Sputtering member

Abstract

Provided is a sputtering member composed of an alloy of Co and a group 5 element in the periodic table, such as a Co-Nb alloy, capable of suppressing particles generated during sputtering. This sputtering member contains not less than 1 at% but less than 25 at% of Nb, the remaining portion being Co and unavoidable impurities. The sputtering member has a relative density of 99.7% or more. This sputtering member contains not less than 1 at% but less than 25 at% of the total of one or more of V, Nb, and Ta, the remaining portion being Co and unavoidable impurities. The sputtering member has a relative density of 99.7% or more.

Description

Sputtering materials

[0001] The present invention relates to sputtering members such as sputtering target members and coils.

[0002] Co alloys are sometimes used for seed layers in the laminated structures of magnetic recording media such as hard disk drives, and for diffusion barrier layers in multilayer wiring structures in semiconductor devices. In recent years, Co—Nb alloys and Co—Ta alloys, which are capable of stably forming amorphous films, have been investigated as Co alloys for use in seed layers and diffusion barrier layers (Patent Document 1, Patent Document 2).

[0003] Due to its high productivity, thin layers such as seed layers and diffusion barrier layers have been formed by sputtering onto a substrate using a sputtering target prepared to obtain a composition appropriate for each layer. Sputtering is a type of physical vapor deposition (PVD) technology in which ionized inert gas atoms such as Ar collide with the surface of a sputtering target at high speed in a vacuum, ejecting particles of the film-forming material that make up the sputtering target and depositing them on the surface of the substrate. Therefore, it would be convenient if sputtering could also be used when forming thin layers such as seed layers and diffusion barrier layers composed of Co—Nb alloys and Co—Ta alloys.

[0004] Patent Document 3 describes a Co alloy target material suitable for forming a seed layer of a magnetic recording medium, which has improved machinability. More specifically, Patent Document 3 describes a Co alloy target material having a Co alloy composition containing 25 to 90 atomic % of one or more refractory metal elements selected from Nb, Ta, Mo, W, and Ti, with the remainder consisting essentially of Co, and in the examples, describes a Co—Nb alloy target material containing 75 atomic % Nb and a Co—Ta alloy target material containing 75 atomic % Ta.

[0005] Japanese Patent Application Laid-Open No. 2002-222518 International Publication No. 2021 / 245893 Patent No. 4427792

[0006] When forming a thin layer of an alloy of Co and a Group 5 element of the periodic table, such as a Co—Nb alloy or a Co—Ta alloy, by sputtering, it is convenient to use a sputtering target made of an alloy of Co and a Group 5 element of the periodic table. Furthermore, when forming a thin layer of an alloy of Co and a Group 5 element of the periodic table by sputtering, it may be desirable to use a component made of an alloy of Co and a Group 5 element of the periodic table, such as a coil (e.g., a high-speed deflection coil or a high-speed focusing coil) made of an alloy of Co and a Group 5 element of the periodic table, in the sputtering apparatus, in order to control the film thickness at the outer periphery of the sputtering target and to increase the linearity of sputtered particles.

[0007] However, conventional alloys of Co and Group 5 elements of the periodic table, such as Co—Nb alloys and Co—Ta alloys, have room for improvement in terms of suppressing particle generation during sputtering. The present invention was created in consideration of the above circumstances, and an object of the present invention is to provide a sputtering member made of a Co—Nb alloy that can suppress particle generation during sputtering. In another embodiment, an object of the present invention is to provide a sputtering member made of an alloy of Co and Group 5 elements of the periodic table that can suppress particle generation during sputtering.

[0008] The present inventors conducted extensive research to solve the above-mentioned problems and found that by using a Co—Nb alloy powder, which takes into consideration particle size and fluidity, as the raw material powder and hot pressing it under appropriate conditions, a distinctive Co—Nb alloy sintered body can be obtained, and that the Co—Nb alloy sintered body can significantly suppress particle generation during sputtering. Furthermore, not only Co—Nb alloys, but also alloys of Co and Group 5 elements of the periodic table (excluding Db) have shown similar trends. This is thought to be because alloys of Co and Group 5 elements of the periodic table exhibit similar phase diagrams. The present invention was completed based on the above findings and is exemplified below.

[0009] [Aspect 1] A sputtering member containing 1 at% or more and less than 25 at% Nb, with the remainder being Co and unavoidable impurities, and having a relative density of 99.7% or more. [Aspect 2] An actual density of 8.80 to 9.00 g / cm 3A sputtering member according to Aspect 1, wherein the Vickers hardness (Hv) measured in accordance with the micro-Vickers hardness test specified in JIS Z2244:2009 is 150 to 700. [Aspect 4] A sputtering member according to any one of Aspects 1 to 3, wherein the sputtering member contains clusters of linked metal Co particles and / or metal Nb particles dispersed in a granular state in a matrix phase of an intermetallic compound, or clusters of linked intermetallic compound particles dispersed in a granular state in a matrix phase of metal Co, the clusters having an average diameter of 50 μm or less. [Aspect 5] A sputtering member according to any one of Aspects 1 to 4, wherein the elongation at break when subjected to a three-point bending strength test according to JIS R1601:2008 is 0.35 to 0.80 mm. [Aspect 6] The sputtering member according to any one of Aspects 1 to 5, containing 10 at% to 22 at% Nb. [Aspect 7] The sputtering member according to any one of Aspects 1 to 6, wherein the sputtering member is a sputtering target member or a coil. [Aspect 8] A sputtering member containing 1 at% or more but less than 25 at% Nb, with the remainder being Co and unavoidable impurities, wherein the sputtering member contains clusters of linked metallic Co particles and / or metallic Nb particles dispersed in a matrix phase of an intermetallic compound, or clusters of linked intermetallic compound particles dispersed in a matrix phase of metallic Co, the average diameter of the clusters being 50 μm or less. [Aspect 9] The sputtering member according to Aspect 8, wherein the Vickers hardness (Hv) measured in accordance with the micro-Vickers hardness test specified in JIS Z2244:2009 is 150 to 700. [Aspect 10] The sputtering member according to Aspect 8 or Aspect 9, which has a breaking elongation of 0.35 to 0.80 mm when subjected to a three-point bending strength test according to JIS R1601: 2008. [Aspect 11] The sputtering member according to any one of Aspects 8 to 10, which contains 10 at % to 22 at % of Nb. [Aspect 12] The sputtering member according to any one of Aspects 8 to 11, which is a sputtering target member or a coil.[Aspect 13] A sputtering member containing one or more of V, Nb, and Ta in total at 1 at % or more but less than 25 at %, with the remainder being Co and unavoidable impurities, and having a relative density of 99.7% or more. [Aspect 14] An actual density of 8.10 to 11.50 g / cm. 3A sputtering member according to Aspect 13, wherein the Vickers hardness (Hv) measured in accordance with the micro-Vickers hardness test specified in JIS Z2244:2009 is 150 to 1000. A sputtering member according to any one of Aspects 13 to 15, wherein the sputtering member has a dispersed cluster of one or more of metal Co particles, metal V particles, metal Nb particles, and metal Ta particles in a matrix phase of an intermetallic compound, or a dispersed cluster of intermetallic compound particles in a matrix phase of metal Co, the cluster having an average diameter of 50 μm or less. Aspect 17: The sputtering member according to any one of Aspects 13 to 16, wherein the elongation at break when subjected to a three-point bending strength test according to JIS R1601:2008 is 0.20 to 0.80 mm. [Aspect 18] The sputtering member according to any one of Aspects 13 to 17, containing 10 at % to 22 at % in total of one or more of V, Nb, and Ta. [Aspect 19] The sputtering member according to Aspects 13 to 18, wherein the sputtering member is a sputtering target member or a coil. [Aspect 20] A sputtering member containing 1 at % to 25 at % in total of one or more of V, Nb, and Ta, with the balance being Co and unavoidable impurities, wherein the sputtering member contains clusters of one or more of metal Co particles, metal V particles, metal Nb particles, and metal Ta particles that are linked together in a granular dispersed state in a matrix phase of an intermetallic compound, or clusters of intermetallic compound particles that are linked together in a granular dispersed state in a matrix phase of metal Co, and the average diameter of the clusters is 50 μm or less. [Aspect 21] The sputtering member according to aspect 20, having a Vickers hardness (Hv) of 150 to 1000 as measured in accordance with the micro Vickers hardness test specified in JIS Z2244: 2009. [Aspect 22] The sputtering member according to aspect 20 or 21, having a breaking elongation of 0.20 to 0.80 mm when subjected to a three-point bending strength test according to JIS R1601: 2008.[Embodiment 23] The sputtering member according to any one of embodiments 20 to 22, containing 10 at % to 22 at % in total of one or more of V, Nb, and Ta. [Embodiment 24] The sputtering member according to embodiment 20 to 23, wherein the sputtering member is a sputtering target member or a coil.

[0010] A sputtering member according to one embodiment of the present invention, which is composed of an alloy of Co and a Group 5 element of the periodic table (excluding Db), such as a Co—Nb alloy, can significantly suppress particle generation during sputtering. First, the sputtering member has improved density, resulting in fewer voids and less impact from foreign particles (dust) adhering to the voids. Second, the sputtering member contains finely dispersed metal phase clusters with a relatively high sputtering rate. This makes it difficult for large defects to occur during sputtering, and spalling originating from these large defects is unlikely to occur. For these reasons, it is believed that particle generation during sputtering is suppressed. Therefore, the sputtering member is expected to produce a thin layer made of an alloy of Co and a Group 5 element of the periodic table, such as a Co—Nb alloy, with excellent quality stability.

[0011] 1 is an example of a structure image of a sputtering member according to an embodiment of the present invention, taken with an optical microscope. 2 is an example of a structure image after image processing of FIG.

[0012] (1. Composition) A sputtering member according to one embodiment of the present invention contains 1 at% or more and less than 25 at% Nb, with the balance consisting of Co and unavoidable impurities. Having a Nb content of less than 25 at% in the sputtering member is advantageous for achieving excellent processability. Furthermore, having a Nb content of 1 at% or more in the sputtering member is advantageous for realizing a predetermined function of Nb (e.g., function as a seed layer or diffusion barrier layer). As long as the Nb content satisfies the condition of 1 at% or more and less than 25 at%, the Nb content may be appropriately set depending on the application. For example, a sputtering member according to another embodiment of the present invention contains 1 at% or more and 22 at% or less Nb, with the balance consisting of Co and unavoidable impurities. A sputtering member according to yet another embodiment of the present invention contains 2 at% or more and 20 at% or less Nb, with the balance consisting of Co and unavoidable impurities. A sputtering member according to yet another embodiment of the present invention contains 2 at% or more and 10 at% or less of Nb, with the balance being Co and unavoidable impurities.A sputtering member according to yet another embodiment of the present invention contains 10 at% or more and 22 at% or less of Nb, with the balance being Co and unavoidable impurities.A sputtering member according to yet another embodiment of the present invention contains 15 at% or more and 22 at% or less of Nb, with the balance being Co and unavoidable impurities.

[0013] Furthermore, a sputtering member according to one embodiment of the present invention contains Ta in an amount of 1 at% or more and less than 25 at% with the remainder being Co and unavoidable impurities. A Ta content of less than 25 at% in the sputtering member is advantageous for achieving excellent processability. Furthermore, a Ta content of 1 at% or more in the sputtering member is advantageous for realizing a predetermined function of Ta (e.g., function as a seed layer or diffusion barrier layer). As long as the Ta content satisfies the condition of 1 at% or more and less than 25 at%, the Ta content may be appropriately set depending on the application. For example, a sputtering member according to another embodiment of the present invention contains Ta in an amount of 1 at% or more and 22 at% or less with the remainder being Co and unavoidable impurities. A sputtering member according to yet another embodiment of the present invention contains Ta in an amount of 2 at% or more and 20 at% or less with the remainder being Co and unavoidable impurities. A sputtering member according to yet another embodiment of the present invention contains 2 at% or more and 10 at% or less of Ta, with the balance being Co and unavoidable impurities.A sputtering member according to yet another embodiment of the present invention contains 10 at% or more and 22 at% or less of Ta, with the balance being Co and unavoidable impurities.A sputtering member according to yet another embodiment of the present invention contains 15 at% or more and 22 at% or less of Ta, with the balance being Co and unavoidable impurities.

[0014] Furthermore, a sputtering member according to one embodiment of the present invention contains one or more of Group 5 elements of the periodic table excluding Db, i.e., one or more of V, Nb, and Ta, in a total content of 1 at% or more but less than 25 at% with the remainder being Co and unavoidable impurities. Having a total content of one or more of V, Nb, and Ta in the sputtering member of less than 25 at% is advantageous for achieving excellent processability. Furthermore, having a total content of one or more of V, Nb, and Ta in the sputtering member of 1 at% or more is advantageous for achieving a predetermined function of the Group 5 elements of the periodic table (e.g., function as a seed layer or diffusion barrier layer). As long as the total content of one or more of V, Nb, and Ta satisfies the condition of 1 at% or more but less than 25 at%, the content of each of the V, Nb, and Ta elements can be appropriately set depending on the application. For example, a sputtering member according to another embodiment of the present invention contains one or more of V, Nb, and Ta in a total content of 1 at% to 22 at% both inclusive, with the balance being Co and unavoidable impurities. A sputtering member according to yet another embodiment of the present invention contains one or more of V, Nb, and Ta in a total content of 2 at% to 20 at% both inclusive, with the balance being Co and unavoidable impurities. A sputtering member according to yet another embodiment of the present invention contains one or more of V, Nb, and Ta in a total content of 2 at% to 10 at% both inclusive, with the balance being Co and unavoidable impurities. A sputtering member according to yet another embodiment of the present invention contains one or more of V, Nb, and Ta in a total content of 10 at% to 22 at% both inclusive, with the balance being Co and unavoidable impurities. A sputtering member according to yet another embodiment of the present invention contains one or more of V, Nb, and Ta in a total amount of 15 at % to 22 at %, with the remainder being Co and unavoidable impurities.

[0015] The unavoidable impurities are present in raw materials or are inevitably mixed in during the manufacturing process. Although they are essentially unnecessary, they are permitted because they are present in trace amounts and do not affect the properties of the sputtering member. The total content of the unavoidable impurities is preferably 0.5 at% or less, more preferably 0.1 at% or less, and even more preferably 0.05 at% or less.

[0016] (2. Density) The sputtering member according to one embodiment of the present invention can have improved density. Having improved density means that when comparing Co—Nb alloys having the same Nb content, or when comparing alloys of Co and Group 5 elements of the periodic table having the same composition, the actual density is higher. High density means that there are fewer voids in the sputtering member, and it is possible to reduce dust that adheres to the voids. This is thought to contribute to the suppression of particles generated during sputtering. Specifically, the sputtering member of the Co—Nb alloy according to one embodiment of the present invention has a density of 8.80 to 9.00 g / cm 3 and preferably has an actual density of 8.85 to 8.95 g / cm 3 and more preferably 8.85 to 8.90 g / cm 3 Furthermore, the Co—Ta alloy sputtering member according to one embodiment of the present invention can have an actual density of 8.80 to 11.50 g / cm 3 and preferably has an actual density of 9.00 to 11.45 g / cm 3 and more preferably from 9.50 to 11.40 g / cm 3 The sputtering member of an alloy of Co and a Group 5 element of the periodic table (one or more of V, Nb, and Ta) according to one embodiment of the present invention can have an actual density of 8.10 to 11.50 g / cm 3 and preferably has an actual density of 8.15 to 11.45 g / cm 3 and more preferably from 8.17 to 11.40 g / cm 3 The actual density of the sputtering member is measured in accordance with JIS Z8807:2012 by the submerged weighing method (measure the temperature of water used as a standard substance, and use the corresponding density as the density of the standard substance). A test piece (4 mm x 3 mm x 20 mm) for measuring the actual density is cut out from any location on the sputtering member.

[0017] Density can also be evaluated by relative density, and generally, the higher the relative density, the higher the density. Specifically, a Co—Nb alloy sputtering member according to one embodiment of the present invention can have a relative density of 99.7% or more, preferably 99.8% or more, and more preferably 100.0% or more. There is no particular upper limit on the relative density, but from the viewpoint of ease of manufacture, it is usually 110% or less, typically 105% or less, and more typically 102% or less. Therefore, a Co—Nb alloy sputtering member according to one embodiment of the present invention can have a relative density of, for example, 99.7 to 110%, preferably 99.8 to 105%, and more preferably 99.8 to 102%. Furthermore, the Co—Ta alloy sputtering member according to one embodiment of the present invention may have a relative density of 99.7% or more, preferably 99.8% or more, and more preferably 100.0% or more. There is no particular upper limit to the relative density, but from the viewpoint of ease of manufacture, it is usually 110% or less, typically 105% or less, and more typically 102% or less. Therefore, the Co—Ta alloy sputtering member according to one embodiment of the present invention may have a relative density of, for example, 99.7 to 110%, preferably 99.8 to 105%, and more preferably 99.8 to 102%. Furthermore, the sputtering member according to one embodiment of the present invention, which is an alloy of Co and one or more elements of Group 5 of the periodic table (V, Nb, and Ta), may have a relative density of 99.7% or more, preferably 99.8% or more, and more preferably 100% or more. There is no particular upper limit to the relative density, but from the viewpoint of ease of production, it is usually 110% or less, typically 105% or less, and more typically 102% or less.Therefore, a sputtering member made of an alloy of Co and a Group 5 element of the periodic table (one or more of V, Nb, and Ta) according to one embodiment of the present invention can have a relative density of, for example, 99.7 to 110%, preferably 99.8 to 105%, and more preferably 99.8 to 102%.

[0018] The relative density of the sputtering member is calculated based on the actual density measured above and the theoretical density as follows: relative density (%) = actual density / theoretical density × 100. In the present invention, the theoretical density of the Co—Nb alloy is calculated based on the densities of pure Co and pure Nb, assuming that Co and Nb exist in the same system without interacting with each other. Similarly, the theoretical density of the Co—Ta alloy is calculated based on the densities of pure Co and pure Ta, assuming that Co and Ta exist in the same system without interacting with each other. Similarly, the theoretical density of an alloy of Co and a Group 5 element of the periodic table (one or more of V, Nb, and Ta) is calculated based on the densities of pure Co and pure Group 5 elements of the periodic table, assuming that Co and Group 5 elements exist in the same system without interacting with each other. Therefore, since the presence of intermetallic compounds is not taken into consideration, the actual density may be greater than the theoretical density, i.e., the relative density may exceed 100%. Specifically, the theoretical density of the Co—Nb alloy is calculated by multiplying the density of Co by 8.90 g / cm. 3 , the atomic weight of Co is 58.93, and the density of Nb is 8.57 g / cm 3 , the atomic weight of Nb is 92.91, and the atomic concentration of Nb in the Co—Nb alloy is X (at%), the theoretical density (g / cm 3 ) is expressed by the following formula: Theoretical density = M(X) / V(X) (0 < X ​​< 100) where, Alloy mass M(X) = 58.93 x (100 - X) / 100 + 92.91 x X / 100 Alloy volume V(X) = {58.93 x (100 - X) / 100} / 8.90 + {92.91 x X / 100} / 8.57 Furthermore, the theoretical density of the Co-Ta alloy is calculated by multiplying the density of Co by 8.90 g / cm 3 , the atomic weight of Co is 58.93, and the density of Ta is 16.4 g / cm 3 , the atomic weight of Ta is 180.95, and the atomic concentration of Ta in the Co—Ta alloy is Y (at%), the theoretical density (g / cm 3) is expressed by the following formula: Theoretical density = M(Y) / V(Y) (0<Y<100) where, Alloy mass M(Y) = 58.93 x (100-Y) / 100 + 180.95 x Y / 100 Alloy volume V(Y) = {58.93 x (100-Y) / 100} / 8.90 + {180.95 x Y / 100} / 16.4 Furthermore, the theoretical density of the Co-V alloy is calculated by multiplying the density of Co by 8.90 g / cm 3 , the atomic weight of Co is 58.93, and the density of V is 6.0 g / cm 3 , the atomic weight of V is 50.94, and the atomic concentration of V in the Co—V alloy is Y (at%), the theoretical density (g / cm 3 ) is expressed by the following formula: Theoretical density = M(Y) / V(Y) (0 < Y < 100) where, Alloy mass M(Y) = 58.93 × (100 - Y) / 100 + 50.94 × Y / 100 Alloy volume V(Y) = {58.93 × (100 - Y) / 100} / 8.90 + {50.94 × Y / 100} / 6.0 The theoretical density of Co alloys containing two or more Group 5 elements of the periodic table can also be calculated using the same concept as above.

[0019] (3. Metallic Phase Clusters) In a sputtering member of a Co—Nb alloy according to one embodiment of the present invention, clusters (groups) of linked metallic Co particles and / or metallic Nb particles are present in a granularly dispersed state in the matrix phase of the intermetallic compound. Alternatively, clusters (groups) of linked intermetallic compound particles are present in a granularly dispersed state in the matrix phase of metallic Co. Furthermore, in a sputtering member of a Co—Ta alloy according to one embodiment of the present invention, clusters (groups) of linked metallic Co particles and / or metallic Ta particles are present in a granularly dispersed state in the matrix phase of the intermetallic compound. Alternatively, clusters (groups) of linked intermetallic compound particles are present in a granularly dispersed state in the matrix phase of metallic Co. In addition, in a sputtering member made of an alloy of Co and one or more of Group 5 elements of the periodic table (V, Nb, and Ta) according to one embodiment of the present invention, clusters (groups) of linked one or more of metallic Co particles, metallic V particles, metallic Nb particles, and metallic Ta particles are present in a granular dispersed state in the matrix phase of the intermetallic compound, or clusters (groups) of linked intermetallic compound particles are present in a granular dispersed state in the matrix phase of metallic Co.

[0020] In the present invention, such clusters are referred to as "metallic phase clusters." Whether an intermetallic compound or metallic Co constitutes the matrix phase varies depending on the Co concentration. As the Co concentration increases, metallic Co constitutes the matrix phase. The matrix phase refers to the phase with the largest volume in the alloy. Specific examples of intermetallic compounds include compounds of Co and Nb (e.g., Co7Nb6, Co2Nb, Co7Nb2), compounds of Co and Ta (e.g., CoTa2, Co2Ta, Co7Ta2), and compounds of Co and V (e.g., Co3V, CoV3).

[0021] When the matrix phase is an intermetallic compound, the composition of the metal phase clusters is influenced by the composition of the sputtering member, and is mainly composed of metallic Co.

[0022] It is desirable that the metallic phase clusters be fine. While not intending to limit the present invention by theory, the mechanism by which particles are suppressed during sputtering by the presence of fine metallic phase clusters will be considered. When the matrix phase is an intermetallic compound, the metallic phase clusters have a high proportion of metallic Co, as mentioned above, and metallic Co has a relatively high sputtering rate. Therefore, if coarse metallic phase clusters are present, the metallic phase clusters are preferentially eroded, resulting in the generation of coarse defects. Because the intermetallic compounds present around the defects are relatively brittle, spalling is likely to occur starting from the coarse defects. In contrast, if the metallic phase clusters are finely dispersed in a granular form, coarse defects are less likely to occur during sputtering, and spalling of the coarse defects is less likely to occur. This is thought to contribute to the suppression of particles generated during sputtering. Conversely, when the matrix phase is metallic Co, if coarse metallic phase clusters are present, the metallic Co surrounding the coarse metallic phase clusters is preferentially eroded, leaving the coarse metallic phase clusters as floating islands. Because the intermetallic compounds that make up the floating islands are relatively brittle, the floating islands peel off, generating coarse particles. On the other hand, if the metallic phase clusters are finely dispersed, coarse particles are less likely to be generated during sputtering. This is thought to contribute to the suppression of particle generation during sputtering.

[0023] The average diameter of the metal phase clusters is preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. There is no particular lower limit set for the average diameter of the metal phase clusters, but it can be, for example, 0.1 μm or more, or 1 μm or more, or 5 μm or more. Therefore, the average diameter of the metal phase clusters can be, for example, 0.1 to 50 μm, or 1 to 30 μm, or 5 to 20 μm.

[0024] The average diameter of the metallic phase clusters is measured by the following procedure. A test piece (10 mm × 10 mm × 8 mm (perpendicular to the sputtering surface)) is cut out from any location on the sputtering surface of the sputtering member and buffed to a mirror finish. It is then etched using dilute nitric acid (in the case of a Co—Nb alloy). For alloys other than Co—Nb alloys (such as a Co—Ta alloy or a Co—V alloy), etching is performed using dilute nitric acid or a mixture of hydrofluoric acid, nitric acid, and hydrochloric acid, taking into account the ease of structure exposure. In the case of a Co—Nb alloy, the test piece is then photographed at 200x magnification using an optical microscope from the direction perpendicular to the sputtering surface (see Figure 1). For alloys other than Co-Nb alloys (Co-Ta alloys, Co-V alloys, etc.), observation using an optical microscope similar to that used for Co-Nb alloys may be performed, but if it is difficult to distinguish the phase boundaries, a backscattered electron image (COMPO image) of the test piece is observed at a magnification of 200 to 500 times using a scanning electron microscope and a backscattered electron detector from the direction perpendicular to the sputtered surface. The obtained image (size per field of view for Co-Nb alloys is 0.3 mm) is then recorded. 2 For the Co—Nb alloy, the magnification was such that the shape of each metal phase cluster observed in one field of view could be visually recognized, and the size per field of view was set to 0.02 to 0.5 mm so that the number of metal phase clusters in one field of view was approximately 100 or more. 2The image (adjusted appropriately within the range of ) was converted to a grayscale image and binarized into white and black regions using the ISODATA method (selecting DefaultIsoData). Next, black regions were highlighted when an intermetallic compound constituted the matrix phase, and white regions were highlighted when metallic Co constituted the matrix phase. Noise was then removed using Open processing (erosion → dilation) using the free software ImageJ (version 1.54f) or software with equivalent performance. After processing the original image in this way, independent highlighted regions in the resulting image (see Figure 2) were considered to be single metal phase clusters, and particle analysis (number of particles and area) of each metal phase cluster was performed. Then, the circle-equivalent diameters based on the areas of all metal phase clusters present in the image were calculated, and the average was calculated, which was used as the average diameter of the metal phase clusters in the image. This area ratio measurement was performed at 10 locations on the test piece without bias, and the overall average value of the average diameters of the metal phase clusters at the 10 locations was used as the average diameter of the metal phase clusters in the sputtering member. It has been confirmed by composition analysis using energy dispersive X-ray analysis (EDS) that the white region can be regarded as an intermetallic compound phase and the black region can be regarded as a metallic Co phase and / or metallic Nb phase (metallic Ta phase). In addition, the metallic V phase is also considered to belong to the black region.

[0025] When the metal phase clusters are finely dispersed, the number density of the metal phase clusters increases. For example, in a sputtering member made of an alloy of Co and one or more elements of Group 5 of the periodic table (V, Nb, and Ta) according to one embodiment of the present invention, such as a Co—Nb alloy sputtering member and a Co—Ta alloy sputtering member, the number density calculated by particle analysis carried out when determining the average diameter of the metal phase clusters described above is 5,000 clusters / mm. 2 or more, and preferably 10,000 pieces / mm 2 More preferably, 15,000 pieces / mm 2 Although no particular upper limit is set for the number density, from the viewpoint of ease of manufacturing, it is preferable that the number density is 50,000 pieces / mm 2 It is usually less than 30,000 pieces / mm 2 Typically, it is 20,000 particles / mm or less. 2Therefore, the number density of the metallic phase clusters is, for example, 5,000 to 50,000 clusters / mm 2 Preferably, the density is 10,000 to 30,000 pieces / mm 2 and more preferably 15,000 to 20,000 pieces / mm 2 The number density may be measured in conjunction with determining the average diameter of the metal phase clusters. Therefore, the average value of the number densities of the metal phase clusters in the 10 fields of view used to determine the average diameter is taken as the number density of the metal phase clusters in the sputtering member.

[0026] (4. Vickers Hardness) The sputtering member according to one embodiment of the present invention can have a relatively low hardness. Having a relatively low hardness means that when comparing Co—Nb alloys having the same Nb content, or when comparing alloys of Co and Group 5 elements of the periodic table having the same composition, the hardness is lower. From the viewpoint of processability, a lower Vickers hardness is preferable. Specifically, the sputtering member of the Co—Nb alloy according to one embodiment of the present invention can have a Vickers hardness (Hv) of 150 to 700, preferably a Vickers hardness (Hv) of 200 to 600, and more preferably a Vickers hardness (Hv) of 200 to 450. A Co—Ta alloy sputtering member according to one embodiment of the present invention may have a Vickers hardness (Hv) of 150 to 1000, preferably a Vickers hardness (Hv) of 200 to 950, and more preferably a Vickers hardness (Hv) of 200 to 900. In addition, a Co—Ta alloy sputtering member may have a Vickers hardness (Hv) of 600 to 1000, or may have a Vickers hardness (Hv) of 600 to 950, or may have a Vickers hardness (Hv) of 600 to 900. A sputtering member made of an alloy of Co and one or more elements of Group 5 of the periodic table (V, Nb, and Ta) according to one embodiment of the present invention may have a Vickers hardness (Hv) of 150 to 1000, preferably a Vickers hardness (Hv) of 200 to 950, and more preferably a Vickers hardness (Hv) of 200 to 900. The Vickers hardness of the sputtering member is measured in accordance with the micro-Vickers hardness test specified in JIS Z2244:2009. Vickers hardness is measured at 20 locations on the sputtering member without bias, using a test force of 0.2 N, a load time of 4 seconds, and a hold time of 10 seconds, and the average value of the Vickers hardness at the 20 locations is taken as the Vickers hardness of the sputtering member.

[0027] (5. Elongation at Break) A sputtering member according to one embodiment of the present invention can have improved elongation at break. Having improved elongation at break means having a larger elongation at break when compared between Co—Nb alloys having the same Nb content, or when compared between alloys of Co and Group 5 elements of the periodic table having the same composition. A large elongation at break makes the sputtering member less likely to crack. Specifically, a sputtering member made of a Co—Nb alloy according to one embodiment of the present invention can have an elongation at break of 0.35 to 0.80 mm, preferably 0.38 to 0.80 mm, and more preferably 0.40 to 0.80 mm. Furthermore, a sputtering member made of a Co—Ta alloy according to one embodiment of the present invention can have an elongation at break of 0.20 to 0.80 mm, preferably 0.23 to 0.80 mm, and more preferably 0.40 to 0.80 mm. A sputtering member made of an alloy of Co and one or more elements of Group 5 of the periodic table (V, Nb, and Ta) according to one embodiment of the present invention can have a fracture elongation of 0.20 to 0.80 mm, preferably 0.23 to 0.80 mm, and more preferably 0.40 to 0.80 mm. The fracture elongation is measured based on the three-point bending strength test of JIS R1601:2008. Specifically, a three-point bending strength test is performed using a fixed three-point bending test jig under the following conditions: support distance: 30 mm, sample size: 3 x 4 x 40 mm, support curvature radius: 5 mm, and crosshead speed: 0.5 mm / min. The fracture elongation is the distance the crosshead descends from the start of application of a bending load to the test piece until the test piece breaks. The test piece is cut from any location on the sputtering member.

[0028] (6. Sputtering Member) The sputtering member according to one embodiment of the present invention can be suitably applied as a member required during sputtering. For example, in addition to a sputtering target member, it can be applied to coils such as a high-speed focusing coil and a high-speed deflection coil that constitute a part of a sputtering apparatus.

[0029] (7. Manufacturing Method) The sputtering member described above can be manufactured by, for example, a powder sintering method, and a specific example of the manufacturing method will be described below.

[0030] First, an alloy powder of Co and a Group 5 element (one or more of V, Nb, and Ta), such as a Co—Nb alloy powder or a Co—Ta alloy powder, with controlled particle size and fluidity, is prepared as the metal powder. Using an alloy powder of Co and a Group 5 element, such as a Co—Nb alloy powder or a Co—Ta alloy powder, is advantageous for increasing density. The Co—Nb alloy powder may contain Co and Nb at a desired content ratio, or the desired content ratio may be adjusted by mixing two or more Co—Nb alloy powders with different content ratios. Similarly, the Co—Ta alloy powder may contain Co and Ta at a desired content ratio, or the desired content ratio may be adjusted by mixing two or more Co—Ta alloy powders with different content ratios. The same applies to other alloy powders of Co and a Group 5 element. It is preferable that the prepared metal powder be as pure as possible. The metal powder is preferably produced by atomization, because it allows for easy production of powder with a nearly spherical shape. Among the atomization methods, gas atomization is more preferred, because rapid cooling refines the structure. Furthermore, if the metal powder is suitably fine, it is easier to ensure both denseness and fine dispersion of metal phase clusters.

[0031] Although the present invention is not intended to be limited by theory, it is believed that the particle size of the metal powder has the following relationship with the density of the sintered body and the characteristics of the generated metal phase clusters. First, finer metal powders are advantageous for increasing the density of the sintered body because they reduce the voids between particles. On the other hand, when atoms in the metal powder undergo mass transfer via surface diffusion, grain boundary diffusion, and volume diffusion during sintering, the generated metal phase clusters become coarse. Of these, surface diffusion has a particularly high diffusion rate, so suppressing surface diffusion is important for finely dispersing the metal phase clusters. However, if the metal powder is excessively fine, the specific surface area becomes large, making surface diffusion more likely to occur during sintering, and the metal phase clusters tend to become coarse. Therefore, to achieve both the density of the sintered body and the fine dispersion of the metal phase clusters, it is desirable for the metal powder to have an appropriate particle size.

[0032] Specifically, the median diameter of the metal powder is preferably within the range of 5 μm to 80 μm or 5 μm to 65 μm, more preferably within the range of 20 μm to 80 μm or 20 μm to 65 μm, and even more preferably within the range of 30 μm to 80 μm or 30 μm to 65 μm. The median diameter refers to the particle size at 50% cumulative volume (D50) in the particle size distribution determined by a laser diffraction / scattering method. In the examples, a particle size distribution analyzer, Model LA-920, manufactured by Horiba, Ltd., was used to measure the powder dispersed in a solvent of pure water.

[0033] Furthermore, it is preferable for metal powders to have high fluidity from the viewpoint of improving density and finely dispersing metal phase clusters. The more spherical the particles constituting the metal powder, the higher the fluidity tends to be. Therefore, one method for improving the fluidity of metal powders is a milling process using dissolution and spraying, as typified by gas atomization. An index for evaluating the fluidity of metal powders is the angle of repose, measured according to the tilt angle method (injection method). The angle of repose is preferably 45° or less, more preferably 40° or less, and even more preferably 35° or less. While no particular lower limit is set for the angle of repose, from the viewpoint of ease of availability, metal powders with angles of 15° or more, 20° or more, or 25° or more may be used. Therefore, the angle of repose of metal powders is preferably 15 to 45°, may be 20 to 40°, or may be 25 to 35°, for example. The angle of repose is described in the Powder Technology Handbook (edited by the Society of Powder Technology), published by Asakura Shoten, first edition, 2014, p. 266.

[0034] Next, the prepared metal powders are weighed so that the Group 5 elements of the periodic table, such as Co and Nb, have the desired content, and mixed using a known method such as a V-type mixer to obtain a mixed powder. At this time, it is desirable to fill the inside of a container used for mixing with an inert gas to suppress oxidation of the mixed powder as much as possible.

[0035] The mixed powder obtained by the above procedure is then pressurized and sintered in a vacuum or inert gas atmosphere, and molded into a predetermined shape such as a disk. As a sintering method, a hot press sintering method can be used. As a hot press sintering method, a hot press sintering method in which the mixed powder is filled into a carbon mold and pressed in one axial direction is preferred. In addition to hot pressing, HIP (hot isostatic pressing) may also be performed.

[0036] When a large amount of mass transfer occurs due to pressure and heat application, the metal phase clusters tend to coarsen in the sintered body. Therefore, in order to finely disperse the metal phase clusters while maintaining density, it is desirable to appropriately set the holding temperature and time during sintering. Specifically, the holding temperature during sintering for Co—Nb alloys is preferably 900 to 1220°C, more preferably 1050 to 1200°C. The holding time within this temperature range is preferably 2 to 6.5 hours, more preferably 3.5 to 5 hours. The pressure during sintering is preferably 15 to 30 MPa, more preferably 22 to 30 MPa. The holding temperature during sintering for Co—Ta alloys is preferably 1000 to 1270°C, more preferably 1100 to 1250°C. The holding time within this temperature range is preferably 2 to 6.5 hours, more preferably 3.5 to 5 hours. The pressure during sintering is preferably 15 to 30 MPa, more preferably 22 to 30 MPa. Furthermore, the holding temperature during sintering of the Co-V alloy is preferably 850 to 1200°C, more preferably 900 to 1150°C. The holding time at this temperature range is preferably 2 to 6.5 hours, more preferably 3.5 to 5 hours. The pressure during sintering is preferably 15 to 30 MPa, more preferably 22 to 30 MPa. For Co alloys containing two or more Group 5 elements of the periodic table, the holding temperature, holding time, and pressure may be determined in consideration of the content ratio of each alloy element, as well as the above-mentioned holding temperature, holding time, and pressure.

[0037] The resulting sintered body can be molded into a desired shape using a lathe or the like to produce a sputtering member according to one embodiment of the present invention. When a sputtering target member is produced as the sputtering member, there are no particular limitations on its shape, and examples include a flat plate (including a disk or rectangular plate) and a cylindrical shape. When the sputtering member is flat, for example, one plate surface has a thickness of 15 to 2000 cm 2 and may have an area of ​​200 to 1900 cm 2 It is preferable that the area of ​​the surface is 100 mm.

[0038] The sputtering member according to one embodiment of the present invention can also be manufactured by a melting and casting method. This melting and casting method is suitable when the content of Group 5 elements, such as Nb, is relatively low. Specifically, it is preferable that the total content of Group 5 elements, such as Nb, in the sputtering member is 5 at% or less. When using the melting and casting method, predetermined amounts of raw material ingots according to the desired composition (e.g., raw material ingots of Co and Nb or Co and Ta) are weighed and melted and alloyed in a vacuum induction melting furnace (VIM) to produce an alloy ingot. Next, an appropriate portion of the upper portion of the alloy ingot is removed to remove shrinkage cavities, and the remaining portion is rolled while heated at 900°C to 1250°C, typically 900°C to 1200°C, to obtain a plate of a predetermined thickness. Furthermore, when manufacturing coils, etc., a method can be used in which a hollow cylindrical alloy ingot is produced using a mold of a predetermined shape, and then the alloy ingot is machined to obtain the desired shape. Alternatively, an alloy ingot melted and alloyed by VIM may be repeatedly rolled in one direction to obtain a rolled plate, which may then be bent in the longitudinal direction using a bending roll or the like to form a hollow cylinder, and then a coil may be produced.

[0039] The sputtering target member may be bonded to a substrate such as a backing plate or a backing tube as needed and mounted in a sputtering apparatus as a sputtering target assembly. Alternatively, the sputtering target member may be mounted in a sputtering apparatus as a sputtering target without using a substrate.

[0040] (8. Film Formation Method) In one embodiment, the present invention provides a film formation method including a step of sputtering using the sputtering member described above. Sputtering conditions can be set appropriately. For example, this film formation method can be used to form a seed layer in a laminate structure of a magnetic recording medium such as a hard disk drive, or a diffusion barrier layer in a multilayer wiring structure of a semiconductor device.

[0041] <1. Production of Sintered Bodies> (Examples 1 to 4, Comparative Examples 1 and 2) As raw material powders, Co powder (median diameter = 4.7 μm, nominal purity = 99.9 at.%) produced by electrolytic deposition, Nb powder (median diameter = 21.2 μm, nominal purity 99.9 at.%) produced by ingot crushing, CoNb powder (Nb content 17.3 at.%, median diameter = 60.8 μm, nominal purity 99.9 at.%) produced by gas atomization, CoNb powder (Nb content 23.3 at.%, median diameter = 55.3 μm, nominal purity 99.9 at.%) produced by gas atomization, and CoNb powder (Nb content 12.8 at.%, median diameter = 55.1 μm, nominal purity 99.9 at.%) produced by gas atomization were purchased from outside. The median diameter of the raw material powder was determined using a laser diffraction particle size distribution analyzer (manufacturer: Horiba, Ltd., model: LA-920). In addition, to investigate the flowability of the raw material powder, the angle of repose was measured using the method described above, and the results are shown in Table 1.

[0042] The raw material powders were weighed out so as to obtain the composition (atomic concentration of Nb) shown in Table 1 for each test number. For Examples 1 to 4, the composition was adjusted using two types of CoNb powder. For Comparative Examples 1 and 2, the composition was adjusted using Co powder and Nb powder. Next, the weighed raw material powders were charged into a V-type mixer and mixed in an Ar atmosphere. The results are shown in Table 1.

[0043] Next, the mixed powder removed from the media stirring mill was filled into a carbon mold. The mixed powder filled into the mold before sintering was disk-shaped, and its size is shown in Table 1. It was then sintered in a vacuum atmosphere using a hot press (HP) that applies pressure in one axial direction. After the holding time at the holding temperature was over, it was allowed to cool naturally in the chamber. The hot press conditions and the size of the sintered body after sintering are shown in Table 1. Note that the number of disk-shaped sintered bodies corresponding to each test number was produced as needed for the following characteristic evaluations.

[0044] Examples 5 and 6 As raw material powders, CoTa powder (Ta content 15 at%, median diameter = 68 μm, nominal purity 99.9 at.%) produced by gas atomization and CoTa powder (Ta content 20 at.%, median diameter = 78 μm, nominal purity 99.9 at.%) produced by gas atomization were purchased from external sources. The median diameters of the raw material powders were determined using a laser diffraction particle size distribution analyzer (manufacturer: Horiba, Ltd., model: LA-920). In addition, to investigate the fluidity of the raw material powders, the angles of repose were measured using the method described above. The results are shown in Table 1.

[0045] The raw material powder was then filled into a carbon mold. The raw material powder filled into the mold before sintering was disk-shaped, and its size is shown in Table 1. Thereafter, it was sintered in a vacuum atmosphere using a hot press (HP) that applies pressure in one axial direction. After the holding time at the holding temperature had ended, it was allowed to cool naturally in the chamber. The hot press conditions and the size of the sintered body after sintering are shown in Table 1. Note that the number of disk-shaped sintered bodies corresponding to each test number required for the following characteristic evaluations was produced.

[0046] <2. Property Evaluation> [Density] The actual density and relative density of the disk-shaped sintered body corresponding to each test number produced by the above procedure were measured and calculated according to the above-mentioned method. The results are shown in Table 1.

[0047] [Elongation at break] The elongation at break of the disk-shaped sintered bodies corresponding to each test number produced by the above procedure was measured according to the method described above. The results are shown in Table 1. However, those for which no measurement was made are indicated by "-".

[0048] [Vickers Hardness] The Vickers hardness of each of the disk-shaped sintered bodies corresponding to each test number manufactured by the above procedure was measured according to the method described above. The results are shown in Table 1.

[0049] [Mean diameter and number density of metallic phase clusters] For the disk-shaped sintered bodies according to each test number produced by the above procedure, the mean diameter and number density of metallic phase clusters were measured according to the method described above. That is, for the Co—Nb alloy, the material was etched with dilute nitric acid and observed at a magnification of 200 times using an optical microscope. The size per field of view was 0.3 mm 2In the case of a Co—Ta alloy, the alloy was etched with a mixture of hydrofluoric acid, nitric acid, and hydrochloric acid, and a backscattered electron image (COMPO image) was observed at a magnification of 500 times using a scanning electron microscope and a backscattered electron detector, with a field of view of 0.04 mm 2 In Examples 1 to 6 and Comparative Examples 1 and 2, the matrix phase was composed of intermetallic compounds. The results are shown in Table 1.

[0050] [Number of Particles During Sputtering] The disk-shaped sintered bodies according to Example 2 and Comparative Example 2, manufactured by the above procedure, were processed into predetermined shapes and then attached to a magnetron sputtering device (Canon Anelva Corporation C-7100 Sputtering System) for sputtering. The sputtering conditions were a power input of 1 kW and an Ar gas flow rate of 30 sccm. After pre-sputtering at 3 kWh, a film was formed on a 12-inch diameter silicon wafer for 90 seconds. The number of particles with a size of 0.16 μm or larger adhering to the wafer was then measured using a surface foreign matter inspection device (Surfscan SP5, KLA-Tencor Corporation). This measurement was performed approximately every 3 kWh of target life up to approximately 27 kWh. The average number of measured particles was taken as the measured value. The results are shown in Table 1.

[0051]

[0052]

[0053] <3. Discussion> From the results in Table 1, it can be seen that the sintered bodies of Examples 1, 2, and 4 have improved density compared to the sintered bodies of Comparative Examples 1 and 2, which have the same composition. Furthermore, in Example 3, the low Nb content resulted in a low Vickers hardness and improved workability. Furthermore, the low Nb content reduced the volume fraction of intermetallic compounds, making them less likely to crack. Furthermore, comparing Examples 1 and 2, Example 2, which had a smaller average diameter of the metallic phase clusters, had a larger fracture elongation and a lower Vickers hardness than Example 1. Therefore, it can be seen that the sintered body of Example 2 also has the advantageous properties of high workability and less likely to crack. Even in Examples 5 and 6, in which the alloying element was changed from Nb to Ta, dense sintered bodies with relative densities exceeding 100% were obtained.

[0054] According to one embodiment of the present invention, particles generated during sputtering can be suppressed, potentially improving product yield. Improving product yield leads to a stable supply of products and reduced loss of metal raw materials, which are limited resources. Therefore, one embodiment of the present invention may contribute to the achievement of Goal 9, "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation," and Goal 12, "Ensure sustainable consumption and production patterns," of the United Nations-led Sustainable Development Goals (SDGs).

Claims

1. A sputtering component containing 1 at% or more but less than 25 at% Nb, with the remainder being Co and unavoidable impurities, and having a relative density of 99.7% or more.

2. Actual density is 8.80 to 9.00 g / cm 3 2. The sputtering member according to claim 1, wherein 3. A sputtering member according to claim 1 or 2, which has a Vickers hardness (Hv) of 150 to 700 as measured in accordance with the micro Vickers hardness test specified in JIS Z2244:2009.

4. A sputtering member according to claim 1 or 2, wherein the sputtering member contains clusters of linked metal Co particles and / or metal Nb particles in a granular dispersed state in a matrix phase of an intermetallic compound, or clusters of linked intermetallic compound particles in a granular dispersed state in a matrix phase of metal Co, and the average diameter of the clusters is 50 μm or less.

5. A sputtering member according to claim 1 or 2, which has a breaking elongation of 0.35 to 0.80 mm when subjected to a three-point bending strength test according to JIS R1601:2008.

6. A sputtering member according to claim 1 or 2, containing 10 at % to 22 at % Nb.

7. A sputtering member according to claim 1 or 2, which is a sputtering target member or a coil.

8. A sputtering member containing 1 at% or more but less than 25 at% Nb, with the remainder being Co and unavoidable impurities, in which clusters of linked metallic Co particles and / or metallic Nb particles exist in a granular dispersed state in a matrix phase of an intermetallic compound, or clusters of linked intermetallic compound particles exist in a granular dispersed state in a matrix phase of metallic Co, and the average diameter of the clusters is 50 μm or less.

9. The sputtering member according to claim 8, which has a Vickers hardness (Hv) of 150 to 700 as measured in accordance with the micro Vickers hardness test specified in JIS Z2244:2009.

10. The sputtering member according to claim 8 or 9, which has a breaking elongation of 0.35 to 0.80 mm when subjected to a three-point bending strength test according to JIS R1601:2008.

11. The sputtering member according to claim 8 or 9, which contains 10 at % to 22 at % of Nb.

12. The sputtering member according to claim 8 or 9, which is a sputtering target member or a coil.

13. A sputtering component containing one or more of V, Nb, and Ta in total at 1 at% or more but less than 25 at% with the remainder being Co and unavoidable impurities, and having a relative density of 99.7% or more.

14. Actual density is 8.10 to 11.50 g / cm 3 The sputtering member according to claim 13, wherein 15. A sputtering member according to claim 13 or 14, which has a Vickers hardness (Hv) of 150 to 1000 as measured in accordance with the micro Vickers hardness test specified in JIS Z2244:2009.

16. A sputtering member according to claim 13 or 14, wherein the sputtering member contains clusters of one or more of metal Co particles, metal V particles, metal Nb particles, and metal Ta particles linked together in a granular dispersed state in a matrix phase of an intermetallic compound, or clusters of intermetallic compound particles linked together in a granular dispersed state in a matrix phase of metal Co, and the average diameter of the clusters is 50 μm or less.

17. A sputtering member according to claim 13 or 14, which has a breaking elongation of 0.20 to 0.80 mm when subjected to a three-point bending strength test according to JIS R1601:2008.

18. A sputtering member according to claim 13 or 14, containing one or more of V, Nb, and Ta in a total amount of 10 at % to 22 at %.

19. The sputtering member according to claim 13 or 14, which is a sputtering target member or a coil.

20. A sputtering component containing one or more of V, Nb, and Ta in total at 1 at% or more but less than 25 at%, with the remainder being Co and unavoidable impurities, wherein the sputtering component contains clusters of one or more of metal Co particles, metal V particles, metal Nb particles, and metal Ta particles linked together in a matrix phase of an intermetallic compound, dispersed in the form of particles, or clusters of intermetallic compound particles linked together in a matrix phase of metal Co, with the average diameter of the clusters being 50 μm or less.

21. A sputtering member according to claim 20, which has a Vickers hardness (Hv) of 150 to 1000 as measured in accordance with the micro Vickers hardness test specified in JIS Z2244:2009.

22. A sputtering member according to claim 20 or 21, which has a breaking elongation of 0.20 to 0.80 mm when subjected to a three-point bending strength test according to JIS R1601:2008.

23. A sputtering member according to claim 20 or 21, containing one or more of V, Nb, and Ta in a total amount of 10 at % to 22 at %.

24. The sputtering member according to claim 20 or 21, which is a sputtering target member or a coil.