Hard nitride-containing sputtering targets

Abstract

To provide a sputtering target capable of preventing an occurrence of arching in sputtering due to mixing of relatively coarse zirconia particles and suppressing the generation of particles during film deposition, and a manufacturing method thereof.SOLUTION: A sputtering target including a hard nitride is composed of an alloy phase including Fe or Co and a non-magnetic phase including a hard nitride selected form AlN, BN, Cr2 N, Si3 N4, HfN, NbN, TaN, TiN, VN, and any combination thereof. A Zr impurity concentration measured as metal Zr is suppressed to 1000 ppm or less. The Vickers hardness Hv measured under a load condition of 3 kgf is 200 or more and 600 or less.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a hard nitride-containing sputtering target and a method for producing the same, and more particularly to a hard nitride-containing sputtering target comprising an alloy phase containing Fe or Co and a non-magnetic phase containing a hard nitride selected from AlN, BN, CrN, SiN, HfN, NbN, TaN, TiN, VN, and any combination thereof, and a method for producing the same. [Background technology]

[0002] Sintered bodies containing an alloy phase mainly composed of ferromagnetic metals, Fe or Co, and non-magnetic materials such as oxides, carbon, and boron nitride are used as sputtering targets for producing granular-structure magnetic thin films for magnetic recording media such as hard disk drives.

[0003] It has been confirmed that sputtering targets containing oxides as nonmagnetic materials can reduce particle generation during film formation by creating a nonmagnetic particle-dispersed structure in which the oxides are uniformly and finely dispersed among the alloy phases. To achieve uniform and fine dispersion of the oxides among the alloy phases, raw material powders that form the oxide and alloy phases are mixed by vigorously stirring using a media-stirring mill such as a zirconia ball mill (Patent Nos. 4673448 and 6728094). Sputtering targets containing nitrides instead of oxides have also been proposed, but the method of vigorously stirring and mixing using a zirconia ball mill, similar to that for oxides, has been adopted (Patent Nos. 5913620 and 6526837).

[0004] Japanese Patent Publication No. 4673448 discloses a non-magnetic particle-dispersed ferromagnetic sputtering target having a phase (A) in which non-magnetic oxide particles are uniformly and finely dispersed, and a spherical alloy phase (B) with a diameter of 50 to 200 μm within the phase (A), with Cr concentrated at 25 mol% or more near the center of the spherical alloy phase (B) and the Cr content decreasing toward the periphery. This sputtering target is manufactured by placing a metal powder with a maximum particle size of 20 μm or less and a non-magnetic powder with a maximum particle size of 5 μm or less into a 10-liter ball mill pot together with zirconia balls, rotating the pot for 20 hours to mix and grind the powder, and then mixing this mixed powder with Co-Cr spherical powder with a diameter of 50 to 200 μm in a planetary mixer and sintering the mixture.

[0005] Japanese Patent Publication No. 6728094 discloses an invention that includes a Co-Pt phase, a Co phase, and a nonmagnetic material, and refines the Co-Pt alloy phase and coarsens the Co phase to suppress particle generation during sputtering. Specifically, the invention describes setting the average particle size of the Co-Pt alloy phase to 0.1 μm to 7 μm, the average particle size of the Co phase to 30 μm to 300 μm, and the average particle size of the oxide nonmagnetic material to 0.05 μm to 2 μm. It also describes using Co-Pt alloy powder with a median diameter of 0.1 μm to 7 μm and nonmagnetic material powder with a median diameter of 0.05 μm to 2 μm as raw materials. It also describes a method for mixing the raw material powders, in which the raw material powders are enclosed in a 10-liter ball mill together with zirconia balls and rotated for 20 hours to mix them.

[0006] Japanese Patent Publication No. 5913620 discloses that in an Fe-Pt sintered sputtering target using hexagonal BN as a nonmagnetic material, improving the orientation of the hexagonal BN suppresses abnormal discharge during sputtering and reduces the amount of particles generated. Specifically, the publication describes placing Fe-Pt alloy powder together with zirconia balls in a 5-L agitation mill and processing it at 300 rpm for two 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, making it insufficient for use as a sputtering target, resulting in the problem of cracking during sputtering.

[0007] Japanese Patent No. 6526837 discloses Fe-Pt-based sputtering targets and Co-Pt-based sputtering targets that use cubic BN, which is less susceptible to cracks occurring within the BN particles than hexagonal BN. The publication describes a method in which raw material powders are placed in a 5-L media stirring mill together with zirconia balls, mixed by rotating (at 300 rpm) for 2 hours, and pulverized until the median diameter (D50) of the raw material mixed powder is 0.3 μm or more and 20 μm or less, preferably 5 μm or less.

[0008] However, experiments by the present inventors have shown that when nitrides are used as non-magnetic materials, the hardness of the nitrides causes wear on the zirconia balls and the inner walls of the media stirring mill when the raw material powders are mixed, resulting in the inclusion of relatively coarse zirconia particles, and because the coarse zirconia particles have a higher electrical resistivity than nitrides or carbides, they are more likely to cause arcing during sputtering and to generate particles during film formation. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 4673448 [Patent Document 2] Patent No. 6728094 [Patent Document 3] Patent No. 5913620 [Patent Document 4] Patent No. 6526837 Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention aims to solve the above-mentioned conventional problems, and to provide a hard nitride-containing sputtering target that can prevent the occurrence of arcing during sputtering due to the inclusion of relatively coarse zirconia particles and suppress the generation of particles during film formation, and a method for manufacturing the same. [Means for solving the problem]

[0011] The present inventors have found that arcing during sputtering of hard nitride-containing sputtering targets is caused by the presence of relatively coarse zirconia particles, and have concluded that arcing during sputtering can be suppressed by preventing the incorporation of zirconia impurity particles originating from a zirconia ball mill that is commonly used when mixing raw material powders in the sputtering target manufacturing process, thereby completing the present invention.

[0012] According to the present invention, an alloy phase containing Fe or Co, a non-magnetic phase including hard nitrides selected from AlN, BN, CrN, SiN, HfN, NbN, TaN, TiN, VN, and any combination thereof; The Zr impurity concentration when measured as metallic Zr is regulated to 1000 ppm or less. A hard nitride-containing sputtering target is provided, characterized in that the Vickers hardness Hv measured under a load condition of 3 kgf is 200 or more and 600 or less.

[0013] It is preferable that the Zr impurity concentration be regulated to 500 ppm or less.

[0014] The non-magnetic phase is The average particle size determined by image analysis of an observation field of 180 μm × 180 μm using an EPMA surface analysis at a magnification of 500 is 4 μm or more and 20 μm or less; An average particle size of 2 μm or more and 20 μm or less, as determined by image analysis of a 90 μm × 90 μm field of view in an EPMA area analysis at a magnification of 1000; and The average particle size determined by image analysis of a 30 μm × 30 μm observation field of view using an EPMA surface analysis at a magnification of 3000 is 1 μm or more and 20 μm or less; It is preferable that at least one of the following conditions is satisfied.

[0015] The content of the non-magnetic phase in the sputtering target is preferably 5 mol % or more and 50 mol % or less.

[0016] The non-magnetic phase may further contain one or more selected from C, B2O3, and SiO2.

[0017] The alloy phase may contain Pt in an amount of 0 mol % or more and 60 mol % or less.

[0018] The alloy phase may further contain one or more elements selected from Ag, Au, Cr, Cu, Ge, Ir, Ni, Pd, Rh, Ru, and B.

[0019] The present invention also provides a method for producing the hard nitride-containing sputtering target, which includes mixing raw material powders constituting the alloy phase and the nonmagnetic phase in a zirconia ball mill at a rotation speed of 50 rpm to 150 rpm for 2 hours to 6 hours to prepare a mixed powder, and sintering the mixed powder.

[0020] The raw material powders constituting the alloy phase are preferably metal powders of the respective raw materials or Fe-based or Co-based atomized alloy powders.

[0021] The raw material powder constituting the non-magnetic phase preferably contains hard nitride powder having an average particle size D50 of 1 μm or more and 40 μm or less. [Effects of the Invention]

[0022] The hard nitride-containing sputtering target of the present invention prevents the inclusion of relatively coarse zirconia impurity particles, which have high electrical resistivity, and limits the Zr impurity concentration measured as metallic Zr to 1000 ppm or less. This makes it possible to suppress the occurrence of arcing during sputtering and reduce particles derived from zirconia particles during film formation. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a graph showing the relationship between the Zr concentration and the number of particles in the sputtering targets of Examples and Comparative Examples. [Figure 2] 1 is a graph showing the relationship between Vickers hardness and particle count in sputtering targets of Examples and Comparative Examples. [Figure 3] 1 is an SEM observation photograph (magnification: 1000) of the structure of the sputtering target of Example 1. [Figure 4] 1 is an SEM observation photograph (magnification: 1000) of the structure of the sputtering target of Example 2. [Figure 5] 1 is an SEM observation photograph (magnification: 1000) of the structure of the sputtering target of Comparative Example 2. Preferred Embodiments

[0024] The present invention will now be described in more detail with reference to the accompanying drawings. The hard nitride-containing sputtering target of the present invention comprises an alloy phase containing Fe or Co, and a non-magnetic phase containing hard nitrides selected from AlN, BN, CrN, SiN, HfN, NbN, TaN, TiN, VN, and any combination thereof, and is characterized in that the Zr impurity concentration, measured as metallic Zr, is regulated to 1000 ppm or less, preferably 500 ppm or less, and more preferably 300 ppm or less, and the Vickers hardness Hv, measured under a load condition of 3 kgf, is 200 to 600, preferably 250 to 600.

[0025] The present invention relates to a hard nitride-containing sputtering target containing hard nitride particles as nonmagnetic material particles. Examples of hard nitrides include AlN, BN, CrN, SiN, HfN, NbN, TaN, TiN, VN, and any combination thereof. The hardness (GPa) of each nitride is 12.0 for AlN, 15.4 for CrN, 19.4 for SiN, 15.7 for HfN, 14.3 for NbN, 23.7 for TaN, 20.1 for TiN, 12.8 for VN, 46.1 for cubic BN, and 2.0 for hexagonal BN (Data Book Handbook of High Melting Point Compounds, Ceramics Processing Handbook: From Fundamentals to Applications, Ceramic Hardness).

[0026] Cubic BN and hexagonal BN are known as BNs used in sputtering targets, but in the present invention, cubic BN is used, which is said to be the second hardest after diamond. Note that as long as cubic BN is included, hexagonal BN may be mixed in.

[0027] The non-magnetic phase contains hard nitrides with an average grain size of 1 μm or more, preferably 2 μm to 20 μm. The average grain size of the non-magnetic phase can be measured by image analysis of the results of EPMA surface analysis. Image analysis by EPMA surface analysis is performed according to the following procedure.

[0028] First, the sputtering surface of the sputtering target is polished, and an elemental mapping image is obtained at a magnification of 100x using an EPMA device. The obtained elemental mapping image is binarized using the "surface processing" function included with the EPMA device. The binarized elemental mapping image is then analyzed using image analysis software (ImageJ 1.53e) to measure the average grain size of the nitride. If the nitride contains only one element other than N (nitrogen) (e.g., element A), the elemental mapping image is used to calculate the locations where both element N and element A are detected. If the nitride contains two or more elements other than N (nitrogen), the elemental mapping images for all elements other than element N are combined, and the locations where both element N and elements other than element N are detected are calculated to determine the average size, and the average grain size (μm) is then calculated using the following formula.

[0029]

number

[0030] If the obtained average particle size is below the judgment standard for each magnification shown in Table 1, increase the magnification step by step to 500, 1000, 3000, and 10000 until the value is greater than the judgment standard, and repeat this series of operations to calculate the average particle size at each magnification.

[0031] [Table 1]

[0032] Depending on the magnification during EPMA surface analysis, fine non-magnetic phases cannot be observed, resulting in a large error in the average grain size, so the ranges of average grain size according to the magnification are classified as follows: The hard nitride-containing sputtering target of the present invention preferably satisfies at least one of the following (A) to (C): (A) an average particle size of 3.6 μm or more and 20 μm or less, preferably 4 μm or more and 15 μm or less, determined by image analysis of an observation field of 180 μm × 180 μm in an EPMA area analysis at a magnification of 500; (B) an average particle size determined by image analysis of a 90 μm × 90 μm observation field of view in EPMA area analysis at a magnification of 1000, of 1.8 μm or more and 20 μm or less, preferably 1.8 μm or more and 4 μm or less, more preferably 1.8 μm or more and 3.6 μm or less; (C) The average particle size determined by image analysis of an observation field of 30 μm×30 μm in an EPMA area analysis at a magnification of 3000 is 1 μm or more and 20 μm or less, preferably 1 μm or more and 2 μm or less, more preferably 1 μm or more and 1.8 μm or less.

[0033] The content of the nonmagnetic phase in the sputtering target varies depending on the physical properties required for the deposition layer formed using the sputtering target, but is generally preferably 5 mol% to 50 mol%, more preferably 5 mol% to 45 mol%. If the content of the nonmagnetic phase is within the above range, the magnetic properties of the deposited layer can be maintained well, and the nonmagnetic phase can be finely dispersed among the magnetic materials in the deposition layer and function as a grain boundary material that separates adjacent magnetic materials.

[0034] The non-magnetic phase may further contain one or more non-magnetic materials selected from C, BO, and SiO, which are commonly used in sputtering targets. The content of the optional non-magnetic material in the sputtering target is preferably 0 mol% to 25 mol%, more preferably 0 mol% to 20 mol%. If the content of the optional non-magnetic material is within the above range, the magnetic properties of the deposited layer can be maintained well, and the optional non-magnetic material can be finely dispersed among the magnetic materials in the deposited layer and function as a grain boundary material that separates adjacent magnetic materials.

[0035] The alloy phase contains Fe or Co, which is a ferromagnetic material. Fe may be contained alone, Co alone, or as 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 main component of the sputtering target. When the alloy phase contains Fe but not Co, the Fe content in the alloy phase is preferably 35 mol% to 100 mol%, more preferably 40 mol% to 100 mol%. When the alloy phase contains Co but not Fe, the Co content in the alloy phase is preferably 50 mol% to 100 mol%, more preferably 55 mol% to 100 mol%. When the alloy phase contains Fe or Co, the total content of Fe and Co in the alloy phase is preferably 35 mol% to 100 mol%, more preferably 40 mol% to 100 mol%. When Fe and Co are contained, the total amount of Fe and Co in the alloy phase is preferably 50 mol% or more and 100 mol% or less, and 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, and 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, and more preferably 25 mol% or more and 45 mol% or less.

[0036] The alloy phase preferably contains Pt in an amount of 0 mol % or more and 60 mol % or less, and more preferably more than 0 mol % and 55 mol % or less.

[0037] The alloy phase may further contain one or more elements selected from Ag, Au, Cr, Cu, Ge, Ir, Ni, Pd, Rh, Ru, and B. The content of the optional elements 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 optional elements in the alloy phase is within the above range, the magnetic properties of the deposited layer can be maintained at a good level.

[0038] Suitable examples of the sputtering target of the present 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, CoPt 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, FeCoPt alloy-nitride, FeCoPt alloy-C-nitride, FeCoPt alloy-oxide-nitride, and FeCoPt alloy-C-oxide-nitride. Specific design compositions 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, Fe-21Pt-21Co-10C-20AlN, and F. Suitable examples include e-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, and Co-48Fe-20AlN.

[0039] Although the design composition of the sputtering target of the present invention may overlap with the composition of known sputtering targets, it differs from known sputtering targets in that the Zr concentration, measured as metallic Zr, is regulated to 1000 ppm or less, preferably 500 ppm or less, and more preferably 300 ppm or less. The Zr impurity in the sputtering target of the present invention is different from the unavoidable impurities in the composition of known sputtering targets, and is controlled in the manufacturing process so that the content is below the regulated value. As shown in the Examples and Comparative Examples described below, it was confirmed that particle generation is significantly suppressed when the Zr concentration is regulated to 1000 ppm or less, even in sputtering targets with the same design composition.

[0040] The sputtering target of the present invention is also characterized in that it has a Vickers hardness Hv of 200 or more and 600 or less, preferably 250 or more and 600 or less, measured under a load condition of 3 kgf. It was thought that the higher the Vickers hardness, the more particles would be generated, but as shown in the examples and comparative examples described below, it has been confirmed that when the Zr concentration is restricted to 1000 ppm or less, particle generation is significantly suppressed when the Vickers hardness Hv is 200 or more and 600 or less, even for sputtering targets of the same design composition.

[0041] The hard nitride-containing sputtering target of the present invention can be produced by a method comprising: mixing raw material powders constituting the alloy phase and the non-magnetic phase using a zirconia ball mill at a rotation speed of 50 rpm to 150 rpm for 2 hours to 6 hours to prepare a mixed powder; and sintering the mixed powder.

[0042] In the manufacturing method of the present invention, the raw material powders are stirred and mixed using a zirconia ball mill at a rotation speed of 50 rpm to 150 rpm, preferably 50 rpm to 100 rpm, more preferably 50 rpm to 75 rpm, for 2 hours to 6 hours, preferably 3 hours to 5 hours. Generally, stirring and mixing using a zirconia ball mill involves rotating the mill at high speed to cause zirconia balls to collide with the raw material powder at high speed, grinding the raw material powder between the zirconia balls for a long period of time, imparting strong mechanical energy to the raw material powder, and kneading the finely divided raw material powder to form a homogeneous powder mixture. The inventors have found that when the raw material powder contains hard particles, the zirconia balls wear, resulting in the incorporation of trace amounts of zirconia as impurities. They have therefore discovered optimal mixing conditions that suppress zirconia ball wear while achieving homogeneous mixing of the raw material powders. In the present invention, it was discovered that by keeping the rotation speed low to cause relatively gentle collisions and by shortening the stirring time, it is possible to prevent wear of the zirconia balls even when the raw material powder contains hard nitride particles, and to suppress the inclusion of zirconia in the raw material powder mixture.

[0043] The raw material powder constituting the alloy phase can be a metal powder or an Fe-based or Co-based atomized alloy powder.

[0044] The Fe powder used has an average particle size D50 of 1 μm to 10 μm, preferably 2 μm to 8 μm. If the average particle size is too small, there is a risk of fire or the concentration of unavoidable impurities may be high, while if the average particle size is too large, it may be difficult to uniformly disperse the nonmagnetic particles.

[0045] The Co powder used has an average particle size D50 of 1 μm to 10 μm, preferably 2 μm to 8 μm. If the average particle size is too small, there is a risk of fire or the concentration of unavoidable impurities may be high, while if the average particle size is too large, it may be difficult to uniformly disperse the nonmagnetic particles.

[0046] The Pt powder used has an average particle size D50 of 0.1 μm to 10 μm, preferably 0.3 μm to 6 μm. If the average particle size is too small, the concentration of unavoidable impurities may be high, while if the average particle size is too large, the non-magnetic particles may not be uniformly dispersed.

[0047] The optional element powder may have an average particle size D50 of 0.1 μm to 30 μm, preferably 0.5 μm to 20 μm. If the average particle size is too small, the concentration of unavoidable impurities may be high, while if the average particle size is too large, uniform dispersion may be impossible.

[0048] The atomized alloy powder of Fe-based or Co-based alloys may have an average particle size D50 of 1 μm to 10 μm, preferably 2 μm to 8 μm. If the average particle size is too small, the concentration of unavoidable impurities may be high, while if the average particle size is too large, the non-magnetic material particles may not be uniformly dispersed.

[0049] The raw material powder constituting the nonmagnetic phase contains 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. The hard nitride powder may be AlN, BN, CrN, SiN, HfN, NbN, TaN, TiN, VN, or any combination thereof. Cubic BN is used as the BN. If the average particle size of the hard nitride powder is outside the above range, a good dispersion state cannot be achieved.

[0050] The raw material powder constituting the non-magnetic phase may further contain one or more non-magnetic materials having 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, selected from C, B2O3, and SiO2. If the average particle size of the additional non-magnetic material powder is outside the above range, a good dispersion state cannot be achieved.

[0051] The sintering conditions for the mixed powder are preferably a sintering temperature of 800° C. to 1300° C., preferably 900° C. to 1250° C., and a sintering pressure of 30 MPa to 120 MPa, preferably 50 MPa to 100 MPa. [Example]

[0052] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these. In the following examples and comparative examples, the Zr concentration, Vickers hardness, average particle size of the hard nitride nonmagnetic phase, relative density, and particle count of the sputtering target were measured as follows.

[0053] [Zr concentration] A test piece with a diameter of 30 mm was cut out from the sputtering target, and the horizontal surface relative to the sputtering surface of the sputtering target was polished using #80, #320, and #1200 SiC polishing paper. The Zr concentration was measured using an X-ray fluorescence analyzer (ZSX PrimusIV, Rigaku Corporation) equipped with an Rh X-ray tube by inputting the conditions in Table 2 into EZ Scan.

[0054] [Table 2]

[0055] [Vickers hardness] Measurement is performed in accordance with JIS Z 2244. Specifically, the horizontal surface of the sputtering target relative to the sputtering surface is polished using SiC polishing paper of #80, #320, and #1200, and then buffed with diamond abrasive grains of 1 μm grain size. Using a Vickers hardness tester (HV-115, Mitutoyo Corporation), a test load of 3.00 kgf is applied with a diamond indenter of a regular square pyramid with a facing angle of 136°. The size of the indentation is observed under a microscope, and the length of the straight line connecting the diagonals of the four sides is measured, and the surface area (mm 2 ) and calculate the test load (kgf) / surface area of ​​the depression (mm 2 ) is calculated.

[0056] [Average grain size of hard nitride non-magnetic phase] The surface perpendicular to the sputtering surface of the sputtering target was polished using #80, #320, and #1200 SiC polishing papers, and then buffed using a diamond spray with a particle size of 1 μm. An elemental mapping image was obtained using an EPMA device (JXA-8500F, JEOL Ltd.) under the EPMA analysis conditions shown in Tables 3 and 4.

[0057] [Table 3]

[0058] [Table 4]

[0059] The obtained elemental mapping image is binarized using the "surface processing" function included with the EPMA system (JXA-8500F). Specifically, the elemental mapping image is displayed with a maximum of 9 maps, the image to be binarized is selected, and the upper and lower limit values ​​are confirmed on the "Level Change" screen. Select "Constant Subtraction" on the "Map Calculation" screen, enter the lower limit value confirmed on the "Level Change" screen in K, and execute. Select "Constant Division" on the "Map Calculation" screen again, and enter the value obtained by subtracting the lower limit value from the upper limit value confirmed on the "Level Change" screen in K, and execute. Change the "Display Mode" selection screen to the contents of Table 5 and execute. Change the "Level Change" screen to the contents of Table 6 and execute.

[0060] [Table 5]

[0061] [Table 6]

[0062] Save a screenshot of the elemental mapping image after completing the binarization process described above in PNG format. Analyze the resulting PNG-format elemental mapping image using image analysis software (ImageJ 1.53e) to measure the average nitride grain size. Specifically, measure the average nitride grain size using the following procedure: Open the PNG-format elemental mapping image in image analysis software (ImageJ 1.53e). When the nitride is composed of elements A and N (nitrogen), copy the area of ​​the mapping image of elements A and N at 286 x 286 pixels and save it as a New Image. Enter the contents of Table 7 into the Image Calculator in the image analysis software (ImageJ 1.53e) and run it to create a file that calculates the areas where both elements A and N are detected.

[0063] [Table 7]

[0064] If there are two or more elements other than N (nitrogen) that make up the nitride, copy the area of ​​the mapping image for each element at 286 x 286 pixels and save it as a New Image, then set Operation in Table 7 to OR, select the mapping images other than the element N that makes up the nitride for Image1 and Image2, and use the Image Calculator to combine all mapping images other than the element N that makes up the nitride.Other than selecting this image as Image1 in the Image Calculator in Table 7, enter the contents of the Image Calculator in Table 7 and run it to create a file that calculates the areas where both the element N and elements other than N that make up the nitride are detected.

[0065] Invert the resulting file to reverse the black and white, then enter the contents of Table 8 in Set Scale and execute. Enter the field of view for each magnification in Known distance. That is, enter 900 for 100x, 180 for 500x, 90 for 1000x, 30 for 3000x, and 10 for 10,000x.

[0066] [Table 8]

[0067] Enter the contents of Table 9 into Analyze particles and execute. 2 ) enter the value in Table 10 according to the observation magnification.

[0068] [Table 9]

[0069] [Table 10]

[0070] Using the Average Size on the Summary screen displayed after analysis, calculate the average particle size (μm) using the following formula.

[0071]

number

[0072] First, perform the above series of analyses on a 100x image. If the obtained average particle size is below the judgment criteria for each magnification shown in Table 11, increase the magnification step by step to 500x, 1000x, 3000x, and 10000x until the value exceeds the judgment criteria.

[0073] [Table 11]

[0074] Relative Density The measurement is carried out by the Archimedes method using pure water as the displacement liquid. The mass of the sintered body is measured, and the buoyancy (=volume of the sintered body) is measured while the sintered body is suspended in the displacement liquid. The mass (g) of the sintered body is multiplied by the volume (cm) of the sintered body. 3 ) and divide by the actual density (g / cm 3The ratio of the theoretical density calculated based on the composition of the sintered body (measured density / theoretical density) is the relative density.

[0075] Number of Particles The sintered body is processed to a diameter of 153 mm and a thickness of 2 mm, and then bonded with indium to a Cu packing plate with a diameter of 161 mm and a thickness of 4 mm to obtain a sputtering target. This sputtering target is attached to a magnetron sputtering device and sputtered for 40 seconds in an Ar gas atmosphere at a power of 500 W and a gas pressure of 1 Pa. After that, the number of particles adhering to the substrate is measured with a particle counter.

[0076] [Examples 1 to 26 and Comparative Examples 1 to 15] Sputtering targets having the design compositions shown in Table 12 were manufactured, and the Zr concentration, Vickers hardness, average grain size of the hard nitride non-magnetic phase, relative density, and number of particles were measured.

[0077] The raw powders for the alloy phase were 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. The additional elements for the alloy phase were 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.

[0078] The hard nitride powders used were 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 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.

[0079] The additional non-magnetic powders used were hexagonal BN powder 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.

[0080] For Examples 1 to 26, each raw material powder was weighed to have the design composition shown in Table 12 and charged into a stirring mill together with 4 kg of zirconia balls, and the mixed powder obtained by stirring and mixing at a rotation speed of 100 rpm for 4 hours was sintered at a sintering pressure of 66 MPa and a sintering temperature shown in Table 12. Hollow cells in Table 12 indicate that no addition was made.

[0081] For Comparative Examples 1 to 15, each raw material powder was weighed to have the design composition shown in Table 13 and charged into a stirring mill together with 4 kg of zirconia balls. The mixed powder obtained by stirring and mixing under the stirring conditions shown in Table 13 was sintered at a sintering pressure of 66 MPa and a sintering temperature shown in Table 13. Hollow cells in Table 13 indicate that no addition was made.

[0082] The relative density of the resulting sintered body was measured, and then processed into a sputtering target, which was then used to measure the Zr concentration, average grain size of the hard nitrides, Vickers hardness, and particle count. The results are shown in Tables 14 and 15. The relationship between Zr concentration and particle count is shown in Figure 1, and the relationship between Vickers hardness and particle count is shown in Figure 2.

[0083] [Table 12]

[0084] [Table 13]

[0085] [Table 14]

[0086] [Table 15]

[0087] Tables 14 to 15 and Fig. 1 show that when the Zr concentration is 2000 ppm or higher, the number of particles is high at 2000 or more, but when the Zr concentration is 1000 ppm or lower, the number of particles is low, and especially when the Zr concentration is 300 ppm or lower, the number of particles is low at less than 400. Furthermore, Tables 14 to 15 and Fig. 2 show that when the Vickers hardness Hv is 600 or higher, the number of particles is high at 2000 or more, but when the Vickers hardness Hv is in the range of 200 to 600, the number of particles is low at less than 400.

[0088] The average particle size of the hard nitride particles in the sputtering targets of Examples 1 to 26 could be measured at a magnification of 500 to 3000, but the average particle size of the hard nitride particles in the sputtering targets of Comparative Examples 1 to 15 required a magnification of up to 10000. Tables 14 and 15 show that the average particle size of the hard nitride particles in Examples 1 to 26 was in the range of 1.3 μm to 12.8 μm, and the average particle size of the hard nitride particles in Comparative Examples 1 to 15 was fine, in the range of 0.3 to 0.9 μm.

[0089] FIG. 3 is an SEM photograph (magnification 1000) of the structure of the sputtering target of Example 1, FIG. 4 is an SEM photograph (magnification 1000) of the structure of the sputtering target of Example 2, and FIG. 5 is an SEM photograph (magnification 1000) of the structure of the sputtering target of Comparative Example 2. EPMA analysis confirmed that the black particles in the figure are hard nitride particles and the white to gray are alloy phases. Comparing FIG. 3 with FIG. 5, it can be seen that the white alloy phase and black particles are more finely dispersed in Comparative Example 2 (FIG. 5) than in Example 1 (FIG. 3). FIG. 4 shows that the relatively large hard nitride particles and alloy phase are uniformly dispersed.

[0090] Tables 14 to 15 and Figures 3 to 5 show that the sputtering targets manufactured by the manufacturing method of the present invention have relatively larger hard nitride particles than the sputtering targets of the comparative examples manufactured by the conventional method, but the non-magnetic phase and alloy phase are dispersed homogeneously.

Claims

1. an alloy phase containing Fe or Co; AlN, BN, Cr ２ N, Si ３ N ４ a non-magnetic phase comprising hard nitrides selected from HfN, NbN, TaN, TiN, VN and any combination thereof; The Zr impurity concentration measured as metallic Zr is regulated to 1000 ppm or less, A hard nitride-containing sputtering target having a Vickers hardness Hv of 200 or more and 600 or less, measured under a load condition of 3 kgf.

2. 2. The hard nitride-containing sputtering target according to claim 1, wherein the Zr impurity concentration is regulated to 500 ppm or less.

3. The non-magnetic phase is an average particle size of 4 μm or more and 20 μm or less, determined by image analysis of an observation field of 180 μm × 180 μm in an EPMA surface analysis at a magnification of 500; An average particle size of 2 μm or more and 20 μm or less, as determined by image analysis of a 90 μm × 90 μm observation field of view in an EPMA surface analysis at a magnification of 1000; and an average particle size of 1 μm or more and 20 μm or less, determined by image analysis of an observation field of 30 μm × 30 μm in an EPMA surface analysis at a magnification of 3000; 3. The hard nitride-containing sputtering target according to claim 1, wherein at least one of the following conditions is satisfied:

4. 4. The hard nitride-containing sputtering target according to claim 1, wherein the content of the non-magnetic phase in the sputtering target is 5 mol % or more and 50 mol % or less.

5. The non-magnetic phase is C, B ２ O ３ and SiO ２ The hard nitride-containing sputtering target according to any one of claims 1 to 4, further comprising one or more selected from the following:

6. 6. The hard nitride-containing sputtering target according to claim 1, wherein the alloy phase contains Pt in an amount of 0 mol % to 60 mol %.

7. 7. The hard nitride-containing sputtering target according to claim 1, wherein the alloy phase further contains one or more elements selected from Ag, Au, Cr, Cu, Ge, Ir, Ni, Pd, Rh, Ru, and B.

8. A method for producing a hard nitride-containing sputtering target according to any one of claims 1 to 7, comprising: raw material powders constituting the alloy phase and the non-magnetic phase are mixed using a zirconia ball mill at a rotation speed of 50 rpm or more and 150 rpm or less for 2 hours or more and 6 hours or less to prepare a mixed powder; sintering the mixed powder.

1. A method for producing a hard nitride-containing sputtering target, comprising:

9. 9. The method for producing a hard nitride-containing sputtering target according to claim 8, wherein the raw material powders constituting the alloy phase are metal powders of the respective raw materials or Fe-based or Co-based atomized alloy powders.

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

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