry.

[0003] Among related technologies, tin oxide-based targets have attracted much attention due to their abundant raw materials and low cost, and have gradually replaced indium oxide-based targets in fields such as photovoltaic heterojunction cells. However, tin oxide-based targets currently face two major problems. First, tin dioxide (SnO2) has a high vacancy formation energy, making it difficult to achieve low resistivity by generating oxygen vacancies, resulting in extremely high resistivity for pure tin dioxide targets. Second, tin dioxide is prone to volatilization and decomposition above 1500℃, making it difficult to achieve a relative density of over 90% under pressureless sintering conditions, ultimately leading to a certain gap in photoelectric properties between the prepared films and those of indium oxide-based films. To address these issues, researchers have discovered that doping with high-valence metal oxides can help improve the conductivity of tin oxide-based targets, such as doping with tannin oxide (Ta2O5), niobium oxide (Nb2O5), and antimony oxide (Sb2O5). However, these dopants suffer from low solid solubility or elemental valence changes, easily forming a non-conductive second phase or generating p-type compensation, resulting in limited resistivity improvement.

[0004] Therefore, there is an urgent need to develop a method that can simultaneously improve the conductivity and sintering density of tin oxide-based targets in order to obtain tin oxide-based targets with both high conductivity and high density. Summary of the Invention

[0005] The first objective of this invention is to provide a highly conductive, high-density tin oxide-based target material.

[0006] The second objective of this invention is to provide a method for preparing the above-mentioned highly conductive, high-density tin oxide-based target.

[0007] A third aspect of the present invention aims to provide the application of the above-mentioned highly conductive, high-density tin oxide-based target material in the preparation of conductive thin films.

[0008] A fourth aspect of the present invention is to provide a thin film.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a highly conductive, high-density tin oxide-based target material, the raw materials for which are prepared include metal oxides, wherein the metal oxides comprise, by mass parts: 96.0-99.8 parts of tin oxide, 0.01-2.0 parts of a first oxide, and 0.1-0.6 parts of a second oxide; Wherein, the first oxide is selected from at least one of RuO2 and ReO3; the second oxide is selected from at least one of ZnO, CuO, PbO2 and MnO2.

[0010] The high-conductivity, high-density tin oxide-based target material according to embodiments of the present invention has at least the following beneficial effects: This invention discovers that doping a tin oxide matrix with a first oxide (RuO2 and / or ReO3) and a second oxide (at least one of ZnO, CuO, PbO2, and MnO2) significantly improves the conductivity and sintering density of the target material. The first oxide, as a low-resistivity oxide, can form a solid solution or a uniformly distributed second conductive phase with tin oxide when doped in small amounts, providing efficient transport channels for charge carriers and thus significantly reducing the resistivity of the tin oxide substrate. The second oxide, as a sintering aid, effectively lowers the sintering temperature of tin oxide, avoiding the volatilization and decomposition problems of tin oxide and the first oxide caused by high-temperature (>1500℃) sintering in traditional processes. This allows the target material to achieve high density at a moderate temperature of 1200~1400℃, reaching a relative density of 97.85%~99.39%, far superior to the density of only 73.28% for pure tin oxide targets sintered at 1300℃.

[0011] In some embodiments of the present invention, the raw materials for preparing the metal oxide include, by mass parts: 97.0 to 99.6 parts of tin oxide, 0.1 to 1.5 parts of the first oxide, and 0.1 to 0.5 parts of the second oxide.

[0012] Preferably, the tin oxide is present in a mass fraction of 97.0 to 99.6 parts. For example, it can be 97, 97.5, 97.8, 98, 98.5, 98.8, 99, 99.2, 99.5, or 99.6 parts.

[0013] Preferably, the mass fraction of the first oxide is 0.1 to 1.5 parts. For example, it can be 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4, 1.5 parts, etc.

[0014] Preferably, the second oxide is present in a mass fraction of 0.1 to 0.5 parts. For example, it can be 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, etc.

[0015] RuO2 and ReO3 are the two oxide materials with the lowest resistivity, with a resistivity of approximately 10⁻⁶. -6 -10 -7 The resistivity of Ω·cm is much lower than that of tin oxide. Low-resistivity targets and thin films can be stably obtained by forming a solid solution with tin oxide or by forming a second phase within tin oxide through small-scale doping. However, it is worth noting that when the doping level is too high, although it helps improve the conductivity of the target or the resulting thin film, the optical properties of the thin film will deteriorate because the film's light absorption is enhanced under high conductivity.

[0016] The second oxide can improve the sintering activity of tin oxide, avoid excessive volatilization of tin oxide and the first oxide at low sintering temperatures, and obtain high-density target materials.

[0017] In some embodiments of the present invention, the first oxide is RuO2 and ReO3.

[0018] Co-doping with RuO2 and ReO3 can further reduce resistivity, and is significantly better than the effect of doping with either alone under the same conditions. This is presumably because co-doping with elements of different valence states and ionic radii expands the solid solubility range and suppresses local segregation and second phase precipitation.

[0019] In some embodiments of the present invention, the raw materials for preparing the tin oxide-based target material further include a dispersant, a binder, and water.

[0020] In some embodiments of the present invention, the raw materials for preparing the tin oxide-based target material, by mass parts, include: 1-5 parts of the dispersant, 1-10 parts of the binder, and 50-200 parts of water.

[0021] In some embodiments of the present invention, the dispersant includes at least one of polyvinylpyrrolidone, polyacrylamide, polyethylene glycol, or hydrogenated nitrile rubber.

[0022] In some embodiments of the present invention, the adhesive includes at least one of polyvinyl alcohol, sodium polyacrylate, butyl rubber, or cyanoacrylate.

[0023] A second aspect of the present invention provides a method for preparing a highly conductive, high-density tin oxide-based target as described in the first aspect, comprising the following steps: The raw materials are mixed and milled according to mass fractions, and then spray-dried and granulated to obtain a mixed powder. The mixed powder is then cold isostatically pressed and sintered to obtain a high-conductivity, high-density tin oxide-based target material.

[0024] In some embodiments of the present invention, the rotational speed of the mill is 1000~3000 r / min.

[0025] In some embodiments of the present invention, the grinding time is 5 to 20 hours.

[0026] In some embodiments of the present invention, the cold isostatic pressing pressure is 150~400MPa and the holding time is 10~50min.

[0027] In some embodiments of the present invention, the sintering includes a first-stage sintering, a second-stage sintering, a third-stage sintering, and a fourth-stage sintering, wherein: The sintering temperature of the first stage sintering is 500~700℃, the holding time is 4~6h, and the atmosphere is an oxygen atmosphere; The sintering temperature of the second stage sintering is 1100~1400℃, the holding time is 8~12h, and the atmosphere is argon atmosphere; The third stage of sintering includes reducing the temperature from the second stage sintering temperature to 700~900℃, and the atmosphere is an argon atmosphere. The fourth stage of sintering includes reducing the temperature from the third stage sintering temperature to 20-80°C, and using an oxygen atmosphere.

[0028] This invention employs a segmented sintering process. The first stage primarily utilizes a low-temperature oxygen atmosphere to remove organic matter. Slow heating promotes the complete decomposition and removal of organic materials such as binders, avoiding cracking and blistering caused by rapid heating. Simultaneously, the oxygen atmosphere helps maintain the stoichiometry of tin oxide, preventing premature formation of low-valence tin (SnO). The second stage primarily utilizes a high-temperature argon atmosphere to suppress oxide volatilization and promote solid-phase reactions. The inert argon atmosphere effectively inhibits the oxidation and volatilization of RuO2 / ReO3 at high temperatures, ensuring effective doping levels. It also reduces the oxygen partial pressure of the system, moderately promoting oxygen vacancy generation and increasing carrier concentration. The third stage involves rapid cooling in an inert atmosphere, which helps stabilize the solid solution structure and conductive phase formed at high temperatures, preventing the precipitation of the second phase or oxidation of the conductive phase during slow cooling. Furthermore, the inert atmosphere also prevents thermal stress cracking of the target material during cooling. Finally, in the fourth stage, oxygen is introduced again at a relatively low temperature to repair oxygen vacancies. By introducing oxygen at a lower temperature, the surface of the target material is oxidized and repaired, eliminating the excessive oxygen vacancies that may be generated in the high-temperature stage, restoring the lattice integrity, and avoiding the low-valence oxide layer on the target surface caused by the reducing atmosphere from affecting the film deposition quality.

[0029] In some embodiments of the present invention, the heating rate of the first stage sintering is 0.8~1.2℃ / min.

[0030] In some embodiments of the present invention, the heating rate of the second stage sintering is 0.2~0.8℃ / min.

[0031] In some embodiments of the present invention, the cooling rate of the third-stage sintering is 1.0~3.0℃ / min.

[0032] In some embodiments of the present invention, the cooling rate of the fourth stage sintering is 0.2~0.8℃ / min.

[0033] The target material prepared by the segmented sintering process of the present invention has a more uniform composition, which is conducive to obtaining high conductivity and high density performance. In the subsequent magnetron sputtering or RPD coating process, the target material has a low poisoning tendency, stable ignition, and better film uniformity.

[0034] In some embodiments of the present invention, the sintering includes: First stage: The sintering temperature is increased from 25~55℃ to 500~700℃ at a heating rate of 0.8~1.2℃ / min, and held for 4~6 hours. The sintering atmosphere is oxygen. Second stage: The sintering temperature is increased from 500~700℃ to 1100~1400℃ at a heating rate of 0.2~0.8℃ / min, and held for 8~12h. The sintering atmosphere is argon. The third stage: The sintering temperature is reduced from 1100~1400℃ to 700~900℃ at a cooling rate of 1.0~3.0℃ / min, and the sintering atmosphere is argon. Fourth stage: The sintering temperature is reduced from 700~900℃ to 25~55℃ at a cooling rate of 0.2~0.8℃ / min, and the sintering atmosphere is oxygen.

[0035] In some embodiments of the present invention, the sintering process further includes further processing.

[0036] In some embodiments of the present invention, the processing includes surface and end face processing.

[0037] A third aspect of the present invention provides the application of a high-conductivity, high-density tin oxide-based target as described in the first aspect in the preparation of conductive thin films.

[0038] In a fourth aspect, the present invention provides a thin film whose raw materials include the high-conductivity, high-density tin oxide-based target material described in the first aspect.

[0039] In some embodiments of the present invention, the thin film is prepared by physical vapor deposition.

[0040] Preferably, the physical vapor deposition method includes magnetron sputtering or reactive plasma deposition.

[0041] Other features and advantages of the present invention will be set forth in the following description. Detailed Implementation

[0042] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0043] The term "preferred" in this invention refers to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of the invention.

[0044] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0045] In the description of this invention, the reference term "and / or" includes all and any combination of one or more of the associated listed items. For example, A and / or B includes (A and B) and (A or B).

[0046] In the embodiments of the present invention, unless otherwise specified, the initial particle size of the metal oxide raw materials (such as SnO2, RuO2, ReO3, and ZnO) is approximately 1~5 μm, and the purity is 4N. The particle size of the mixed powder after spray drying and granulation is approximately 10~300 μm.

[0047] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0048] Example 1 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0049] (1) High conductivity, high density tin oxide-based target material The oxide raw material composition of the high conductivity, high density tin oxide-based target material in this embodiment, by mass parts, is: 99.6 parts tin oxide (SnO2), 0.1 parts rhenium trioxide (ReO3), and 0.3 parts zinc oxide (ZnO). In addition, the raw materials for preparing this target material also include 100 parts deionized water, 2.5 parts dispersant, and 5 parts binder.

[0050] The dispersant is polyvinylpyrrolidone, and the binder is polyvinyl alcohol (PVA).

[0051] (2) Preparation process The preparation method of the high-conductivity, high-density tin oxide-based target in this embodiment includes the following steps: S1. Weigh SnO2, ReO3 and ZnO powder according to the above oxide raw material mass parts, mix them, and then mix them with dispersant and water at a mass ratio of 100:2.5:100. Use a sand mill to grind at a speed of 2500 r / min for 10 h to obtain slurry. Then add 5 parts by mass of PVA to the slurry, mix well, spray dry and granulate to obtain mixed powder.

[0052] S2. Place the uniformly mixed powder into the mold, press it at 250MPa for 30 minutes using a cold isostatic press, and demold to obtain the target blank.

[0053] S3. Place the target blank into a pressureless sintering furnace, set the sintering curve and sintering atmosphere to obtain the sintered body. The sintering curve is divided into four stages: First stage: The sintering temperature is increased from 50℃ to 600℃ at a heating rate of 1.0℃ / min, and held at 600℃ for 5 hours. The sintering atmosphere in this stage is oxygen. Second stage: The sintering temperature is increased from 600℃ to 1300℃ at a heating rate of 0.5℃ / min, and held at 1300℃ for 10 hours. The sintering atmosphere in this stage is argon. The third stage: The sintering temperature is reduced from 1300℃ to 800℃ at a cooling rate of 2℃ / min. The sintering atmosphere in this stage is argon. Fourth stage: The sintering temperature is reduced from 800℃ to 50℃ at a cooling rate of 0.5℃ / min. The sintering atmosphere in this stage is oxygen.

[0054] S4. The sintered body after the above sintering is completed is processed according to the size requirements for subsequent actual use or measurement, thus obtaining a high-conductivity, high-density tin oxide-based target material.

[0055] Example 2 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0056] The only difference between this embodiment and Example 1 is the mass fraction of the metal oxide raw material components. The metal oxide raw material composition of the high-conductivity, high-density tin oxide-based target material in this embodiment, by mass fraction, is: 99.4 parts tin oxide, 0.3 parts rhenium trioxide, and 0.3 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0057] Example 3 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0058] The only difference between this embodiment and Example 1 is the mass fraction of the metal oxide raw material components. The metal oxide raw material composition of the high-conductivity, high-density tin oxide-based target material in this embodiment, by mass fraction, is: 98.7 parts tin oxide, 1.0 part rhenium trioxide, and 0.3 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0059] Example 4 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0060] The only difference between this embodiment and Example 1 is the mass fraction of the metal oxide raw material components. The metal oxide raw material composition of the high-conductivity, high-density tin oxide-based target material in this embodiment, by mass fraction, is: 98.5 parts tin oxide, 1.0 part rhenium trioxide, and 0.5 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0061] Example 5 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0062] The only difference between this embodiment and Example 1 is the mass fraction of the metal oxide raw material components. The metal oxide raw material composition of the high-conductivity, high-density tin oxide-based target material in this embodiment, by mass fraction, is: 98.4 parts tin oxide, 1.0 part rhenium trioxide, and 0.6 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0063] Example 6 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0064] The only difference between this embodiment and Example 1 is the mass fraction of the metal oxide raw material components. The metal oxide raw material composition of the high-conductivity, high-density tin oxide-based target material in this embodiment, by mass fraction, is: 98.2 parts tin oxide, 1.5 parts rhenium trioxide, and 0.3 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0065] Example 7 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0066] The only difference between this embodiment and Embodiment 6 is the sintering temperature. Specifically, the sintering curve of the high-conductivity, high-density tin oxide-based target material in this embodiment is divided into four stages during preparation: First stage: The sintering temperature is increased from 50℃ to 600℃ at a heating rate of 1.0℃ / min, and held at 600℃ for 5 hours. The sintering atmosphere in this stage is oxygen. Second stage: The sintering temperature is increased from 600℃ to 1400℃ at a heating rate of 0.5℃ / min, and held at 1400℃ for 10 hours. The sintering atmosphere in this stage is argon. The third stage: The sintering temperature is reduced from 1400℃ to 800℃ at a cooling rate of 2℃ / min. The sintering atmosphere in this stage is argon. Fourth stage: The sintering temperature is reduced from 800℃ to 50℃ at a cooling rate of 0.5℃ / min. The sintering atmosphere in this stage is oxygen.

[0067] The raw material components and other preparation methods in this embodiment are the same as those in Example 6.

[0068] Example 8 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0069] The only difference between this embodiment and Embodiment 6 is the sintering temperature. Specifically, the sintering curve of the high-conductivity, high-density tin oxide-based target material in this embodiment is divided into four stages during preparation: First stage: The sintering temperature is increased from 50℃ to 600℃ at a heating rate of 1.0℃ / min, and held at 600℃ for 5 hours. The sintering atmosphere in this stage is oxygen. The second stage: The sintering temperature is increased from 600℃ to 1200℃ at a heating rate of 0.5℃ / min, and held at 1200℃ for 10 hours. The sintering atmosphere in this stage is argon. The third stage: The sintering temperature is reduced from 1200℃ to 800℃ at a cooling rate of 2℃ / min. The sintering atmosphere in this stage is argon. Fourth stage: The sintering temperature is reduced from 800℃ to 50℃ at a cooling rate of 0.5℃ / min. The sintering atmosphere in this stage is oxygen.

[0070] The raw material components and other preparation methods in this embodiment are the same as those in Example 6.

[0071] Example 9 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0072] The only difference between this embodiment and Example 1 is the mass fraction of the metal oxide raw materials and components. The metal oxide raw material composition of the high-conductivity, high-density tin oxide-based target material in this embodiment, by mass fraction, is: 98.7 parts tin oxide, 1.0 part ruthenium dioxide (RuO2), and 0.3 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0073] Example 10 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0074] The only difference between this embodiment and Example 1 is the mass fraction of the metal oxide raw materials and components. The metal oxide raw material composition of the high-conductivity, high-density tin oxide-based target material in this embodiment, by mass fraction, is: 98.7 parts tin oxide, 1.0 part ruthenium dioxide, and 0.3 parts copper oxide (CuO). The remaining raw material components and preparation methods are the same as in Example 1.

[0075] Example 11 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0076] The only difference between this embodiment and Example 1 is the mass fraction of the metal oxide raw materials and components. The metal oxide raw material composition of the high-conductivity, high-density tin oxide-based target material in this embodiment, by mass fraction, is: 98.7 parts tin oxide, 1.0 part ruthenium dioxide, and 0.3 parts lead oxide (PbO2). The remaining raw material components and preparation methods are the same as in Example 1.

[0077] Example 12 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0078] The only difference between this embodiment and Example 1 is the mass fraction of the metal oxide raw materials and components. The metal oxide raw material composition of the high-conductivity, high-density tin oxide-based target material in this embodiment, by mass fraction, is: 98.7 parts tin oxide, 1.0 part ruthenium dioxide, and 0.3 parts manganese oxide (MnO2). The remaining raw material components and preparation methods are the same as in Example 1.

[0079] Example 13 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0080] The only difference between this embodiment and Example 1 is the mass fraction of the metal oxide raw materials and components. The metal oxide raw material composition of the high-conductivity, high-density tin oxide-based target material in this embodiment, by mass fraction, is: 98.7 parts tin oxide, 0.5 parts ruthenium dioxide, 0.5 parts rhenium trioxide, and 0.3 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0081] Example 14 This embodiment provides a highly conductive, high-density tin oxide-based target and its preparation method.

[0082] The only difference between this embodiment and Example 1 is the mass fraction of the metal oxide raw materials and components. The metal oxide raw material composition of the high-conductivity, high-density tin oxide-based target material in this embodiment, by mass fraction, is: 98.7 parts tin oxide, 1.0 part ruthenium dioxide, 0.15 parts zinc oxide, and 0.15 parts copper oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0083] Comparative Example 1 This comparative example provides a tin oxide-based target and its preparation method.

[0084] The only difference between this comparative example and Example 1 is the mass fraction of the metal oxide raw materials and components. The metal oxide raw material composition of the tin oxide-based target in this comparative example, by mass fraction, is: 99.7 parts tin oxide and 0.3 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0085] Comparative Example 2 This comparative example provides a tin oxide-based target and its preparation method.

[0086] The only difference between this comparative example and Example 1 is that this comparative example does not contain any other metal oxides. The metal oxide raw material composition of the tin oxide-based target in this comparative example, by mass parts, is 100 parts tin oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0087] Comparative Example 3 This comparative example provides a tin oxide-based target and its preparation method.

[0088] The only difference between this comparative example and Example 1 is that this comparative example is not doped with other metal oxides and the sintering temperature is 1500°C.

[0089] Specifically, the metal oxide raw material composition of the tin oxide-based target material in this comparative example is: 100 parts by mass of tin oxide.

[0090] The sintering curve of this comparative tin oxide-based target material was divided into four stages during its preparation: First stage: The sintering temperature is increased from 50℃ to 600℃ at a heating rate of 1.0℃ / min, and held at 600℃ for 5 hours. The sintering atmosphere in this stage is oxygen. The second stage: The sintering temperature is increased from 600℃ to 1500℃ at a heating rate of 0.5℃ / min, and held at 1500℃ for 10 hours. The sintering atmosphere in this stage is argon. The third stage: The sintering temperature is reduced from 1500℃ to 800℃ at a cooling rate of 2℃ / min. The sintering atmosphere in this stage is argon. Fourth stage: The sintering temperature is reduced from 800℃ to 50℃ at a cooling rate of 0.5℃ / min. The sintering atmosphere in this stage is oxygen.

[0091] The remaining raw material components and preparation methods of this comparative example are the same as those in Example 1.

[0092] Comparative Example 4 This comparative example provides a tin oxide-based target and its preparation method.

[0093] The only difference between this comparative example and Example 1 is the mass fraction of the metal oxide raw materials and components. The metal oxide raw material composition of the tin oxide-based target in this comparative example, by mass fraction, is: 98.7 parts tin oxide, 1.0 part tantalum oxide (Ta2O5), and 0.3 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0094] Comparative Example 5 This comparative example provides a tin oxide-based target and its preparation method.

[0095] The only difference between this comparative example and Example 1 is the mass fraction of the metal oxide raw materials and components. The metal oxide raw material composition of the tin oxide-based target in this comparative example, by mass fraction, is: 98.7 parts tin oxide, 1.0 part niobium oxide (Nb₂O₅), and 0.3 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0096] Comparative Example 6 This comparative example provides a tin oxide-based target and its preparation method.

[0097] The only difference between this comparative example and Example 1 is the mass fraction of the metal oxide raw material components. The metal oxide raw material composition of the tin oxide-based target in this comparative example, by mass fraction, is: 97.2 parts tin oxide, 2.5 parts rhenium trioxide (ReO3), and 0.3 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0098] Comparative Example 7 This comparative example provides a tin oxide-based target and its preparation method.

[0099] The only difference between this comparative example and Example 1 is the mass fraction of the metal oxide raw materials and components. The metal oxide raw material composition of the tin oxide-based target in this comparative example, by mass fraction, is: 96.7 parts tin oxide, 3.0 parts ruthenium dioxide, and 0.3 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0100] Comparative Example 8 This comparative example provides a tin oxide-based target and its preparation method.

[0101] The only difference between this comparative example and Example 1 is the mass fraction of the metal oxide raw materials and components. The metal oxide raw material composition of the tin oxide-based target in this comparative example, by mass fraction, is: 98.5 parts tin oxide and 1.5 parts rhenium trioxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0102] Comparative Example 9 This comparative example provides a tin oxide-based target and its preparation method.

[0103] The only difference between this comparative example and Example 1 is the mass fraction of the metal oxide raw materials and components. The metal oxide raw material composition of the tin oxide-based target in this comparative example, by mass fraction, is: 97.0 parts tin oxide, 1.5 parts rhenium trioxide, and 1.5 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0104] Comparative Example 10 This comparative example provides a tin oxide-based target and its preparation method.

[0105] The only difference between this comparative example and Example 1 is the mass fraction of the metal oxide raw material components. The metal oxide raw material composition of the high-conductivity, high-density tin oxide-based target material in this example, by mass fraction, is: 98.2 parts tin oxide, 1.0 part rhenium trioxide, and 0.8 parts zinc oxide. The remaining raw material components and preparation methods are the same as in Example 1.

[0106] Test example: This test example performs performance tests on the tin oxide-based target materials prepared in the above embodiments and comparative examples. Density was measured using the Archimedes displacement method, and the relative density is the ratio of the actual density to the theoretical density of the target material measured by the displacement method. Resistivity was measured using a resistivity meter with a four-point probe method. Transmittance testing involved sputtering each target material using a magnetron sputtering machine to prepare a 100nm thick oxide film on a 10*10mm ultra-white glass substrate, using a dual-beam ultraviolet light... A visible light photometer was used to measure the transmittance, and the average value of 380-1150 nm was calculated.

[0107] Each embodiment or comparative example has 10 test samples. After removing defective products, the average value of the test data is taken.

[0108] The oxide raw materials used and performance parameters in each embodiment and comparative example are shown in Table 1.

[0109] Table 1: Results of oxide raw material usage and performance parameters in each embodiment and comparative example

[0110] The above test results show that the relative density of the target material obtained based on the oxide raw material composition and preparation process of this invention reaches over 97%, with a maximum of 99.39%, and the lowest resistivity is 4.05 × 10⁻⁶. -4 With a light transmittance of over 88% (Ω·cm), it exhibits high conductivity, high density, and excellent light transmittance.

[0111] Under the same conditions, as the ReO3 doping concentration increased from 0.1 wt% to 1.5 wt%, the resistivity decreased significantly (as in Examples 1-3 and Example 6), while the conductivity increased significantly compared to the undoped Comparative Example 1. This is presumably due to the increased ReO3 doping concentration. 6+ An ion (approximately 0.56 Å in radius) partially substitutes for Sn. 4+ (Radius approximately 0.69 Å) forming an n-type solid solution, releasing free electrons; simultaneously, the difference in ionic radii causes lattice distortion, increasing the oxygen vacancy concentration and further enhancing the carrier concentration, indicating that appropriate ReO3 doping can significantly reduce resistivity and also promote sintering density. However, it is noteworthy that when doped with 1 wt% ReO3, as the ZnO doping amount increases (e.g., Examples 3-5 and Comparative Example 10), the density slightly increases (from 99.21% to 99.45%), but the conductivity significantly decreases, presumably due to the Zn... 2+ (0.60 Å) replaces Sn 4+ In order to maintain charge balance, acceptor defects or hole compensation will be generated. Excessive ZnO doping will lead to the dominance of p-type compensation effect, which will offset the n-type doping effect of ReO3. At the same time, it may form a non-conductive second phase (such as Zn2SnO4) and block the conductive path. Therefore, in the actual preparation process, it is necessary to control the content of the second oxide (such as ZnO) within a suitable ratio range.

[0112] Furthermore, comparing Examples 6-8, it can be seen that different sintering temperatures also have a certain impact on the resistivity and density of the target material. The resistivity is lowest when sintered at 1200℃, and the density is highest at 1300℃, but the resistivity increases slightly. At 1400℃, both the density and conductivity decrease significantly. This is presumably related to the easy oxidation and volatilization of ReO3 at high temperatures. At higher temperatures (such as 1400℃), volatilization intensifies, the effective doping amount decreases, and the porosity defects caused by volatilization increase, ultimately leading to a rebound in resistivity and a decrease in density. However, the overall sintering density remains high and the resistivity remains low.

[0113] Furthermore, Examples 9-12 tested the effects of RuO2 doping and the type of second oxide on resistivity and density. The results showed that adding ZnO, CuO, PbO2, or MnO2 (i.e., the second oxide) while doping RuO2 could all result in a target material with a high density of over 97.85% and a density of 10. -3 The low resistivity in the Ω·cm range indicates that the appropriate addition of low-valence oxides can promote grain boundary diffusion and mass migration during sintering, reduce the sintering activation energy, and enable the system to achieve high densification at a lower temperature, while avoiding excessive volatilization of RuO2.

[0114] In summary, this invention provides a highly conductive, high-density tin oxide-based target material and its preparation method. Using tin oxide as the matrix, a dual-oxide synergistic doping strategy is employed. Specifically, a first oxide (RuO2 and / or ReO3) with extremely low resistivity is incorporated to form a solid solution or a second conductive phase, significantly reducing the target material's resistivity. Simultaneously, a second oxide (at least one of ZnO, CuO, PbO2, and MnO2) is incorporated as a sintering aid, effectively lowering the sintering temperature and suppressing the volatilization of the first oxide and tin oxide at high temperatures, thereby achieving highly dense sintering. Furthermore, this invention employs a staged atmosphere sintering process (including low-temperature oxygen atmosphere degreasing, high-temperature argon atmosphere sintering, and oxygen recovery during cooling) to further optimize the microstructure and conductivity. The target material prepared using the raw material formulation and process of this invention achieves a relative density of over 97.85% and a resistivity as low as 10⁻⁶. -4 ~10 -3 With a strength of Ω·cm, compared to the target materials in the comparative example that are undoped or only doped with traditional high-valence oxides (such as Ta2O5 and Nb2O5), the conductivity and density are significantly improved, showing great application potential.

[0115] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A high-conductivity, high-density tin oxide-based target material, characterized in that, The raw materials for preparation include metal oxides, which, by mass parts, include: 96.0~99.8 parts of tin oxide, 0.01~2.0 parts of the first oxide, and 0.1~0.6 parts of the second oxide; Wherein, the first oxide is selected from at least one of RuO2 and ReO3; the second oxide is selected from at least one of ZnO, CuO, PbO2 and MnO2.

2. The high-conductivity, high-density tin oxide-based target material according to claim 1, characterized in that, The metal oxide comprises, by mass parts: 97.0 to 99.6 parts of tin oxide, 0.1 to 1.5 parts of the first oxide, and 0.1 to 0.5 parts of the second oxide.

3. The high-conductivity, high-density tin oxide-based target material according to claim 1 or 2, characterized in that, The raw materials for preparing the tin oxide-based target also include dispersants, binders, and water.

4. The high-conductivity, high-density tin oxide-based target material according to claim 3, characterized in that, The raw materials for preparation, by weight, include: 1-5 parts of the dispersant, 1-10 parts of the binder, and 50-200 parts of water; And / or, the dispersant includes at least one of polyvinylpyrrolidone, polyacrylamide, polyethylene glycol, or hydrogenated nitrile rubber; And / or, the adhesive includes at least one of polyvinyl alcohol, sodium polyacrylate, butyl rubber, or cyanoacrylate.

5. A method for preparing a highly conductive, high-density tin oxide-based target material as described in any one of claims 1 to 4, characterized in that, Includes the following steps: The raw materials are mixed and milled according to mass fractions, and then spray-dried and granulated to obtain a mixed powder. The mixed powder is then cold isostatically pressed and sintered to obtain a high-conductivity, high-density tin oxide-based target material.

6. The preparation method according to claim 5, characterized in that, The cold isostatic pressing pressure is 150~400MPa, and the holding time is 10~50min.

7. The preparation method according to claim 5 or 6, characterized in that, The sintering process includes a first-stage sintering, a second-stage sintering, a third-stage sintering, and a fourth-stage sintering, wherein: The sintering temperature of the first stage sintering is 500~700℃, the holding time is 4~6h, and the atmosphere is an oxygen atmosphere; The sintering temperature of the second stage sintering is 1100~1400℃, the holding time is 8~12h, and the atmosphere is argon atmosphere; The third stage of sintering includes reducing the temperature from the second stage sintering temperature to 700~900℃, and the atmosphere is an argon atmosphere. The fourth stage of sintering includes reducing the temperature from the third stage sintering temperature to 20-80°C, and using an oxygen atmosphere.

8. The preparation method according to claim 7, characterized in that, The cooling rate of the third stage sintering is 1.0~3.0℃ / min; and / or, the cooling rate of the fourth stage sintering is 0.2~0.8℃ / min.

9. The application of a high-conductivity, high-density tin oxide-based target as described in any one of claims 1 to 4 in the preparation of conductive thin films.

10. A thin film, characterized in that, The raw materials for preparation include the high-conductivity, high-density tin oxide-based target material as described in any one of claims 1 to 4.

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