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

Abstract

The present invention provides a sputtering target for a magnetic material, which is capable of effectively suppressing peeling of a redeposition film, a sputtering target assembly for a magnetic material, and a method for manufacturing a sputtering target for a magnetic material. The sputtering target has a sputtering region and a non-sputtering region and is for magnetic materials. The arithmetic mean curvature Spc of the peaks on the surface of the non-sputtering region is 3200 to 6000 mm. -1 A sputtering target for magnetic materials.

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 producing a film for a HDD. [Background technology]

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

[0003] Sputtering is a technique in which the surface of a sputtering target, which serves as the sputtering source, is sputtered with accelerated argon ions, causing particles (sputtered particles) to be released from the sputtering target and deposited on the surface of a substrate that has been placed opposite the sputtering target, forming a thin film on the surface of the substrate.

[0004] Some of the sputtered particles may redeposit at certain 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] In response to such problems, Patent Document 1 discloses that the area of ​​the sputtering target where the redeposited film is formed is roughened by blasting with glass beads. It also discloses that this makes it possible to suppress peeling of the redeposited film 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] JP 2018-141202 A Summary of the Invention [Problem to be solved by the invention]

[0007] Both Patent Documents 1 and 2 merely 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 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. [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 non-sputtering region has a developed surface area ratio Sdr of 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 a magnetic material 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. (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 producing a sputtering target for a magnetic material having a sputtering region and a non-sputtering region, comprising the steps of: In the non-sputtering region, the arithmetic mean curvature Spc of the peak is 3200 to 6000 mm -1 A method for producing a sputtering target for a magnetic material, comprising the step of forming a surface which is Effect of the Invention

[0010] According to the embodiments of the present invention, it is possible to provide a sputtering target for a magnetic material, which is capable of effectively suppressing peeling of a redeposition film, a sputtering target assembly for a magnetic material, and a method for manufacturing a sputtering target for a magnetic material. [Brief description 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. [Diagram 2] Figures 2(A) and (B) are the operation screens of the Keyence VK-X3000. [Diagram 3] FIG. 3 is an optical microscope photograph of the surface of the non-sputtered area of ​​Example 3. [Figure 4] (A) is a photograph of the appearance of the sample surface after spray coating with lacquer 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 PREFERRED EMBODIMENTS

[0012] Next, the 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 changes and improvements in the design 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 magnetic material according to the embodiment of the present invention is not particularly limited, and may be a flat plate (including a disk or a rectangular plate), a cylindrical shape, or any other shape. In this specification, the sputtering target for magnetic material may be simply referred to as a sputtering target.

[0014] The sputtering target according to the present embodiment is used, for example, for forming a magnetic recording layer and a thin film of a HDD. The material of the sputtering target according to the present 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 in the composition, or 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 material of the sputtering target may be a material containing 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 later. Thus, the front surface has a sputtering region and a non-sputtering region. The sputtering region is a region on the front surface of the sputtering target where accelerated argon ions are bombarded to perform sputtering, and the non-sputtering region is a region on the front surface of the sputtering target other than the sputtering region. This non-sputtering region is a region where some of the sputtered particles are redeposited 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 characteristic 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 each showing a schematic diagram of a sputtering target 10a, 10b formed in a disk shape, respectively.

[0017] In the sputtering target 10a of FIG. 1(A), only the peripheral portion of the surface of the sputtering target 10a where the redeposition film is formed is the non-sputtering region 12a, and the other regions including the central portion are the sputtering region 11a. The non-sputtering region 12a of the peripheral portion 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 non-sputtering region 12a of the peripheral portion is not particularly limited as long as it covers at least the position where the redeposition film is formed. In addition, the sputtering target 10a may have a non-sputtering region where the entire surface or part of the side surface is roughened, as well as the peripheral portion of the surface as described above. In this case, the non-sputtering region of the entire surface or part of the side surface has the same characteristics as the non-sputtering region described later.

[0018] In the sputtering target 10b of FIG. 1(B), the peripheral portion of the surface of the sputtering target 10b on which the redeposition film is formed is a non-sputtering region 12b, and the central portion of the surface is also a non-sputtering region 13b, and the region other than these non-sputtering regions 12b and 13b is a sputtering region 11b. The non-sputtering region 12b of the peripheral portion 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 ratio of the non-sputtering region 13b of the central portion and the non-sputtering region 12b of the peripheral portion is not particularly limited as long as it covers at least the position where the redeposition film is formed. In addition, the sputtering target 10b may have only the central portion of its surface roughened. In addition, the sputtering target 10b may have a non-sputtering region in which not only the peripheral portion and central portion of the surface as described above, but also the entire surface or a part of the side surface is roughened. In that case, the entire surface or a part of the side surface of the non-sputtering region has the same characteristics as the non-sputtering region described later.

[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 of the surface is controlled to be 3200 mm. If the arithmetic mean curvature Spc of the peaks of the surface is small, it indicates that the points of contact with other objects are rounded, and if the arithmetic mean curvature Spc is large, it indicates that the points of contact with other objects are sharp. -1 If the surface roughness of the non-sputtered region 12a is increased, 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 thickness exceeds 100 nm, the convex portion becomes too sharp, which may easily induce arcing. -1 More preferably, it 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 more. The developed area ratio Sdr indicates how much the developed area (surface area) of a given region is increased relative to the area of ​​the given region, and for example, the developed area ratio Sdr of a completely flat surface is 0. If the developed area ratio Sdr of the surface of the non-sputtered region 12a is 4.5 or more, the roughness of the non-sputtered region 12a is increased, thereby increasing the contact area with the redeposited film, and the adhesion of the redeposited film can be improved. The developed area ratio Sdr of the surface of the non-sputtered region 12a is more preferably 5.0 or more. 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 increased, and the adhesion of the redeposition film can be improved. When the surface roughness Sa of the non-sputtering region 12a exceeds 40 μm, it means that there are too many protruding parts, which are parts that protrude in a direction away from the surface of the sputtering target. The increase in the protruding parts 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. In addition, the average roughness Ra of the surface is evaluated by a "line", whereas the surface roughness Sa is evaluated by a "surface". When using average roughness Ra, the measurement results change depending on which part is set as the measurement target. For example, when the measurement target is set to follow a predetermined area and Ra is measured, Ra is smaller than when the measurement target is set to cross the predetermined area and Ra is measured. 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 height difference 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, it means that there is a high possibility that a very large convex portion exists. Therefore, it may become a factor that induces 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 has the meaning of the standard deviation of roughness, a small Sq indicates that the roughness itself is small. Therefore, it is preferable that the root mean square height Sq of the non-sputtered region 12a is 3 μm or more. If the root mean square height Sq of the non-sputtered region 12a is 45 μm or less, it indicates that the standard deviation of the surface roughness is small, indicating that the unevenness is uniform, 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 that the surface height variation is large, and therefore it is easy for a specifically high position to exist. Therefore, the possibility of arcing occurring increases. 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). The procedure is 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 multi-file analysis application ver. 3.3.1.85 included with the VK-X3000 is used as the analysis software. First, select surface roughness measurement as the measurement mode, and select the desired roughness parameters and area. When selecting the area, specify a range of (896 μm x 672 μm) from the acquired image (360x image). Note that the above-mentioned area is determined by performing this range specification operation on the laser microscope. Next, the analysis is performed with the following filter settings. When setting surface shape correction, use "plane tilt correction." Note that "plane tilt correction" is used when measuring any non-sputtered area of ​​the surface or side of the sputtering target. <Filter settings> Filter type: Gaussian S-Filter: None F-Operation: Enabled L-Filter: None End effect compensation: Check The surface area is measured under the following conditions using a function called volume area measurement. <Surface area measurement conditions> Measurement mode: Convex Setting the height threshold: Set so that all unevenness in the measurement field of view is included in the measurement. Selecting the height threshold setting button in Figure 2(A), which is one of the operation screens of the Keyence VK-X3000, displays the screen in Figure 2(B). By dragging the bar on that screen upwards so that it covers all the spectrum shown in black, it is possible to set so that all unevenness in the measurement field of view is included in the measurement. Ignore small irregularities: None (Do not check the "Ignore small irregularities" checkbox in Figure 2(A)) Ignore small areas: Enabled (check the "Ignore small areas" checkbox in Figure 2(A)) Include top and bottom surfaces in surface area calculation: No (Do not check the box for "Include top and bottom surfaces in surface area calculation" in Fig. 2(A)) Using a laser microscope (Keyence VK-X3000), such measurements can be used to unambiguously evaluate Spc, Sdr, Sa, Sz, and Sq.

[0025] The configuration of the non-sputtering region described above has been described for non-sputtering region 12a of sputtering target 10a shown in FIG. 1(A), but is not limited thereto and may also be provided in non-sputtering regions 12b, 13b of sputtering target 10b shown in FIG. 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 necessary to form a sputtering target assembly. The sputtering target assembly may be mounted on a sputtering device and used. As the brazing material, indium or indium tin may be used. The sputtering target according to the embodiment of the present invention may be mounted on a sputtering device as it is 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 a high thermal conductivity, and from this viewpoint, Cu is suitable.

[0027] <Manufacturing method of sputtering target> Hereinafter, a method for producing a sputtering target according to an embodiment of the present invention will be described in detail. In the method for producing a sputtering target according to an embodiment of the present invention, first, raw materials constituting a sintered body are prepared. The raw materials for the sintered body may be powders 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 powders containing an alloy or ceramics 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 powders containing an alloy particle phase and a nonmagnetic material. The purity of these raw materials is usually 2N (99% by mass) or more, preferably 3N (99.9% by mass) or more, and more preferably 4N (99.99% by mass) or more. 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 obtained (for example, a decrease in the transmittance of the formed thin film, an increase in resistance, and 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 powdered raw materials are pulverized and mixed. The pulverization and mixing of the powdered raw materials can be performed using a ball mill using ceramic balls.

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

[0030] Next, the sintered body is machined on a lathe to obtain a target of a desired shape. Note that 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 the above-mentioned Spc, Sdr, Sa, Sz, and Sq controlled can be formed in the non-sputtering region of the sintered body by laser processing. The numerical values ​​of Spc, Sdr, Sa, Sz, and Sq can be appropriately adjusted by the output of the laser irradiation, the scanning speed of the laser light, and multiple scanning of the same place. More specifically, by appropriately adjusting each condition in the following laser processing conditions, the Spc, Sdr, Sa, Sz, and Sq of the non-sputtering region of the sputtering target according to the embodiment of the present invention can be controlled to a 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 the sputtering target would facilitate oxidation. In addition, it is not anticipated that any particular treatment will be performed before, after, or during the roughening treatment to remove residual stress in the sputtering target. In addition, the back surface of the sputtering target is not roughened. This is because performing the roughening treatment on the back surface may 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 spot: 1 to 10 times Frequency: 140~400kHz Scanning pitch: 0.05~0.18mm ·Wavelength: 1064nm Spot diameter: 80μm Power density: 298567~497611W / cm 2 Also, the laser processing may be performed based on the above conditions by first drawing an intersecting pattern (angle 0°) as "Layer 1" with a laser, and then drawing an overlapping intersecting pattern with a laser without rotation (rotated 0°) or rotated by a predetermined angle as "Layer 2", thereby drawing a straight line pattern at 0° or a predetermined angle. Furthermore, laser processing may be performed a desired number of times. In the manner described above, 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, it is not assumed that the non-sputtered region is roughened by another method after the non-sputtered region is roughened. For example, physical roughening means such as bead blasting or chemical roughening means such as chemical etching are not assumed. For example, if the non-sputtered region is roughened and then bead blasted, the blasting media will remain. If the desired surface state can be achieved, the non-sputtered region may be roughened by other means than laser irradiation. However, by roughening the non-sputtered region by laser irradiation, the surface of the non-sputtered region 12a free of ZrO2 and SiC can be achieved. The presence of ZrO2 and SiC on the surface of the non-sputtered region 12a means, for example, that the 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 can prevent the elements of the blasting media from being mixed into the thin film and can suppress arcing during sputtering. Furthermore, when the composition of the sputtering target does not contain Al2O3, Al2O3 is not present. The presence of Al2O3 on the surface of the non-sputtering region 12a even though 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 the non-sputtering region 12a. The absence of Al2O3 on the surface of the non-sputtering region 12a can prevent elements of the blasting media from being mixed into the thin film and can suppress arcing during sputtering.

[0035] <Film formation method using sputtering targets> Using the sputtering target according to the embodiment of the present invention, a thin film that mainly constitutes a magnetic recording medium can be formed. Specifically, a sputtering device is used to sputter the surface of the sputtering target with accelerated argon ions, particles (sputter particles) are released from the sputtering target, and the sputter particles are deposited on the surface of a substrate that is placed in a position opposite to the sputtering target in advance, thereby forming a thin film on the surface of the substrate. The sputtering conditions can be appropriately set according to the desired film thickness, composition, etc.

[0036] A part of the sputtered particles is redeposited on the non-sputtered region of the sputtering target to form a redeposited film. The sputtering target according to the embodiment of the present invention has a surface of the non-sputtered region with an arithmetic mean curvature Spc of the peaks of 3200 to 6000 mm -1 Since the temperature is controlled to be within the range of 1000 to 1500° C., the adhesion of the redeposited film formed in the non-sputtered region is improved, and peeling of the redeposited film is effectively suppressed. EXAMPLES

[0037] The following examples of the present invention 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 forming 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 each 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 Spc, Sdr, Sa, Sz, and Sq controlled was formed in the non-sputtered region of the sintered compact by laser processing. In the laser processing, a cross pattern was first drawn with a laser (angle 0°) as "layer 1", and then a cross pattern was drawn without rotation (0° rotation) or rotated 45° as "layer 2" by overlapping with the laser, thereby drawing a straight line pattern every 0° or 45°. 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] (Layer 1 laser processing conditions) Laser processing power: 20W Scanning speed: 200~400mm / s Number of scans of the same spot: 1 Frequency: 140~220kHz Scanning pitch: 0.1mm ·Wavelength: 1064nm Spot diameter: 80μm Power density: 398089W / cm 2

[0040] (Layer 2 laser processing conditions) Laser processing power: 20W Scanning speed: 200~800mm / s Number of scans of the same spot: 1 Frequency: 140~220kHz Scanning pitch: 0.1~0.131mm ·Wavelength: 1064nm Spot diameter: 80μm 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 each produced by the following production method. First, raw materials for forming 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 each of these raw materials was 3N (99.9% by mass). Next, the powders of these raw materials were pulverized in a media stirring 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 Spc, Sdr, Sa, Sz, and Sq controlled was formed in the non-sputtered region of the sintered body by laser processing. In the laser processing, a cross pattern was first drawn with a laser (angle 0°) as "layer 1", and then a cross pattern rotated by 45° or 120° was drawn by overlapping with the laser as "layer 2", thereby drawing a straight line pattern every 45° or 120°. Note that only the laser processing of layer 1 was performed for Comparative Examples 1 and 2. In addition, 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 show the laser processing conditions for each comparative example. (Layer 1 laser processing conditions) Laser processing power: 4.8~20W Scanning speed: 100~1000mm / s Number of scans of the same spot: 1 to 6 Frequency: 50~140kHz Scanning pitch: 0.2mm ·Wavelength: 1064nm Spot diameter: 80μm Power density: 95541~398089W / cm 2

[0042] (Layer 2 laser processing conditions) Laser processing power: 4.8~20W Scanning speed: 100~500mm / s Number of scans of the same spot: 1 to 3 times Frequency: 50~140kHz Scanning pitch: 0.2mm ·Wavelength: 1064nm Spot diameter: 80μm 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, the developed area ratio Sdr, the surface roughness Sa, the maximum height Sz, and the 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 carried out to confirm the adhesion of the redeposited film for Examples 1 to 5. The peel test was carried out in accordance with JIS-K5400 (checkerboard tape method). A commercially available lacquer spray was applied to each non-sputtered area and left to dry for 6 hours or more. Then, a cutter was used to make cuts in the coating film generated by applying the lacquer spray, creating 100 1 mm square grids (square grids). Furthermore, cellophane tape was applied to the surface of the coating film with the cuts, and when the cellophane tape was peeled off, the degree of peeling of the checkerboard was evaluated on a scale of 0 to 10 according to JIS-K5400. In all of Examples 1 to 5, each cut was fine and smooth on both sides, and no peeling was observed at the intersections of the cuts and at each of the 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%, so it was rated as 2 points. From this result, it was confirmed that peeling of the redeposition film could be suppressed well in Examples 1 to 5. As an example of the peel test method, Fig. 4(A) shows an appearance observation photograph of the sample surface after lacquer spray coating in Example 3, Fig. 4(B) shows an appearance observation photograph of the sample surface after cutting out a 1 mm square grid in Example 3, and Fig. 4(C) shows an appearance observation photograph of the sample surface after the peel test in Example 3. Fig. 4(D) shows an appearance observation photograph of the sample surface after the peel test in Comparative Example 7. The evaluation results are shown in Table 2.

[0046] [Table 1]

[0047] [Table 2]

[0048] <Consideration> In each 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 is 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. In addition, 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 manner. 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-sputtered region of 3200 mm -1In addition, in the sputtering targets of Comparative Examples 1 to 6, as in Comparative Example 7, the arithmetic mean curvature Spc of the peaks of the surfaces of the non-sputtered regions was 3200 mm -1 It was less than 100%. Therefore, it is considered that the coating film shows large peeling in the peel test, similarly to Comparative Example 7. From this result, it is considered 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 suppressed well. [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 sputter region and a non-sputter 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. 2. The sputtering target for a magnetic material according to claim 1, wherein a developed area ratio Sdr of the surface 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-sputtered 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 non-sputtering region has a maximum height Sz of 100 to 250 μm.

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

6. The sputtering target for magnetic material according to claim 1 or 2, 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 in its composition.

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

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

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