Tungsten oxide sintered body, sputtering target and oxide thin film

Abstract

The present invention provides a tungsten oxide sintered body, a sputtering target comprising the sintered body, and an oxide thin film formed therefrom. In the present invention, by adding a specific (quasi)metal oxide within a predetermined range to a difficult-to-sinter tungsten oxide, it is possible to simultaneously secure improved sinterability and high density characteristics even when performing pressureless sintering.

Description

Technology Field

[0001] The present invention relates to a tungsten oxide sintered body, a sputtering target including the sintered body, and an oxide thin film formed therefrom. More specifically, the invention relates to a tungsten oxide-based oxide sintered body, a sputtering target, and an oxide thin film formed therefrom, wherein sinterability and density characteristics are simultaneously improved by adding a specific element within a predetermined range when manufacturing a sputtering target used in the TFT structure of LCDs and OLEDs. Background Technology

[0002] Recently, with the increasing integration of LSIs, there has been a review of using materials with lower electrical resistance values ​​as electrode materials or wiring materials. Among these, high-purity tungsten, which has low resistance values ​​and is thermally and chemically stable, is being used as an electrode material or wiring material.

[0003] These electrode materials or wiring materials are generally manufactured by sputtering and CVD methods. Sputtering is more widely used than CVD because the structure and operation of the device are relatively simple, film deposition can be done easily, and it is also low-cost. At this time, when depositing electrode materials or wiring materials by sputtering, the tungsten target used requires high purity and high density. Conventional methods for manufacturing tungsten-based targets include a method of producing an ingot using electron beam melting and then hot rolling it, a method of pressure-sintering tungsten powder and then rolling it, and / or the so-called CVD-W method, which involves depositing a tungsten layer on one side of a tungsten base plate by the CVD method.

[0004] Meanwhile, as shown in the tungsten-oxygen (WO) phase diagram of Fig. 1, tungsten oxide (WOx) is a difficult-to-sinter material, as it has many intermediate phases and severe oxygen deficiency. When using tungsten oxide-based ceramic materials that are difficult to sinter and have low density, it is difficult to construct a high-density target (e.g., a relative density of 90% or more). Furthermore, when sputtering is performed using the manufactured target, foreign substances are generated due to back deposition and nodule formation, which inevitably leads to a degradation of the physical properties of the thin film. The problem to be solved

[0005] The present invention has been devised to solve the aforementioned problems, and its technical objective is to provide a novel tungsten oxide sintered body in which sinterability is improved and high density can be secured by adding a specific element within a predetermined range to the main raw material, a difficult-to-sinter tungsten oxide, a sputtering target including said sintered body, and an oxide thin film formed therefrom.

[0006] Other objects and advantages of the present invention may be more clearly explained by the following detailed description of the invention and claims. means of solving the problem

[0007] To achieve the above-mentioned technical problem, the present invention provides a tungsten oxide sintered body comprising tungsten; and at least one element (A) selected from the group consisting of Co, Al, Y and Si.

[0008] In one embodiment of the present invention, the atomic ratio of tungsten present in the oxide sintered body to at least one element (A) may be 0.9 to 0.99 : 0.1 to 0.01.

[0009] In one embodiment of the present invention, the sintered body may have a relative density exceeding 90%.

[0010] In one embodiment of the present invention, based on the total atomic weight present in the sintered body, the atomic weight of tungsten may be 90 to 99.0 atomic percent, and the atomic weight of at least one element (A) may be 0.1 to 10 atomic percent.

[0011] In one embodiment of the present invention, the oxide sintered body comprises tungsten oxide and a (meta)metal oxide containing at least one element (A) selected from the group consisting of Co, Al, Y and Si, and the (meta)metal oxide (A) containing at least one element may be included in an amount of 1.0 to 7.0 weight% based on the total weight of the sintered body.

[0012] In one embodiment of the present invention, the (quasi)metal oxide may include one or more selected from the group consisting of Co3O4, Al2O3, Y2O3, and SiO2.

[0013] In one embodiment of the present invention, the oxide sintered body may be manufactured by mixing tungsten oxide and at least one type of (quasi)metal oxide, molding the mixture, and then sintering it without pressure.

[0014] In addition, the present invention provides a sputtering target comprising the aforementioned tungsten oxide sintered body.

[0015] In addition, the present invention provides an oxide thin film formed from the aforementioned sputtering target. Effects of the invention

[0016] According to one embodiment of the present invention, by adding a (quasi)metal oxide containing a specific element to a difficult-to-sinter tungsten oxide within a predetermined range, the sinterability of the tungsten oxide sintered body can be improved and high density can be secured.

[0017] Accordingly, the tungsten oxide sintered body and sputtering target according to the present invention can be usefully applied to the formation of electrodes or wiring used in the TFT structures of LCDs and OLEDs.

[0018] The effects according to the present invention are not limited to those exemplified above, and a wider variety of effects are included in this specification. Brief explanation of the drawing

[0019] Figure 1 is a phase diagram between tungsten and oxygen (WO). Figure 2 is a graph of the relative density of the molded bodies prepared in Examples 1 to 4. Figure 3 is a graph of the relative density of oxide sintered bodies prepared in Comparative Examples 1 to 3. Figure 4 is a graph evaluating the shrinkage rate between the molded bodies and oxide sintered bodies prepared in Examples 1 to 4. Figure 5 is a graph evaluating the shrinkage rate between the molded bodies and oxide sintered bodies prepared in Comparative Examples 1 to 3. Specific details for implementing the invention

[0020] The present invention will be described in detail below.

[0021] All terms used in this specification (including technical and scientific terms) may be used in a meaning that is commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0022] Furthermore, throughout the specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Also, throughout the specification, the terms "above" or "on" mean not only cases where a part is located above or below the subject part but also cases where another part is located in between, and do not necessarily mean that it is located above based on the direction of gravity. Furthermore, in this specification, terms such as "first," "second," etc., are used to distinguish components from one another, rather than indicating an arbitrary order or degree of importance.

[0023] The present invention relates to a high-density sintered body and a sputtering target based on tungsten oxide (WO3), a difficult-to-sinter material. More specifically, the invention aims to provide a sintered body and a sputtering target that can simultaneously achieve improved sinterability and high density even by a non-pressure sintering method by using a small amount of a specific dopant that assists the sinterability of tungsten oxide.

[0024] As shown in Figure 1 below, conventional tungsten oxide (WOx) is a difficult-to-sinter material because it contains many intermediate phases and is severely oxygen-deficient. When sintering this tungsten oxide (WO3) without pressure, there is a limit to the increase in sintering density, and if the temperature is raised, the amount of volatilization increases, which actually causes a problem of decreasing density. In other words, heat is required as a driving force during sintering; generally, higher temperatures are advantageous for securing sinterability (densification), whereas in the case of some raw materials, problems such as volatilization occur, resulting in lower density. To suppress the aforementioned phenomenon, sinterability can be partially improved by applying pressure at a relatively low temperature using a hot press (HP) or hot isostatic press (HIP); however, this is not suitable for mass production as manufacturing process costs increase due to the equipment cost, and there was a limit to increasing the size of the sintered body in the manufacturing process that applies high pressure.

[0025] Accordingly, in the present invention, by adding a specific dopant that assists the sinterability of tungsten oxide within a predetermined range, the sintering density can be improved due to the temperature drop effect even when pressureless sintering is performed. In particular, the tungsten oxide sintered without pressure according to the present invention can secure density characteristics and resistivity characteristics equivalent to those of oxide sintered through conventional pressure sintering (e.g., HP, HIP, etc.). Furthermore, compared to pressure-sintered oxide sintered bodies, it is highly superior in terms of the size and mass production of the sintered body, and has the advantage of a lower equipment unit cost.

[0026] In addition, if no added elements are present, the density of the tungsten oxide target is very low and the resistivity is high. When the resistance of the target is high in this way, a problem arises in that plasma is not formed during DC sputtering. In contrast, the tungsten oxide target according to the present invention secures sinterability through the addition of a dopant, thereby providing a high-density sintered target capable of sputtering even by pressureless sintering.

[0027] Oxide sintered body

[0028] An oxide sintered body according to one embodiment of the present invention is tungsten oxide (WO X This is for making a sputtering target with ) as the main component, by heat-treating raw material powder of metal (e.g., W) or ceramic (e.g., WO3) to form a single mass.

[0029] For example, the oxide sintered body comprises tungsten; and at least one element (A) selected from the group consisting of Co, Al, Y, and Si; and the atomic ratio of tungsten atoms present in the sintered body to at least one element (A) satisfies 0.9 to 0.99 : 0.1 to 0.01.

[0030] At this time, at least one element (A) or a compound containing said element (A) (e.g., (quasi)metal oxide) acts as a dopant that assists in the sinterability of difficult-to-sinter tungsten oxide and produces a density-increasing effect.

[0031] Since the atomic ratio of tungsten (W) atoms and at least one type of (quasi)metal atom in the oxide sintered body according to the present invention satisfies the aforementioned value, it is possible to improve sinterability and increase density by adding a small amount of sintering aid (dopant). Accordingly, even without performing pressure sintering that applies high pressure as in the past, a high-density sputtering target can be produced using tungsten oxide (WO3), which is a difficult-to-sinter material.

[0032] In a sintered body comprising a (quasi)metal oxide containing at least one element as described above, based on the total atomic weight present in the sintered body, the atomic weight of tungsten may be 90 to 99.0 atomic percent, and the atomic weight of at least one element (A) may be 0.1 to 10 atomic percent. Specific examples of at least one element (A) include the atomic weight of cobalt (Co) may be 0.5 to 1.5 atomic percent, and the atomic weight of aluminum (Al) may be 0.01 to 0.1 atomic percent. Additionally, the atomic weight of yttrium (Y) may be 0.01 to 0.3 atomic percent, and the atomic weight of silicon (Si) may be 0.01 to 0.1 atomic percent.

[0033] Here, the tungsten and at least one element (A) included in the oxide sintered body are not particularly limited in their compound form, etc., as long as they satisfy the aforementioned atomic ratio values. For example, tungsten and at least one element (A) may each be included as a metal component alone, or include all conventional compound forms known in the industry containing the said element. Preferably, they may be oxides containing tungsten or at least one element (A), respectively.

[0034] More specifically, the oxide sintered body according to the present invention is composed of a tungsten oxide (WO3) as a base material and at least one specific element additionally added, and specifically includes a (quasi)metal oxide containing tungsten oxide and at least one element (A) selected from the group consisting of Co, Al, Y and Si.

[0035] The above (quasi)metal oxide is not particularly limited as long as it is in the form of an oxide containing at least one element (A), and may include, for example, one or more selected from the group consisting of Co3O4, Al2O3, Y2O3, and SiO2.

[0036] Based on the weight of the (quasi)metal oxide added, the (quasi)metal oxide (A) containing at least one element may be included in an amount of 1.0 to 7.0 weight% based on the total weight (e.g., 100 weight%) of the sintered body. Specific examples of the above (quasi)metal oxide include an amount of cobalt oxide (Co3O4) added in an amount of 2 to 5 weight%, and an amount of aluminum oxide (Al2O3) added in an amount of 0.5 to 3 weight%. Additionally, an amount of yttrium oxide (Y2O3) added in an amount of 2 to 7 weight%, and an amount of silicon oxide (SiO2) added in an amount of 0.5 to 3 weight%. Furthermore, the content of tungsten oxide may be the remainder excluding the aforementioned (quasi)metal oxide, and may be, for example, 93 to 99.0 weight%, and specifically 95 to 99.0 weight%.

[0037] The tungsten oxide sintered body according to the present invention, configured as described above, may have a relative density exceeding 90%, and the upper limit thereof is not particularly limited. In addition, the size of the crystal grains included in the sintered body is not particularly limited, and may be, for example, 1 to 20 μm, and specifically 1 to 10 μm.

[0038] In addition, a sputtering target according to another embodiment of the present invention comprises the aforementioned tungsten oxide sintered body; and a backing plate bonded to one surface of the sintered body to support the sintered body.

[0039] Here, the backing plate serves as a substrate supporting a sintered body for a sputtering target, and any conventional backing plate known in the art may be used without limitation. In this case, the material constituting the backing plate and its shape are not particularly limited.

[0040] Method for manufacturing oxide sintered body and sputtering target

[0041] Hereinafter, a method for manufacturing an oxide sintered body according to one embodiment of the present invention will be described. However, the method is not limited to the following manufacturing method, and the steps of each process may be modified or selectively combined as needed.

[0042] A preferred embodiment of the above manufacturing method may be configured to include: (i) a step of preparing a raw material powder comprising tungsten oxide and a (mega)metal oxide containing at least one element (A) selected from the group consisting of Co, Al, Y and Si ('S10'); (ii) a step of manufacturing a molded body using the raw material powder ('S20'); and (iii) a step of manufacturing a sintered body by non-pressurizing sintering the molded body at 900 to 1200°C for 0.5 to 3 hours ('S30').

[0043] The above manufacturing method is described below, divided into each process step.

[0044] (i) Preparation of raw powder ('S10 Step')

[0045] In the above S10 step, a raw material powder is prepared comprising tungsten oxide and a (quasi)metal oxide containing at least one element (A). Specifically, tungsten oxide powder and one or more (quasi)metal oxide powders selected from the group consisting of Co3O4, Al2O3, Y2O3, and SiO2 are weighed according to the target composition, and then each powder is fed into a mixer and ground and mixed to produce a mixture.

[0046] When mixing the aforementioned raw material powders, conventional additives known in the industry, such as binders, dispersants, defoaming agents, etc., may be additionally included as needed. In this case, the amount of additive used can be appropriately adjusted within the conventional range known in the industry, and, for example, can be used in an amount of 0.01 to 10 weight% relative to the total weight of the powder in the slurry (e.g., 100 weight%).

[0047] Dispersants are added to satisfy the purpose of ensuring that the ground raw material particles maintain an even and stable dispersion within the solution for an extended period while simultaneously being finely ground. Non-limiting examples of usable dispersants include organic acids with attached carboxyl groups, such as citric acid; polyacrylic acid (PAA) or its salts, copolymers, or combinations thereof.

[0048] In addition, binders are added to maintain the molding strength of the molded body during the process of drying the slurry into powder and then molding it. Non-limiting examples of these include polymers such as polyvinyl alcohol and polyethylene glycol.

[0049] Antifoaming agents are used to remove foam in the slurry, and typically silicone oil, octyl alcohol, borax, etc. can be used.

[0050] The mixing and grinding of the raw material powder are not particularly limited and can be carried out using conventional ball mills, attraction mills, bead mills, etc. known in the art. At this time, the grinding and mixing conditions are not particularly limited, and for example, the speed of the ball mill may be about 150 to 300 rpm, and the mixing time may be 8 to 15 hours.

[0051] As a specific example of the above S10 step, to proceed with mixing and grinding raw material powder through a wet ball mill, a pre-measured elemental powder is introduced using a prepared PE container, and zirconia balls are introduced in a weight of approximately 2 to 4 times, preferably 3 times, the raw material. Subsequently, distilled water or pure water is introduced at a level of approximately 1.5 times the raw material, and the ball mill is carried out.

[0052] Afterward, the wet-ground mixture is dried in a drying oven and then ball-milled again to obtain the dried raw material powder. At this time, the drying conditions are not particularly limited, and for example, drying can be performed in a drying oven at approximately 90 to 110°C for about 10 to 15 hours.

[0053] Next, the dried mixture is subjected to a ball mill again to obtain dry raw material powder. If necessary, the zirconia balls and powder are separated by filtering through a mesh of approximately 90 to 110 mesh, specifically 100 mesh.

[0054] (ii) Manufacturing of molded body ('S20 step')

[0055] The above S0 step is a step of manufacturing a molded body using prepared raw material powder; more specifically, a molded body of a predetermined size is manufactured by feeding the raw material powder into a molding machine and going through a molding process.

[0056] To increase the density of the molded body, the molding process can be carried out in two stages. For example, the first molding process may use a uniaxial molding machine, and the second molding process may use an isostatic molding machine.

[0057] The conditions in the above first and second molding processes are not particularly limited and can be appropriately adjusted within the ordinary conditions known in the art. For example, the pressure during the first molding after feeding the raw material powder into a uniaxial molding machine is not particularly limited, and specifically, it may be 10 MPa or more per unit area. In addition, the pressure during the second molding after feeding the first molded body into an isostatic molding machine is not particularly limited, and for example, it may be 2000 MPa or more per unit area, and preferably in the range of 2000 to 3000 MPa.

[0058] As a specific example of the above S20 step, a primary molded body is manufactured using a 20Φ STS mold according to the weight of the powder. At this time, the pressure can be applied under minimum pressure conditions required to form the shape, for example, at approximately 10 MPa, and the time can be maintained for 1 minute. Subsequently, secondary molding is performed using hydrostatic forming (CIP) under conditions of 200 MPa with a holding time of several hours. Since the secondary hydrostatic process is carried out with an organic solvent containing water, it can be performed while the product is placed in an acrylic-based sealant (e.g., a bag).

[0059] (iii) Sintering body manufacturing ('S30 step')

[0060] In the above S30 step, a sintered body is produced by sintering the manufactured molded body under predetermined conditions.

[0061] At this time, the sintering conditions are not particularly limited and can be appropriately adjusted within the usual conditions known in the art. For example, pressureless sintering can be performed at 900 to 1200°C for 0.5 to 3 hours. The sintering can be carried out under an oxygen atmosphere or under inert conditions.

[0062] As a specific example of the above S30 step, the prepared molded body is placed in an alumina crucible of a certain size and sintered. In this experiment, the process was carried out in a nitrogen atmosphere to improve electrical conductivity by depleting some oxygen in the tungsten oxide. To confirm the difference in characteristics between the molded body before heat treatment and the sintered body after heat treatment, the weight, diameter, height, etc., of the molded body and the sintered body were measured (see Table 1 and Figures 1–4 below).

[0063] The sintered body produced through this process has a relative density exceeding 90%, and the upper limit is not specifically restricted.

[0064] (iv) Sputtering Target Manufacturing

[0065] Subsequently, a sputtering target is manufactured through diffusion bonding and final processing, which are commonly known in the industry.

[0066] Specifically, the sintered body obtained in step S30 above is bonded with a backing plate to secure a bonding rate of 99.5% or higher, then processed using processing equipment to reach the final target thickness, and a final sputtering target can be obtained by performing bead and / or arc spray treatment on the surface of the backing plate.

[0067] <Oxide Thin Film>

[0068] The present invention provides an oxide thin film deposited using the aforementioned tungsten oxide target.

[0069] Although slight variations in composition may occur in the oxide thin film depending on the deposition atmosphere, since it is manufactured by sputtering the aforementioned tungsten oxide target, its composition is substantially identical to that of the target. Accordingly, an oxide thin film having high density characteristics exceeding 90% relative density and excellent resistivity characteristics can be formed.

[0070] For example, the oxide thin film comprises tungsten; and at least one element (A) selected from the group consisting of Co, Al, Y and Si; and the atomic ratio of tungsten and at least one element (A) present in the oxide thin film may be 0.9 to 0.99 : 0.1 to 0.01.

[0071] The oxide thin film formed using the above tungsten oxide target may be in an amorphous form or a crystalline form. An amorphous oxide thin film may be crystallized by performing heat treatment at a temperature in the range of 200 to 350°C after deposition.

[0072] The transparent conductive thin film according to the present invention can be manufactured using a conventional sputtering method known in the art. One embodiment of the above manufacturing method includes the step of mounting the aforementioned tungsten oxide sintered body sputtering target and then depositing it at room temperature in a vacuum chamber under an oxygen and / or argon atmosphere.

[0073] The substrate and sputtering apparatus used may be any conventional ones known in the industry without limitation. Specifically, the film can be formed by supplying oxygen or oxygen and high-purity argon gas into a vacuum chamber at a rate of 80 to 110 sccm (standard cubic centimeters per minute), specifically at a rate of 95 to 105 sccm, and can be deposited at room temperature (RT) without applying heat to the substrate forming the film.

[0074] The oxide thin film obtained as described above can be used in various ways during the manufacture of semiconductor devices; for example, it can be applied for forming wiring or electrodes during semiconductor manufacturing. In particular, it can be usefully utilized as a barrier layer for electrodes during the manufacture of thin-film transistors. Specifically, when the thin film of the present invention is used as a barrier layer for source and drain electrodes included in a thin-film transistor, contact resistance can be lowered, and the physical properties of the thin-film transistor can be improved by having excellent transparency and a low refractive index.

[0075] The tungsten oxide-based sputtering target and the oxide thin film formed therefrom according to the present invention described above have high density and excellent resistivity characteristics, so the contact resistance with the TFT structure of LCDs and OLEDs or the electron injection layer of organic electroluminescent devices can be suppressed to a low level. Accordingly, the oxide thin film described above can be applied without limitation to various display devices such as liquid crystal display devices or organic electroluminescent display devices, information transmission devices such as flat panel displays such as LCDs, PDPs, OLEDs, and LEDs; touch panels of surface light source illumination devices such as OLEDs and LEDs; and / or information transmission devices utilizing the same.

[0076] The present invention will be described in detail below through examples. However, the following examples are merely illustrative of the present invention, and the present invention is not limited by the following examples.

[0077] [Example 1] Preparation of W-Co based sintered body

[0078] Metal W and Co were mixed and molded in a molar mass ratio of 0.9:0.1, and WO3:Co3O4 was mixed in a ratio of 96.3:3.7 based on the weight ratio of the added oxides to produce a molded body. Subsequently, a sintered body was produced by heat treating at approximately 970–1200°C for 2 hours under a nitrogen atmosphere using a heat treatment facility.

[0079] [Example 2] Preparation of W-Al based sintered body

[0080] Metal W and Al were mixed and molded in a molar mass ratio of 0.95:0.05, and WO3:Al2O3 was mixed in a ratio of 98.8:1.2 based on the weight ratio of the added oxide, and then a molded body was produced. Subsequently, a sintered body was produced by heat treating at approximately 970–1200°C for 2 hours in a nitrogen atmosphere using a heat treatment facility.

[0081] [Example 3] Preparation of WY-based sintered body

[0082] Metals W and Y were mixed and molded in a molar mass ratio of 0.9:0.1, and WO3:Y2O3 was mixed in a ratio of 95.0:5.0 based on the weight ratio of the added oxide to produce a molded body. Subsequently, a sintered body was produced by heat treating at approximately 970–1200°C for 2 hours in a nitrogen atmosphere using a heat treatment facility.

[0083] [Example 4] Preparation of W-Si-based sintered body

[0084] Metal W and Si were mixed and molded in a molar mass ratio of 0.95:0.05, and WO3:SiO2 was mixed in a ratio of 98.6:1.4 based on the weight ratio of the added oxide, and then a molded body was produced. Subsequently, a sintered body was produced by heat treating at approximately 970–1200°C for 2 hours in a nitrogen atmosphere using a heat treatment facility.

[0085] [Comparative Example 1] Preparation of W-based sintered body

[0086] A sintered body was prepared by performing the same method as in Example 1 above, except that WO3 powder was used alone without using a dopant.

[0087] [Comparative Example 2] Preparation of W-Ta-based sintered body

[0088] Metals W and Ta were mixed and molded in a molar mass ratio of 0.9:0.1, and WO3:Ta2O5 was mixed in a weight ratio of 90.4:9.6 based on the input oxide, and then a molded body was produced. Subsequently, a sintered body was produced by heat treating at approximately 970–1200°C for 2 hours under a nitrogen atmosphere using a heat treatment facility.

[0089] [Comparative Example 3] Preparation of Mo-Co based sintered body

[0090] Metallic Mo and Co were mixed and molded in a molar mass ratio of 0.97 : 0.03, and MoO based on the weight ratio of the added oxide x: A molded body was prepared by mixing Co3O4 in a ratio of 98:2. Subsequently, a sintered body was prepared by heat treating at approximately 900–1050°C for 2 hours under a nitrogen atmosphere using a heat treatment facility.

[0091] In this case, for the sintered body of Comparative Example 3 in which Mo was added, MoO x Considering the volatilization and melting of WO3, heat treatment was performed at a relatively lower temperature compared to the sintered body of the example with WO3 added.

[0092] [Experimental Example 1] Evaluation of Physical Properties of Molded Body

[0093] The physical properties of each molded body prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated as follows.

[0094] Specifically, for each molded body, the diameter (D) and height (T) were measured using a vernier caliper, and the weight (Mass) was weighed using a balance. In addition, the relative density was calculated by converting the input amount of each weight into a volume percentage and then converting the level relative to the theoretical density into a percentage, and the results are shown in Table 1 below. The density of the measured samples was calculated as weight / volume.

[0095] D (mm) T (mm) Mass (g) Relative density (%) Example 1 19.52 6.26 7.9225 59.5 Example 2 19.55 6.41 7.9208 58.1 Example 3 19.52 6.31 7.8758 59.6 Example 4 19.71 6.31 7.8893 58.6 Comparative Example 1 19.82 5.85 7.8638 60.9 Comparative Example 2 19.37 6.21 7.8835 59.5 Comparative Example 3 19.54 6.48 7.9100 66.0

[0096] [Experimental Example 2] Evaluation of Density and Shrinkage Rate of Sintered Body

[0097] After heat treatment was performed on each sample prepared in Examples 1 to 4 and Comparative Examples 1 to 3, the change in physical properties of each sintered body was measured.

[0098] The physical properties of the sintered body after heat treatment were evaluated in the same manner as in Experimental Example 1 described above, and for example, the results of the relative density calculated by measuring the diameter, height, and weight of the sintered body are shown in Figures 2 and 3 below.

[0099] Experimental results showed that in Examples 1 to 4, the relative density also significantly increased as the sintering temperature was raised from 950°C to 1150°C (see Fig. 2). In contrast, in Comparative Examples 1 to 3, the relative density decreased compared to that of the molded body as sintering progressed (see Fig. 3).

[0100] In addition, the diameter and height of the molded body before heat treatment and the sintered body after heat treatment were measured to calculate the shrinkage rate, and the results are shown in Figures 4 and 5 below.

[0101] [Experimental Example 3] Evaluation of Resistivity of Sintered Body

[0102] Resistivity characteristics were evaluated for each sintered body sample prepared in Examples 1 to 4 and Comparative Examples 1 to 3.

[0103] Specifically, a 1150°C sample with a relatively high relative density was used as the sintered sample, and the resistivity of the sample was measured using a Loresta-GX MCP-T700 (Mitsubishi Chemical). The results are shown in Table 2 below.

[0104] Top surface underneath Unit (Ωcm) Example 1 0.96 1.35 10^-1 Example 2 0.75 1.21 10^-1 Example 3 0.67 1.35 10^-1 Example 4 1.69 1.97 10^-1 Comparative Example 1 10.1 11.5 10^-1 Comparative Example 2 9.9 10.1 10^4 Comparative Example 3 4.5 7.5 10^1

Claims

Claim 1 A tungsten oxide sintered body comprising: tungsten oxide; and a (mega)metal oxide containing at least one element (A) selected from the group consisting of Co, Al, Y, and Si; wherein WO3 is included as the tungsten oxide, and the (mega)metal oxide containing at least one element (A) is included in an amount of 1.0 to 7.0 weight% based on the total weight of the sintered body, wherein the tungsten oxide sintered body is manufactured by mixing and molding the tungsten oxide and the (mega)metal oxide containing at least one element (A), and then sintering without pressure, and the tungsten oxide sintered body has a relative density exceeding 90%. Claim 2 A tungsten oxide sintered body according to claim 1, wherein the atomic ratio of tungsten present in the oxide sintered body to at least one element (A) is 0.9 to 0.99 : 0.1 to 0.

01. Claim 3 delete Claim 4 delete Claim 5 In claim 1, the (quasi)metal oxide comprises one or more selected from the group consisting of Co3O4, Al2O3, Y2O3, and SiO2, forming a tungsten oxide sintered body. Claim 6 delete Claim 7 A sputtering target comprising a tungsten oxide sintered body as described in any one of claims 1, 2 and 5. Claim 8 Oxide thin film formed from the sputtering target of claim 7. Claim 9 (i) a step of preparing a raw material powder comprising tungsten oxide and a (mega)metal oxide containing at least one element (A) selected from the group consisting of Co, Al, Y and Si; (ii) a step of manufacturing a molded body using the raw material powder; and (iii) a step of manufacturing a sintered body by non-pressurized sintering of the molded body at 900 to 1200°C for 0.5 to 3 hours; comprising a method for manufacturing a tungsten oxide sintered body according to claim 1.

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