Sputtering target containing hard nitride

Abstract

The present invention provides a hard nitride-containing sputtering target and a method for producing the same, which can prevent generation of arc in sputtering due to mixing of relatively coarse zirconia particles and can suppress generation of particles at the time of film formation. A hard nitride-containing sputtering target is characterized by comprising an alloy phase containing Fe or Co and a non-magnetic phase containing a hard nitride selected from the group consisting of AlN, BN, Cr2N, Si3N4, HfN, NbN, TaN, TiN, VN, and any combination thereof, the Zr impurity concentration when measured in terms of metal Zr is limited to 1000 ppm or less, and the Vickers hardness Hv measured under a load of 3 kgf is 200 or more and 600 or less.

Description

Technical Field

[0001] This invention relates to sputtering targets containing hard nitrides and methods for manufacturing the same, particularly to sputtering targets containing hard nitrides and methods for manufacturing the same, which are composed of an alloy phase containing Fe or Co and a non-magnetic phase containing hard nitrides selected from AlN, BN, Cr2N, Si3N4, HfN, NbN, TaN, TiN, VN and any combination thereof. Background Technology

[0002] As a sputtering target for granular magnetic thin films used in the manufacture of magnetic recording media such as hard disk drives, a sintered body containing an alloy phase with strongly magnetic metals Fe or Co as the main component and non-magnetic materials such as oxides, carbon, and boron nitride is used.

[0003] For sputtering targets containing oxides as nonmagnetic materials, it has been confirmed that by creating a nonmagnetic material particle dispersion structure in which the oxides are uniformly and finely dispersed between the alloy phases, particle generation during film formation can be reduced. To achieve this uniform and fine dispersion of the oxides between the alloy phases, a media stirring mill such as a zirconia ball mill is used for vigorous stirring to mix the oxides and the raw material powders forming the alloy phases (Japanese Patent No. 4673448, Japanese Patent No. 6728094). Sputtering targets containing nitrides instead of oxides have also been proposed, but the same method of vigorous stirring and mixing using a zirconia ball mill is employed (Japanese Patent No. 5913620, Japanese Patent No. 6526837).

[0004] Japanese Patent No. 4673448 discloses a non-magnetic material particle dispersion type strong magnetic material sputtering target, which has the following composition: a phase (A) having non-magnetic particles with uniformly finely dispersed oxides, and an alloy phase (B) with spherical diameters of 50 to 200 μm in phase (A). More than 25 mol% of Cr is concentrated near the center of the spherical alloy phase (B), and the Cr content in the outer periphery is lower than that in the center. The manufacturing process of this sputtering target is described as follows: metal powder with a maximum particle size of 20 μm or less and non-magnetic material powder with a maximum particle size of 5 μm or less are sealed together with zirconia balls in a 10-liter ball mill jar and mixed by rotation for 20 hours. This mixed powder is then mixed with Co-Cr spherical powder with a diameter of 50 to 200 μm in a planetary mixer and sintered to manufacture the sputtering target.

[0005] Japanese Patent No. 6728094 discloses the following invention: To suppress particle generation during sputtering, an invention comprising a Co-Pt phase, a Co phase, and a non-magnetic material is used, wherein the Co-Pt alloy phase is fined and the Co phase is coarsened. Specifically, the invention describes using Co-Pt alloy powder with a median diameter of 0.1 μm or more and 7 μm or less, Co phase with an average particle size of 30 μm or more and 300 μm or less, and the non-magnetic oxide material with an average particle size of 0.05 μm or more and 2 μm or less as raw materials. Furthermore, as a method for mixing the raw material powders, the invention describes sealing the raw material powders together with zirconia balls in a 10-liter ball mill and mixing them by rotation for 20 hours.

[0006] Japanese Patent No. 5913620 discloses a method for reducing the amount of particles generated in Fe-Pt sintered sputtering targets using hexagonal boron nanotubes (BN) as a non-magnetic material by improving the orientation of BN. Specifically, it describes feeding Fe-Pt alloy powder and zirconia balls into a 5L media stirring mill and processing at 300 rpm for 2 hours to produce Fe-Pt alloy powder with an average particle size of 10 μm. The Fe-Pt alloy powder and hexagonal BN powder are then mixed in a V-type mixer and further mixed using a 150 μm sieve. However, hexagonal BN has low hardness, resulting in insufficient hardness as a sputtering target and the potential for cracking during sputtering.

[0007] Japanese Patent No. 6526837 discloses Fe-Pt and Co-Pt sputtering targets using cubic BN, which is less prone to cracking within BN particles compared to hexagonal BN. The method described is to feed the raw material powder and zirconia balls together into a 5L media stirring mill, mix them at 300 rpm for 2 hours, and pulverize them until the median diameter (D50) of the raw material mixture is 0.3 μm or more and 20 μm or less, preferably 5 μm or less.

[0008] However, through the inventors' experiments, it was found that when using nitrides as non-magnetic materials, during the mixing of raw material powders, because nitrides are hard, the zirconia balls and the inner wall of the media stirring mill are worn, and relatively coarse zirconia particles are mixed in. The resistivity of coarse zirconia particles is higher than that of nitrides and carbides. Therefore, arcing is easily caused during sputtering, and particle generation is easily generated during film formation.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: Japanese Patent No. 4673448

[0012] Patent Document 2: Japanese Patent No. 6728094

[0013] Patent Document 3: Japanese Patent No. 5913620

[0014] Patent Document 4: Japanese Patent No. 6526837 Summary of the Invention

[0015] The problem that the invention aims to solve

[0016] The purpose of this invention is to provide a sputtering target containing hard nitride and a method for manufacturing the same. This sputtering target containing hard nitride can solve the above-mentioned problems, prevent the generation of arc light during sputtering caused by the incorporation of relatively coarse zirconium oxide particles, and suppress particle generation during film formation.

[0017] Methods for solving problems

[0018] The inventors discovered that the arc light in sputtering of a sputtering target containing hard nitrides is caused by the presence of relatively coarse zirconia particles. They believed that by preventing the incorporation of zirconia impurity particles from the zirconia ball mill commonly used in the mixing of raw material powders during the manufacturing process of the sputtering target, the arc light in sputtering can be suppressed, thus completing the present invention.

[0019] According to the present invention, a sputtering target containing hard nitrides is provided, which is composed of an alloy phase containing Fe or Co and a nonmagnetic phase containing hard nitrides selected from AlN, BN, Cr2N, Si3N4, HfN, NbN, TaN, TiN, VN and any combination thereof.

[0020] When measuring Zr in metallic Zr, the Zr impurity concentration is limited to below 1000 ppm, and the Vickers hardness Hv measured under a load of 3 kgf is above 200 and below 600.

[0021] The concentration of the Zr impurities mentioned above is preferably limited to below 500 ppm.

[0022] The aforementioned nonmagnetic phase preferably satisfies at least one of the following:

[0023] Image analysis of EPMA surface analysis at magnification 500, with an observation field of 180μm×180μm, yielded an average particle size greater than 4μm and less than 20μm.

[0024] Image analysis of EPMA surface analysis at magnification 1000, with an observation field of 90 μm × 90 μm, yielded an average particle size greater than 2 μm and less than 20 μm; and

[0025] Image analysis of EPMA surface analysis at magnification 3000, with an observation field of 30μm×30μm, yielded an average particle size greater than 1μm and less than 20μm.

[0026] The content of the non-magnetic phase in the sputtering target is preferably 5 mol% or more and 50 mol% or less.

[0027] The aforementioned non-magnetic phase may also contain one or more selected from C, B2O3 and SiO2.

[0028] The alloy phase described above may contain more than 0 mol% and less than 60 mol% of Pt.

[0029] The alloy phases described above may also contain one or more elements selected from Ag, Au, Cr, Cu, Ge, Ir, Ni, Pd, Rh, Ru, and B.

[0030] According to the present invention, a method for manufacturing the above-mentioned sputtering target containing hard nitride is also provided. The manufacturing method of the present invention is characterized by comprising: preparing a mixed powder by mixing raw material powders constituting the above-mentioned alloy phase and the above-mentioned non-magnetic phase at a rotation speed of 50 rpm or more and 150 rpm for 2 hours or more and 6 hours, and sintering the above-mentioned mixed powder.

[0031] The raw material powder constituting the above alloy phase is preferably metal powder of each raw material or Fe-based or Co-based atomized alloy powder.

[0032] The raw material powder constituting the above-mentioned non-magnetic phase preferably contains hard nitride powder with an average particle size D50 of 1 μm or more and 40 μm or less.

[0033] Invention Effects

[0034] The sputtering target containing hard nitride of the present invention prevents the incorporation of zirconium oxide impurity particles with high resistivity and relatively large size, and limits the Zr impurity concentration when measured in terms of metallic Zr to below 1000 ppm. Therefore, it can suppress the generation of arc light during sputtering and reduce the particles of zirconium oxide particles from the film formation process. Attached Figure Description

[0035] Figure 1 This is a graph showing the relationship between Zr concentration and particle number in the sputtering targets of the Examples and Comparative Examples.

[0036] Figure 2 This is a graph showing the relationship between the Vickers hardness and the number of particles of the sputtering targets in the examples and comparative examples.

[0037] Figure 3 This is a SEM image (1000x magnification) of the tissue of the sputtering target in Example 1.

[0038] Figure 4 This is a SEM image (1000x magnification) of the tissue of the sputtering target in Example 2.

[0039] Figure 5 This is a SEM image (1000x magnification) of the tissue of the sputtering target in Comparative Example 2. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings.

[0041] The sputtering target containing hard nitrides of the present invention is characterized in that it is composed of an alloy phase containing Fe or Co and a non-magnetic phase containing hard nitrides selected from AlN, BN, Cr2N, Si3N4, HfN, NbN, TaN, TiN, VN and any combination thereof. The Zr impurity concentration when measured with metallic Zr is limited to 1000 ppm or less, preferably 500 ppm or less, more preferably 300 ppm or less, and the Vickers hardness Hv measured under a load of 3 kgf is 200 or more and 600 or less, preferably 250 or more and 600 or less.

[0042] This invention relates to sputtering targets containing hard nitrides as non-magnetic material particles. The hard nitrides include AlN, BN, Cr2N, Si3N4, HfN, NbN, TaN, TiN, VN, and any combination thereof. Regarding the hardness (GPa) of each nitride, AlN is 12.0, Cr2N is 15.4, Si3N4 is 19.4, HfN is 15.7, NbN is 14.3, TaN is 23.7, TiN is 20.1, VN is 12.8, cubic BN is 46.1, and hexagonal BN is 2.0 (Datasheet: High Melting Point Compounds Guide, Ceramic Processing Handbook: From Basics to Applications, Ceramic Hardness).

[0043] As a type of boron nanomaterial (BN) used for sputtering targets, cubic BN and hexagonal BN are known. In this invention, cubic BN, which is known to have a hardness second only to diamond, is used. It should be noted that if cubic BN is present, hexagonal BN may also be mixed in.

[0044] The nonmagnetic phase contains hard nitrides with an average particle size of 1 μm or more, preferably 2 μm or more and 20 μm or less. The average particle size of the nonmagnetic phase can be determined by image analysis of the EPMA surface analysis results. The image analysis based on EPMA surface analysis is performed through the following steps.

[0045] First, the sputtering surface of the sputtering target is ground, and an elemental mapping image is obtained at 100x magnification using an EPMA apparatus. The obtained elemental mapping image is then binarized using the "surface processing" function provided with the EPMA apparatus. The binarized elemental mapping image is analyzed using image analysis software (ImageJ 1.53e) to determine the average particle size of the nitride. If the nitride consists of only one element other than nitrogen (e.g., element A), the locations of both element N and element A are calculated from the elemental mapping image. If the nitride consists of two or more elements other than nitrogen, a composite elemental mapping image is created from the mapping images of each element, and the locations of both elements other than nitrogen and element N are calculated. The average size is then determined, and the average particle size (μm) is calculated using the following formula.

[0046]

[0047] If the obtained average particle size is below the judgment criteria for each magnification shown in Table 1, the magnification is increased step by step in the order of magnification 500, 1000, 3000, and 10000 until it becomes a value larger than the judgment criteria. This series of operations is repeated to calculate the average particle size at each magnification.

[0048] [Table 1]

[0049] Table 1 Judgment Criteria

[0050] 500 times 3.6μm 1000 times 1.8μm 3000 times 0.6μm 10000 times none

[0051] The observation magnification during EPMA surface analysis cannot detect fine non-magnetic phases, leading to a larger error in the average particle size. Therefore, the range of average particle size based on the observation magnification is classified as follows. The sputtering target containing hard nitrides of the present invention preferably satisfies at least one of the following (A) to (C).

[0052] (A) The average particle size obtained by image analysis of the 180μm×180μm field of view of EPMA surface analysis at magnification of 500 is 3.6μm or more and 20μm or less, preferably 4μm or more and 15μm or less;

[0053] (B) The average particle size obtained by image analysis of the 90μm×90μm field of view of the EPMA surface analysis at magnification of 1000 is 1.8μm or more and 20μm or less, preferably 1.8μm or more and 4μm or less, and more preferably 1.8μm or more and 3.6μm or less;

[0054] (C) The average particle size obtained by image analysis of the 30μm×30μm field of view of the EPMA surface analysis at magnification of 3000 is 1μm or more and 20μm or less, preferably 1μm or more and 2μm or less, and more preferably 1μm or more and 1.8μm or less.

[0055] The content of the non-magnetic phase in the sputtering target varies depending on the required physical properties of the deposited layer formed using the sputtering target, and is generally preferably 5 mol% or more and 50 mol% or less, more preferably 5 mol% or more and 45 mol% or less. If the content of the non-magnetic phase is within the above range, the magnetic properties of the deposited layer can be well maintained, and the magnetic materials finely dispersed in the deposited layer can function as grain boundary materials that isolate adjacent magnetic materials from each other.

[0056] The nonmagnetic phase may also contain one or more nonmagnetic materials selected from C, B2O3, and SiO2, which are commonly used in sputtering targets. The content of the optionally added nonmagnetic material in the sputtering target is preferably 0 mol% or more and 25 mol% or less, more preferably 0 mol% or more and 20 mol% or less. If the content of the optionally added nonmagnetic material is within the above range, the magnetic properties of the deposited layer can be well maintained, and the finely dispersed magnetic materials in the deposited layer function as grain boundary materials that isolate adjacent magnetic materials from each other.

[0057] The alloy phase contains Fe or Co as a strongly magnetic material. It may contain Fe alone, Co alone, an alloy of Fe and Co, an alloy of Fe and other elements, an alloy of Co and other elements, or an alloy of Fe, Co, and other elements. Fe or Co is contained as a major component of the sputtering target. When the alloy phase contains Fe but does not contain Co, the Fe content is preferably 35 mol% or more and 100 mol% or less, more preferably 40 mol% or more and 100 mol% or less. When the alloy phase contains Co but does not contain Fe, the Co content is preferably 50 mol% or more and 100 mol% or less, more preferably 55 mol% or more and 100 mol% or less. The total content of Fe and Co in the alloy phase containing Fe or Co is preferably 35 mol% or more and 100 mol% or less, more preferably 40 mol% or more and 100 mol% or less. When Fe and Co are present, the total amount of Fe and Co in the alloy phase is preferably 50 mol% or more and 100 mol% or less, more preferably 60 mol% or more and 100 mol% or less, the Fe content in the alloy phase is preferably 30 mol% or more and 70 mol% or less, more preferably 35 mol% or more and 65 mol% or less, and the Co content in the alloy phase is preferably 20 mol% or more and 50 mol% or less, more preferably 25 mol% or more and 45 mol% or less.

[0058] The alloy phase preferably contains 0 mol% or more and 60 mol% or less of Pt, more preferably greater than 0 mol% and 55 mol% or less.

[0059] The alloy phase may also contain one or more elements selected from Ag, Au, Cr, Cu, Ge, Ir, Ni, Pd, Rh, Ru, and B. The content of the optionally added element in the alloy phase is preferably 0 mol% or more and 30 mol% or less, more preferably 0 mol% or more and 25 mol% or less. If the content of the optionally added element in the alloy phase is within the above range, the magnetic properties of the deposited layer can be well maintained.

[0060] Preferred sputtering targets for this invention include Fe alloy-nitride, Fe alloy-C-nitride, Fe alloy-oxide-nitride, Fe alloy-C-oxide-nitride, Co alloy-nitride, Co alloy-C-nitride, Co alloy-oxide-nitride, Co alloy-C-oxide-nitride, FePt alloy-nitride, FePt alloy-C-nitride, FePt alloy-oxide-nitride, FePt alloy-C-oxide-nitride, and CoPt alloy-C-oxide-nitride. Alloy-nitride, CoPt alloy-C-nitride, CoPt alloy-oxide-nitride, CoPt alloy-C-oxide-nitride, FeCo alloy-nitride, FeCo alloy-C-nitride, FeCo alloy-oxide-nitride, FeCo alloy-C-oxide-nitride, FeCo alloy-C-oxide-nitride, FeCoPt alloy-nitride, FeCoPt alloy-C-nitride, FeCoPt alloy-oxide-nitride, FeCoPt alloy-C-oxide-nitride, FeCoPt alloy-C-oxide-nitride. As specific design components, preferred examples include Fe-51Pt-7Si3N4, Fe-40Pt-20AlN, Fe-39Pt-25TaN, Fe-38Pt-15Cr2N, Fe-35Pt-25VN, Fe-40Pt-20NbN, Fe-40Pt-20HfN, Fe-28Pt-30BN, Fe-35Pt-25TiN, Fe-41Pt-5Cu-5BN-8Si3N4, Fe-46Pt-3B2O3-8Si3N4, Fe-41Pt-4SiO2-10AlN-3Si3N4, and Fe-21Pt-21Co-10C. -20AlN, Fe-30Pt-5C-30AlN, Fe-30Pt-5Ag-6C-11BN-20AlN, Fe-32Pt-6B-6Rh-20HfN, Fe-34Pt-3Ge-5C-20TiN, Co-23Pt-7Si3N4, Co-20Pt- 19AlN, Co-19Pt-25TaN, Co-14Pt-30BN, Co-16Pt-4Cr-4SiO2-15Cr2N, Co-13Pt-6Ru-8Cr-16C-22VN, Co-15TiN, Fe-20TaN, Co-48Fe-20AlN.

[0061] The sputtering target of the present invention can be designed to replicate the composition of known sputtering targets, but the Zr concentration, when measured in terms of metallic Zr, is limited to 1000 ppm or less, preferably 500 ppm or less, and more preferably 300 ppm or less, which differs from known sputtering targets. The Zr impurities in the sputtering target of the present invention are different from the unavoidable impurities in the composition of known sputtering targets, and are controlled during the manufacturing process to be below the limit value. As shown in the examples and comparative examples described later, it has been confirmed that even with sputtering targets of the same design composition, limiting the Zr concentration to 1000 ppm or less significantly suppresses particle generation.

[0062] Furthermore, the sputtering target of the present invention is characterized in that its Vickers hardness Hv, measured under a load of 3 kgf, is 200 or higher and 600 or lower, preferably 250 or higher and 600 or lower. It is generally believed that higher Vickers hardness leads to more particle generation, but if the Zr concentration is limited to 1000 ppm or lower, as shown in the examples and comparative examples described later, it has been confirmed that even sputtering targets with the same design composition significantly suppress particle generation when the Vickers hardness Hv is 200 or higher and 600 or lower.

[0063] The sputtering target containing hard nitride of the present invention can be manufactured by a method characterized by the following aspects: preparing a mixed powder by mixing the raw material powder constituting the alloy phase and the non-magnetic phase at a rotation speed of 50 rpm or more and 150 rpm or less for 2 hours or more and 6 hours, and sintering the mixed powder.

[0064] In the manufacturing method of this invention, the mixing conditions for the raw material powder are set as follows: using a zirconia ball mill at a rotation speed of 50 rpm or more and 150 rpm or less, preferably 50 rpm or more and 100 rpm or less, more preferably 50 rpm or more and 75 rpm or less, for 2 hours or more and 6 hours or less, preferably 3 hours or more and 5 hours or less. Typically, mixing using a zirconia ball mill involves high-speed rotation of the mill causing the zirconia balls to collide with the raw material powder at high speed, continuously grinding the raw material powder between the zirconia balls for a long time. This imparts strong mechanical energy to the raw material powder, causing it to break down and resulting in the finely ground powder mixture, thereby forming a homogeneous powder mixture. The inventors have discovered that when the raw material powder contains hard particles, the zirconia balls wear down, and trace amounts of zirconia are incorporated as impurities. They have also discovered optimal mixing conditions that simultaneously achieve homogeneous mixing of the raw material powder and suppress the wear of the zirconia balls. In this invention, it was discovered that by suppressing the rotation speed to a low speed for gentler collisions and shortening the stirring time, wear of zirconia balls can be prevented even in raw material powders containing hard nitride particles, and the mixing of zirconia into the raw material powder mixture can be suppressed.

[0065] The raw material powder constituting the alloy phase can be metal powder or Fe-based or Co-based atomized alloy powder.

[0066] As Fe powder, powders with an average particle size D50 of 1 μm or more and 10 μm or less, preferably 2 μm or more and 8 μm or less, can be used. If the average particle size is too small, there may be a risk of fire and an unavoidable increase in impurity concentration; if the average particle size is too large, it may be impossible to uniformly disperse the non-magnetic material particles.

[0067] As the Co powder, powders with an average particle size D50 of 1 μm or more and 10 μm or less, preferably 2 μm or more and 8 μm or less, can be used. If the average particle size is too small, there may be a risk of fire and an unavoidable increase in impurity concentration; if the average particle size is too large, it may be impossible to uniformly disperse the non-magnetic material particles.

[0068] As Pt powder, powders with an average particle size D50 of 0.1 μm or more and 10 μm or less, preferably 0.3 μm or more and 6 μm or less, can be used. If the average particle size is too small, the impurity concentration may inevitably become high; if the average particle size is too large, it may be impossible to uniformly disperse the non-magnetic material particles.

[0069] As an optional additional elemental powder, powder with an average particle size D50 of 0.1 μm or more and 30 μm or less, preferably 0.5 μm or more and 20 μm or less, can be used. If the average particle size is too small, the impurity concentration may inevitably become high; if the average particle size is too large, uniform dispersion may not be possible.

[0070] As the Fe-based or Co-based atomizing alloy powder, an atomizing alloy powder with an average particle size D50 of 1 μm or more and 10 μm or less, preferably 2 μm or more and 8 μm or less, can be used. If the average particle size is too small, the impurity concentration may inevitably become high; if the average particle size is too large, it may be impossible to uniformly disperse the non-magnetic material particles.

[0071] The raw material powder constituting the nonmagnetic phase comprises hard nitride powder with an average particle size D50 of 1 μm or more and 40 μm or less, preferably 2 μm or more and 35 μm or less. AlN, BN, Cr2N, Si3N4, HfN, NbN, TaN, TiN, VN, and any combination thereof are used as the hard nitride powder. Cubic BN is used as the BN. If the average particle size of the hard nitride powder is within the above range, a good dispersion state can be achieved.

[0072] The raw material powder constituting the nonmagnetic phase may also contain one or more nonmagnetic materials selected from C, B2O3, and SiO2, with an average particle size D50 of 1 μm or more and 10 μm or less, preferably 1 μm or more and 8 μm or less. If the average particle size of the added nonmagnetic material powder is within the above range, a good dispersion state can be achieved.

[0073] The sintering conditions for the mixed powder are preferably set as a sintering temperature of 800°C or higher and 1300°C or lower, more preferably 900°C or higher and 1250°C or lower, and a sintering pressure of 30 MPa or higher and 120 MPa or lower, more preferably 50 MPa or higher and 100 MPa or lower.

[0074] Example

[0075] The present invention will now be specifically described through examples and comparative examples, but the present invention is not limited thereto. The methods for determining the Zr concentration, Vickers hardness, average particle size, relative density, and particle number of the sputtering target in the following examples and comparative examples are described below.

[0076] [Zr concentration]

[0077] A 30 mm diameter test piece was cut from the sputtering target. The horizontal surface of the sputtering target relative to the sputtering surface was polished using SiC polishing paper of grades #80, #320, and #1200. The Zr concentration was determined using a fluorescence X-ray analysis device (ZSXPrimus IV, Rigaku Co., Ltd.) equipped with an X-ray tube containing Rh and the conditions in Table 2 were entered into the EZ scanner.

[0078] [Table 2]

[0079] Table 2 Automatic Setting Conditions

[0080] Measurement range B~U Determine diameter 20mm Measurement time standard

[0081] Vickers hardness

[0082] The measurements were performed according to JIS Z 2244. Specifically, the horizontal surface of the sputtering target relative to the sputtering surface was ground using #80, #320, and #1200 SiC abrasive paper, followed by polishing with 1μm diamond abrasive grains. A Vickers hardness tester (HV-115, Mitutoyo Corporation) was used, and the size of the indentation was observed under a microscope when a diamond indenter with a 136° face angle was used to apply a test load of 3.00 kgf. The length of the straight line connecting the diagonals was measured, and the surface area of ​​the indentation (mm²) was calculated. 2 ), calculate the test load (kgf) / indentation surface area (mm) 2 ).

[0083] [Average particle size of the hard nitride nonmagnetic phase]

[0084] After grinding the perpendicular surface of the sputtering target to the sputtering surface using SiC polishing paper of #80, #320 and #1200, polishing was performed using diamond spray with a particle size of 1 μm. Elemental mapping images were obtained using an EPMA apparatus (JXA-8500F, Nippon Electronics Corporation) under the EPMA analysis conditions shown in Tables 3 and 4.

[0085]

[0086] [Table 4]

[0087] Table 4 EPMA Analysis Conditions 2

[0088]

[0089] The obtained element mapping image is binarized using the "Surface Processing" function provided with the EPMA device (JXA-8500F). Specifically, the element mapping image is displayed with a maximum mapping number of 9 and binarized. The upper and lower limit values ​​are confirmed in the "Level Change" screen. In the "Mapping Calculation" screen, "Constant Subtraction" is selected, and the lower limit value confirmed in the "Level Change" screen is entered into K to perform the calculation. Next, in the "Mapping Calculation" screen, "Constant Division" is selected, and the value obtained by subtracting the lower limit value from the upper limit value confirmed in the "Level Change" screen is entered into K to perform the calculation. The "Display Mode" selection screen is changed to the content in Table 5 to perform the calculation. The "Level Change" screen is changed to the content in Table 6 to perform the calculation.

[0090] [Table 5]

[0091] Table 5 shows the mode.

[0092] Display color grayscale Color bars On the mapping Number of colors 2 Step interval Equal interval Mapping display No interpolation

[0093] [Table 6]

[0094] Table 6 Grade Change

[0095] Calibration curve factor A 0 Calibration curve factor B 0 lower limit 0.25 upper limit 0.5

[0096] A screenshot of the element mapping image after the above binarization process is saved as a PNG file. The obtained PNG element mapping image is analyzed using image analysis software (ImageJ 1.53e) to determine the average particle size of the nitrides. Specifically, the average particle size of the nitrides is determined according to the following steps: Open the PNG element mapping image using image analysis software (ImageJ 1.53e). When the nitride is composed of elements A and N (nitrogen), the regions of the mapping images of elements A and N are copied at 286×286 pixels and saved as a new image. The contents of Table 7 are entered into the Image Calculator of the Image Analysis Software (ImageJ 1.53e) and executed to create a file that calculates the locations where elements A and N are detected.

[0097] [Table 7]

[0098] Table 7 Image Calculator

[0099] Operation and Image2 Image files cut from the mapping image of element N. Create new window choose 32-bit (float) result Non-selective

[0100] When there are two or more elements besides N (nitrogen) constituting nitrides, the mapped regions of each element are copied at 286×286 pixels and saved as a new image. The operation in Table 7 is then set to OR. Mapped images other than element N constituting nitrides are selected from Image 1 and Image 2. The Image Calculator is used to synthesize all mapped images except those of element N constituting nitrides. In the Image Calculator in Table 7, the image is selected as Image 1. Otherwise, the contents of the Image Calculator in Table 7 are entered and executed to create a file that calculates the locations of both elements other than N constituting nitrides and element N.

[0101] Invert the resulting file to black and white, then enter the values ​​from Table 8 in the Set scale field and execute the command. Note that you should enter the field of view for each magnification in the Known distance field. Specifically, enter 900 for 100x, 180 for 500x, 90 for 1000x, 30 for 3000x, and 10 for 10000x.

[0102] [Table 8]

[0103] Table 8: Set scale

[0104] Pixel aspect ratio 1.0 Unit of length μm Global Non-selective

[0105] Enter the contents of Table 9 in the "Analyze particles" dialog box and execute the command. It should be noted that in the "Size (μm)" field... 2 Enter the value of Table 10 according to the observation magnification.

[0106] [Table 9]

[0107] Table 9 Analyze particles

[0108] Circularity 0.00-1.00 Sow Outlines Display results choose Clear results choose Summarize choose Add to Manager Non-selective Exclude on edges choose Include holes choose Record starts Non-selective In situ Show Non-selective

[0109] [Table 10]

[0110] Table 10 Dimensions (μm) 2 )

[0111] 500 times 1.46-infinity 1000 times 0.37-infinity 3000 times 0.05-infinity 10000 times 0.01-infinity

[0112] The average particle size (μm) is calculated using the average size of the Summary image shown after analysis, using the following formula.

[0113]

[0114] First, the above series of analyses are performed on the 100x image. If the obtained average particle size is below the judgment criteria for each magnification shown in Table 11, the magnification is increased one stage at a time in the order of 500x, 1000x, 3000x, and 10000x until it becomes a value larger than the judgment criteria.

[0115] [Table 11]

[0116] Table 11 Judgment Criteria

[0117] 500 times 3.6μm 1000 times 1.8μm 3000 times 0.6μm 10000 times none

[0118] [Relative density]

[0119] Using pure water as the displacement fluid, the Archimedes method was employed for determination. The mass of the sintered body was measured, and the buoyancy (equal to the volume of the sintered body) was measured while the sintered body was suspended in the displacement fluid. The mass (g) of the sintered body was divided by its volume (cm³). 3 ), calculate the measured density (g / cm³) 3 The ratio of the measured density to the theoretical density calculated based on the composition of the sintered body is the relative density.

[0120] [Number of particles]

[0121] The sintered body was processed into a diameter of 153 mm and a thickness of 2 mm, and then soldered with indium to a Cu backplate with a diameter of 161 mm and a thickness of 4 mm to obtain a sputtering target. The sputtering target was installed in a magnetron sputtering apparatus, and sputtered for 40 seconds in an Ar gas atmosphere with an output power of 500 W and a gas pressure of 1 Pa. The number of particles attached to the substrate was then measured using a particle counter.

[0122] [Examples 1-26 and Comparative Examples 1-15]

[0123] Sputtering targets with the designs shown in Tables 12 and 13 were manufactured, and the Zr concentration, Vickers hardness, average particle size, relative density, and particle number of the hard nitride nonmagnetic phase were measured. In the designs in Tables 12 and 13, Fe or Co constitutes the balance, therefore the content is omitted. For example, Fe-51Pt-7Si3N4 in Example 1 means 42Fe-51Pt-7Si3N4.

[0124] As raw material powders for the alloy phase, Fe powder with an average particle size D50 of 7 μm, Co powder with an average particle size D50 of 3 μm, and Pt powder with an average particle size D50 of 1 μm were used. As additional elements for the alloy phase, Cu powder with an average particle size D50 of 5 μm, Ag powder with an average particle size D50 of 4 μm, B powder with an average particle size D50 of 8 μm, Ge powder with an average particle size D50 of 10 μm, Cr powder with an average particle size D50 of 15 μm, Ru powder with an average particle size D50 of 13 μm, and Rh powder with an average particle size D50 of 13 μm were used.

[0125] As hard nitride powders, the following powders were used: Si3N4 powder with an average particle size D50 of 20 μm, AlN powder with an average particle size D50 of 8 μm, TaN powder with an average particle size D50 of 4 μm, Cr2N powder with an average particle size D50 of 7 μm, NbN powder with an average particle size D50 of 10 μm, HfN powder with an average particle size D50 of 35 μm, cubic BN powder (cBN) with an average particle size D50 of 3 μm, TiN powder with an average particle size D50 of 9 μm, and VN powder with an average particle size D50 of 7 μm.

[0126] As additional non-magnetic material powders, hexagonal BN powder (BN) with an average particle size D50 of 5 μm, B2O3 powder with an average particle size D50 of 5 μm, C powder with an average particle size D50 of 5 μm, and SiO2 powder with an average particle size D50 of 1 μm were used.

[0127] For Examples 1-26, each raw material powder was weighed and added together with 4 kg of zirconia balls in the manner shown in Table 12 into a stirred mill. The mixture was stirred at 100 rpm for 4 hours, and the resulting powder mixture was sintered at a sintering pressure of 66 MPa and the sintering temperatures shown in Table 12. Empty columns in Table 12 indicate no addition.

[0128] For Comparative Examples 1-15, the raw material powders weighed in the manner shown in Table 13 were added together with 4 kg of zirconia balls into a stirred mill and mixed under the stirring conditions shown in Table 13. The resulting mixed powder was then sintered at a sintering pressure of 66 MPa and a sintering temperature shown in Table 13. Empty columns in Table 13 indicate no addition.

[0129] After determining the relative density of the obtained sintered body, the sputtering target was processed, and the Zr concentration, average particle size of the hard nitride, Vickers hardness, and particle number were measured. The results are shown in Tables 14 and 15. The relationship between Zr concentration and particle number is shown in... Figure 1 The relationship between Vickers hardness and particle number is shown in the figure. Figure 2 middle.

[0130]

[0131]

[0132]

[0133]

[0134] From Tables 14-15 and Figure 1 It can be seen that when the Zr concentration is above 2000 ppm, the number of particles can reach more than 2000, but when the Zr concentration is below 1000 ppm, the number of particles is small, especially when the Zr concentration is below 300 ppm, the number of particles is as low as less than 400. Furthermore, from Tables 14-15 and... Figure 2 It is known that when the Vickers hardness Hv is above 600, the number of particles can be as high as 2000 or more, but in the range of Vickers hardness Hv of 200 to 600, the number of particles is as low as less than 400.

[0135] The average particle size of the hard nitride particles in the sputtering targets of Examples 1-26 could be determined at magnifications of 500-3000, but the average particle size of the hard nitride particles in the sputtering targets of Comparative Examples 1-15 required a magnification of 10000. As shown in Tables 14 and 15, the average particle size of the hard nitride in Examples 1-26 was in the range of 1.3 μm to 12.8 μm, while the average particle size of the hard nitride in Comparative Examples 1-15 was fine particles in the range of 0.3-0.9 μm.

[0136] Figure 3 These are SEM images (1000x magnification) of the tissue of the sputtering target in Example 1. Figure 4 These are SEM images (1000x magnification) of the tissue of the sputtering target in Example 2. Figure 5 This is a SEM image (1000x magnification) of the microstructure of the sputtering target in Comparative Example 2. EPMA analysis confirmed that the black particles in the image are hard nitride particles, and the white to gray areas are alloy phases. Figure 3 and Figure 5 A comparison shows that, compared with Example 1 ( Figure 3 Compared to Example 2, Figure 5 The white alloy phase and black particles are more finely dispersed. Figure 4 It can be seen that the larger hard nitride particles and alloy phases are uniformly dispersed.

[0137] From Tables 14-15 and Figures 3-5 It can be seen that, compared with the sputtering target of the comparative example manufactured by conventional methods, the sputtering target manufactured by the manufacturing method of the present invention has larger hard nitride particles, but the non-magnetic phase and alloy phase are uniformly dispersed.

Claims

1. A sputtering target containing hard nitrides, comprising an alloy phase containing Fe or Co and a nonmagnetic phase containing hard nitrides selected from AlN, BN, Cr2N, Si3N4, HfN, NbN, TaN, TiN, VN, and any combination thereof, When measuring Zr metal, the Zr impurity concentration is limited to below 1000 ppm. The Vickers hardness Hv measured under a load of 3 kgf is above 200 and below 600.

2. The sputtering target containing hard nitride according to claim 1, characterized in that, The concentration of Zr impurities is limited to below 500 ppm.

3. The sputtering target containing hard nitride according to claim 1 or 2, characterized in that, The nonmagnetic phase satisfies at least one of the following: Image analysis of EPMA surface analysis at magnification 500, with an observation field of 180μm×180μm, yielded an average particle size greater than 4μm and less than 20μm. Image analysis of EPMA surface analysis at magnification 1000, with an observation field of 90 μm × 90 μm, yielded an average particle size greater than 2 μm and less than 20 μm; and Image analysis of EPMA surface analysis at magnification 3000, with an observation field of 30μm×30μm, yielded an average particle size greater than 1μm and less than 20μm.

4. The sputtering target containing hard nitride according to any one of claims 1 to 3, characterized in that, The content of the non-magnetic phase in the sputtering target is more than 5 mol% and less than 50 mol%.

5. The sputtering target containing hard nitride according to any one of claims 1 to 4, characterized in that, The non-magnetic phase also contains one or more selected from C, B2O3 and SiO2.

6. The sputtering target containing hard nitride according to any one of claims 1 to 5, characterized in that, The alloy phase contains more than 0 mol% and less than 60 mol% of Pt.

7. The sputtering target containing hard nitride according to any one of claims 1 to 6, characterized in that, The alloy phase also contains one or more elements selected from Ag, Au, Cr, Cu, Ge, Ir, Ni, Pd, Rh, Ru, and B.

8. A method for manufacturing a sputtering target containing hard nitride, which is the method for manufacturing a sputtering target containing hard nitride according to any one of claims 1 to 7, characterized in that, include: A mixed powder is prepared by mixing the raw material powders constituting the alloy phase and the non-magnetic phase using a zirconia ball mill at a speed of 50 rpm to 150 rpm for 2 hours to 6 hours. The mixed powder is then sintered.

9. The method for manufacturing a sputtering target containing hard nitride according to claim 8, characterized in that, The raw material powder constituting the alloy phase is the metal powder of each raw material or the atomized alloy powder of Fe or Co system.

10. The manufacturing method according to claim 8 or 9, characterized in that, The raw material powder constituting the non-magnetic phase contains hard nitride powder with an average particle size D50 of 1 μm or more and 40 μm or less.

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