A RPD coating ceramic target and its preparation method

Abstract

The present application relates to the technical field of target material preparation, and provides an RPD coating ceramic target material and a preparation method thereof. The RPD coating ceramic target material includes a solid cylindrical target material body for evaporation coating, and the target material body includes: a target core, which is made of a first ceramic powder; a target sleeve, which surrounds the target core, and the target sleeve is made of a second ceramic powder, and the evaporation rate or sublimation rate of the target core material is lower than the evaporation rate or sublimation rate of the target sleeve material. The target material of the present application is designed with a special structure to avoid burn-in residue or burn-off on the periphery of the target material, promote uniform evaporation or sublimation, thereby improving the quality of the film, and at the same time reduce the residual powder or debris falling into the crucible or the gap between the crucible and the target material body, reduce the frequency of opening the cavity to replace the crucible and the target opening cavity maintenance, and extend the continuous coating time. In addition, it also includes a target tube, which is arranged around the target material body to block Ar + The plasma splashes onto the crucible wall to prevent the crucible material from evaporating and reduce the risk of impurities being introduced.

Description

Technical Field

[0001] The present application belongs to the technical field of target material preparation, and in particular relates to an RPD coating ceramic target material and a preparation method thereof. Background Art

[0002] Transparent conductive oxide (TCO) films (such as ICO, ITO, IWO, and AZO) are core materials for photovoltaic cells and display devices (LEDs, OLEDs, and LCDs). They require high conductivity, high light transmittance, and compatibility with low-temperature processes. Magnetron sputtering, the most commonly used thin-film deposition technique, poses a risk of directly exposing the substrate to a plasma containing a large number of high-energy particles, including secondary electrons exceeding 100 eV, argon ions, and oxygen ions. These high-energy particles have a strong bombardment and etching effect on the substrate surface, severely impacting the performance of batteries and displays. In contrast, reactive plasma deposition (RPD), as a new ion-assisted evaporation technology, exhibits many advantages: 1) Low substrate damage: RPD relies on the thermal energy of plasma to vaporize and dissociate the target material, and diffuse it to the substrate surface in the form of ions, which has a weak bombardment effect on the substrate and can effectively protect the substrate surface; 2) Low-temperature, high-quality film formation: The substrate temperature can be as low as below 200°C. The special properties of plasma are used to vaporize and dissociate the atoms on the surface of the target material. The dissociated reactants react on the substrate surface to achieve the growth of high-crystallinity thin films at low temperatures; 3) High target material utilization: By controlling the plasma beam power density of the crucible, the utilization rate of the evaporation source material is improved, which greatly reduces the cost compared to sputtering coating.

[0003] However, during the RPD coating process, Ar + When plasma bombards the target surface, it is easy to form localized high temperatures in the target while other areas are relatively low in temperature. For example, the middle area is hot while the outer area is cold. This causes the central area of ​​the target to evaporate or sublime quickly while the outer area evaporates or sublimates slowly, forming a molten pool. This leads to the target material having burn-in residue or burn-off phenomenon. This not only causes uneven target vaporization and affects the accuracy of the composition ratio, but also increases the risk of target structure collapse and powder particle splash. The resulting target fragments or residual powder fall into the crucible or the gap between the target and the crucible, easily filling the crucible and causing the target to get stuck, thus affecting the continuous coating process. At the same time, the residual powder particles may also drift to the substrate to form a film, especially in the nucleation stage, which will seriously affect the density, continuity and composition uniformity of the film growth. In particular, for multi-component ceramic targets with low or difficult to ionize components, evaporation in the outer area is more difficult, and the burn-in residue phenomenon is more significant, which seriously affects the film quality. In addition, high-energy plasma during the coating process may also ablate the crucible and introduce impurities, thereby affecting the purity and performance of the film.

[0004] Therefore, there is an urgent need to develop an RPD coating ceramic target that can be produced continuously for a long time and has high film quality. Summary of the Invention

[0005] The purpose of this application is to provide an RPD coating ceramic target and a preparation method thereof, aiming to solve the problems of low film quality and inability to continuously coat films for a long time in existing RPD coating ceramic targets.

[0006] To achieve the above application objectives, the technical solutions adopted in this application are as follows:

[0007] In a first aspect, the present application provides an RPD coating ceramic target, wherein the RPD coating ceramic target comprises a solid cylindrical target body for evaporation coating, wherein the target body comprises:

[0008] A target core is made of a first ceramic powder;

[0009] a target sleeve, surrounding the target core, wherein the target sleeve is made of a second ceramic powder;

[0010] The evaporation rate of the target core material is lower than that of the target cover material, or the sublimation rate of the target core material is lower than that of the target cover material.

[0011] In an embodiment, when the radius of the target core is set to R and the radial thickness of the target sleeve is set to D, R / D is (2.5~75) / (1~10).

[0012] In an embodiment, the target cover comprises at least two target cover layers stacked sequentially along the radial direction of the target core, and the evaporation rate or sublimation rate of the target cover layers increases layer by layer along the radial direction away from the target core.

[0013] In an embodiment, the target jacket comprises a first target jacket layer and a second target jacket layer, wherein the first target jacket layer surrounds the target core, and the second target jacket layer surrounds an outer surface of the first target jacket layer.

[0014] In an embodiment, the target jacket comprises a first target jacket layer, a second target jacket layer and a third target jacket layer, wherein the first target jacket layer surrounds the target core, the second target jacket layer surrounds the outer surface of the first target jacket layer, and the third target jacket layer surrounds the outer surface of the second target jacket layer.

[0015] In an embodiment, the first ceramic powder includes a first oxide powder and a doped oxide powder in a mass ratio of (50~100):(0~50); the doped oxide powder is formed by mixing the first oxide powder and the second oxide powder and then calcining, and the first oxide powder and the second oxide powder are different; the first oxide powder includes at least one of indium oxide powder, zinc oxide powder, and tin oxide powder; the second oxide includes at least one of indium oxide powder, tin oxide powder, tungsten oxide powder, aluminum oxide powder, gallium oxide powder, zirconium oxide powder, yttrium oxide powder, tantalum oxide powder, niobium oxide powder, antimony oxide powder, copper oxide powder, cerium oxide powder, lanthanum oxide powder, scandium oxide powder, silicon oxide powder, molybdenum oxide powder, and hafnium oxide powder.

[0016] In an embodiment, the particle size of the first oxide powder is 0.5-10.0 μm, and the particle size of the doped oxide powder is 20-500 nm.

[0017] In an embodiment, the second ceramic powder includes the first oxide powder and the doped oxide powder in a mass ratio of (60~100):(0~40); the doped oxide powder is formed by mixing the first oxide powder and the second oxide powder and then calcining, and the first oxide powder and the second oxide powder are different; the first oxide powder includes at least one of indium oxide powder, zinc oxide powder, and tin oxide powder; the second oxide includes at least one of indium oxide powder, tin oxide powder, tungsten oxide powder, aluminum oxide powder, gallium oxide powder, zirconium oxide powder, yttrium oxide powder, tantalum oxide powder, niobium oxide powder, antimony oxide powder, copper oxide powder, cerium oxide powder, lanthanum oxide powder, scandium oxide powder, silicon oxide powder, molybdenum oxide powder, and hafnium oxide powder.

[0018] In an embodiment, the relative density of the target core and the target sleeve is 40-80%.

[0019] In an embodiment, the RPD coating ceramic target further includes a target tube, which is sleeved around the target body to block plasma from splashing onto the crucible wall to prevent the crucible material from evaporating.

[0020] In an embodiment, the target tube is made of the first ceramic powder and / or the second ceramic powder.

[0021] In an embodiment, the relative density of the target tube is 95.0-99.5%.

[0022] In an embodiment, the inner diameter of the target tube is 0.1-2 mm larger than the diameter of the target body.

[0023] In an embodiment, the radial thickness of the target tube is 5-10 mm.

[0024] In a second aspect, the present application provides a method for preparing an RPD coating ceramic target, including a method for preparing a target body; the method for preparing the target body comprises the following steps:

[0025] preparing a target material blank with a primary target sleeve surrounding the primary target core;

[0026] The target material blank is subjected to a first sintering treatment to obtain a target material body with a target sleeve surrounding a target core.

[0027] In an embodiment, the forming mold of the target material blank includes a first mold and a second mold concentrically arranged in the first mold; the step of preparing the target material blank with a preliminary target sleeve surrounding the preliminary target core includes: filling the first ceramic powder in the second mold, and then filling the second ceramic powder between the first mold and the second mold, and then pulling out the second mold to perform a first compression molding to obtain the target material blank with the preliminary target sleeve surrounding the preliminary target core.

[0028] In an embodiment, the temperature of the first sintering treatment is 1000-1800° C., and the time is 8-36 hours.

[0029] In an embodiment, the preparation method of the RPD coated ceramic target material also includes a preparation method of a target tube; the preparation method of the target tube includes the following steps: pre-pressing the first ceramic powder and / or the second ceramic powder into a shape, and then isostatically pressing the shape to obtain a target tube blank; and performing a second sintering treatment on the target tube blank to obtain a target tube.

[0030] In the embodiment, it is characterized in that the temperature of the second sintering treatment is 1400-1800° C. and the time is 24-48 hours.

[0031] Compared with the prior art, this application has the following beneficial effects:

[0032] The RPD coating ceramic target provided in the first aspect of the present application comprises a target core and a target sleeve surrounding the target core, and the evaporation rate or sublimation rate of the target core material is lower than that of the target sleeve material. This special structural design improves the film quality on the one hand: the target core material has a low evaporation rate or sublimation rate, and the target sleeve material has a high evaporation rate or sublimation rate, which is consistent with the Ar deposition process. +The high temperature on the target core surface and the low temperature on the target sleeve generated by the plasma complement each other, solving the problem of insufficient thermal energy at the edge of the target body. This promotes uniform evaporation or sublimation of the target body, avoiding burn-in residue or biased burning at the periphery of the target body, thereby preventing target structural collapse and spattering, thereby improving the density, continuity, uniformity, and composition accuracy of the film. Furthermore, long-term continuous coating is achieved: by achieving uniform evaporation or sublimation of the target body, residual powder or fragments that fall into the crucible or the gap between the crucible and the target are effectively reduced, thereby reducing the frequency of opening the chamber to replace the crucible and the maintenance of the target clamping chamber, thereby achieving long-term continuous production and improving production efficiency.

[0033] The second aspect of the present application provides a method for preparing an RPD coated ceramic target material. First, a target material blank is prepared in which a preliminary target sleeve surrounds a preliminary target core. Then, a first sintering treatment is performed to obtain a target material body in which a target sleeve surrounds the target core. The preparation process of the present application is simple, easy to operate, and suitable for large-scale mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0035] Figure 1 This is a schematic structural diagram of a target material body provided in one embodiment of the present application;

[0036] Figure 2 is a structural schematic diagram of a target material body provided by another embodiment of the present application;

[0037] Figure 3 is a structural schematic diagram of a target material body provided by another embodiment of the present application;

[0038] Figure 4 Schematic diagram of the structure of the RPD coating ceramic target provided in the embodiment of the present application;

[0039] Figure 5 This is an SEM image of a thin film prepared using the RPD coating ceramic target provided in Example 1 of the present application;

[0040] Figure 6 This is an SEM image of a thin film prepared using the RPD coating ceramic target provided in Comparative Example 1 of the present application.

[0041] Among them, the reference numerals in the figures are:

[0042] 0—RPD coating ceramic target, 1—target body, 11—target core, 12—target sleeve, 2—target tube, 121—first target sleeve layer, 122—second target sleeve layer, 123—third target sleeve layer. DETAILED DESCRIPTION

[0043] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0044] The evaporation rate in this application refers to the relative ease with which the target material 1 evaporates to form gaseous atoms under the same RPD process parameters. The sublimation rate refers to the relative ease with which the target material 1 sublimates to form gaseous atoms under the same RPD process parameters.

[0045] In the RPD process, high energy Ar + Plasma bombards the target surface, causing the target's components to evaporate or sublime, transforming into gaseous metal atoms. These gaseous metal atoms enter the high-density plasma region, where they collide with high-energy electrons and ionize into metal ions. These metal ions combine with the reactive gas to form a film on the substrate. Therefore, achieving uniform evaporation or sublimation across the entire target surface is crucial to overcoming burnout residue or uneven burnout around the target.

[0046] However, the evaporation or sublimation of target material components is primarily influenced by a combination of factors, including their sublimation energy, chemical bond energy (such as metal-oxygen bond energy), metal electronegativity, lattice stability, phase transition characteristics, and volatilization. Sublimation energy refers to the energy required to directly transform a unit of material from solid to gas. The higher the sublimation energy of a material, the more difficult it is for atoms to escape from the lattice, making evaporation or sublimation more difficult. Chemical bond energy refers to the energy required to break the chemical bonds within the material. The higher the bond energy, the more difficult it is to break them under plasma bombardment, making evaporation or sublimation more difficult. Metal electronegativity refers to the ability of atoms to attract electrons. The higher the electronegativity and the more ionic a material is, the more difficult it is to evaporate or sublime. Lattice stability is primarily influenced by the density of the atoms / molecules within the material. The more stable the lattice, the tighter the arrangement of atoms / molecules within the lattice, the stronger the bonds between atoms / molecules, the higher the energy required to break this structure, and the more difficult evaporation or sublimation is.

[0047] Taking In2O3 and WO3 as examples, although the sublimation energy of In2O3 is lower than that of WO3, In atoms are more likely to break away from the lattice than W atoms; the bond energy of In-O is lower than that of WO, and In-O bonds are more likely to break away from the lattice than WO bonds in Ar. +It is more susceptible to fracture under plasma bombardment; In has a lower electronegativity than W, and the In-O bond is weaker than the WO bond; the lattice stability of In2O3 is less stable than that of WO3, and the energy required to destroy this structure is lower. Based on these factors, In evaporates or sublimates more easily than W; however, tungsten oxide is more volatile than indium oxide, which promotes W sublimation. Because the sublimation or evaporation of In and W is affected by a combination of factors, it is difficult to directly determine the ease of their sublimation or evaporation. In the system of the present invention, the content of "doped oxide powder" is a key means to adjust the evaporation rate / sublimation rate. When the evaporation rate / sublimation rate of the first oxide powder is higher than the evaporation rate / sublimation rate of the second oxide powder, the evaporation rate / sublimation rate of the doped oxide powder is lower than that of the first oxide powder, and the higher the content, the more difficult the evaporation / sublimation; when the evaporation rate / sublimation rate of the first oxide powder is lower than the evaporation rate / sublimation rate of the second oxide powder, the evaporation rate / sublimation rate of the doped oxide powder is higher than that of the first oxide powder, and the higher the content, the easier the evaporation / sublimation.

[0048] In the technical solution of the present application, the relative evaporation rate or sublimation rate of each component of the target material can be determined by comparative experiments: the components used to make the target material body are mixed to form an RPD target material, and film coating is carried out under the same RPD process parameters. By testing the composition of the deposited film or the composition of the remaining target material, if the content of a certain element in the film is greater than the original content of the target material, or the content of a certain element in the remaining target material is less than the original content of the target material, its evaporation rate or sublimation rate is relatively higher. Alternatively, the components used to prepare the target material body are made into RPD target materials respectively, and film coating is carried out under the same RPD process parameters and the coating time is the same, and then the weight of each remaining target material is tested. The lighter the weight of the remaining target material, the higher its evaporation rate or sublimation rate. Finally, the specific composition and component ratio of the target core and target sleeve of the target material body are designed according to the evaporation rate or sublimation rate of the specific material.

[0049] In a first aspect, an embodiment of the present application provides an RPD coating ceramic target 0, wherein the RPD coating ceramic target 0 comprises a solid cylindrical target body 1 for evaporation coating, such as Figure 1 As shown, the target body 1 includes:

[0050] The target core 11 is made of a first ceramic powder;

[0051] a target sleeve 12 surrounding the target core 11, the target sleeve 12 being made of a second ceramic powder;

[0052] The evaporation rate of the target core material is lower than that of the target cover material, or the sublimation rate of the target core material is lower than that of the target cover material.

[0053] The RPD coating ceramic target provided in the embodiment of the present application comprises a target core and a target sleeve surrounding the target core, and the evaporation rate or sublimation rate of the target core material is lower than that of the target sleeve material. This special structural design improves the film quality on the one hand: the target core material has a low evaporation rate or sublimation rate, and the target sleeve material has a high evaporation rate or sublimation rate, which is consistent with the Ar deposition process. + The high temperature on the target core surface and the low temperature on the target sleeve generated by the plasma complement each other, solving the problem of insufficient thermal energy at the edge of the target body. This promotes uniform evaporation or sublimation of the target body, avoiding burn-in residue or biased burning at the periphery of the target body, thereby preventing target structural collapse and spattering, thereby improving the density, continuity, uniformity, and composition accuracy of the film. Furthermore, long-term continuous coating is achieved: by achieving uniform evaporation or sublimation of the target body, residual powder or fragments that fall into the crucible or the gap between the crucible and the target are effectively reduced, thereby reducing the frequency of opening the chamber to replace the crucible and the maintenance of the target clamping chamber, thereby achieving long-term continuous production and improving production efficiency.

[0054] In the embodiment, when the radius of the target core 11 is set to R and the radial thickness of the target sleeve 12 is set to D, R / D is (2.5-75) / (1-10). The radial thickness of the target sleeve 12 is (target sleeve outer diameter - target sleeve inner diameter) / 2. Within this ratio range, the target core 11 and the target sleeve 12 can better cooperate, fully leveraging the advantages of the low evaporation or sublimation rate of the target core 11 and the high evaporation or sublimation rate of the target sleeve 12, promoting uniform vaporization and dissociation of the target material body, avoiding burn-in residue or burn-off on the periphery of the target material body 1, and preventing target material structural collapse and splashing, thereby ensuring more stable and reliable film quality. At the same time, it also reduces the amount of residual powder or debris that falls into the crucible and the gap between the crucible and the target material, thereby reducing the frequency of opening the chamber to replace the crucible or maintaining the target clamping chamber, and achieving long-term continuous film coating.

[0055] In the embodiment, the target sleeve 12 includes at least two target sleeve layers stacked in sequence along the radial direction of the target core, and the evaporation rate or sublimation rate of the target sleeve layer increases layer by layer along the radial direction away from the target core. The evaporation rate or sublimation rate of the target sleeve layer in this embodiment increases layer by layer, which helps to optimize the Ar of the target material body during the coating process. + Plasma heat distribution avoids heat concentration that may cause residual or off-center burning of the target body, and promotes uniform evaporation or sublimation.

[0056] In an embodiment, Figure 2 As shown, the target sleeve 12 includes a first target sleeve layer 121 and a second target sleeve layer 122. The first target sleeve layer 121 surrounds the target core 11, and the second target sleeve layer 122 surrounds the outer surface of the first target sleeve layer 121. The double-layer structure of the target sleeve 12 facilitates uniform heat conduction, reduces thermal stress and thermal gradients within the target material, and mitigates the effects of local high temperatures on evaporation or sublimation of the target material.

[0057] In an embodiment, Figure 3 As shown, the target sleeve 12 includes a first target sleeve layer 121, a second target sleeve layer 122, and a third target sleeve layer 123. The first target sleeve layer 121 surrounds the target core 11, the second target sleeve layer 122 surrounds the outer surface of the first target sleeve layer 121, and the third target sleeve layer 123 surrounds the outer surface of the second target sleeve layer 122. The three-layer structure of the target sleeve facilitates uniform heat conduction and promotes uniform evaporation or sublimation of the target material.

[0058] In an embodiment, the first ceramic powder includes a first oxide powder and a doped oxide powder in a mass ratio of (50~100):(0~50); the doped oxide powder is formed by mixing the first oxide powder and the second oxide powder and then calcining, and the first oxide powder and the second oxide powder are different; the first oxide powder includes at least one of indium oxide powder, zinc oxide powder, and tin oxide powder; the second oxide includes at least one of indium oxide powder, tin oxide powder, tungsten oxide powder, aluminum oxide powder, gallium oxide powder, zirconium oxide powder, yttrium oxide powder, tantalum oxide powder, niobium oxide powder, antimony oxide powder, copper oxide powder, cerium oxide powder, lanthanum oxide powder, scandium oxide powder, silicon oxide powder, molybdenum oxide powder and hafnium oxide powder.

[0059] In an embodiment, in the doped oxide powder, the mass ratio of the first oxide powder to the second oxide powder may be (70-95):(5-30).

[0060] In an embodiment, the step of preparing the first ceramic powder may include: uniformly mixing the first oxide powder and the doped oxide powder, or preparing the first oxide powder and the doped oxide powder into a slurry, and then spray granulating. The specific method or process for preparing the slurry may be performed in accordance with the techniques or conditions described in literature in the art, and the parameters for spray granulation may also be set in accordance with the techniques or conditions described in literature in the art, or in accordance with the product manual of the spray granulation tower.

[0061] In an embodiment, the particle size of the first oxide powder is 0.5-10.0 μm, and the particle size of the doping powder is 20-500 nm.

[0062] In an embodiment, the second ceramic powder includes a first oxide powder and a doped oxide powder in a mass ratio of (60-100): (0-40). The specific materials of the first oxide powder and the doped oxide powder of this embodiment are as described above and will not be repeated here to save space.

[0063] In an embodiment, the step of preparing the second ceramic powder may include uniformly mixing the first oxide powder and the doped oxide powder, or preparing the first oxide powder and the doped oxide powder into a slurry and then spray granulating the slurry to obtain the second ceramic powder. The specific method or process for preparing the slurry may be performed in accordance with the techniques or conditions described in literature in the art, and the parameters for spray granulation may also be set in accordance with the techniques or conditions described in literature in the art, or in accordance with the product manual of the spray granulation tower.

[0064] In the embodiment, the relative density of the target core 11 and the target sleeve 12 is 40-80%, preferably 56-65%. The target core 11 and the target sleeve 12 have the same relative density and a porous structure, which can effectively prevent the target body 1 from structural collapse and splashing during the coating process, thereby ensuring the quality of the film.

[0065] In an embodiment, Figure 4 As shown, the RPD coating ceramic target 0 also includes a target tube 2, which is sleeved around the target body 1 to prevent plasma splashing onto the crucible wall and thus prevent evaporation of the crucible material. The RPD coating ceramic target 0 also includes a target tube 2 sleeved around the target body 1 to prevent the evaporation of the crucible material and the introduction of the film into the film, thereby ensuring the purity and quality of the film and improving the reliability of the film.

[0066] In the embodiment, the target tube 2 is made of a first ceramic powder and / or a second ceramic powder. Specifically, the target tube 2 can be made of the first ceramic powder, the second ceramic powder, or any ratio of the first and second ceramic powders. The target tube 2 is made of the same material (element) as the target body 1, avoiding the introduction of new components that could affect the performance of the target material in thin film production.

[0067] In the embodiment, the relative density of the target tube 2 is 95.0-99.5%. This density range can ensure that the target tube 2 has sufficient density to isolate the plasma and prevent the plasma from directly acting on the crucible through the gap.

[0068] In the embodiment, the inner diameter of the target tube 2 is 0.1-2 mm larger than the diameter of the target body 1 .

[0069] In this embodiment, the target tube 2 is a cylindrical structure with a radial thickness of 5-10 mm. The radial thickness of the target tube 2 is (target tube outer diameter - target tube inner diameter) / 2. If the target tube 2 is too thin, it may not effectively block plasma bombardment of the crucible. If the target tube 2 is too thick, it will increase costs and adversely affect the spatial layout of the coating chamber. Therefore, within the thickness range of this embodiment, plasma bombardment of the crucible can be effectively blocked, maintaining the purity of the film.

[0070] In an embodiment, the target tube 2 may include a single-section target tube or a multi-section stacked target tube. Using a multi-section stacked target tube allows for replenishment of evaporated single-section target tubes, thereby better preventing plasma from directly bombarding the crucible and introducing impurities into the crucible. This also helps extend the coating time and reduces the need for frequent opening and tube replacement.

[0071] In the embodiment, since the target body 1 is consumed quickly and the target tube 2 is consumed slowly, different target delivery assemblies can be used to push the target body 1 and the target tube 2 to move respectively, which can more effectively replenish the target body for coating, thereby improving the coating efficiency and quality.

[0072] A second aspect of the present application provides a method for preparing the above-mentioned RPD coating ceramic target, including a method for preparing a target body. The method for preparing the target body includes:

[0073] S01: preparing a target material blank that surrounds the primary target core with a primary target sleeve;

[0074] S02: performing a first sintering process on the target material blank to obtain a target material body with a target sleeve surrounding the target core.

[0075] The preparation method of the RPD coated ceramic target provided in the embodiment of the present application first prepares a target material blank with a preliminary target sleeve surrounding the preliminary target core, and then performs a first sintering treatment to obtain a target material body with a target sleeve surrounding the target core. The preparation process of the present application is simple, easy to operate, and suitable for large-scale mass production.

[0076] In the above-mentioned step S01, in some embodiments, the molding die of the target blank includes a first mold and a second mold concentrically arranged in the first mold. The first mold can be a mold made of stainless steel, tungsten steel, etc., and the second mold can be a cylindrical mold made of stainless steel, tungsten steel, etc. The second mold is mainly used to separate the first ceramic powder and the second ceramic powder during the powder filling stage, so that the compression molding can form a target blank with a preliminary target sleeve surrounding the preliminary target core, thereby realizing special structural molding. The step of preparing the target blank with the preliminary target sleeve surrounding the preliminary target core includes: filling the first ceramic powder in the second mold, and then filling the second ceramic powder between the first mold and the second mold, and then withdrawing the second mold to perform the first compression molding to obtain the target blank with the preliminary target sleeve surrounding the preliminary target core. The compression molding of this embodiment can be carried out according to the technology or conditions described in the literature in this field, or according to the product manual.

[0077] In the above step S02, in the embodiment, the temperature of the first sintering treatment is 1000-1800° C., and the time is 8-36 hours; preferably, the temperature of the sintering treatment is 1200-1500° C., and the time is 8-12 hours.

[0078] In an embodiment, the preparation method of the RPD coating ceramic target material also includes a method for preparing a target tube; the preparation method of the target tube includes the following steps: pre-pressing the first ceramic powder and / or the second ceramic powder into a mold, and then isostatically pressing the mold to obtain a target tube blank; and subjecting the target tube blank to a second sintering treatment to obtain the target tube. The second sintering treatment temperature is 1400-1800°C, and the time is 24-48 hours. The pre-pressing and isostatic pressing of this embodiment can be performed according to the techniques or conditions described in the literature in this field, or according to the product manual. Parameters such as the molding pressure and molding time can be adjusted according to the actual ceramic material and the thickness of the blank.

[0079] The following describes the details in conjunction with specific embodiments.

[0080] RPD coating ceramic target material and preparation method

[0081] Example 1

[0082] This embodiment provides a RPD coating ceramic target material, such as Figure 4 As shown, the RPD coating ceramic target consists of a solid cylindrical target body for coating and a target tube sleeved around the target body; the target body consists of a target core and a target sleeve surrounding the target core, with a relative density of 60.0%; wherein the radius of the target core is 13.0 mm, and it is made of indium oxide powder and indium oxide powder doped with cerium oxide in a mass ratio of 70:30, and the mass ratio of indium oxide to cerium oxide in the indium oxide powder doped with cerium oxide is 90:10; the radial thickness of the target sleeve is 2.0 mm, and it is made of indium oxide powder; the relative density of the target tube is 98.0%, the inner diameter is 31.0 mm, and the radial thickness is 7.0 mm, and it is made of indium oxide powder and indium oxide powder doped with cerium oxide in a mass ratio of 70:30.

[0083] The method for preparing the RPD coating ceramic target in this embodiment includes the following steps:

[0084] S1: Preparation of target body

[0085] (1) Preparation of cerium oxide-doped indium oxide powder

[0086] Weigh indium oxide powder and cerium oxide powder in a mass ratio of 90:10;

[0087] Indium oxide powder, cerium oxide powder, polyethylene glycol and pure water are ball-milled and mixed using a planetary ball mill, and then polyvinyl alcohol is added and ball-milled uniformly to obtain a mixed slurry;

[0088] After the mixed slurry was dried, it was calcined at 1200°C for 6 h and then ball-milled to obtain cerium oxide-doped indium oxide powder (D50 = 100 nm).

[0089] (2) Preparation of the first ceramic powder

[0090] Weighing appropriate amounts of indium oxide powder (D50=3.0 μm) and cerium oxide-doped indium oxide powder in a mass ratio of 70:30 and mixing them uniformly to obtain a first ceramic powder;

[0091] (3) Prepare the target material blank that surrounds the primary target core.

[0092] A customized stainless steel cylinder is placed in a stainless steel mold, and the stainless steel cylinder and the stainless steel mold are arranged concentrically. A first ceramic powder is filled into the stainless steel cylinder, and then indium oxide powder (D50 = 3.0 μm) is filled between the cylinder and the stainless steel mold. The cylinder is then pulled out, and a press is used to pressurize the first ceramic powder and the indium oxide powder simultaneously to form a target blank.

[0093] (4) First sintering treatment

[0094] The target material body is placed in a high-pressure sintering furnace, and the temperature is initially raised to 1250°C and kept at this temperature for 18 hours under air to obtain the target material body;

[0095] S2: Prepare target tube

[0096] (1) Preparation of target tube blank

[0097] The first ceramic powder is placed in a stainless steel mold, preformed using a hydraulic press, and then subjected to cold isostatic pressing at a pressure of 100 MPa to obtain a target tube blank;

[0098] (2) Second sintering treatment

[0099] The target tube blank was placed in a high-pressure sintering furnace, and the temperature was initially raised to 1550° C. and kept at this temperature for 36 hours under air to obtain the target tube.

[0100] Example 2

[0101] This embodiment provides a RPD coating ceramic target material, such as Figure 1 and 5 As shown, the difference from Example 1 is that the RPD coating ceramic target is composed of a solid cylindrical target body for coating (that is, it does not include a target tube).

[0102] Example 3

[0103] This embodiment provides a RPD coating ceramic target material, such as Figure 3As shown, the difference from Example 1 is that the radius of the target core is 10.5 mm; the target sleeve consists of a first target sleeve layer, a second target sleeve layer and a third target sleeve layer, the radial thickness of the first target sleeve layer is 2.0 mm, and it is made of indium oxide powder and indium oxide doped with cerium oxide in a mass ratio of 80:20; the radial thickness of the second target sleeve layer is 1.5 mm, and it is made of indium oxide powder and indium oxide doped with cerium oxide in a mass ratio of 90:10; the radial thickness of the third target sleeve layer is 1.0 mm, and it is made of indium oxide powder.

[0104] The preparation method of the RPD coating ceramic target in this embodiment is different from that in Example 1 in that:

[0105] S1: Preparation of target body

[0106] (1) Preparation of cerium oxide-doped indium oxide powder

[0107] Weigh indium oxide powder and cerium oxide powder in a mass ratio of 90:10;

[0108] Indium oxide powder, cerium oxide powder, polyethylene glycol and pure water are ball-milled and mixed using a planetary ball mill, and then polyvinyl alcohol is added and ball-milled uniformly to obtain a mixed slurry;

[0109] After the mixed slurry was dried, it was calcined at 1200°C for 6 h and then ball-milled to obtain cerium oxide-doped indium oxide powder (D50 = 100 nm).

[0110] (2) Preparation of the first ceramic powder

[0111] Weighing appropriate amounts of indium oxide powder (D50=3.0 μm) and cerium oxide-doped indium oxide powder in a mass ratio of 70:30 and mixing them uniformly to obtain a first ceramic powder;

[0112] (3) Preparation of the second ceramic powder

[0113] Weighing appropriate amounts of indium oxide powder (D50=3.0 μm) and cerium oxide-doped indium oxide powder in a mass ratio of 80:20 and mixing them uniformly to obtain a second ceramic powder a;

[0114] Weighing appropriate amounts of indium oxide powder (D50=3.0 μm) and cerium oxide-doped indium oxide powder in a mass ratio of 90:10 and mixing them uniformly to obtain a second ceramic powder b;

[0115] (4) Prepare the target material blank that surrounds the primary target core.

[0116] The customized first cylinder, second cylinder, and third cylinder are placed in a stainless steel mold, and the first cylinder, second cylinder, and third cylinder are arranged concentrically with the stainless steel mold; the first ceramic powder is filled in the first cylinder, the second ceramic powder a is filled between the first cylinder and the second cylinder, the second ceramic powder b is filled between the second cylinder and the third cylinder, and indium oxide powder (D50 = 3.0 μm) is filled between the third cylinder and the stainless steel mold. Subsequently, the first cylinder, the second cylinder, and the third cylinder are pulled out, and the powders are pressurized by a press to form a target blank;

[0117] (4) First sintering treatment

[0118] The target material blank was placed in a high-pressure sintering furnace, and the temperature was initially raised to 1250° C. under air and kept warm for 18 hours to obtain the target material body.

[0119] Example 4

[0120] This embodiment provides an RPD coating ceramic target, which differs from Example 1 in that the target core is made of indium oxide powder and tin oxide-doped indium oxide powder in a mass ratio of 70:30, and the mass ratio of indium oxide to tin oxide in the tin oxide-doped indium oxide powder is 90:10.

[0121] The method for preparing the RPD coating ceramic target in this embodiment is different from that in Example 1 in that cerium oxide is replaced by tin oxide in step S1.

[0122] Comparative Example 1

[0123] This comparative example provides an RPD coating ceramic target material. The radius of the RPD coating ceramic target material is 15 mm and the relative density is 60%. The target material is made of indium oxide powder and indium oxide powder doped with cerium oxide in a mass ratio of 70:30. The mass ratio of indium oxide to cerium oxide in the indium oxide powder doped with cerium oxide is 90:10.

[0124] The preparation method of the RPD coating ceramic target material of this comparative example includes the following steps:

[0125] S1: Preparation of indium oxide powder doped with cerium oxide

[0126] Weigh indium oxide powder and cerium oxide powder in a mass ratio of 90:10;

[0127] Indium oxide powder, cerium oxide powder, polyethylene glycol and pure water are ball-milled and mixed using a planetary ball mill, and then polyvinyl alcohol is added and ball-milled uniformly to obtain a mixed slurry;

[0128] After the mixed slurry was dried, it was calcined at 1200°C for 6 h and then ball-milled to obtain cerium oxide-doped indium oxide powder (D50 = 100 nm).

[0129] S2: Preparation of the first ceramic powder

[0130] Weighing appropriate amounts of indium oxide powder (D50=3.0 μm) and cerium oxide-doped indium oxide powder in a mass ratio of 70:30 and mixing them uniformly to obtain a first ceramic powder;

[0131] S3: Compression molding

[0132] Filling a stainless steel mold with a first ceramic powder, and then pressurizing the first ceramic powder with a press to form a green body;

[0133] S3: Sintering treatment

[0134] The green blank was placed in a high-pressure sintering furnace, and the temperature was initially raised to 1250°C and kept warm for 18 hours to obtain an RPD coated ceramic target.

[0135] Comparative Example 2

[0136] This comparative example provides an RPD coating ceramic target, which differs from Example 1 in that the radius of the target core is 13.0 mm, and it is made of indium oxide powder; the radial thickness of the target sleeve is 2.0 mm, and it is made of indium oxide powder and cerium oxide-doped indium oxide powder with a mass ratio of 70:30, and the mass ratio of indium oxide to cerium oxide in the cerium oxide-doped indium oxide powder is 90:10.

[0137] The preparation method of the RPD coating ceramic target in this comparative example is different from that in Example 1 in that:

[0138] S1: Preparation of target body

[0139] (1) Preparation of cerium oxide-doped indium oxide powder

[0140] Weigh indium oxide powder and cerium oxide powder in a mass ratio of 90:10;

[0141] Indium oxide powder, cerium oxide powder, polyethylene glycol and pure water are ball-milled and mixed using a planetary ball mill, and then polyvinyl alcohol is added and ball-milled uniformly to obtain a mixed slurry;

[0142] After the mixed slurry was dried, it was calcined at 1200°C for 6 h and then ball-milled to obtain cerium oxide-doped indium oxide powder (D50 = 100 nm).

[0143] (2) Preparation of the first ceramic powder

[0144] Weighing appropriate amounts of indium oxide powder (D50=3.0 μm) and cerium oxide-doped indium oxide powder in a mass ratio of 70:30 and mixing them uniformly to obtain a first ceramic powder;

[0145] (3) Prepare the target material blank that surrounds the primary target core.

[0146] A customized cylinder is placed in a stainless steel mold, and the cylinder and the stainless steel mold are set concentrically. Indium oxide powder (D50 = 3.0 μm) is filled in the cylinder, and then the first ceramic powder is filled between the cylinder and the stainless steel mold. The cylinder is then pulled out, and a press is used to press the first ceramic powder and the indium oxide powder simultaneously to form a target blank.

[0147] (4) First sintering treatment

[0148] The target material blank was placed in a high-pressure sintering furnace, and the temperature was initially raised to 1250° C. under air and kept warm for 18 hours to obtain the target material body.

[0149] Related performance test analysis:

[0150] The RPD coating ceramic targets prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were deposited on a quartz substrate using an RPD device under the same coating conditions. Five thin films were prepared from each target, each with a thickness of about 100 nm.

[0151] 1. The metal element contents of the RPD coating ceramic targets and corresponding films prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were tested using ICP (Inductively Coupled Plasma) respectively. The test results are shown in Tables 1 and 2 below:

[0152] Table 1

[0153]

[0154] Table 2

[0155]

[0156] It can be seen from Tables 1-2 that the atomic percentages of In and Ce in each thin film prepared from the target materials provided in Examples 1-3 are close to the atomic percentages of In and Ce in the target materials, and the atomic percentages of In and Sn in each thin film prepared from the target material provided in Example 4 are close to the atomic percentages of In and Sn in the target material; while the Ce content in each thin film prepared from the target materials provided in Comparative Examples 1 and 2 is significantly lower than the Ce content in the target material, and the Ce content in each thin film fluctuates greatly, indicating that the embodiment of the present application designs the target material into a multi-layer structure, the target core is made of a first ceramic powder with a low evaporation rate or sublimation rate, and the target sleeve is made of a second ceramic powder with a high evaporation rate or sublimation rate and surrounds the target core, which can effectively prevent uneven evaporation or sublimation caused by insufficient thermal energy at the peripheral edge of the target material, and significantly improves the composition uniformity and the accuracy of the composition ratio of the thin film. In Comparative Example 2, the first ceramic powder with a low evaporation rate or sublimation rate is made into a target sleeve and distributed on the periphery. The Ce content in the film deviates more seriously from the target material, indicating that it is more unfavorable for uniform ionization of the target material.

[0157] 2. The copper content of the targets and corresponding films provided in Examples 1, 2, and Comparative Example 1 was tested using ICP (inductively coupled plasma testing); the sheet resistance of the films was tested using a four-probe method; and the visible light transmittance of the films was tested using a UV-visible spectrophotometer. The test results are shown in Table 3 below:

[0158] Table 3

[0159]

[0160] As can be seen from Table 3, the Cu content of the film prepared by the RPD coated ceramic target provided in Example 1 of the present application is maintained at an extremely low level, the same as the target material. However, the Cu content of the film prepared by the RPD coated ceramic target provided in Example 2 and Comparative Example 1 is much higher than that of the target material, indicating that the RPD coated ceramic provided in the embodiment of the present application includes a target sleeve arranged around the target body, which can effectively block the plasma from splashing onto the wall of the copper crucible to cause direct bombardment of the copper crucible, thereby avoiding the introduction of copper impurities into the film.

[0161] At the same time, the sheet resistance of the thin film corresponding to the RPD coated ceramic target provided in Example 1 of the present application is significantly lower than that of Comparative Example 1, and the visible light transmittance of the thin film corresponding to the RPD coated ceramic target provided in Example 1 of the present application is significantly higher than that of Comparative Example 1, further illustrating that the RPD coated ceramic provided in the embodiment of the present application includes a target tube arranged around the target body, which can effectively block the plasma from splashing onto the wall of the copper crucible to cause direct bombardment of the copper crucible, thereby avoiding the introduction of copper impurities into the thin film, thereby significantly improving the photoelectric performance of the thin film.

[0162] 3. The surface morphology of the films prepared by the evaporation ceramic targets provided in Example 1 and Comparative Example 1 was tested using a scanning electron microscope. The test results are as follows: Figure 5 and 6 shown.

[0163] from Figure 5 and 6It can be seen that the SEM image of the film prepared by the target material provided in Example 1 has no obvious light and dark contrast, texture, or large particles, indicating that the film surface is highly flat and dense, and has good continuity and uniformity. However, the SEM image of the film prepared by the target material provided in Comparative Example 1 has obvious large particles, indicating that the film surface density and uniformity are poor. This is mainly due to the fact that the target material in the embodiment of the present application adopts a double-layer structure of a target core and a target sleeve, and makes the evaporation rate or sublimation rate of the target core material low, and the evaporation rate or sublimation rate of the target sleeve material high, which effectively prevents local ablation of the target material, avoids the peripheral burning residue phenomenon during the target material coating process, promotes uniform evaporation or sublimation of the target material, thereby preventing the target material from collapsing or splashing, and ensuring the density, continuity, and uniformity of the film. However, since Comparative Example 1 adopts a traditional evaporation ceramic target material structure, the target material inevitably suffers from burning deviation and peripheral burning residue during the coating process, resulting in structural collapse or splashing of the target material, causing powder particles to float into the substrate, so that its film is inlaid with some large particles.

[0164] The embodiments described above are merely some examples of numerous implementation options. These detailed descriptions are intended to better illustrate this application and are not intended to limit the scope of this application. It should be understood that those skilled in the art can make various modifications and improvements based on this application without departing from the underlying principles of this application. For example, in addition to TCO (transparent conductive oxide) targets, targets for carrier transport layers and thermal barrier coatings also fall within the technical implications of this application, and these modifications and improvements are encompassed within the scope of protection of this application. Furthermore, certain specific terms are used in this specification for ease of explanation only and do not constitute any limitation on the present invention.

Claims

1. A RPD coating ceramic target, characterized in that: The RPD coating ceramic target comprises a solid cylindrical target body for evaporation coating, and the target body comprises: A target core is made of a first ceramic powder; a target sleeve, surrounding the target core, wherein the target sleeve is made of a second ceramic powder; Wherein, the evaporation rate of the target core material is lower than the evaporation rate of the target cover material, or the sublimation rate of the target core material is lower than the sublimation rate of the target cover material; The first ceramic powder comprises a first oxide powder and a doped oxide powder in a mass ratio of (50-100): (0-50); The doped oxide powder is formed by mixing the first oxide powder and the second oxide powder and then calcining the mixture, and the first oxide powder and the second oxide powder are different; The first oxide powder includes at least one of indium oxide powder, zinc oxide powder, and tin oxide powder; The second oxide powder includes at least one of indium oxide powder, tin oxide powder, tungsten oxide powder, aluminum oxide powder, gallium oxide powder, zirconium oxide powder, yttrium oxide powder, tantalum oxide powder, niobium oxide powder, antimony oxide powder, copper oxide powder, cerium oxide powder, lanthanum oxide powder, scandium oxide powder, silicon oxide powder, molybdenum oxide powder and hafnium oxide powder; The second ceramic powder includes the first oxide powder and the doped oxide powder in a mass ratio of (60-100):(0-40).

2. The RPD coating ceramic target according to claim 1, wherein: When the radius of the target core is set to R and the radial thickness of the target sleeve is set to D, R / D is (2.5-75) / (1-10).

3. The RPD coating ceramic target according to claim 1, wherein: The target sleeve comprises at least two target sleeve layers stacked in sequence along the radial direction of the target core, and the evaporation rate or sublimation rate of the target sleeve layers increases layer by layer along the radial direction away from the target core.

4. The RPD coating ceramic target according to claim 3, wherein: The target sleeve comprises a first target sleeve layer and a second target sleeve layer, wherein the first target sleeve layer surrounds the target core, and the second target sleeve layer surrounds the outer surface of the first target sleeve layer; Alternatively, the target jacket comprises a first target jacket layer, a second target jacket layer and a third target jacket layer, wherein the first target jacket layer surrounds the target core, the second target jacket layer surrounds an outer surface of the first target jacket layer, and the third target jacket layer surrounds an outer surface of the second target jacket layer.

5. The RPD coating ceramic target according to claim 1, wherein: The particle size of the first oxide powder is 0.5-10.0 μm, and the particle size of the doped oxide powder is 20-500 nm.

6. The RPD coating ceramic target according to claim 1, wherein: The relative density of the target core and the target sleeve is 40-80%.

7. The RPD coating ceramic target according to any one of claims 1 to 6, wherein: The RPD coating ceramic target further includes a target tube, which is sleeved around the target body and is used to block plasma from splashing onto the crucible wall to prevent the crucible material from evaporating.

8. The RPD coating ceramic target according to claim 7, wherein: Meet at least one of the following conditions: The target tube is made of the first ceramic powder and / or the second ceramic powder; The relative density of the target tube is 95.0-99.5%; The inner diameter of the target tube is 0.1-2 mm larger than the diameter of the target body; The radial thickness of the target tube is 5-10 mm.

9. A method for preparing an RPD coating ceramic target according to any one of claims 1 to 8, characterized in that: The invention relates to a method for preparing a target material body; the method for preparing the target material body comprises the following steps: preparing a target material blank with a primary target sleeve surrounding the primary target core; The target material blank is subjected to a first sintering treatment to obtain a target material body with a target sleeve surrounding a target core.

10. The method for preparing an RPD coating ceramic target according to claim 9, wherein: The molding die of the target blank comprises a first die and a second die concentrically arranged in the first die; The step of preparing a target material blank with a primary target sleeve surrounding the primary target core comprises: filling a first ceramic powder into the second mold, then filling a second ceramic powder between the first mold and the second mold, then withdrawing the second mold, and performing a first compression molding to obtain a target material blank with the primary target sleeve surrounding the primary target core; And / or, the temperature of the first sintering treatment is 1000-1800° C., and the time is 8-36 hours.

11. The method for preparing an RPD coating ceramic target according to claim 9 or 10, wherein: Also provided is a method for preparing a target tube; the method for preparing the target tube comprises the following steps: Pre-pressing the first ceramic powder and / or the second ceramic powder, and then isostatically pressing the powder to obtain a target tube blank; The target tube blank is subjected to a second sintering process to obtain a target tube.

12. The method for preparing an RPD coating ceramic target according to claim 11, wherein: The temperature of the second sintering treatment is 1400-1800° C., and the time is 24-48 hours.

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