Sputtering target for magnetic material, sputtering target assembly for magnetic material, and method for manufacturing sputtering target for magnetic material

Abstract

To provide a sputtering target for a magnetic material capable of satisfactorily suppressing peeling of a redeposited film, a sputtering target assembly for a magnetic material, and a method for manufacturing a sputtering target for a magnetic material.SOLUTION: A sputtering target for magnetic materials, comprising a sputtering region and a non-sputtering region, wherein the non-sputtering region has an arithmetic average peak curvature Spc of 3200 to 6000mm-1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sputtering target for a magnetic material, a sputtering target assembly for a magnetic material, and a method for manufacturing a sputtering target for a magnetic material, and mainly relates to a sputtering target for manufacturing films for HDDs. [Background technology]

[0002] For example, the layers of hard disks that employ perpendicular magnetic recording systems are made of materials based on ferromagnetic metals such as Co, Fe, and Ni, and the recording layers are often made of composite materials consisting of ferromagnetic alloys, such as Co-Cr, Co-Pt, Co-Cr-Pt, and Fe-Pt, which are primarily composed of Co or Fe, and non-magnetic inorganic materials. Thin films for magnetic recording media such as hard disks are often produced by sputtering targets containing the above materials, due to their high productivity.

[0003] Sputtering is a technique for forming a thin film on the surface of a substrate by sputtering the surface of a sputtering target, which serves as the sputtering source, with accelerated argon ions, releasing particles (sputter particles) from the sputtering target and depositing the sputter particles on the surface of a substrate that has been placed opposite the sputtering target.

[0004] Some of the sputtered particles may redeposit at specific locations on the sputtering target to form a laminate (also called a redeposited film). If this redeposited film peels off from the sputtering target, it can cause arcing (abnormal discharge) during sputtering, increase the number of particles during sputtering, and cause problems such as contamination of the thin film, resulting in a lower product yield.

[0005] To address these problems, Patent Document 1 discloses that the area of ​​the sputtering target where the redeposited film is to be formed is roughened by blasting with glass beads. It also discloses that this makes it possible to prevent the redeposited film from peeling off from the roughened surface. Patent Document 2 also discloses that the sputtering target is roughened. Patent Document 2 also discloses that the area to be roughened is within a range from the outer periphery (0%) of the sputtering target to a position 2 to 13% in the center direction, and / or within a range from the center (0%) to a position 12 to 33% in the outer periphery direction. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 4-301074 [Patent Document 2] Japanese Patent Application Publication No. 2018-141202 Summary of the Invention [Problem to be solved by the invention]

[0007] Both Patent Documents 1 and 2 only mention controlling the arithmetic mean roughness Ra, and there is room for improvement in terms of suppressing peeling of the redeposition film.

[0008] Therefore, an object of an embodiment of the present invention is to provide a sputtering target for magnetic materials, a sputtering target assembly for magnetic materials, and a method for manufacturing a sputtering target for magnetic materials that can effectively suppress peeling of a redeposition film. [Means for solving the problem]

[0009] The above problems are solved by the present invention, which is specified as follows. (1) A sputtering target for magnetic materials having a sputtering region and a non-sputtering region, The arithmetic mean curvature Spc of the peaks on the surface of the non-sputtered area is 3200 to 6000 mm -1 A sputtering target for magnetic materials. (2) The sputtering target for a magnetic material according to (1), wherein the developed surface area ratio Sdr of the non-sputtering region is 4.5 or more. (3) The sputtering target for a magnetic material according to (1) or (2), wherein the non-sputtering region has a surface roughness Sa of 10 to 40 μm. (4) The sputtering target for a magnetic material according to any one of (1) to (3), wherein the non-sputtering region has a maximum height Sz of 100 to 250 μm. (5) The sputtering target for a magnetic material according to any one of (1) to (4), wherein the root mean square height Sq of the non-sputtered region is 3 to 45 μm. (6) The sputtering target for magnetic materials according to any one of (1) to (5), which contains at least one of Co, Pt, Fe, Ru, Cr, Ti, Si, Zr, B, C, N, Al, O, Mg, Zn, Ag, Cu, Ni, Ta, Nb, V, W, Mn, Bi, Ge, and Ir in its composition. (7) A sputtering target for a magnetic material according to any one of (1) to (6), a backing plate bonded to the sputtering target for magnetic material; 1. A sputtering target assembly for a magnetic material, comprising: (8) A method for manufacturing a sputtering target for a magnetic material having a sputtering region and a non-sputtering region, comprising: In the non-sputtering region, the arithmetic mean curvature Spc of the peak is 3200 to 6000 mm -1 A method for manufacturing a sputtering target for a magnetic material, comprising a step of forming a surface in which [Effects of the Invention]

[0010] According to the embodiments of the present invention, it is possible to provide a sputtering target for a magnetic material, a sputtering target assembly for a magnetic material, and a method for manufacturing a sputtering target for a magnetic material, which are capable of effectively suppressing peeling of a redeposition film. [Brief explanation of the drawings]

[0011] [Figure 1] 1(A) and 1(B) are plan views each showing a schematic diagram of a sputtering target formed in a disk shape. [Figure 2] Figures 2(A) and (B) are the operation screens of the Keyence VK-X3000. [Figure 3] FIG. 3 is an optical microscope photograph of the surface of the non-sputtered region of Example 3. [Figure 4] (A) is a photograph of the appearance of the sample surface after lacquer spray application in Example 3. (B) is a photograph of the appearance of the sample surface after cutting out a 1 mm square grid in Example 3. (C) is a photograph of the appearance of the sample surface after a peel test in Example 3. (D) is a photograph of the appearance of the sample surface after a peel test in Comparative Example 7. DETAILED DESCRIPTION OF THE INVENTION

[0012] Next, embodiments of the present invention will be described in detail with reference to the drawings. It should be understood that the present invention is not limited to the following embodiments, and that appropriate design changes and improvements may be made based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention.

[0013] <Sputtering targets for magnetic materials> The shape of the sputtering target for a magnetic material according to the embodiment of the present invention is not particularly limited, and may be a flat plate (including a disk or rectangular plate), a cylindrical shape, or any other shape. In this specification, the sputtering target for a magnetic material may also be simply referred to as a sputtering target.

[0014] The sputtering target according to this embodiment is used, for example, to form magnetic recording layers and thin films in HDDs. The material of the sputtering target according to this embodiment is not particularly limited, but may include at least one of Co, Pt, Fe, Ru, Cr, Ti, Si, Zr, B, C, N, Al, O, Mg, Zn, Ag, Cu, Ni, Ta, Nb, V, W, Mn, Bi, Ge, and Ir. Alternatively, the sputtering target may include an alloy containing at least one of Co, Pt, Fe, Ru, Cr, Ti, Si, Zr, B, C, N, Al, Mg, Zn, Ag, Cu, Ni, Ta, Nb, V, W, Mn, Bi, Ge, and Ir. The sputtering target may also include an alloy particle phase and a non-magnetic material. The non-magnetic material may be one or more selected from carbon, oxides, nitrides, and carbides.

[0015] The sputtering target according to the embodiment of the present invention mainly has a front surface, a back surface, and a side surface. The front surface is subjected to a roughening treatment described below. Therefore, the front surface has a sputtering region and a non-sputtering region. The sputtering region is a region on the surface of the sputtering target that is sputtered by bombarding accelerated argon ions, and the non-sputtering region is a region on the surface of the sputtering target other than the sputtering region. This non-sputtering region is a region where some of the sputtered particles redeposit to form a redeposited film, and in order to effectively suppress peeling of the redeposited film, the sputtering target according to the embodiment of the present invention is subjected to a very distinctive roughening treatment.

[0016] Specific examples of the sputtering region and the non-sputtering region of the sputtering target according to the embodiment of the present invention are shown in Figures 1(A) and 1(B), which are plan views schematically showing disk-shaped sputtering targets 10a and 10b, respectively.

[0017] In the sputtering target 10a shown in FIG. 1(A), only the peripheral portion of the surface of the sputtering target 10a, where the redeposition film is formed, is a non-sputtering region 12a, while the remaining area, including the central portion, is a sputtering region 11a. The peripheral non-sputtering region 12a is preferably formed with a uniform width of a predetermined size along the circumferential direction of the surface of the sputtering target 10a. The area ratio of the peripheral non-sputtering region 12a is not particularly limited as long as it covers at least the position where the redeposition film is formed. Furthermore, the sputtering target 10a may have a non-sputtering region that is roughened not only on the peripheral portion of the surface as described above, but also on the entire or part of the side surface. In this case, the non-sputtering region on the entire or part of the side surface has the same characteristics as the non-sputtering region described below.

[0018] In the sputtering target 10b shown in FIG. 1(B), the peripheral portion of the surface of the sputtering target 10b where the redeposition film is formed is a non-sputtering region 12b, and the central portion of the surface is a non-sputtering region 13b. The area other than these non-sputtering regions 12b and 13b is a sputtering region 11b. The peripheral non-sputtering region 12b is preferably formed with a uniform width of a predetermined size along the circumferential direction of the surface of the sputtering target 10b. The area ratios of the central non-sputtering region 13b and the peripheral non-sputtering region 12b are not particularly limited as long as they cover at least the position where the redeposition film is formed. Furthermore, only the central portion of the surface of the sputtering target 10b may be roughened. Furthermore, the sputtering target 10b may have a non-sputtering region where the entire or a portion of the side surface is roughened, in addition to the peripheral and central portions of the surface as described above. In this case, the entire or a portion of the side surface non-sputtering region has the same characteristics as the non-sputtering region described below.

[0019] The non-sputtering region 12a of the sputtering target according to the embodiment of the present invention has a surface peak arithmetic mean curvature Spc of 3200 to 6000 mm -1The arithmetic mean curvature Spc of the peaks on the surface is controlled to be 3200 mm. If the arithmetic mean curvature Spc of the peaks on the surface is small, it indicates that the points that come into contact with other objects are rounded, and if the arithmetic mean curvature Spc is large, it indicates that the points that come into contact with other objects are sharp. -1 If the surface roughness of the non-sputtered region 12a is higher, the adhesion of the redeposited film formed in the non-sputtered region is improved, and peeling of the redeposited film can be effectively suppressed. As a result, the inclusion of particles during sputtering is suppressed, and the product yield can be improved. In addition, the arithmetic mean curvature Spc of the peaks on the surface of the non-sputtered region 12a is 6000 mm -1 If the height exceeds 1000 mm, the convex portions become too sharp, which may easily induce arcing. -1 It is more preferable that the thickness is 3700 to 5100 mm. -1 It is even more preferable that the arithmetic mean curvature Spc of the peaks on the surface of the non-sputtered region 12a can be measured using a laser microscope in accordance with ISO-25178.

[0020] The developed area ratio Sdr of the surface of the non-sputtered region 12a is preferably 4.5 or greater. The developed area ratio Sdr represents the increase in the developed area (surface area) of a given region relative to the area of ​​the given region. For example, the developed area ratio Sdr of a completely flat surface is 0. When the developed area ratio Sdr of the surface of the non-sputtered region 12a is 4.5 or greater, the roughness of the non-sputtered region 12a is increased, thereby increasing the contact area with the redeposited film and improving the adhesion of the redeposited film. The developed area ratio Sdr of the surface of the non-sputtered region 12a is more preferably 5.0 or greater. The upper limit of the developed area ratio Sdr of the surface of the non-sputtered region 12a is not particularly limited, but may be 10.0 or less, or may be 9.0 or less. The developed area ratio Sdr of the surface of the non-sputtered region 12a can be measured using a laser microscope in accordance with ISO-25178.

[0021] The surface roughness Sa of the non-sputtering region 12a is preferably 10 to 40 μm. When the surface roughness Sa of the non-sputtering region 12a is 10 μm or more, the roughness of the non-sputtering region 12a is further increased, thereby improving the adhesion of the redeposited film. When the surface roughness Sa of the non-sputtering region 12a exceeds 40 μm, this means that there are too many protruding portions, which are portions that protrude away from the surface of the sputtering target. The increased number of protruding portions may induce arcing. The surface roughness Sa of the non-sputtering region 12a is more preferably 15 to 35 μm, and even more preferably 18 to 33 μm. The surface roughness Sa of the non-sputtering region 12a can be measured using a laser microscope in accordance with ISO-25178. Furthermore, while the average surface roughness Ra is evaluated using a line, the surface roughness Sa is evaluated using a surface. When using average roughness Ra, the measurement results vary depending on which part is set as the measurement target. For example, if the measurement target is set along a predetermined area and Ra is measured, Ra will be smaller than if the measurement target is set across the predetermined area. Therefore, by using surface roughness Sa, the variation in Sa depending on the setting position of the measurement target is reduced, improving the accuracy of control of the surface shape of the sputtering target. As a result, the quality stability of the sputtering target can be improved.

[0022] The maximum height Sz of the non-sputtered region 12a is preferably 100 to 250 μm. If the maximum height Sz of the non-sputtered region 12a is 100 μm or more, the difference in elevation of the non-sputtered region 12a becomes large, and when a redeposited film is formed in the non-sputtered region 12a, the redeposited film is easily secured at high and low positions of the non-sputtered region 12a. Therefore, the redeposited film is less likely to peel off from the non-sputtered region. If the maximum height Sz of the non-sputtered region 12a exceeds 250 μm, there is a high possibility that very large convex portions will be present. This may cause arcing during sputtering. The maximum height Sz of the non-sputtered region 12a is more preferably 110 to 210 μm, and even more preferably 120 to 200 μm. The maximum height Sz of the non-sputtered region 12a can be measured using a laser microscope in accordance with ISO-25178.

[0023] The root-mean-square height Sq of the non-sputtered region 12a is preferably 3 to 45 μm. Since Sq represents the standard deviation of roughness, a small Sq indicates small roughness itself. Therefore, the root-mean-square height Sq of the non-sputtered region 12a is preferably 3 μm or more. If the root-mean-square height Sq of the non-sputtered region 12a is 45 μm or less, it indicates a small standard deviation of surface roughness, indicating uniformity of the irregularities, and is advantageous in terms of preventing arcing. If the root-mean-square height Sq of the non-sputtered region 12a exceeds 45 μm, it indicates large variations in surface height, making it more likely that specifically high positions will exist. This increases the likelihood of arcing. The root-mean-square height Sq of the non-sputtered region 12a is more preferably 15 to 40 μm, and even more preferably 18 to 39 μm. The root mean square height Sq of the non-sputtered region 12a can be measured using a laser microscope in accordance with ISO-25178.

[0024] The above Spc, Sdr, Sa, Sz, and Sq can be measured using a laser microscope (Keyence VK-X3000) as follows: In the case of the VK-X3000, a 10x objective lens, 1.5x digital zoom, and 24x screen magnification are used to obtain a 360x (10x x 1.5x x 24x) image. The analysis software used was the multi-file analysis application ver. 3.3.1.85 included with the VK-X3000. First, select surface roughness measurement as the measurement mode, and select the desired roughness parameters and region area. When selecting the region area, specify a range of (896 μm x 672 μm) from the acquired image (360x image). Note that the region area mentioned above is determined by performing this range specification operation on the laser microscope. Next, the analysis is performed with the filter settings set to the following conditions. When setting the surface shape correction, use "plane tilt correction." Note that "plane tilt correction" is used whether the non-sputtered region of the surface or side of the sputtering target is the measurement target. <Filter settings> Filter type: Gaussian S-filter: None F-Operation: Enabled L-filter: None End effect correction: Check The surface area is measured under the following conditions using a function called volume area measurement. <Surface area measurement conditions> Measurement mode: Convex part Setting the height threshold: Set this so that all irregularities in the measurement field are included in the measurement. Selecting the height threshold setting button in Figure 2(A), one of the operation screens of the Keyence VK-X3000, displays the screen shown in Figure 2(B). By dragging the bar on this screen upwards so that it covers all the spectra shown in black, it is possible to set it so that all irregularities in the measurement field are included in the measurement. Ignore small irregularities: None (Do not check the "Ignore small irregularities" checkbox in Figure 2(A)) Ignore small areas: Enable (check the "Ignore small areas" checkbox in Figure 2(A)) Include top and bottom surfaces in surface area calculation: No (Do not check the "Include top and bottom surfaces in surface area calculation" checkbox in Figure 2(A)) Using a laser microscope (Keyence VK-X3000), Spc, Sdr, Sa, Sz, and Sq can be evaluated unambiguously by such measurements.

[0025] The configuration of the non-sputtering region described above has been described for non-sputtering region 12a of sputtering target 10a shown in Figure 1(A), but is not limited to this and may also be present in non-sputtering regions 12b, 13b of sputtering target 10b shown in Figure 1(B), or in non-sputtering regions of sputtering targets according to other embodiments of the present invention.

[0026] <Sputtering target assembly> The sputtering target according to the embodiment of the present invention may be bonded to a backing plate as needed to form a sputtering target assembly. The sputtering target assembly can be mounted in a sputtering apparatus for use. Indium or indium tin can be used as the brazing material. The sputtering target according to the embodiment of the present invention may be mounted directly in a sputtering apparatus for use without using a backing plate. The material of the backing plate is not particularly limited, and examples thereof include Cu, Ti, Mo, and alloys containing at least one of these (e.g., Cu-Ni-Si alloys (e.g., C18000, etc.), CuZn alloys, and CuCr alloys). The material of the backing plate preferably has high thermal conductivity, and from this perspective, Cu is suitable.

[0027] <Method for manufacturing sputtering targets> A method for manufacturing a sputtering target according to an embodiment of the present invention will be described in detail below. In the method for manufacturing a sputtering target according to an embodiment of the present invention, first, raw materials for forming a sintered body are prepared. The raw materials for the sintered body may be a powder containing at least one of Co, Pt, Fe, Ru, Cr, Ti, Si, Zr, B, C, N, Al, O, Mg, Zn, Ag, Cu, Ni, Ta, Nb, V, W, Mn, Bi, Ge, and Ir, or a powder containing an alloy or ceramic containing at least one of Co, Pt, Fe, Ru, Cr, Ti, Si, Zr, B, C, N, Al, Mg, Zn, Ag, Cu, Ni, Ta, Nb, V, W, Mn, Bi, Ge, and Ir. The raw materials for the sintered body may also be a powder containing an alloy particle phase and a nonmagnetic material. The purity of these raw materials is usually 2N (99% by mass) or higher, preferably 3N (99.9% by mass) or higher, and more preferably 4N (99.99% by mass) or higher. If the purity is lower than 2N, the sintered body will contain a large amount of impurities, which may result in problems such as the desired physical properties not being achieved (for example, a decrease in the transmittance of the formed thin film, an increase in resistance, and the generation of particles due to arcing). These raw materials can be appropriately prepared based on the composition and purity of the desired sintered body.

[0028] Next, the powders of these raw materials are pulverized and mixed. The pulverization and mixing of the powders of the raw materials can be performed using a ball mill using ceramic balls.

[0029] The mixture obtained by mixing and pulverizing as described above is then hot-pressed to obtain a sintered body. Sintering conditions can be appropriately selected depending on the composition of the sintered body.

[0030] The sintered body is then machined on a lathe to obtain a target of the desired shape. The surface roughness after lathe machining is preferably set to 1 μm or less, Ra, so as not to affect laser machining.

[0031] Next, under atmospheric pressure, a surface with controlled Spc, Sdr, Sa, Sz, and Sq can be formed in the non-sputtering region of the sintered body by laser processing. The values ​​of Spc, Sdr, Sa, Sz, and Sq can be adjusted appropriately by adjusting the output of the laser irradiation, the scanning speed of the laser light, and scanning the same location multiple times. More specifically, by appropriately adjusting each condition in the following laser processing conditions, the values ​​of Spc, Sdr, Sa, Sz, and Sq in the non-sputtering region of the sputtering target according to an embodiment of the present invention can be controlled to fall within the desired numerical range.

[0032] In this embodiment, the sintered body is not heated using a separate heating device during the roughening treatment (laser irradiation). This is because the roughening treatment is performed under atmospheric pressure, and heating would facilitate oxidation of the sputtering target. Furthermore, it is not anticipated that any particular treatment will be performed to remove residual stress in the sputtering target before, after, or during the roughening treatment. Furthermore, the back surface of the sputtering target is not roughened. This is because performing the roughening treatment on the back surface could reduce the strength of the sputtering target.

[0033] (Laser processing conditions) Laser processing power: 15~25W Scanning speed: 150~1000mm / s Number of scans of the same area: 1 to 10 times Frequency: 140-400kHz Scanning pitch: 0.05~0.18mm ·Wavelength: 1064nm Spot diameter: 80 μm Power density: 298567~497611W / cm 2 Furthermore, laser processing may be performed based on the above conditions by first drawing a cross pattern (angle 0°) as "Layer 1" with a laser, and then drawing an overlapping cross pattern as "Layer 2" without rotation (rotated 0°) or rotated by a predetermined angle with a laser, thereby drawing a linear pattern at 0° or a predetermined angle. Furthermore, laser processing may be performed a desired number of times. In this manner, the sputtering target according to the embodiment of the present invention can be manufactured. However, since the above conditions basically depend on the target composition (because the thermal conductivity and melting point are different), it is necessary to find the conditions by trial and error for the composition.

[0034] In this embodiment, further roughening of the non-sputtered region after roughening treatment is not anticipated. For example, physical roughening methods such as bead blasting or chemical roughening methods such as chemical etching are not anticipated. For example, if the non-sputtered region is further bead blasted after roughening treatment, the blasting media would remain. Note that the non-sputtered region may be roughened by other methods besides laser irradiation as long as the desired surface condition can be achieved. However, roughening the non-sputtered region 12a by laser irradiation can achieve a surface free of ZrO2 and SiC. The presence of ZrO2 and SiC on the surface of the non-sputtered region 12a means, for example, that elements of the blasting media are present on the surface of the non-sputtered region 12a. The absence of ZrO2 and SiC on the surface of the non-sputtered region 12a prevents elements of the blasting media from being mixed into the thin film and suppresses arcing during sputtering. Furthermore, if the composition of the sputtering target does not contain Al2O3, Al2O3 is not present. The presence of Al2O3 on the surface of non-sputtering region 12a even when the composition of the sputtering target does not contain Al2O3 means, for example, that elements of the blasting media are present on the surface of non-sputtering region 12a. The absence of Al2O3 on the surface of non-sputtering region 12a can prevent elements of the blasting media from being mixed into the thin film and can also suppress arcing during sputtering.

[0035] <Film formation method using sputtering targets> The sputtering target according to the embodiment of the present invention can be used to form a thin film that mainly constitutes a magnetic recording medium. Specifically, a sputtering device is used to sputter the surface of the sputtering target with accelerated argon ions, releasing particles (sputtered particles) from the sputtering target, and depositing the sputtered particles on the surface of a substrate previously positioned opposite the sputtering target, thereby forming a thin film on the surface of the substrate. Sputtering conditions can be appropriately set depending on the desired film thickness, composition, etc.

[0036] A portion of the sputtered particles re-adhere to the non-sputtering region of the sputtering target to form a redeposited film. In the sputtering target according to the embodiment of the present invention, the arithmetic mean curvature Spc of the peaks on the surface of the non-sputtering region is 3200 to 6000 mm -1 Since the temperature is controlled to be 0.15° C., the adhesion of the redeposited film formed in the non-sputtered region is improved, and peeling of the redeposited film is effectively suppressed. [Example]

[0037] Examples of the present invention are given below, but these examples are provided for a better understanding of the present invention and its advantages, and are not intended to limit the invention.

[0038] <Examples 1 to 7> - Manufacturing of sputtering targets The sputtering targets according to Examples 1 to 7 were each produced by the following production method. First, raw materials for the sintered body were prepared. The raw materials for the sintered body were powders containing Co, Cr, Pt, B, O, Ti, and Si (Examples 1 to 5), powders containing Co, Pt, B, O, Ti, and Si (Example 6), and powders containing Co, Pt, Ru, Ti, O, and Si (Example 7). The purity of these raw materials was 3N (99.9% by mass). Next, the powders of these raw materials were pulverized in a ball mill using beads, and the mixture obtained by mixing was hot pressed to obtain a sintered body. Next, the sintered body was machined using a lathe to obtain a disk-shaped target. Next, under atmospheric pressure, a surface with controlled Spc, Sdr, Sa, Sz, and Sq was formed in the non-sputtered region of the sintered compact by laser processing. For the laser processing, a cross pattern was first drawn with a laser (angle 0°) as "Layer 1," and then, as "Layer 2," a cross pattern was drawn with the laser either without rotation (0° rotation) or rotated 45°, overlapping with the laser, thereby drawing a linear pattern at 0° or 45° angles. Note that in Example 4, only Layer 1 was laser processed. The laser processing conditions for Layer 1 and Layer 2 are shown below. Tables 1 and 2 show the laser processing conditions for each example.

[0039] (Laser processing conditions for layer 1) Laser processing power: 20W Scanning speed: 200~400mm / s Number of scans of the same location: 1 Frequency: 140-220kHz Scanning pitch: 0.1mm ·Wavelength: 1064nm Spot diameter: 80 μm Power density: 398089W / cm 2

[0040] (Laser processing conditions for Layer 2) Laser processing power: 20W Scanning speed: 200~800mm / s Number of scans of the same location: 1 Frequency: 140-220kHz Scanning pitch: 0.1~0.131mm ·Wavelength: 1064nm Spot diameter: 80 μm Power density: 398089W / cm 2

[0041] <Comparative Examples 1 to 7> - Manufacturing of sputtering targets The sputtering targets according to Comparative Examples 1 to 7 were manufactured by the following manufacturing method. First, raw materials for the sintered body were prepared. The raw materials for the sintered body were powders containing Co, Cr, Si, and O (Comparative Examples 1 to 4), powders containing Co, Fe, B, and N (Comparative Example 5), powders containing Co, Pt, B, O, Ti, and Si (Comparative Example 6), and powders containing Co, Cr, Pt, B, O, Ti, and Si (Comparative Example 7). The purity of these raw materials was 3N (99.9% by mass). Next, the powders of these raw materials were pulverized in a media agitation mill using beads, and the mixture obtained by mixing was hot pressed to obtain a sintered body. Next, the sintered body was machined using a lathe to obtain a disk-shaped target. Next, under atmospheric pressure, a surface with controlled Spc, Sdr, Sa, Sz, and Sq was formed in the non-sputtered region of the sintered compact by laser processing. For the laser processing, first, a cross pattern was drawn with a laser (angle 0°) as "Layer 1," and then, as "Layer 2," a cross pattern rotated by 45° or 120° was drawn with the laser, overlapping the cross pattern, thereby drawing a linear pattern every 45° or 120°. Note that for Comparative Examples 1 and 2, only Layer 1 was laser processed. For Comparative Example 7, only the lathe processing described above was performed, and no laser processing was performed. The laser processing conditions for Layer 1 and Layer 2 are shown below. Tables 1 and 2 also show the laser processing conditions for each comparative example. (Laser processing conditions for layer 1) Laser processing power: 4.8~20W Scanning speed: 100~1000mm / s Number of scans of the same area: 1 to 6 times Frequency: 50-140kHz Scanning pitch: 0.2mm ·Wavelength: 1064nm Spot diameter: 80 μm Power density: 95541~398089W / cm 2

[0042] (Laser processing conditions for Layer 2) Laser processing power: 4.8~20W Scanning speed: 100~500mm / s Number of scans of the same area: 1 to 3 times Frequency: 50-140kHz Scanning pitch: 0.2mm ·Wavelength: 1064nm Spot diameter: 80 μm Power density: 95541~398089W / cm 2

[0043] Optical microscope photograph An optical microscope photograph was taken using a laser microscope VK-X3000 of the non-sputtered region of Example 3. The optical microscope photograph (magnification: 360 times) of Example 3 is shown in FIG.

[0044] Spc, Sdr, Sa, Sz, Sq For the sputtering targets of Examples 1 to 7 and Comparative Examples 1 to 7, the arithmetic mean curvature Spc, developed area ratio Sdr, surface roughness Sa, maximum height Sz, and root mean square height Sq of the peaks of the non-sputtered regions were measured using a laser microscope (Keyence VK-X3000). The measurement procedures were as described above.

[0045] Peel test A peel test was conducted on Examples 1 to 5 to confirm the adhesion of the redeposited film. The peel test was conducted in accordance with JIS-K5400 (cross-cut tape method). A commercially available lacquer spray was applied to each non-sputtered area and left to dry for at least 6 hours. Then, a cutter was used to make cuts in the coating film formed by applying the lacquer spray, creating 100 1 mm square grids (square grids). Furthermore, cellophane tape was applied to the surface of the cut coating film, and when the cellophane tape was peeled off, the degree of cross-cut peeling was evaluated on a scale of 0 to 10 according to JIS-K5400. In all of Examples 1 to 5, each cut was small and smooth on both sides, and no peeling was observed at the intersections of the cuts or at the individual squares, so they were rated 10 points. The same test was also carried out on Comparative Example 7, and the peeled area was between 35 and 65%, and the sample was evaluated as 2 points. These results confirmed that peeling of the redeposited film was successfully suppressed in Examples 1 to 5. As examples of the peel test method, Fig. 4(A) shows a photograph of the appearance of the sample surface after lacquer spray application in Example 3, Fig. 4(B) shows a photograph of the appearance of the sample surface after cutting out a 1 mm square grid in Example 3, and Fig. 4(C) shows a photograph of the appearance of the sample surface after the peel test in Example 3. Fig. 4(D) shows a photograph of the appearance of the sample surface after the peel test in Comparative Example 7. Table 2 shows the evaluation results.

[0046] [Table 1]

[0047] [Table 2]

[0048] <Consideration> In all of the sputtering targets of Examples 1 to 5, the arithmetic mean curvature Spc of the peaks on the surface of the non-sputtering region was 3200 to 6000 mm -1 As a result, the adhesion of the coating film formed in the non-sputtered region was improved, and peeling of the coating film was effectively suppressed. Also, in Examples 6 and 7, similarly to Examples 1 to 5, the arithmetic mean curvature Spc of the peaks on the surface of the non-sputtered region was 3200 to 6000 mm -1 Therefore, it is believed that peeling of the coating film can be effectively suppressed in the same way. From this result, it is believed that peeling of the redeposited film can be effectively suppressed even during sputtering. In addition, the sputtering target of Comparative Example 7 has an arithmetic mean curvature Spc of the peaks on the surface of the non-sputtering region of 3200 mm -1In addition, the sputtering targets of Comparative Examples 1 to 6, like Comparative Example 7, all had an arithmetic mean curvature Spc of the peaks on the surface of the non-sputtered region of 3200 mm -1 It is believed that this is why significant peeling of the coating film was observed in the peel test, similar to Comparative Example 7. From this result, it is believed that the adhesion of the redeposited film formed in the non-sputtered region is reduced, and peeling of the redeposited film during sputtering cannot be effectively suppressed. [Explanation of symbols]

[0049] 10a, 10b Sputtering target 11a, 11b Sputtering area 12a, 12b, 13b Non-sputtered area

Claims

1. A sputtering target for magnetic materials having a sputtering region and a non-sputtering region, The arithmetic mean curvature Spc of the peaks on the surface of the non-sputtered region is 3200 to 6000 mm -1 A sputtering target for magnetic materials.

2. 2. The sputtering target for a magnetic material according to claim 1, wherein the developed surface area ratio Sdr of the non-sputtering region is 4.5 or more.

3. 3. The sputtering target for a magnetic material according to claim 1, wherein the non-sputtering region has a surface roughness Sa of 10 to 40 μm.

4. 3. The sputtering target for a magnetic material according to claim 1, wherein the maximum height Sz of the non-sputtering region is 100 to 250 μm.

5. 3. The sputtering target for a magnetic material according to claim 1, wherein the root mean square height Sq of the non-sputtered region is 3 to 45 μm.

6. 3. The sputtering target for a magnetic material according to claim 1 or 2, which has a composition comprising at least one of Co, Pt, Fe, Ru, Cr, Ti, Si, Zr, B, C, N, Al, O, Mg, Zn, Ag, Cu, Ni, Ta, Nb, V, W, Mn, Bi, Ge, and Ir.

7. The sputtering target for a magnetic material according to claim 1 or 2, a backing plate bonded to the sputtering target for magnetic material; 1. A sputtering target assembly for a magnetic material, comprising:

8. A method for manufacturing a sputtering target for a magnetic material having a sputtering region and a non-sputtering region, comprising: The non-sputtering region has an arithmetic mean curvature Spc of the peak of 3200 to 6000 mm -1 A method for manufacturing a sputtering target for a magnetic material, comprising a step of forming a surface in which

Images