Composite target and method for preparing the composite target

Abstract

To provide a composite target capable of coupling an oxide component containing target to a support plate without using deposition, and a preparation method thereof.SOLUTION: A composite target includes a support plate, and a Ru-containing sputtering target coupled to the support plate. The support plate contains a first component. The first component can be exposed to a Ru-containing solid-solution, and has heat transfer coefficient over 50 W / m K. A total content of the first component is 70-100 at% based on the total atom number of the support plate. The Ru-containing sputtering target contains Ru and an oxide component, and a total content of the oxide component is 20-42 at% based on a total atom number of the Ru-containing sputtering targets. A ratio of bending strength of the Ru-containing sputtering target and bending strength of the support plate is 0.1 to 0.8. A ratio of a linear thermal expansion coefficient of the Ru-containing sputtering target and a linear thermal expansion coefficient of the support plate is 0.8 to 1.2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a composite target, more particularly to a composite target suitable for the production of perpendicular magnetic recording (PMR) media, and further to a method for preparing a composite target. [Background technology]

[0002] Magnetic recording media involve the use of hysteresis properties of magnetic materials to store data within the recording medium. Today, consumer demand for portable recording media and the increasing prevalence of big data is driving a growing need for higher-density magnetic recording, based on the premise that the aforementioned recording media can operate stably. Therefore, how to increase the recording density of magnetic recording media has always been a focus of researchers in the relevant fields.

[0003] Generally, a thin layer of PMR media comprises, from bottom to top, a substrate, an adhesive layer, a soft underlayer, a seed layer, an intermediate underlayer, a magnetic recording layer, a lubricating layer, and a cover layer. Industry insiders believe that the recording density of PMR media can be further improved by controlling the crystalline properties of the magnetic recording layer. Therefore, in recent years, industry insiders have been attempting to add a base layer beneath the magnetic recording layer. This base layer facilitates better growth of the magnetic recording layer, resulting in a more uniformly distributed particle structure, and allowing for easier adjustment of properties such as segregation and crystal orientation.

[0004] The aforementioned base layer is often formed by sputtering a target, and the target material contains a certain amount of oxide components. However, conventional targets containing a certain amount of oxide components typically have problems such as insufficient heat dissipation and low strength. Therefore, the aforementioned targets are prone to cracking and deformation during the sputtering process, which affects the feasibility of the sputtering process in subsequent applications and the quality of the coating film formed by sputtering deposition.

[0005] To improve the strength of the target as described above, the target is usually joined to a support plate to form a target assembly, thereby increasing the overall strength of the target assembly. However, the bonding strength between the target and the support plate in the target assembly is often not sufficiently high. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 6288620 [Overview of the project] [Problems that the invention aims to solve]

[0007] To overcome the shortcomings of the prior art, the object of this disclosure is to provide a composite target that can bond an oxide component-containing target to a support plate without using welding, thereby improving the bonding between the target and the support plate. Therefore, when the composite target is subjected to a subsequent sputtering process, distortion of the oxide component-containing target can be reduced or even avoided.

[0008] Another object of this disclosure is to provide a composite target in which an oxide component-containing target can have good flatness after sputtering of a composite oxide target.

[0009] Another object of this disclosure is to provide a composite target having a bending strength higher than that of the oxide component-containing target itself. Thus, the oxide component-containing target can reduce or even avoid cracking of the oxide component-containing target during the sputtering of the subsequent composite oxide target. [Means for solving the problem]

[0010] To achieve the above-mentioned objective, the present disclosure provides a composite target comprising a support plate and a ruthenium (Ru)-containing sputtering target bonded to the support plate. The support plate comprises a first component, the first component may be exposed to a Ru-containing solid solution, the first component has a thermal conductivity greater than 50 watts per meter per kelvin (W / m·K), and the total content of the first component is 70–100 atomic percent (at%) based on the total number of atoms in the support plate. Ru-containing sputtering targets contain Ru and oxide components. Based on the total number of atoms in the Ru-containing sputtering target, the total content of oxide components is 20-42 at%, the ratio of the bending strength of the Ru-containing sputtering target to the bending strength of the support plate is 0.1 to 0.8, and the ratio of the coefficient of linear thermal expansion (CTE or CLTE, α) of the Ru-containing sputtering target to the coefficient of linear thermal expansion of the support plate is 0.8 to 1.2.

[0011] The composite target of this disclosure has the following technical features: (I) the support plate contains a first component, the first component can be exposed to a Ru-containing solid solution and has a thermal conductivity greater than 50 W / m·K; (II) the total content of the first component in the composite target is 70-100 at%; (III) the total content of oxide components in the composite target is 20-42 at%; (IV) the ratio of the bending strength of the Ru-containing sputtering target to the bending strength of the support plate is 0.1 to 0.8; and (V) the ratio of the CTE of the Ru-containing sputtering target to the CTE of the support plate is 0.8 to 1.2. By controlling the composite target of this disclosure to simultaneously have these characteristics, the support plate and the Ru-containing sputtering target no longer need to be joined by welding. Therefore, this disclosure not only reduces the number of manufacturing steps but also avoids the problem of solder flash due to temperature rise during the subsequent sputtering process, thereby reducing the risk of contamination of the coating film. Furthermore, between the support plate and the Ru-containing sputtering target, (120 kgf / cm²) 2 The composite target has excellent bonding strength (extremely high), and may have a higher bending strength than the Ru-containing sputtering target itself. This reduces, or even avoids, strain, deformation, or cracking of the Ru-containing sputtering target during subsequent sputtering processes. Furthermore, after the sputtering process, the Ru-containing sputtering target may still have good flatness.

[0012] According to this disclosure, the ability of a first component to be exposed to a Ru-containing solid solution means that the first component has a solid solubility of more than 5 mole% in Ru metal. Solid solubility is defined as the maximum content of solute in the solid solution at 1000°C. The solid solution refers to an alloy phase in which the atoms of the solute (e.g., the first component) are uniformly distributed within the crystal lattice of a solvent (e.g., Ru metal) that still maintains the type of solvent.

[0013] Preferably, the thermal conductivity of the first component may be 70 W / m·K or higher, but is not limited thereto.

[0014] Preferably, the first component may contain cobalt (Co), iron (Fe), chromium (Cr), molybdenum (Mo), nickel (Ni), or any combination thereof.

[0015] In some embodiments, the support plate may further include a second component. The second component may include aluminum (Al), zinc (Zn), tin (Sn), copper (Cu), palladium (Pd), tungsten (W), silicon (Si), niobium (Nb), magnesium (Mg), or any combination thereof.

[0016] Preferably, based on the total number of atoms in the support plate, the total content of the second component may be greater than 0 at% and 30 at% or less, but is not limited thereto. According to this disclosure, if the second component has only one type, the term "total content of the second component" means only the content of the single type of second component. If the second component has two or more types, the term "total content of the second component" refers to the sum of the individual contents of the two or more second components. For example, if the second component is a combination of 5 at% Cu and 3 at% Sn, the total content of the second component is 8 at%.

[0017] Preferably, the bending strength of the support plate may be greater than 700 million pascals (MPa), but is not limited thereto. More preferably, the bending strength of the support plate may be in the range of 760 MPa to 1550 MPa. In this specification, the term "bending strength" refers to the fracture stress experienced by an article (e.g., a support plate or a Ru-containing sputtering target) when a bending load is applied to the article per unit area, and the unit of bending strength is million pascals (MPa).

[0018] In some embodiments, the oxide components contained in the Ru-containing sputtering target can be selected from the group consisting of aluminum oxide, titanium oxide, silicon oxide, boron oxide, cobalt oxide, chromium oxide, magnesium oxide, niobium oxide, tantalum oxide, yttrium oxide, tungsten oxide, manganese oxide, zirconium oxide, and any combination thereof. In particular, aluminum oxide may be aluminum(III) oxide (Al2O3). Titanium oxide may be titanium dioxide (TiO2). Silicon oxide may be silicon dioxide (SiO2). Boron oxide may be boron trioxide (B2O3). Cobalt oxide may be cobalt monoxide (CoO) or tricobalt tetroxide (Co3O4). Chromium oxide may be dichromium trioxide (Cr2O3). Magnesium oxide may be magnesium monoxide (MgO). Niobium oxide may be niobium pentoxide (Nb2O5). Tantalum oxide may be ditantalum pentoxide (Ta2O5). Yttrium oxide may be yttrium trioxide (Y2O3). Tungsten oxide may be tungsten(VI) oxide (WO3). Manganese oxide may be manganese(II) oxide (MnO), manganese dioxide (MnO2), or dimanganese trioxide (Mn2O3). Zirconium oxide may be zirconium(IV) oxide (ZrO2).

[0019] According to this disclosure, if the oxide component has only one type, the term "total content of oxide component" means only the content of that single type of oxide component. If the oxide component has two or more types, the term "total content of oxide component" refers to the sum of the individual contents of the two or more oxide components. For example, if the oxide component is a combination of 28 at% chromium oxide and 5 at% manganese oxide, the total content of oxide component is 33 at%. Preferably, based on the total number of atoms in the Ru-containing sputtering target, the total content of oxide component is 20-39 at% but is not limited thereto.

[0020] In some embodiments, the Ru-containing sputtering target may include additional components. The additional components include platinum (Pt), Co, Cr, boron (B), titanium (Ti), rhenium (Re), Al, or any combination thereof.

[0021] Preferably, based on the total number of atoms of the Ru-containing sputtering target, the total content of the additional components can be 18 atomic percent or more and 47 atomic percent or less.

[0022] Preferably, based on the total number of atoms of the Ru-containing sputtering target, the total content of Ru is from 15 at% to 62 at%, but is not limited thereto. <00�0096> In some embodiments, the ratio of the bending strength of the Ru-containing sputtering target to the bending strength of the support plate can be from 0.1 to 0.65, but is not limited thereto. In another embodiment, the ratio of the bending strength of the Ru-containing sputtering target to the bending strength of the support plate can be from 0.25 to 0.8 but is not limited thereto. The bending strength can be measured by employing a four-point bending test.

[0024] In some embodiments, the bending strength of the Ru-containing sputtering target can be from 152 MPa to 700 MPa, but is not limited thereto.

[0025] In some embodiments, the bending strength of the support plate can be from 710 MPa to 1550 MPa, but is not limited thereto.

[0026] Preferably, the ratio of the CTE of the Ru-containing sputtering target to the CTE of the support plate can be from 0.88 to 1.14, but is not limited thereto. The CTE can be measured according to the standard method ASTM E831.

[0027] In some embodiments, the CTE of the Ru-containing sputtering target is 5.0×10 -6 / °C to 12.3×10 -6 / °C, but is not limited thereto.

[0028] In some embodiments, the CTE of the support plate is 4.9 × 10 -6 / ℃ to 12.0 × 10 -6 It can be expressed as / ℃, but is not limited to that.

[0029] Furthermore, the present invention further provides a method for preparing composite targets. The preparation method consists of the following steps: To obtain a composite target, the support plate and the Ru-containing sputtering target are bonded together. Includes, The support plate contains a first component, which can be exposed to a Ru-containing solid solution and has a thermal conductivity greater than 50 W / m·K. Based on the total number of atoms in the support plate, the total content of the first component is 70-100 at%. Ru-containing sputtering targets contain Ru and oxide components, and based on the total number of atoms in the Ru-containing sputtering target, the total content of oxide components is 20-42 at%. The ratio of the bending strength of the Ru-containing sputtering target to the bending strength of the support plate is between 0.1 and 0.8. The ratio of the bending strength of the Ru-containing sputtering target to the bending strength of the support plate is between 0.8 and 1.2.

[0030] Therefore, the method for preparing the composite target employs the following technical means: (1) means for controlling the support plate to contain a large amount of specific components that have good thermal conductivity and can be exposed to a Ru-containing solid solution in order to bond better with the Ru-containing sputtering target; (2) means for controlling the above-mentioned specific components within a specific content range; (3) means for controlling the ratio range of bending strength between the Ru-containing sputtering target and the support plate; and (4) means for controlling the ratio range of CTE between the Ru-containing sputtering target and the support plate. These technical means contribute to improving the mechanical strength between the Ru-containing sputtering target and the support plate. Thus, even without a welding process, this disclosure still makes it possible to obtain a composite target that goodly and directly bonds the Ru-containing sputtering target and the support plate and has good bonding strength between the Ru-containing sputtering target and the support plate. Thus, the problem of solder flash due to high temperature during the subsequent sputtering process can be avoided, and the phenomena of distortion, deformation or cracking of the Ru-containing sputtering target can also be reduced or even avoided. Furthermore, even after the sputtering process is completed, the Ru-containing sputtering target may still have good flatness.

[0031] According to this disclosure, the support plate can be prepared by using conventional raw materials, or the support plate can be the remaining target after use.

[0032] In some embodiments, the support plate may be formed by a forming method involving a base material containing a first component. Preferably, the forming method may be, but is not limited to, a sintering process.

[0033] According to this disclosure, the sintering process may employ hot pressurization (HP), hot isostatic pressurization (HIP), or plasma discharge sintering (SPS) individually. Furthermore, the sintering process may be carried out by employing a combination of two or more of the above-described sintering methods.

[0034] Preferably, the sintering temperature in the sintering process can be 700°C or higher and 1200°C or lower, and the sintering pressure in the sintering process can be 220 bar or higher and 1300 bar or lower. For example, when HP is used, the sintering temperature of HP can be 800°C to 1200°C, the sintering pressure can be 350 bar to 400 bar, and the sintering duration can be 1 hour to 3 hours, but is not limited thereto. When SPS is used, the sintering temperature of SPS can be 700°C to 1100°C, the sintering pressure can be 900 bar to 1300 bar, and the sintering duration can be 5 minutes to 1 hour, but is not limited thereto.

[0035] Specifically, the raw materials for the first component may include Co raw materials, Fe raw materials, Cr raw materials, Mo raw materials, Ni raw materials, or any combination thereof. Preferably, the purity of each component of the first raw materials is 99.9% or higher.

[0036] In some embodiments, the basic raw material may further include a raw material for a second component. That is, the basic raw material includes a raw material for a first component and a raw material for a second component. When the basic raw material includes a raw material for a second component, the resulting support plate includes the second component. The raw material for the second component may include Al raw material, Zn raw material, Sn raw material, Cu raw material, Pd raw material, W raw material, Si raw material, niobium raw material, magnesium raw material, or any combination thereof. Preferably, the purity of each component of the second raw material is 99.9% or higher.

[0037] In some embodiments, the basic materials for the support plate may be mixed together by rolling or grinding.

[0038] According to this disclosure, a Ru-containing sputtering target can be formed from a raw material mixture that has undergone the aforementioned sintering process.

[0039] Specifically, the raw material mixture for a Ru-containing sputtering target may, but is not limited to, include at least Ru raw materials and oxide component raw materials.

[0040] According to this disclosure, the Ru raw material may, but is not limited to, Ru metal having a purity of 99.95% or higher, a Ru alloy containing Ru in an amount of 50% by weight or more, or any combination thereof. Preferably, the Ru raw material is Ru metal having a purity of 99.95% or higher. Preferably, the Ru raw material may have an average particle size in the range of 35 μm to 80 μm.

[0041] According to this disclosure, the raw materials for the oxide components can be selected from the group consisting of aluminum oxide raw materials, titanium oxide raw materials, silicon oxide raw materials, boron oxide raw materials, cobalt oxide raw materials, chromium oxide raw materials, magnesium oxide raw materials, niobium oxide raw materials, tantalum oxide raw materials, yttrium oxide raw materials, tungsten oxide raw materials, manganese oxide raw materials, zirconium oxide raw materials, and any combination thereof. Preferably, the purity of each component of the oxide component raw materials is 99.9% or higher.

[0042] In some embodiments, the raw material mixture for the Ru-containing sputtering target may further include raw materials for additional components. That is, the raw material mixture includes Ru raw materials, oxide component raw materials, and additional component raw materials. When the raw material mixture includes additional component raw materials, the resulting Ru-containing sputtering target includes the additional components. The additional raw materials include platinum raw materials, cobalt raw materials, chromium raw materials, boron raw materials, titanium raw materials, rhenium raw materials, aluminum raw materials, or any combination thereof. Preferably, the purity of each component of the additional component raw materials is 99.9% or higher.

[0043] According to this disclosure, any method can be employed to uniformly mix the raw material mixture. For example, the raw material mixture can be mixed by a grinding process using a high-speed grinder, but is not limited to this. Preferably, the grinding duration of the grinding process can be from one hour to four hours, but is not limited thereto.

[0044] In some embodiments, the preparation method may further include a pre-pressing step performed before the raw material mixture undergoes the preceding sintering step. That is, the raw material mixture undergoes a grinding step and then a pre-pressing step. The pre-pressing step can be any method that allows the raw material mixture to be pressed into a fixed shape. For example, the raw material mixture may be placed in a hydraulic press to be pre-pressed under a pressure of about 15 to 110 bar, but is not limited thereto. Preferably, the pressure of the pre-pressing step may be 20 to 105 bar.

[0045] According to this disclosure, the aforementioned sintering step may employ HP, HIP, or SPS individually. Alternatively, the aforementioned sintering step may be carried out by employing a combination of two or more of the above-described sintering methods. Preferably, the sintering temperature of the aforementioned sintering step may be 650°C or higher and 1250°C or lower. The sintering pressure of the aforementioned sintering step may be 220 bar or higher and 1300 bar or lower. For example, when HP is employed, the sintering temperature of HP may be 800°C to 1200°C, the sintering pressure may be 350 bar to 400 bar, and the sintering duration may be 1 hour to 4 hours, but is not limited thereto. When SPS is employed, the sintering temperature of SPS may be 700°C to 1150°C, the sintering pressure may be 900 bar to 1300 bar, and the sintering duration may be 5 minutes to 1.5 hours, but is not limited thereto.

[0046] In some embodiments, a method for bonding a support plate and a Ru-containing sputtering target may include a placement step in which a raw material mixture for producing the Ru-containing sputtering target is placed directly on the support plate, and a sintering step following the placement step.

[0047] In some other embodiments, a method for bonding a support plate and a Ru-containing sputtering target may include a bonding step of placing the Ru-containing sputtering target on the support plate for a sintering bonding step, the Ru-containing sputtering target being formed by a forming step of a raw material mixture (i.e., the raw material mixture described above) undergoing a sintering step (i.e., the aforementioned sintering step described above).

[0048] Specifically, the parameters of the sintering bonding process, such as the sintering method, sintering duration, sintering temperature, and sintering pressure, can be performed by referring to the parameters of the aforementioned sintering process. Furthermore, the aforementioned sintering process may be the same as or different from the sintering bonding process.

[0049] Preferably, prior to the sintering bonding step, the support plate and the Ru-containing sputtering target may undergo a black layer removal step and / or a cleaning step.

[0050] In some embodiments, the structure of the support plate may have, but is not limited to, a flat structure parallel to the Ru-containing sputtering target, or a bumpy structure embedded together with the Ru-containing sputtering target. For example, the vertical cross-section of the support plate may have concave holes or a zigzag pattern, and the edges of the Ru-containing sputtering target may engage with the vertical cross-section of the support plate.

[0051] In this specification, unless otherwise specified, the range expressed as "from lower endpoint value to upper endpoint value" indicates that the range is greater than or equal to the lower endpoint value and less than or equal to the upper endpoint value. For example, a total content of the first component of 70-100 at% indicates that the first component is "70 at% or more and 100 at% or less".

[0052] Other objects, advantages, and novel features of the present invention will become more apparent from the following detailed description in conjunction with the accompanying drawings. [Brief explanation of the drawing]

[0053] [Figure 1] This is a schematic diagram showing the composite target specimen used in Analysis 3. [Modes for carrying out the invention]

[0054] To verify the influence of the raw material composition of the Ru-containing sputtering target, the raw material composition of the support plate, the relationship between the bending strength of the Ru-containing sputtering target and the bending strength of the support plate, and the relationship between the CTE of the Ru-containing sputtering target and the CTE of the support plate, several composite targets illustrating the implementation form of this disclosure are provided below as examples.

[0055] Those skilled in the art will readily understand the advantages and effects of this disclosure as provided herein. Various modifications and variations can be made without departing from the scope and spirit of the invention in order to carry out or apply the invention.

[0056] Preparation examples B1 to B38: Support plate First, appropriate amounts of the raw material powder for the first component and / or the raw material powder for the second component were sequentially weighed in each group according to the composition of the support plates listed in Table 2. The average particle size of the raw material powder for the first component ranged from 5 μm to 200 μm, and the average particle size of the raw material powder for the second component ranged from 5 μm to 200 μm. Next, in order to obtain the basic raw materials, these powders from each group were placed in a mixing device and subjected to a mixing step by rolling. The first component was selected from the group consisting of Co, Fe, Cr, Mo, Ni, and any combination thereof, and their thermal conductivity is listed in Table 1.

[0057] [Table 1]

[0058] Next, the basic raw materials for each group were placed in the mold, and then subjected to a sintering process to obtain support plates for preparation examples B1 to B38.

[0059] When using HP, the sintering pressure was approximately 380 bar, the sintering temperature was approximately 800°C to 1200°C, and the sintering duration was approximately 1 to 3 hours. When using SPS, the sintering pressure was approximately 1188 bar, the sintering temperature was approximately 700°C to 1100°C, and the sintering duration was approximately 5 minutes to 1 hour.

[0060] In Table 2, the composition of the support plates for preparation examples B1 to B38 can be expressed by the general formula "aY-bZ", where "a" represents the content of the first component relative to the total number of atoms in the support plate as an atomic percentage, "Y" represents the first component which can be selected from the group consisting of Co, Fe, Cr, Mo, Ni and any combination thereof, "b" represents the content of the second component relative to the total number of atoms in the support plate as an atomic percentage, and "Z" represents the second component which can be selected from the group consisting of Al, Zn, Sn, Cu, Pd, W, Si, Nb, Mg and any combination thereof.

[0061] Preparation examples T1 to T10 and T24 to T26: Ru-containing sputtering targets First, appropriate amounts of Ru metal powder, oxide component raw material powder, and / or additional component raw material powder were sequentially weighed for each group according to the composition of the Ru-containing sputtering targets listed in Table 2. The average particle size of the Ru metal powder was 40 μm, the average particle size of the oxide component raw material powder ranged from 0.1 μm to 5 μm, and the average particle size of the additional component raw material powder ranged from 1 μm to 40 μm.

[0062] Next, these powders from each group were placed in a high-speed grinder and subjected to a mixing step, followed by a grinding step for 1 to 4 hours to obtain the raw material mixtures from each group.

[0063] Next, the raw material mixtures from each group were placed in the mold and then subjected to a pre-pressurization step with a pressure of approximately 103 bar. After that, the pre-pressurized raw material mixtures underwent the sintering process described above. After the completion of the sintering process, a disc-shaped target was obtained with a diameter of 165 mm and a thickness of 5 mm. That is, Ru-containing sputtering targets for preparation examples T1 to T10 and T24 to T26 were obtained, respectively.

[0064] When using HP, the sintering pressure was approximately 380 bar, the sintering temperature was approximately 800°C to 1200°C, and the sintering duration was approximately 1 to 3 hours. When using SPS, the sintering pressure was approximately 1188 bar, the sintering temperature was approximately 700°C to 1100°C, and the sintering duration was approximately 5 minutes to 1 hour.

[0065] Examples 1 to 10 (E1 to E10): Composite Targets First, a grinder was used to remove the black layer on the surface to be bonded to the support plates of preparation examples B1 to B10 and the Ru-containing sputtering targets of preparation examples T1 to T10.

[0066] Subsequently, the support plates and Ru-containing sputtering targets adopted in each group were stacked according to the descriptions listed in Table 2 to form a thin-layer structure.

[0067] Next, each thin-layer structure was subjected to a sintering bonding process to obtain composite targets for Examples 1 to 10.

[0068] When using HP, the sintering pressure was approximately 380 bar, the sintering temperature was approximately 800°C to 1200°C, and the sintering duration was approximately 1 to 3 hours. When using SPS, the sintering pressure was approximately 1188 bar, the sintering temperature was approximately 700°C to 1100°C, and the sintering duration was approximately 5 minutes to 1 hour.

[0069] Comparative Examples 1 to 3 (CE1 to CE3): Target Assembly First, the support plates for preparation examples B24 to B26 and the Ru-containing sputtering targets for preparation examples T24 to T26 were processed by wire cutting and lathe use, respectively, as needed. Then, according to the descriptions listed for each group in Table 2, the support plates and Ru-containing sputtering targets adopted in each group were welded together to obtain the target assemblies CE1 to CE3.

[0070] The welding parameters for the relevant CE1 to CE3 target assemblies are listed below: 1.Welding temperature: 200℃ 2. Solder: Indium solder 3. Welding rate: Over 98%

[0071] Preparation Examples T11 to T23 and T27 to T38: Raw material mixtures for Ru-containing sputtering targets First, appropriate amounts of Ru metal powder, oxide component raw material powder, and / or additional component raw material powder were sequentially weighed for each group according to the composition of the Ru-containing sputtering targets listed in Table 2. The average particle size of the Ru metal powder was 40 μm, the average particle size of the oxide component raw material powder ranged from 0.1 μm to 5 μm, and the average particle size of the additional component raw material powder ranged from 1 μm to 40 μm.

[0072] Next, these powders from each group were placed in a high-speed grinder and subjected to a mixing step, followed by a grinding step for 1 to 4 hours to obtain the raw material mixture for each group. Thus, the raw material mixtures of Preparation Examples T11 to T23 and Preparation Examples T27 to T38 were obtained by the same method as described above.

[0073] Examples 11 to 23 (E11 to E23) and Comparative Examples 4 to 15 (CE4 to CE15): Composite Targets First, the support plates for each group in the examples and comparative examples (i.e., preparation examples B11 to B23 and preparation examples B27 to B38) were prepared according to the descriptions listed in each group in Table 2, and then placed in the mold.

[0074] Next, the raw material mixtures of preparation examples T11 to T23 and T27 to T38 were placed in molds according to Table 2. The molds were then subjected to a pre-pressurization step at a pressure of approximately 103 bar. The pre-pressurized raw material mixtures then underwent a sintering step. After the completion of the sintering step, composite targets E11 to E23 and CE4 to CE15 were obtained, respectively.

[0075] When using HP, the sintering pressure was approximately 380 bar, the sintering temperature was approximately 800°C to 1200°C, and the sintering duration was approximately 1 to 3 hours. When using SPS, the sintering pressure was approximately 1188 bar, the sintering temperature was approximately 700°C to 1100°C, and the sintering duration was approximately 5 minutes to 1 hour.

[0076] In Table 2, the Ru-containing sputtering targets in the composite targets E1 to E23, the target assemblies CE1 to CE3, and the composite targets CE4 to CE15 can be represented by the general formula "cRu-dX-e(OE)", where "c" represents the content of Ru as an atomic percentage relative to the total number of atoms in the Ru-containing sputtering target, "d" represents the content of additional components as an atomic percentage relative to the total number of atoms in the Ru-containing sputtering target, and "X" is P "e" represents an additional component that can be selected from the group consisting of t, Co, Cr, B, Ti, Re, A1 and any combination thereof, and "e" represents the content of the oxide component as an atomic percentage relative to the total number of atoms in the Ru-containing sputtering target. "OE" represents an oxide component that can be selected from the group consisting of Al2O3, TiO2, SiO2, B2O3, CoO, Co3O4, Cr2O3, MgO, Nb2O5, Ta2O5, Y2O3, WO3, MnO2, ZrO2 and any combination thereof. For example, if Al2O3 is taken as the oxide component, "e" represents the sum of the content of "O" (atomic percentage) and "Al" (atomic percentage) relative to the total number of atoms in the Ru-containing sputtering target.

[0077] [Table 2] JPEG0007835799000003.jpg124170

[0078] Analysis 1: Bending strength First, fragments of the support plates from preparation examples B1 to B38 were processed by wire cutting and then turned on a lathe to create multiple test specimens. Each test specimen had a thickness of 3 mm, a width of 4 mm, and a length of 50 mm.

[0079] Next, fragments of Ru-containing sputtering targets from preparation examples T1 to T10 and T24 to T26, as well as fragments of Ru-containing sputtering targets in composite targets E11 to E23 and CE4 to CE15, were processed by wire cutting and then turned on a lathe to produce multiple test specimens. Each test specimen had a thickness of 3 mm, a width of 4 mm, and a length of 50 mm.

[0080] Furthermore, the composite targets E1 to E23, the target assemblies CE1 to CE3, and the composite targets CE4 to CE15 were processed by wire cutting, then turned on a lathe to create multiple test specimens. Each test specimen had a thickness of 3 mm, a width of 4 mm, and a length of 50 mm.

[0081] Each of the above-mentioned test specimens was placed on a universal material testing machine (model: Instron 3365), and a four-point bending test was performed. The specific procedure was as follows: Each test specimen was placed on a four-point bending fixture, and under operating conditions of a pressurization rate of 0.5 mm / min and a span of 40 mm, the specimen was bent to fracture, the maximum load at the fracture point was measured, and then calculated using the following formula: Bending strength = (3 × maximum load × span) / (2 × width of test specimen × thickness of test specimen)

[0082] Finally, the bending strengths of the composite targets E1 to E23, the target assemblies CE1 to CE3, the composite targets CE4 to CE15, and their support plates and Ru-containing sputtering targets were obtained and are shown in Table 3.

[0083] Furthermore, the ratio of the bending strength of the Ru-containing sputtering target to the bending strength of the support plate within each group was calculated and recorded in Table 3.

[0084] Analysis 2: Linear thermal expansion coefficient First, test specimens of the composite targets E1 to E23, the target assemblies CE1 to CE3, and the composite targets CE4 to CE15, as well as their support plates and Ru-containing sputtering targets, were prepared in the same manner as in Analysis 1. The only difference between the test specimens in Analysis 2 and those in Analysis 1 was the size of the specimens. The dimensions of the test specimens in Analysis 2 were 5 mm thick, 5 mm wide, and 20 mm long, respectively.

[0085] Next, each of the above specimens was placed inside a dilatometer (brand: NETZSCH, model: DIL402). The analytical parameters for the relevant specimens are listed below: 1.Vacuum degree: 10 -3 From millibars to 10 -4 millibars, 2. Type of atmosphere: Argon (Ar), 3. Analysis temperature range: Room temperature to 1200°C

[0086] Finally, the CTEs of the composite targets E1 to E23, the target assemblies CE1 to CE3, and the composite targets CE4 to CE15, as well as their support plates and Ru-containing sputtering targets, were analyzed and are shown in Table 3.

[0087] Furthermore, the ratio of the CTE of the Ru-containing sputtering target to the bending strength of the support plate within each group was calculated and recorded in Table 3.

[0088] Analysis 3: Shear strength of the joint surface First, the composite targets from E1 to E23, the target assemblies from CE1 to CE3, and the composite targets from CE4 to CE15 were each processed by wire cutting, lathed, and made into a plurality of test pieces 10 shown in FIG. 1. That is, in each group of the test pieces 10, the support plates 11 and the Ru-containing sputtering targets 12 were arranged alternately in the length direction. The support plate 11 had a thickness of 1 centimeter (cm), a width of 2.5 cm, and a length of 7.5 cm, and the Ru-containing sputtering target 12 had a thickness of 1 centimeter (cm), a width of 2.5 cm, and a length of 5.5 cm. The contact length in the length direction between the support plate 11 and the Ru-containing sputtering target 12 was 4 cm, and the contact area between the support plate 11 and the Ru-containing sputtering target 12 was 10 cm 2 (calculated from 4 cm × 2.5 cm).

[0089] Each group of the test pieces 10 was placed on a tensile jig of a universal material testing machine (model: Instron3365), and a tensile strength test was carried out. The maximum shear strength until the fracture of the joint surface between the support plate 11 and the Ru-containing sputtering target 12 in each group of the test pieces 10 was measured, and then the obtained results were converted into the shear strength per unit area. Accordingly, the shear strengths of the joint surfaces of these test pieces are listed in Table 3.

[0090] If the measured shear strength of the joint surface is more than 120 kgf / cm 2 sup, then that test piece is defined as "qualified". On the contrary, if the measured shear strength of the joint surface is less than 120 kgf / cm 2 below, then that test piece is defined as "unqualified".

[0091] Analysis 4: Flatness of the Ru-containing sputtering target The test specimens of the composite targets E1 to E23, the target assemblies CE1 to CE3, and the composite targets CE4 to CE15 were each subjected to a sputtering process. Each of the aforementioned composite targets / target assemblies was disc-shaped, with a diameter of 165 mm and a thickness of 5 mm. The relevant parameters of the sputtering process were listed below: 1. Machine type: Magnetron sputtering machine, 2.Vacuum degree: 10 -2 From Toru 10 -3 Toru, 3. Power: 3000 watts (W) 4. Sputtering duration: 1800 seconds. 5. Ice water machine temperature: 25℃.

[0092] Next, each group of sputtered specimens was placed on a marble platform of a 3D coordinate measuring instrument (model: Brown & Sharpe Global Performance), and the outer surface of the Ru-containing sputtering target in each group of specimens was analyzed by measuring the height of five sampling locations on the Ru-containing sputtering target. The five sampling locations were the center point of the outer surface of the Ru-containing sputtering target and four of its sides (i.e., the four sides were above, below, left, and right of the center point, and each of the four points was 30 mm from the edge). The heights of the five sampling locations obtained from the 3D coordinate measuring instrument were used to calculate the "flatness" using the least squares method, and the results are recorded in Table 3.

[0093] If the measured flatness is less than 0.3 mm, the test specimen is defined as "good". Conversely, if the measured flatness is 0.3 mm or more, the test specimen is defined as "poor".

[0094] The amounts of Ru, additional components, and oxide components in the Ru-containing sputtering targets E1 to E23 and CE1 to CE15, the amounts of the first and second components in the support plates E1 to E23 and CE1 to CE15, the bending strength of the Ru-containing sputtering targets, support plates, and composite targets E1 to E23 and CE1 to CE15, the ratio of the bending strength of the Ru-containing sputtering targets to the bending strength of the support plates E1 to E23 and CE1 to CE15, the CTE of the Ru-containing sputtering targets and support plates E1 to E23 and CE1 to CE15, the ratio of the CTE of the Ru-containing sputtering targets to the CTE of the support plates E1 to E23 and CE1 to CE15, the shear strength of E1 to E23 and CE1 to CE15, and the flatness of the Ru-containing sputtering targets after sputtering E1 to E23 and CE1 to CE15.

[0095] [Table 3]

[0096] Review of experimental results According to the preparation methods and results of the examples listed in Table 3, if the composite target satisfies the following technical conditions simultaneously: (I) the support plate contains a first component, the first component can be exposed to a Ru-containing solid solution and has a thermal conductivity of more than 50 W / m·K; (II) the total content of the first component is 70-100 at% based on the total number of atoms in the support plate; (III) the total content of the oxide component is 20-42 at% based on the total number of atoms in the Ru-containing sputtering target; (IV) the ratio of the bending strength of the Ru-containing sputtering target to the bending strength of the support plate is 0.1 to 0.8; and (V) the ratio of the CTE of the Ru-containing sputtering target to the CTE of the support plate is 0.8 to 1.2, then the Ru-containing sputtering target and support plate in the composite target have a thermal conductivity of 120 kgf / cm². 2Due to the shear strength of the joint surface, excellent bonding strength can be achieved without soldering. The technical means of the present invention described above have proven to effectively improve the bonding ability between the Ru-containing sputtering target and the support plate. In addition, all composite targets of the examples have a bending strength higher than the bending strength of the Ru-containing sputtering target itself, thus reducing or even avoiding the phenomena of strain, deformation or cracking of the Ru-containing sputtering target during the subsequent sputtering process. Furthermore, the outer surface of the Ru-containing sputtering target was able to maintain good flatness after the completion of sputtering. In contrast, the composite targets of CE4 to CE15 did not employ technical means (I) to (V) simultaneously, and therefore the composite targets of CE4 to CE15 were unable to simultaneously achieve excellent bonding strength and maintain good flatness after the completion of sputtering.

[0097] Referring to the results for E1, CE1, and CE4, the Ru-containing sputtering targets in the three groups had the same main composition, expressed as 40Ru-25Co-25TiO2-10SiO2. However, the entire composition of the support plates in CE1 and CE4 was different; the Cu component could not be exposed to the Ru-containing solid solution, and the CTE of the support plates in CE1 and CE4 was too high. As a result, the concentration ratio of the CTE of the Ru-containing sputtering target to the CTE of the support plate was less than 0.8 (i.e., 0.43). Therefore, even when the Ru-containing sputtering target and support plate were joined by welding or sintering, the shear strength of the joint surface between the Ru-containing sputtering target and support plate in the target assembly of CE1, and the shear strength of the joint surface between the Ru-containing sputtering target and support plate in CE4, was significantly lower than that of E1. Furthermore, after the sputtering was completed, the outer surface of the Ru-containing sputtering target within the target assembly of CE1 and the outer surface of the Ru-containing sputtering target within the composite target of CE4 failed to maintain good flatness.

[0098] Similarly, referring to the results for CE5 to CE8 and E1, the Ru-containing sputtering targets of the five groups had the same main composition expressed as 40Ru-25Co-25TiO2-10SiO2. However, none of the support plates from CE5 to CE8 contained at least 70 at% of the first component. Therefore, the composite targets from CE5 to CE8 could not simultaneously achieve a high shear strength bonding surface and maintain good flatness after sputtering was completed.

[0099] Further reference to the results for the composite targets E1, CE13, and CE14, the Ru-containing sputtering targets of the three groups had the same main composition, but the support plates of the CE13 and CE14 composite targets contained the first component at 70 at% or more, and the CE13 and CE14 composite targets could not control the ratio of the CTE of the Ru-containing sputtering target to the CTE of the support plate. Therefore, although the CE13 and CE14 composite targets had good shear strength at the joint surface between the Ru-containing sputtering target and the support plate, the outer surface of the Ru-containing sputtering target in the CE13 and CE14 composite targets could not maintain good flatness after the completion of sputtering.

[0100] Furthermore, referring to the CE15 composite target, while both the Ru-containing sputtering target and support plate of CE15 had the appropriate composition in the appropriate amounts, the CE15 composite target did not control the ratio of the bending strength of the Ru-containing sputtering target to the bending strength of the support plate. The bending strength of the CE15 support plate was less than 700 MPa, which was also lower than the bending strength of the Ru-containing sputtering target. In other words, the bending strength of the CE15 composite target was lower than the bending strength of the Ru-containing sputtering target itself. In the circumstances described above, a person skilled in the art would not consider using the CE15 composite target.

[0101] In short, by controlling the content of the first component in the support plate and the oxide component in the Ru-containing sputtering target, the ratio range of CTE between the Ru-containing sputtering target and the support plate, the ratio range of bending strength between the Ru-containing sputtering target and the support plate, and the bonding ability between the Ru-containing sputtering target and the support plate can be enhanced. Furthermore, after the composite target is subjected to the sputtering process, the outer surface of the Ru-containing sputtering target within the composite target can still maintain good flatness. Therefore, the composite target of the present invention can not only reduce or even avoid the phenomena of strain, deformation or cracking of the Ru-containing sputtering target during subsequent sputtering processes, but also increase the possibility of continuous use of the Ru-containing sputtering target, thereby further increasing the commercial value of the Ru-containing sputtering target.

[0102] While numerous features and advantages of the present invention, along with details of its structure and characteristics, have been described above, this disclosure is merely illustrative. Modifications may be made in detail, particularly with respect to size, to the maximum extent indicated by the broad general meaning of the terms expressed in the appended claims, within the scope of the principles of the present invention.

Claims

1. A composite target comprising a support plate and a ruthenium (Ru)-containing sputtering target bonded to the support plate, The support plate comprises a first component, which can be exposed to a Ru-containing solid solution and has a thermal conductivity greater than 50 watts per meter per Kelvin, and based on the total number of atoms in the support plate, the total content of the first component is 70-100 atomic percent. The Ru-containing sputtering target comprises Ru and oxide components. Based on the total number of atoms in the Ru-containing sputtering target, the total content of Ru is 15-62 atomic percentages, and the total content of the oxide components is 20-42 atomic percentages. The ratio of the bending strength of the Ru-containing sputtering target to the bending strength of the support plate is 0.1 to 0.

8. A composite target characterized in that the ratio of the linear thermal expansion coefficient of the Ru-containing sputtering target to the linear thermal expansion coefficient of the support plate is 0.8 to 1.

2.

2. The composite target according to claim 1, characterized in that the bending strength of the support plate exceeds 700 million Pascals.

3. The composite target according to claim 1, characterized in that the first component comprises cobalt, iron, chromium, molybdenum, nickel, or any combination thereof.

4. The composite target according to claim 3, wherein the support plate further comprises a second component, the second component comprising aluminum, zinc, tin, copper, palladium, tungsten, silicon, niobium, magnesium, or any combination thereof, and based on the total number of atoms of the support plate, the total content of the second component is greater than 0 atomic percent and 30 atomic percent or less.

5. The composite target according to claim 1, characterized in that the oxide component is selected from the group consisting of aluminum oxide, titanium oxide, silicon oxide, boron oxide, cobalt oxide, chromium oxide, magnesium oxide, niobium oxide, tantalum oxide, yttrium oxide, tungsten oxide, manganese oxide, zirconium oxide, and any combination thereof.

6. The composite target according to any one of claims 1 to 5, wherein the Ru-containing sputtering target further comprises an additional component, the additional component comprising platinum, cobalt, chromium, boron, titanium, rhenium, aluminum, or any combination thereof.

7. The composite target according to claim 6, characterized in that, based on the total number of atoms in the Ru-containing sputtering target, the total content of the additional component is 18 atoms or more and 47 atoms or less.

8. A method for preparing a composite target, wherein the preparation method is: To obtain the aforementioned composite target, a support plate and a Ru-containing sputtering target are combined. Includes, The support plate comprises a first component, which can be exposed to a Ru-containing solid solution and has a thermal conductivity greater than 50 watts per meter per Kelvin, and based on the total number of atoms in the support plate, the total content of the first component is 70-100 atomic percent. The Ru-containing sputtering target comprises Ru and oxide components. Based on the total number of atoms in the Ru-containing sputtering target, the total content of Ru is 15-62 atomic percentages, and the total content of the oxide components is 20-42 atomic percentages. The ratio of the bending strength of the Ru-containing sputtering target to the bending strength of the support plate is 0.1 to 0.

8. Preparation method wherein the ratio of the linear thermal expansion coefficient of the Ru-containing sputtering target to the linear thermal expansion coefficient of the support plate is 0.8 to 1.

2.

9. The preparation method according to claim 8, characterized in that the oxide component is selected from the group consisting of aluminum oxide, titanium oxide, silicon oxide, boron oxide, cobalt oxide, chromium oxide, magnesium oxide, niobium oxide, tantalum oxide, yttrium oxide, tungsten oxide, manganese oxide, zirconium oxide, and any combination thereof.

10. The preparation method according to claim 8, characterized in that the first component comprises cobalt, iron, chromium, molybdenum, nickel, or any combination thereof.

11. A method for bonding the support plate and the Ru-containing sputtering target is: The steps include forming the Ru-containing sputtering target with the raw material mixture that has undergone the preceding sintering process, A bonding step in which the Ru-containing sputtering target is placed on the support plate in order to undergo a sintering bonding process, A preparation method according to any one of claims 8 to 10, characterized by including the following:

12. A method for bonding the support plate and the Ru-containing sputtering target is: The arrangement step involves placing the raw material mixture for producing the Ru-containing sputtering target directly onto the support plate, The sintering step following the arrangement step and A preparation method according to any one of claims 8 to 10, characterized by including the following:

13. The preparation method according to claim 12, wherein the raw material mixture for producing the Ru-containing sputtering target comprises a ruthenium raw material, an oxide raw material, and an additional raw material, the Ru-containing sputtering target further comprises an additional component, the additional raw material comprises a platinum raw material, a cobalt raw material, a chromium raw material, a boron raw material, a titanium raw material, a rhenium raw material, an aluminum raw material, or any combination thereof, and the additional component comprises platinum, cobalt, chromium, boron, titanium, rhenium, aluminum, or any combination thereof.

14. The preparation method according to claim 11, characterized in that, in the sintering bonding step, the sintering temperature is in the range of 650°C to 1250°C, and the sintering pressure is in the range of 220 bar to 1300 bar.

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