WO2014125897A1 - SPUTTERING TARGET CONTAINING Co OR Fe - Google Patents

SPUTTERING TARGET CONTAINING Co OR Fe Download PDF

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WO2014125897A1
WO2014125897A1 PCT/JP2014/051494 JP2014051494W WO2014125897A1 WO 2014125897 A1 WO2014125897 A1 WO 2014125897A1 JP 2014051494 W JP2014051494 W JP 2014051494W WO 2014125897 A1 WO2014125897 A1 WO 2014125897A1
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Prior art keywords
particles
diameter
powder
metal
target
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PCT/JP2014/051494
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French (fr)
Japanese (ja)
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荒川　篤俊
英生 高見
中村　祐一郎
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Jx日鉱日石金属株式会社
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Priority to CN201480003726.9A priority Critical patent/CN104903488B/en
Priority to SG11201503676WA priority patent/SG11201503676WA/en
Priority to JP2015500172A priority patent/JP6332869B2/en
Publication of WO2014125897A1 publication Critical patent/WO2014125897A1/en

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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C19/00—Alloys based on nickel or cobalt
    • C22C19/07—Alloys based on nickel or cobalt based on cobalt
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
    • C22C32/001—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides
    • C22C32/0015—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides with only single oxides as main non-metallic constituents
    • C22C32/0026—Matrix based on Ni, Co, Cr or alloys thereof
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/02—Making ferrous alloys by powder metallurgy
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/34—Sputtering
    • C23C14/3407—Cathode assembly for sputtering apparatus, e.g. Target
    • C23C14/3414—Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy

Definitions

  • the present invention relates to a magnetic material sputtering target used to form a magnetic thin film of a magnetic recording medium, in particular, a granular film in a magnetic recording medium of a hard disk adopting a perpendicular magnetic recording method, and causes the generation of particles during sputtering.
  • the present invention relates to a non-magnetic material particle-dispersed magnetic material sputtering target containing Co or Fe as a main component, which can suppress abnormal discharge of the non-magnetic material.
  • a material based on Co, Fe, and Ni, which are ferromagnetic metals, is used for a recording layer of a hard disk that employs a perpendicular magnetic recording system.
  • composite materials composed of a ferromagnetic alloy such as Co—Cr, Co—Pt, Co—Cr—Pt, Fe—Pt, and the like, which are mainly composed of Co and Fe, and a nonmagnetic inorganic material are often used.
  • the magnetic thin film of such a magnetic recording medium such as a hard disk is often produced by sputtering a ferromagnetic material sputtering target containing the above material as a component because of its high productivity.
  • a melting method or a powder metallurgy method can be considered as a method for producing such a sputtering target for a magnetic recording medium. Which method is used depends on the required characteristics, so it cannot be generally stated, but the sputtering target made of a ferromagnetic alloy and non-magnetic inorganic particles used for the recording layer of a perpendicular magnetic recording hard disk is Generally, it is produced by a powder metallurgy method. This is because the inorganic particles need to be uniformly dispersed in the alloy substrate, and thus it is difficult to produce by the melting method.
  • Patent Document 1 As a powder metallurgy method, for example, in Patent Document 1, mixed powder obtained by mixing Co powder, Cr powder, TiO 2 powder, and SiO 2 powder and Co spherical powder are mixed by a planetary motion mixer, and this mixing is performed.
  • Patent Document 2 proposes a method of forming a powder by hot pressing to obtain a sputtering target for a magnetic recording medium. It can be seen that the target structure in this case has a spherical phase (B) in the phase (A) which is a metal substrate in which inorganic particles are uniformly dispersed (see FIG. 1 of Patent Document 2).
  • Such a structure is good in terms of improving leakage magnetic flux, but cannot be said to be a suitable sputtering target for a magnetic recording medium from the viewpoint of suppressing generation of particles during sputtering.
  • Patent Document 2 discloses a sputtering target for forming a magnetic recording medium thin film by mixing Co—Cr binary alloy powder, Pt powder, and SiO 2 powder and hot-pressing the obtained mixed powder. A method has been proposed. Although the target structure in this case is not shown in the figure, a Pt phase, a SiO 2 phase, and a Co—Cr binary alloy phase can be seen, and a diffusion layer can be observed around the Co—Cr binary alloy phase. It is described. Such a structure is not a suitable sputtering target for magnetic recording media.
  • Patent Document 3 proposes a sputtering target composed of a matrix phase of Co and Pt and a metal oxide phase having an average particle size of 0.05 ⁇ m or more and less than 7.0 ⁇ m, which suppresses the growth of crystal grains, Proposals have been made to increase the film formation efficiency by obtaining a magnetic permeability and high density target.
  • Patent Document 4 discloses that the average particle diameter of the particles formed by the oxide phase is 3 ⁇ m or less
  • Patent Document 5 discloses that the silica particles or titania particles are in a cross section perpendicular to the main surface of the sputtering target.
  • the non-magnetic material such as SiO 2 , Cr 2 O 3 , or TiO 2 contained is an insulator, so abnormal discharge It is the cause. Due to this abnormal discharge, generation of particles during sputtering becomes a problem.
  • an object of the present invention is to suppress abnormal discharge of the nonmagnetic material while maintaining a high PTF, and to reduce the generation of particles during sputtering caused by abnormal discharge.
  • the probability of abnormal discharge has been reduced by reducing the particle size of the non-magnetic material particles.
  • the allowable particle level has become stricter.
  • An object of the present invention is to provide a non-magnetic material particle-dispersed ferromagnetic material sputtering target that is further improved.
  • the present inventors have conducted intensive research. As a result, by adjusting the structure of the target (non-magnetic material particles) structure, abnormal discharge due to the non-magnetic material during sputtering does not occur, It has been found that a target with less generation of particles can be obtained.
  • a sintered sputtering target made of a material in which non-magnetic material particles are dispersed in a magnetic material containing Co or Fe,
  • the structure observed on the polished surface in the target is composed of nonmagnetic material particles having an average particle size of 1.8 ⁇ m or less, and a metal phase and metal particles containing Co or Fe in which the nonmagnetic material particles are dispersed,
  • the maximum value of the distance between any two points on the outer periphery of the non-magnetic material particle is the maximum diameter
  • the minimum value of the distance between the two lines when the particle is sandwiched between two parallel straight lines is the minimum diameter.
  • the nonmagnetic material particles having a difference between the maximum diameter and the minimum diameter of 0.7 ⁇ m or less account for 60% or more of the nonmagnetic material particles in the structure observed on the polished surface in the target,
  • the maximum value of the distance between any two points on the outer periphery of the metal grain is the maximum diameter
  • the minimum value of the distance between the two straight lines when the metal grain is sandwiched between two parallel straight lines is the minimum diameter.
  • an average of one or more metal particles having a maximum diameter and a minimum diameter of 30 ⁇ m or more are present in a 1 mm 2 field of view.
  • the non-magnetic material particles are B 2 O 3 , CoO, Co 3 O 4 , MnO, Mn 3 O 4 , SiO 2 , SnO 2 , TiO 2 , Ti 2 O 3 , Cr 2 O 3 , Ta 2 O. 5.
  • the sputtering target according to 1) above which is one or more oxides selected from WO 2 , WO 3 , and ZrO 2 , and contains 0.5 to 20 mol% of these.
  • the non-magnetic material particle dispersion type magnetic material sputtering target of the present invention thus adjusted maintains a high PTF, does not cause abnormal discharge due to the non-magnetic material during sputtering, and provides a target with less generation of particles. . Thereby, it has the outstanding effect that the cost improvement effect by a yield improvement can be acquired.
  • FIG. 1 is a diagram (photograph) showing a Co—Pt—Cr—SiO 2 —TiO 2 —Cr 2 O 3 target structure of Example 1.
  • FIG. It is a figure (enlarged photograph of FIG. 1) which shows the structure
  • FIG. 3 is a view obtained by performing image analysis processing (binarization processing) on FIG. 2 in order to clarify the outline of nonmagnetic material particles.
  • 4 is a diagram (photograph) showing a Co—Pt—Ru—Ta—SiO 2 —TiO 2 —CoO—B 2 O 3 target structure of Example 2.
  • FIG. It is a figure (enlarged photograph of FIG. 4) which shows the structure
  • the sputtering target of the present invention is a sintered sputtering target made of a material in which non-magnetic material particles are dispersed in a magnetic material containing Co or Fe, and the structure observed on the polished surface of the target is an average grain.
  • Non-magnetic material particles having a diameter of 1.8 ⁇ m or less, a metal phase containing Co or Fe in which the non-magnetic material particles are dispersed, and metal particles are included. It is because generation
  • the inventors of the present application have previously found that it is desirable that the shape of the non-magnetic material particles is a perfect sphere, and that at least a shape close to that is an effective means for preventing the generation of particles (Patent Document) 6).
  • Patent Document 6 In other words, in order to improve the magnetic properties, a certain amount of oxide (non-magnetic material) needs to be present, but if it is irregularly shaped, the location of the oxide in a certain area of the target surface A difference occurs in the distribution in a place where no oxide is present, and segregation is likely to occur. As long as it is a true sphere or an oxide particle close to a true sphere, segregation is reduced because the shape of the particles is uniform, and it has been found that particle generation can be effectively suppressed.
  • the maximum value of the distance between any two points on the outer periphery of the non-magnetic material particles observed on the polished surface in the target is the maximum diameter
  • the particles are represented by two parallel straight lines
  • the minimum value of the distance between the two straight lines when the gap is sandwiched is the minimum diameter
  • the difference between the maximum diameter and the minimum diameter is 0.7 ⁇ m or less.
  • the present invention has found further new findings in the above knowledge, and not only the form of the non-magnetic material particles but also the form of the metal particles containing Co or Fe can be used to suppress abnormal discharge and further increase the generation of particles. It can be greatly suppressed. That is, the maximum value of the distance between any two points on the outer periphery of the metal grain observed on the polished surface in the target is the maximum diameter, and the distance between the two straight lines when the metal grain is sandwiched between two parallel straight lines the minimum value when the smallest diameter the distance, its average maximum diameter and the minimum diameter of the sum 30 ⁇ m or more metal grains in 1 mm 2 field of view one or more, and preferably an average of 3 or more, more preferably an average 5 It is characterized by the presence of more than one.
  • any five locations within the target surface are observed with a microscope, and the number of metal particles whose sum of the maximum diameter and the minimum diameter within a 1 mm 2 visual field at each location is 30 ⁇ m or more is counted. The average number is obtained from the total.
  • the maximum value of the distance between any two points on the outer periphery of the metal particle is the maximum diameter
  • the minimum value of the distance between the two lines when the metal particle is sandwiched between two parallel lines is the minimum diameter
  • the sum of the maximum diameter and the minimum diameter is 30 ⁇ m or more and there is an average of 1 or more in a 1 mm 2 field of view
  • the leakage magnetic flux increases.
  • the promotion of ionization of the inert gas proceeds efficiently, and a stable discharge can be obtained.
  • the maximum value of the distance between any two points on the outer periphery of the metal grain is the maximum diameter
  • the minimum value of the distance between the two lines when the metal grain is sandwiched between two parallel straight lines is the minimum diameter.
  • the sum of the maximum diameter and the minimum diameter is smaller than 30 ⁇ m, or when the presence of metal particles of 30 ⁇ m or more is less than 1 on average within 1 mm 2 field of view, the above effect is hardly obtained.
  • the sum of the maximum diameter and the minimum diameter is 50 ⁇ m or more, the above effect appears even more strongly.
  • the sum of the maximum diameter and the minimum diameter exceeds 300 ⁇ m, the distribution of the oxide particles is biased. May occur.
  • the ferromagnetic material sputtering target of the present invention is particularly effective for Co-based alloys such as Co-Cr based alloys, Co-Pt based alloys, Co-Cr-Pt based alloys or Fe based alloys such as Fe-Pt based alloys.
  • the present invention can be applied to already known ferromagnetic materials, and the mixing ratio of components required as a magnetic recording medium can be appropriately adjusted according to the purpose.
  • the Co-based alloy a sputtering target in which Cr is 0 mol% or more and 15 mol% or less, Pt is 5 mol% or more and 30 mol% or less, and the balance is made of Co and unavoidable impurities except for a nonmagnetic material.
  • Fe-based alloy a sputtering target in which Pt is more than 0 mol% and not more than 60 mol%, and the remainder is made of Fe and inevitable impurities except for a nonmagnetic material can be used.
  • These component compositions show a suitable numerical range for utilizing the characteristics as a ferromagnetic material, and needless to say, they can be applied to other numerical values.
  • Nonmagnetic materials to be added to the ferromagnetic material are B 2 O 3 , CoO, Co 3 O 4 , MnO, Mn 2 O 3 , SiO 2 , TiO 2 , Ti 2 O 3 , Cr 2 O 3 , Ta 2.
  • One or more oxides selected from O 5 , WO 2 , WO 3 , and ZrO 2 , and usually 0.5 to 20 mol% of these are contained in the target. These oxides can be arbitrarily selected and added according to the type of ferromagnetic film required. The said addition amount is an effective amount for exhibiting the effect of addition.
  • 0.5 to 12 mol% of one or more elements selected from Mg, Al, Si, Mn, Nb, Mo, Ru, Pd, Ta, W, and B may be added. It can. These are elements added as necessary in order to improve the characteristics as a magnetic recording medium.
  • the said addition amount is an effective amount for exhibiting the effect of addition.
  • the structure of the sputtering target of the present invention is composed of non-magnetic material particles and a metal phase and metal particles containing Co or Fe in which the non-magnetic material particles are dispersed, and the metal particles are composed of Co or Fe. Is preferred.
  • the metal grains have a maximum magnetic permeability higher than that of metal bases having different compositions (metal phases in which non-magnetic material particles are dispersed), and have a structure in which the metal grains are separated from each other by surrounding structures made of the metal base.
  • the reason why the leakage magnetic field improves is not necessarily clear at the present time, but a dense part and a sparse part are generated in the magnetic flux inside the target, compared with a structure having a uniform magnetic permeability. This is because the magnetostatic energy increases, and it is considered that it is advantageous in terms of energy to leak the magnetic flux outside the target.
  • the sputtering target of the present invention can be produced by powder metallurgy.
  • powder metallurgy metal raw material powders such as Co, Cr, Pt and Fe, non-magnetic material raw material powders such as SiO 2 and, if necessary, additive metal powders such as Ru are prepared, except for metal coarse powder described later.
  • the particle size of the raw material it is desirable to use metal powder having an average particle diameter of 10 ⁇ m or less and non-magnetic material powder of 5 ⁇ m or less.
  • the non-magnetic material raw powder is more likely to be as spherical as possible to achieve the microstructure of the present invention.
  • the particle size of the powder can be measured with a laser diffraction particle size distribution analyzer (HORIBA LA-920).
  • these metal powders and alloy powders are weighed so as to have a desired composition, and mixed by pulverization using a known method such as a ball mill.
  • a ball mill In order to shorten the mixing time and increase the productivity, it is preferable to use a high energy ball mill.
  • the metal raw material powder it is preferable to mix a small amount of at least one component metal coarse powder having a particle size in the range of 50 ⁇ m to 300 ⁇ m.
  • the metal particles become flat and the difference between the major axis and the minor axis increases.
  • the metal particles can be spherical or flat (strip-shaped), but each of the spherical or flat metal particles has advantages and disadvantages depending on the shape. It is desirable to select this shape according to the intended use of the target. Specifically, when the target material is produced by the sintering method in the spherical shape, holes are less likely to be generated at the interface between the metal substrate (A) and the phase (B), and the target density can be increased. In addition, since the spherical surface area is smaller in the same volume, the diffusion of the metal element is less likely to proceed between the metal substrate (A) and the phase (B) when the target material is sintered.
  • the spherical shape here represents a solid shape including a true sphere, a pseudo-true sphere, an oblate (spheroid), and an artificial oblate. In either case, the difference between the major axis and the minor axis is 0 to 50%.
  • the metal particles when the metal particles are made flat, it has the effect of preventing the metal particles from detaching from the surrounding metal substrate (A) at the time of sputtering due to the wedge effect. Further, by destroying the spherical shape, it is possible to reduce the bias of the erosion speed that is likely to occur in the spherical shape, and it is possible to suppress the generation of particles due to the boundary having different erosion speeds.
  • the maximum value of the distance between any two points on the outer periphery of the nonmagnetic material particles in the structure observed on the polished surface in the target is the maximum diameter, and is parallel.
  • the minimum value of the distance between two straight lines when the same particle is sandwiched between two straight lines is defined as the minimum diameter
  • the difference between the maximum diameter and the minimum diameter is 0.7 ⁇ m or less.
  • the maximum diameter and the minimum diameter are calculated by projecting a microscope image of the polished surface in the target on a PC and using image processing analysis software.
  • image processing analysis software Keyence Corporation shape analysis software (VK-Analyzer VK-H1A1) was used.
  • the mixed powder obtained as described above is sintered using a hot press or a hot isostatic press.
  • a hot press or a hot isostatic press find the conditions for non-magnetic material particles to become spherical and the conditions for metal particles to be flat by setting the mixing conditions and sintering conditions for the above raw materials, and fix the manufacturing conditions.
  • a sintered body target in which such non-magnetic material particles and metal particles are always dispersed can be obtained.
  • Example 1 As the metal raw material powder, Co powder having an average particle diameter of 4 ⁇ m, Cr powder having an average particle diameter of 5 ⁇ m, Pt powder having an average particle diameter of 3 ⁇ m, and TiO 2 powder having an average particle diameter of 1.2 ⁇ m as the nonmagnetic material powder, an average particle diameter of 0 A spherical SiO 2 powder having a thickness of 7 ⁇ m and a Cr 2 O 3 powder having an average particle diameter of 1 ⁇ m were prepared. Moreover, Co coarse powder adjusted so that a particle size might be in the range of 50 micrometers or more and 150 micrometers or less was prepared, and the ratio of Co powder with an average particle diameter of 4 micrometers and the said Co coarse powder was set to 7: 3 by weight ratio. These powders were weighed 2000 g with the following composition ratio. Composition: 69Co-18Pt-2Cr-5SiO 2 -2TiO 2 -4Cr 2 O 3 (mol%)
  • the Co coarse powder was removed, and the weighed powder was enclosed in a ball mill pot with a capacity of 10 liters together with a tungsten alloy ball as a grinding medium, and rotated and mixed for 120 hours. Thereafter, Co coarse powder was additionally added to the ball mill pot and mixed for 1 hour.
  • the mixed powder thus obtained was filled in a carbon mold and hot-pressed in a vacuum atmosphere under conditions of a temperature of 1100 ° C., a holding time of 2 hours, and a pressure of 30 MPa to obtain a sintered body. . Further, this was cut with a lathe to obtain a disk-shaped target having a diameter of 180 mm and a thickness of 5 mm.
  • the average leakage magnetic flux density of the target As a result of measuring the average leakage magnetic flux density of the target thus obtained, it was 30%.
  • the measurement of leakage magnetic flux was carried out in accordance with ASTM F2086-01 (Standard Test Method for Pass Flow Through Flux of Crystal Circular Magnetic Sputtering Targets, Method 2). Specifically, the magnetic flux leakage density measured by fixing the center of the target and rotating it at 0 degrees, 30 degrees, 60 degrees, 90 degrees, and 120 degrees is divided by the value of the reference field defined by ASTM. , Multiplied by 100 and expressed as a percentage. And the result averaged about these 5 points
  • FIG. 2 shows an enlarged view of FIG. 1 in order to observe the non-magnetic material particles.
  • the maximum value of the distance between any two points on the outer periphery of the nonmagnetic material particle is the maximum diameter
  • the minimum value of the distance between the two lines when the particle is sandwiched between two parallel lines is the minimum diameter.
  • 85% of the oxide particles having a difference between the maximum diameter and the minimum diameter of 0.7 ⁇ m or less were present in the microscopic field, and the average particle diameter was 0.75 ⁇ m.
  • a microscopic image is projected on a PC screen, and image analysis processing (binarization processing) is performed. These were calculated after clarifying the outline of the particle (black part).
  • this target was attached to a DC magnetron sputtering apparatus, and sputtering was performed.
  • the sputtering conditions were a sputtering power of 1.2 kW, an Ar gas pressure of 1.5 Pa, and after performing 2 kWhr pre-sputtering, sputtering was performed on a 4-inch diameter silicon substrate with a target film thickness of 1000 nm.
  • the number of particles adhering to the substrate was measured with a particle counter. At this time, the number of particles on the silicon substrate was four. Even when sputtering is not performed, the number of particles on the silicon substrate may be counted as 0 to 5 when measured with a particle counter. Therefore, it can be said that the number of particles in this embodiment is at an extremely small level. .
  • a powder, a spherical SiO 2 powder having an average particle size of 0.7 ⁇ m, a CoO powder having an average particle size of 0.8 ⁇ m, and a B 2 O 3 powder having an average particle size of 5 ⁇ m were prepared.
  • Co coarse powder adjusted to have a particle size in the range of 50 ⁇ m to 300 ⁇ m was prepared, and the ratio of Co powder having an average particle size of 4 ⁇ m to the Co coarse powder was set to 7: 3 by weight. These powders were weighed 2000 g with the following composition ratio.
  • the Co coarse powder was removed, and the weighed powder was enclosed in a ball mill pot with a capacity of 10 liters together with a tungsten alloy ball as a grinding medium, and rotated and mixed for 120 hours. Thereafter, Co coarse powder was additionally added to the ball mill pot and mixed for 1 hour.
  • the mixed powder thus obtained was filled into a carbon mold and hot-pressed in a vacuum atmosphere under the conditions of a temperature of 1000 ° C., a holding time of 2 hours, and a pressure of 30 MPa to obtain a sintered body. . Further, this was cut with a lathe to obtain a disk-shaped target having a diameter of 180 mm and a thickness of 5 mm.
  • the average leakage magnetic flux density of the target of Example 2 was 28%.
  • the surface of the target is polished and the structure is observed with a microscope, it can be seen that metal particles are scattered in the structure in which the nonmagnetic material particles are dispersed in the metal phase as shown in FIG.
  • an average of 19 metal grains having a sum of the maximum diameter and the minimum diameter of 30 ⁇ m or more were confirmed in a 1 mm 2 visual field.
  • FIG. 5 shows an enlarged view of FIG. 4 in order to observe the non-magnetic material particles.
  • the ratio of the non-magnetic material particles having a difference between the maximum diameter and the minimum diameter of 0.7 ⁇ m or less evaluated in the same manner as in Example 1 was 64%, and the average particle diameter was 1.26 ⁇ m.
  • this target was attached to a DC magnetron sputtering apparatus, and sputtering was performed.
  • the sputtering conditions were the same as in Example 1.
  • the sputtering power was 1.2 kW
  • the Ar gas pressure was 1.5 Pa
  • sputtering was performed on a 4-inch diameter silicon substrate with a target film thickness of 1000 nm.
  • the number of particles adhering to the substrate was measured with a particle counter. At this time, the number of particles on the silicon substrate was four.
  • Co coarse powder adjusted to have a particle size in the range of 50 ⁇ m to 300 ⁇ m was prepared, and the ratio of Co powder having an average particle size of 4 ⁇ m to the Co coarse powder was set to 7: 3 by weight. These powders were weighed 2000 g with the following composition ratio.
  • the Co coarse powder was removed, and the weighed powder was enclosed in a ball mill pot with a capacity of 10 liters together with a tungsten alloy ball as a grinding medium, and rotated and mixed for 120 hours. Thereafter, Co coarse powder was additionally added to the ball mill pot and mixed for 1 hour.
  • the mixed powder thus obtained was filled into a carbon mold and hot-pressed in a vacuum atmosphere under the conditions of a temperature of 1000 ° C., a holding time of 2 hours, and a pressure of 30 MPa to obtain a sintered body. . Further, this was cut with a lathe to obtain a disk-shaped target having a diameter of 180 mm and a thickness of 5 mm.
  • the average leakage magnetic flux density of the target of Example 3 was 31%.
  • the surface of the target is polished and the structure is observed with a microscope, it can be seen that metal particles are scattered in the structure in which the nonmagnetic material particles are dispersed in the metal phase.
  • an average of 18 metal particles having a sum of the maximum diameter and the minimum diameter of 30 ⁇ m or more were confirmed in a 1 mm 2 field of view.
  • the proportion of non-magnetic material particles having a difference between the maximum diameter and the minimum diameter evaluated in the same manner as in Example 1 of 0.7 ⁇ m or less was 60%, and the average particle diameter was 1.16 ⁇ m.
  • this target was attached to a DC magnetron sputtering apparatus, and sputtering was performed.
  • the sputtering conditions were the same as in Example 1.
  • the sputtering power was 1.2 kW
  • the Ar gas pressure was 1.5 Pa
  • sputtering was performed on a 4-inch diameter silicon substrate with a target film thickness of 1000 nm.
  • the number of particles adhering to the substrate was measured with a particle counter. At this time, the number of particles on the silicon substrate was five.
  • Example 4 Fe powder having an average particle diameter of 4 ⁇ m, Pt powder having an average particle diameter of 3 ⁇ m, Fe—B powder having an average particle diameter of 7 ⁇ m, and spherical SiO 2 powder having an average particle diameter of 0.8 ⁇ m were prepared as metal raw material powders.
  • coarse Fe powder adjusted to have a particle size in the range of 50 ⁇ m to 300 ⁇ m was prepared, and the ratio of Fe powder with an average particle size of 4 ⁇ m to the coarse Fe powder was 8: 2. These powders were weighed 2000 g with the following composition ratio.
  • the Fe coarse powder was removed, and the weighed powder was enclosed in a ball mill pot with a capacity of 10 liters together with a tungsten alloy ball as a grinding medium, and rotated and mixed for 120 hours. Thereafter, Fe coarse powder was additionally added to the ball mill pot and mixed for 1 hour.
  • the mixed powder thus obtained was filled in a carbon mold and hot-pressed in a vacuum atmosphere under the conditions of a temperature of 1300 ° C., a holding time of 2 hours, and a pressure of 30 MPa to obtain a sintered body. . Further, this was cut with a lathe to obtain a disk-shaped target having a diameter of 180 mm and a thickness of 5 mm.
  • the average leakage magnetic flux density of the target of Example 4 was 61%.
  • the surface of the target is polished and the structure is observed with a microscope, it can be seen that metal particles are scattered in the structure in which the nonmagnetic material particles are dispersed in the metal phase.
  • an average of four metal particles having a maximum diameter and a minimum diameter of 30 ⁇ m or more were confirmed in a 1 mm 2 field of view.
  • the ratio of the nonmagnetic material particles having a difference between the maximum diameter and the minimum diameter of 0.7 ⁇ m or less evaluated in the same manner as in Example 1 was 65%, and the average particle diameter was 1.29 ⁇ m.
  • this target was attached to a DC magnetron sputtering apparatus, and sputtering was performed.
  • the sputtering conditions were the same as in Example 1.
  • the sputtering power was 1.2 kW
  • the Ar gas pressure was 1.5 Pa
  • sputtering was performed on a 4-inch diameter silicon substrate with a target film thickness of 1000 nm.
  • the number of particles adhering to the substrate was measured with a particle counter. At this time, the number of particles on the silicon substrate was six.
  • Co powder with an average particle size of 4 ⁇ m, Cr powder with an average particle size of 5 ⁇ m, Pt powder with an average particle size of 3 ⁇ m, TiO 2 powder with an average particle size of 1.2 ⁇ m as an oxide powder, Average particle size of 0.7 ⁇ m Core-like SiO 2 powder and Cr 2 O 3 powder having an average particle diameter of 1 ⁇ m were prepared. Then, 2000 g of these powders were weighed at the following composition ratio. Composition: 69Co-18Pt-2Cr-5SiO 2 -2TiO 2 -4Cr 2 O 3 (mol%)
  • the weighed powder was enclosed in a ball mill pot with a capacity of 10 liters together with a tungsten alloy ball as a grinding medium, and rotated and mixed for 120 hours.
  • the mixed powder thus obtained was filled into a carbon mold and hot-pressed in the same manner as in Example 1 in a vacuum atmosphere at a temperature of 1100 ° C., a holding time of 2 hours, and a pressure of 30 MPa.
  • a sintered body was obtained. Further, this was cut with a lathe to obtain a disk-shaped target having a diameter of 180 mm and a thickness of 5 mm.
  • the average leakage magnetic flux density of the target of Comparative Example 1 was 18%.
  • metal particles having a maximum diameter and a minimum diameter of 30 ⁇ m or more evaluated in the same manner as in Example 1 were not averaged in a 1 mm 2 field of view.
  • the ratio of the non-magnetic material particles having a difference between the maximum diameter and the minimum diameter of 0.7 ⁇ m or less evaluated in the same manner as in Example 1 was 89%, and the average particle diameter was 0.71 ⁇ m.
  • this target was attached to a DC magnetron sputtering apparatus, and sputtering was performed.
  • the sputtering conditions were a sputtering power of 1.2 kW and an Ar gas pressure of 1.5 Pa. However, since a stable discharge was not obtained, the sputtering power was 1.7 kW and the Ar gas pressure was 2.8 Pa.
  • sputtering was performed on a 4-inch diameter silicon substrate with a target film thickness of 1000 nm. The number of particles adhering to the substrate was measured with a particle counter. At this time, the number of particles on the silicon substrate was nine.
  • Co powder with an average particle size of 4 ⁇ m, Cr powder with an average particle size of 5 ⁇ m, Pt powder with an average particle size of 3 ⁇ m, TiO 2 powder with an average particle size of 1.2 ⁇ m as an oxide powder, Average particle size of 0.7 ⁇ m Core-like SiO 2 powder and Cr 2 O 3 powder having an average particle diameter of 1 ⁇ m were prepared. Further, Co coarse powder adjusted to have a particle size in the range of 50 ⁇ m to 300 ⁇ m was prepared, and the ratio of Co powder having an average particle size of 4 ⁇ m to the Co coarse powder was set to 7: 3 by weight. These powders were weighed 2000 g with the following composition ratio. Composition: 69Co-18Pt-2Cr-5SiO 2 -2TiO 2 -4Cr 2 O 3 (mol%)
  • the coarse Co powder was removed, and the weighed powder was enclosed in a ball mill pot with a capacity of 10 liters together with a tungsten alloy ball as a grinding medium, and rotated and mixed for 70 hours. Thereafter, Co coarse powder was additionally added to the ball mill pot and mixed for 1 hour.
  • the mixed powder thus obtained was filled in a carbon mold and hot-pressed in a vacuum atmosphere under conditions of a temperature of 1100 ° C., a holding time of 2 hours, and a pressure of 30 MPa to obtain a sintered body. . Further, this was cut with a lathe to obtain a disk-shaped target having a diameter of 180 mm and a thickness of 5 mm.
  • the average leakage magnetic flux density of the target of Comparative Example 2 was 29%.
  • an average of 36 metal grains having a maximum diameter and a minimum diameter of 30 ⁇ m or more evaluated in the same manner as in Example 1 were confirmed in a 1 mm 2 field of view.
  • the ratio of the nonmagnetic material particles having a difference between the maximum diameter and the minimum diameter of 0.7 ⁇ m or less evaluated in the same manner as in Example 1 was 54%, and the average particle diameter was 1.87 ⁇ m.
  • this target was attached to a DC magnetron sputtering apparatus, and sputtering was performed.
  • the sputtering conditions were the same as in Example 1.
  • the sputtering power was 1.2 kW
  • the Ar gas pressure was 1.5 Pa
  • sputtering was performed on a 4-inch diameter silicon substrate with a target film thickness of 1000 nm.
  • the number of particles adhering to the substrate was measured with a particle counter. At this time, the number of particles on the silicon substrate was as large as 28.
  • the present invention adjusts the structure of the sputtering target, particularly the shape of the nonmagnetic material particles and metal particles, thereby improving the leakage magnetic field during sputtering and suppressing abnormal discharge due to the nonmagnetic material.
  • a stable discharge can be obtained when sputtering with a magnetron sputtering apparatus.
  • the magnetic recording medium has an excellent effect of suppressing the abnormal discharge of the nonmagnetic material, reducing the generation of particles during sputtering caused by the abnormal discharge, and obtaining the cost improvement effect by improving the yield. It is useful as a ferromagnetic sputtering target used for forming a magnetic thin film, particularly a hard disk drive recording layer.

Abstract

The structure observed on the polished surface in this sintered sputtering target is configured from metal particles and a metal phase in which non-magnetic material particles with an average particle diameter of 1.8μm or less are dispersed and which contains Co or Fe. Defining the maximum diameter as the greatest value of the distance between any two points on the outer periphery of a non-magnetic material particle and the minimum diameter as the smallest value of the distance between two parallel lines when said lines sandwich the same particle, non-magnetic material particles in which the difference between the maximum diameter and the minimum diameter is less than or equal to 0.7μm make up 60% or more of the non-magnetic material particles in the structure observed on the polished surface of the target; and, defining the maximum diameter as the greatest value of the distance between any two points on the outer periphery of a metal particle and the minimum diameter as the smallest value of the distance between two parallel lines when these sandwich the metal particle, there are, in a 1mm2 field of view, on average 1 or more the metal particles for which the sum of the maximum value and the minimum value is 30μm or greater. This sputtering target can suppress abnormal discharge due to non-magnetic materials that cause the generation of particles during sputtering.

Description

Ｃｏ又はＦｅを含有するスパッタリングターゲットSputtering target containing Co or Fe
　本発明は、磁気記録媒体の磁性体薄膜、特に垂直磁気記録方式を採用したハードディスクの磁気記録媒体におけるグラニュラー膜の成膜に使用される磁性材スパッタリングターゲットに関し、スパッタリングの際にパーティクル発生の原因となる非磁性材の異常放電を抑制することができる、Ｃｏ又はＦｅを主成分とする非磁性材粒子分散型磁性材スパッタリングターゲットに関する。 The present invention relates to a magnetic material sputtering target used to form a magnetic thin film of a magnetic recording medium, in particular, a granular film in a magnetic recording medium of a hard disk adopting a perpendicular magnetic recording method, and causes the generation of particles during sputtering. The present invention relates to a non-magnetic material particle-dispersed magnetic material sputtering target containing Co or Fe as a main component, which can suppress abnormal discharge of the non-magnetic material.
　垂直磁気記録方式を採用するハードディスクの記録層には、強磁性金属であるＣｏ、Ｆｅ、Ｎｉをベースとした材料が用いられている。中でも、ＣｏやＦｅを主成分とするＣｏ－Ｃｒ系、Ｃｏ－Ｐｔ系、Ｃｏ－Ｃｒ－Ｐｔ系、Ｆｅ－Ｐｔ系などの強磁性合金と非磁性の無機材料からなる複合材料が多く用いられている。そして、このようなハードディスクなどの磁気記録媒体の磁性薄膜は、生産性の高さから、上記の材料を成分とする強磁性材スパッタリングターゲットをスパッタリングして作製されることが多い。 A material based on Co, Fe, and Ni, which are ferromagnetic metals, is used for a recording layer of a hard disk that employs a perpendicular magnetic recording system. Of these, composite materials composed of a ferromagnetic alloy such as Co—Cr, Co—Pt, Co—Cr—Pt, Fe—Pt, and the like, which are mainly composed of Co and Fe, and a nonmagnetic inorganic material are often used. ing. And the magnetic thin film of such a magnetic recording medium such as a hard disk is often produced by sputtering a ferromagnetic material sputtering target containing the above material as a component because of its high productivity.
　このような磁気記録媒体用スパッタリングターゲットの作製方法としては、溶解法や粉末冶金法が考えられる。どちらの手法で作製するかは、要求される特性によるので一概には言えないが、垂直磁気記録方式のハードディスクの記録層に使用される、強磁性合金と非磁性の無機物粒子からなるスパッタリングターゲットは、一般に粉末冶金法によって作製されている。これは無機物粒子を合金素地中に均一に分散させる必要があるため、溶解法では作製することが困難だからである。 As a method for producing such a sputtering target for a magnetic recording medium, a melting method or a powder metallurgy method can be considered. Which method is used depends on the required characteristics, so it cannot be generally stated, but the sputtering target made of a ferromagnetic alloy and non-magnetic inorganic particles used for the recording layer of a perpendicular magnetic recording hard disk is Generally, it is produced by a powder metallurgy method. This is because the inorganic particles need to be uniformly dispersed in the alloy substrate, and thus it is difficult to produce by the melting method.
　粉末冶金法として、例えば、特許文献１には、Ｃｏ粉末とＣｒ粉末とＴｉＯ２粉末とＳｉＯ２粉末を混合して得られた混合粉末とＣｏ球形粉末を遊星運動型ミキサーで混合し、この混合粉をホットプレスにより成形し特許文献２に磁気記録媒体用スパッタリングターゲットを得る方法が提案されている。
　この場合のターゲット組織は、無機物粒子が均一に分散した金属素地である相（Ａ）の中に、球形の相（Ｂ）を有している様子が見える（特許文献２の図１参照）。このような組織は、漏洩磁束向上の点では良いが、スパッタ時のパーティクルの発生抑制の点からは好適な磁気記録媒体用スパッタリングターゲットとは言えない。 As a powder metallurgy method, for example, in Patent Document 1, mixed powder obtained by mixing Co powder, Cr powder, TiO 2 powder, and SiO 2 powder and Co spherical powder are mixed by a planetary motion mixer, and this mixing is performed. Patent Document 2 proposes a method of forming a powder by hot pressing to obtain a sputtering target for a magnetic recording medium.
It can be seen that the target structure in this case has a spherical phase (B) in the phase (A) which is a metal substrate in which inorganic particles are uniformly dispersed (see FIG. 1 of Patent Document 2). Such a structure is good in terms of improving leakage magnetic flux, but cannot be said to be a suitable sputtering target for a magnetic recording medium from the viewpoint of suppressing generation of particles during sputtering.
　また、特許文献２には、Ｃｏ－Ｃｒ二元系合金粉末とＰｔ粉末とＳｉＯ２粉末を混合して、得られた混合粉末をホットプレスすることにより、磁気記録媒体薄膜形成用スパッタリングターゲットを得る方法が提案されている。
　この場合のターゲット組織は、図によって示されていないが、Ｐｔ相、ＳｉＯ２相およびＣｏ-Ｃｒ二元系合金相が見られ、Ｃｏ-Ｃｒ二元系合金相の周囲に拡散層が観察できたことが記載されている。このような組織も、好適な磁気記録媒体用スパッタリングターゲットとは言えない。 Patent Document 2 discloses a sputtering target for forming a magnetic recording medium thin film by mixing Co—Cr binary alloy powder, Pt powder, and SiO 2 powder and hot-pressing the obtained mixed powder. A method has been proposed.
Although the target structure in this case is not shown in the figure, a Pt phase, a SiO 2 phase, and a Co—Cr binary alloy phase can be seen, and a diffusion layer can be observed around the Co—Cr binary alloy phase. It is described. Such a structure is not a suitable sputtering target for magnetic recording media.
　さらに、特許文献３には、Ｃｏ、Ｐｔのマトリックス相と、平均粒径が０．０５μｍ以上７．０μｍ未満の金属酸化物相からなるスパッタリングターゲットが提案され、結晶粒の成長を抑制し、低透磁率、高密度のターゲットを得て、成膜効率を上げる提案がなされている。
　その他、特許文献４には酸化物相が形成する粒子の平均粒径を３μｍ以下とすること、特許文献５にはシリカ粒子又はチタニア粒子はスパッタリングターゲットの主表面に垂直な断面において、スパッタリングターゲットの主表面に対して垂直な方向の粒径をＤｎ、前記主表面に平行な方向の粒径をＤｐとした時に、２≦Ｄｐ／Ｄｎを満たすことが記載されている。
　しかし、これらの条件では、いずれも充分ではなく、さらなる改善が求められているのが現状である。 Further, Patent Document 3 proposes a sputtering target composed of a matrix phase of Co and Pt and a metal oxide phase having an average particle size of 0.05 μm or more and less than 7.0 μm, which suppresses the growth of crystal grains, Proposals have been made to increase the film formation efficiency by obtaining a magnetic permeability and high density target.
In addition, Patent Document 4 discloses that the average particle diameter of the particles formed by the oxide phase is 3 μm or less, and Patent Document 5 discloses that the silica particles or titania particles are in a cross section perpendicular to the main surface of the sputtering target. It is described that 2 ≦ Dp / Dn is satisfied, where Dn is a particle size in a direction perpendicular to the main surface and Dp is a particle size in a direction parallel to the main surface.
However, none of these conditions is sufficient and the present situation is that further improvement is required.
国際公開第２０１１／０８９７６０号パンフレットInternational Publication No. 2011/089760 Pamphlet 特開２００９－１８６０号公報JP 2009-1860 A 特開２００９－１０２７０７号公報JP 2009-102707 A 特開２００９－２１５６１７号公報JP 2009-215617 A 特開２０１１－２２２０８６号公報JP 2011-2222086 特願２０１２－０３６５６２Japanese Patent Application No. 2012-036562
　一般に、Ｃｏ又はＦｅを主成分とする非磁性材粒子分散型強磁性材スパッタリングターゲットにおいては、含有するＳｉＯ２、Ｃｒ２Ｏ３、ＴｉＯ２などの非磁性材が絶縁体であるため異常放電の原因となっている。そして、この異常放電が原因でスパッタリング中のパーティクル発生が問題となる。 In general, in a non-magnetic material particle-dispersed ferromagnetic sputtering target containing Co or Fe as a main component, the non-magnetic material such as SiO 2 , Cr 2 O 3 , or TiO 2 contained is an insulator, so abnormal discharge It is the cause. Due to this abnormal discharge, generation of particles during sputtering becomes a problem.
　本発明は上記問題を鑑みて、高ＰＴＦを維持しつつ、上記非磁性材の異常放電を抑制し、異常放電が原因となるスパッタリング中のパーティクル発生を減少させることを課題とする。これまで、非磁性材粒子の粒径を小さくすることで異常放電の確率を減らすことが行われてきたが、磁気記録媒体の記録密度向上に伴い、許容パーティクルレベルが厳しくなってきていることから、より改善された非磁性材粒子分散型強磁性材スパッタリングターゲットを提供することを課題とする。 In view of the above problems, an object of the present invention is to suppress abnormal discharge of the nonmagnetic material while maintaining a high PTF, and to reduce the generation of particles during sputtering caused by abnormal discharge. Until now, the probability of abnormal discharge has been reduced by reducing the particle size of the non-magnetic material particles. However, as the recording density of magnetic recording media has improved, the allowable particle level has become stricter. An object of the present invention is to provide a non-magnetic material particle-dispersed ferromagnetic material sputtering target that is further improved.
　上記の課題を解決するために、本発明者らは鋭意研究を行った結果、ターゲットの組織（非磁性材粒子）構造を調整することにより、スパッタリング時の非磁性材による異常放電が生じず、パーティクルの発生の少ないターゲットが得られることを見出した。 In order to solve the above-mentioned problems, the present inventors have conducted intensive research. As a result, by adjusting the structure of the target (non-magnetic material particles) structure, abnormal discharge due to the non-magnetic material during sputtering does not occur, It has been found that a target with less generation of particles can be obtained.
　このような知見に基づき、本発明は、以下の発明を提供するものである。
　１）Ｃｏ又はＦｅを含有する磁性材の中に非磁性材粒子が分散した材料からなる焼結体スパッタリングターゲットであって、
　前記ターゲット中の研磨面で観察される組織が平均粒径１．８μｍ以下の非磁性材粒子と該非磁性材粒子が分散したＣｏ又はＦｅを含有する金属相及び金属粒とから構成されており、
　前記非磁性材粒子の外周上にある任意の２点の距離の最大値を最大径とし、平行な２本の直線で同粒子を挟んだときの２直線間の距離の最小値を最小径とした場合、その最大径と最小径の差が０．７μｍ以下である非磁性材粒子が前記ターゲット中の研磨面で観察される組織内の非磁性材粒子に対して６０％以上占めており、かつ、
　前記金属粒の外周上にある任意の２点の距離の最大値を最大径とし、平行な２本の直線で同金属粒を挟んだときの２直線間の距離の最小値を最小径とした場合、その最大径と最小径の和が３０μｍ以上の金属粒が１ｍｍ２視野内に平均１個以上存在することを特徴とするスパッタリングターゲット。
　２）前記非磁性材粒子が、Ｂ２Ｏ３、ＣｏＯ、Ｃｏ３Ｏ４、ＭｎＯ、Ｍｎ３Ｏ４、ＳｉＯ２、ＳｎＯ２、ＴｉＯ２、Ｔｉ２Ｏ３、Ｃｒ２Ｏ３、Ｔａ２Ｏ５、ＷＯ２、ＷＯ３、ＺｒＯ２から選択した一種以上の酸化物であり、これらを０．５～２０ｍｏｌ％含有することを特徴とする上記１）記載のスパッタリングターゲット。
　３）Ｃｒが０ｍｏｌ％以上１５ｍｏｌ％以下、Ｐｔが５ｍｏｌ％以上３０ｍｏｌ％以下、非磁性材料を除き残部がＣｏ及び不可避的不純物であることを特徴とする上記１）又は２）記載のスパッタリングターゲット。
　４）さらにＭｇ、Ａｌ、Ｓｉ、Ｍｎ、Ｎｂ、Ｍｏ、Ｒｕ、Ｐｄ、Ｔａ、Ｗ、Ｂから選択した一種以上の元素を、０．５ｍｏｌ％以上１２ｍｏｌ％以下含有することを特徴とする上記３）記載のスパッタリングターゲット。
　５）前記金属粒が、Ｃｏ又はＦｅからなることを特徴とする上記１）～４）のいずれか一に記載のスパッタリングターゲット。 Based on such knowledge, the present invention provides the following inventions.
1) A sintered sputtering target made of a material in which non-magnetic material particles are dispersed in a magnetic material containing Co or Fe,
The structure observed on the polished surface in the target is composed of nonmagnetic material particles having an average particle size of 1.8 μm or less, and a metal phase and metal particles containing Co or Fe in which the nonmagnetic material particles are dispersed,
The maximum value of the distance between any two points on the outer periphery of the non-magnetic material particle is the maximum diameter, and the minimum value of the distance between the two lines when the particle is sandwiched between two parallel straight lines is the minimum diameter. In that case, the nonmagnetic material particles having a difference between the maximum diameter and the minimum diameter of 0.7 μm or less account for 60% or more of the nonmagnetic material particles in the structure observed on the polished surface in the target, And,
The maximum value of the distance between any two points on the outer periphery of the metal grain is the maximum diameter, and the minimum value of the distance between the two straight lines when the metal grain is sandwiched between two parallel straight lines is the minimum diameter. In this case, an average of one or more metal particles having a maximum diameter and a minimum diameter of 30 μm or more are present in a 1 mm 2 field of view.
2) The non-magnetic material particles are B 2 O 3 , CoO, Co 3 O 4 , MnO, Mn 3 O 4 , SiO 2 , SnO 2 , TiO 2 , Ti 2 O 3 , Cr 2 O 3 , Ta 2 O. 5. The sputtering target according to 1) above, which is one or more oxides selected from WO 2 , WO 3 , and ZrO 2 , and contains 0.5 to 20 mol% of these.
3) The sputtering target according to 1) or 2) above, wherein Cr is 0 mol% or more and 15 mol% or less, Pt is 5 mol% or more and 30 mol% or less, and the remainder is Co and inevitable impurities except for a nonmagnetic material.
4) The above-mentioned 3 characterized by further containing 0.5 mol% or more and 12 mol% or less of one or more elements selected from Mg, Al, Si, Mn, Nb, Mo, Ru, Pd, Ta, W, and B ) The sputtering target described.
5) The sputtering target according to any one of 1) to 4) above, wherein the metal particles are made of Co or Fe.
　このように調整した本発明の非磁性材粒子分散型の磁性材スパッタリングターゲットは、高ＰＴＦを維持しつつ、スパッタリング時の非磁性材による異常放電が生ぜず、パーティクルの発生の少ないターゲットが得られる。これにより、歩留まり向上によるコスト改善効果を得ることができるという優れた効果を有する。 The non-magnetic material particle dispersion type magnetic material sputtering target of the present invention thus adjusted maintains a high PTF, does not cause abnormal discharge due to the non-magnetic material during sputtering, and provides a target with less generation of particles. . Thereby, it has the outstanding effect that the cost improvement effect by a yield improvement can be acquired.
実施例１のＣｏ－Ｐｔ－Ｃｒ－ＳｉＯ２－ＴｉＯ２－Ｃｒ２Ｏ３ターゲット組織を示す図（写真）である。1 is a diagram (photograph) showing a Co—Pt—Cr—SiO 2 —TiO 2 —Cr 2 O 3 target structure of Example 1. FIG. 実施例１のターゲットの非磁性材粒子が金属相に分散した組織を示す図（図１の拡大写真）である。It is a figure (enlarged photograph of FIG. 1) which shows the structure | tissue in which the nonmagnetic material particle | grains of the target of Example 1 were disperse | distributed to the metal phase. 非磁性材粒子の輪郭を明確にするために図２を画像解析処理（二値化処理）した図である。FIG. 3 is a view obtained by performing image analysis processing (binarization processing) on FIG. 2 in order to clarify the outline of nonmagnetic material particles. 実施例２のＣｏ－Ｐｔ－Ｒｕ－Ｔａ－ＳｉＯ２－ＴｉＯ２－ＣｏＯ－Ｂ２Ｏ３ターゲット組織を示す図（写真）である。4 is a diagram (photograph) showing a Co—Pt—Ru—Ta—SiO 2 —TiO 2 —CoO—B 2 O 3 target structure of Example 2. FIG. 実施例２のターゲットの非磁性材粒子が金属相に分散した組織を示す図（図４の拡大写真）である。It is a figure (enlarged photograph of FIG. 4) which shows the structure | tissue in which the nonmagnetic material particle | grains of the target of Example 2 were disperse | distributed to the metal phase.
　本発明のスパッタリングターゲットは、Ｃｏ又はＦｅを含有する磁性材の中に非磁性材粒子が分散した材料からなる焼結体スパッタリングターゲットであって、ターゲットの研磨面で観察される組織が、平均粒径１．８μｍ以下の非磁性材粒子と、前記非磁性材粒子が分散したＣｏもしくはＦｅを含む金属相と金属粒とから構成されるものである。非磁性材粒子の大きさを平均粒径１．８μｍ以下とすることによりパーティクルの発生を抑制することができるからである。 The sputtering target of the present invention is a sintered sputtering target made of a material in which non-magnetic material particles are dispersed in a magnetic material containing Co or Fe, and the structure observed on the polished surface of the target is an average grain. Non-magnetic material particles having a diameter of 1.8 μm or less, a metal phase containing Co or Fe in which the non-magnetic material particles are dispersed, and metal particles are included. It is because generation | occurrence | production of a particle can be suppressed by making the magnitude | size of a nonmagnetic material particle into an average particle diameter of 1.8 micrometers or less.
　本願発明者らは以前、非磁性材粒子の形状が真球状であることが望ましく、少なくともそれに近い形状であることが、パーティクルの発生を防止できる有効な手段であるという知見を得た（特許文献６）。
　つまり、磁気的性質を向上させるためには一定量の酸化物（非磁性材）の存在が必要であるが、それが異形状であると、ターゲット表面の一定面積における酸化物の存在する場所と酸化物の存在しない場所とにおいて、分布に差異が生じ、偏析が生じ易くなる。真球又は真球に近い酸化物粒子であれば、粒の形状が揃っているため偏析が少なくなり、パーティクル発生を効果的に抑制できるという知見を得た。 The inventors of the present application have previously found that it is desirable that the shape of the non-magnetic material particles is a perfect sphere, and that at least a shape close to that is an effective means for preventing the generation of particles (Patent Document) 6).
In other words, in order to improve the magnetic properties, a certain amount of oxide (non-magnetic material) needs to be present, but if it is irregularly shaped, the location of the oxide in a certain area of the target surface A difference occurs in the distribution in a place where no oxide is present, and segregation is likely to occur. As long as it is a true sphere or an oxide particle close to a true sphere, segregation is reduced because the shape of the particles is uniform, and it has been found that particle generation can be effectively suppressed.
　本発明は上記知見に沿って、ターゲット中の研磨面で観察される非磁性材粒子の外周上にある任意の２点の距離の最大値を最大径とし、平行な２本の直線で同粒子を挟んだときの２直線間の距離の最小値を最小径とした場合、その最大径と最小径の差が０．７μｍ以下とする。
　また、このような非磁性材粒子がターゲットの大半を占めること、すなわち６０％以上を占めること、好ましくは９０％以上、さらに好ましくは１００％であることが望ましい。これによって、パーティクルの発生を大きく抑制することができる。 According to the present invention, in accordance with the above knowledge, the maximum value of the distance between any two points on the outer periphery of the non-magnetic material particles observed on the polished surface in the target is the maximum diameter, and the particles are represented by two parallel straight lines When the minimum value of the distance between the two straight lines when the gap is sandwiched is the minimum diameter, the difference between the maximum diameter and the minimum diameter is 0.7 μm or less.
Further, it is desirable that such non-magnetic material particles occupy most of the target, that is, occupy 60% or more, preferably 90% or more, and more preferably 100%. Thereby, the generation of particles can be greatly suppressed.
　本発明は上記知見にさらに新たな知見を見出したもので、非磁性材粒子の形態だけでなく、Ｃｏ又はＦｅを含む金属粒の形態を特定することで異常放電を抑え、パーティクルの発生をさらに大きく抑制することができる。
　すなわち、ターゲット中の研磨面で観察される金属粒の外周上にある任意の２点の距離の最大値を最大径とし、平行な２本の直線で同金属粒を挟んだときの２直線間の距離の最小値を最小径とした場合、その最大径と最小径の和が３０μｍ以上の金属粒が１ｍｍ２視野内に平均１個以上、また好ましくは平均３個以上、さらに好ましくは平均５個以上存在することを特徴とするものである。
　なお、本発明では、ターゲット面内の任意の５箇所を顕微鏡観察して、それぞれの場所の１ｍｍ２視野内における最大径と最小径の和が３０μｍ以上の金属粒の数をカウントして、その合計から平均個数を求めている。 The present invention has found further new findings in the above knowledge, and not only the form of the non-magnetic material particles but also the form of the metal particles containing Co or Fe can be used to suppress abnormal discharge and further increase the generation of particles. It can be greatly suppressed.
That is, the maximum value of the distance between any two points on the outer periphery of the metal grain observed on the polished surface in the target is the maximum diameter, and the distance between the two straight lines when the metal grain is sandwiched between two parallel straight lines the minimum value when the smallest diameter the distance, its average maximum diameter and the minimum diameter of the sum 30μm or more metal grains in 1 mm 2 field of view one or more, and preferably an average of 3 or more, more preferably an average 5 It is characterized by the presence of more than one.
In the present invention, any five locations within the target surface are observed with a microscope, and the number of metal particles whose sum of the maximum diameter and the minimum diameter within a 1 mm 2 visual field at each location is 30 μm or more is counted. The average number is obtained from the total.
　金属粒の外周上にある任意の２点の距離の最大値を最大径とし、平行な２本の直線で同金属粒を挟んだときの２直線間の距離の最小値を最小径とした場合、その最大径と最小径の和が３０μｍ以上で１ｍｍ２視野内に平均１個以上存在すると、漏洩磁束が大きくなる。そして、マグネトロンスパッタ装置で使用したとき、不活性ガスの電離促進が効率的に進み、安定した放電が得られる。
　一方、金属粒の外周上にある任意の２点の距離の最大値を最大径とし、平行な２本の直線で同金属粒を挟んだときの２直線間の距離の最小値を最小径とした場合、その最大径と最小径の和が３０μｍよりも小さいか、もしくは３０μｍ以上の金属粒の存在が１ｍｍ２視野内に平均１個未満の場合、上記の効果はほとんど得られない。
　また、前記最大径と最小径の和は５０μｍ以上であると、上記の効果はより一層強く現れるが、前記最大径と最小径との和が３００μｍを超えると、酸化物粒子の存在分布に偏りが生じることがある。 When the maximum value of the distance between any two points on the outer periphery of the metal particle is the maximum diameter, and the minimum value of the distance between the two lines when the metal particle is sandwiched between two parallel lines is the minimum diameter When the sum of the maximum diameter and the minimum diameter is 30 μm or more and there is an average of 1 or more in a 1 mm 2 field of view, the leakage magnetic flux increases. When used in a magnetron sputtering apparatus, the promotion of ionization of the inert gas proceeds efficiently, and a stable discharge can be obtained.
On the other hand, the maximum value of the distance between any two points on the outer periphery of the metal grain is the maximum diameter, and the minimum value of the distance between the two lines when the metal grain is sandwiched between two parallel straight lines is the minimum diameter. In this case, when the sum of the maximum diameter and the minimum diameter is smaller than 30 μm, or when the presence of metal particles of 30 μm or more is less than 1 on average within 1 mm 2 field of view, the above effect is hardly obtained.
In addition, when the sum of the maximum diameter and the minimum diameter is 50 μm or more, the above effect appears even more strongly. However, when the sum of the maximum diameter and the minimum diameter exceeds 300 μm, the distribution of the oxide particles is biased. May occur.
　本発明の強磁性材スパッタリングターゲットは、Ｃｏ－Ｃｒ系合金、Ｃｏ－Ｐｔ系合金、Ｃｏ－Ｃｒ－Ｐｔ系合金などのＣｏ系合金あるいはＦｅ－Ｐｔ系合金などのＦｅ系合金に特に有効であるが、本願発明は、すでに公知の強磁性材に適用でき、磁気記録媒体として必要とされる成分の配合割合は目的に応じて適宜調整できる。
　Ｃｏ系合金としては、Ｃｒが０ｍｏｌ％以上１５ｍｏｌ％以下、Ｐｔが５ｍｏｌ％以上３０ｍｏｌ％以下、非磁性材料を除き残部がＣｏ及び不可避的不純物からなるスパッタリングターゲットとすることができる。Ｆｅ系合金としては、Ｐｔが０ｍｏｌ％を超え６０ｍｏｌ％以下、非磁性材料を除き残部がＦｅ及び不可避的不純物からなるスパッタリングターゲットとすることができる。
　これらの成分組成は、強磁性材としての特性を活かすための好適な数値範囲を示すもので、これ以外の数値に適用できることは言うまでもない。 The ferromagnetic material sputtering target of the present invention is particularly effective for Co-based alloys such as Co-Cr based alloys, Co-Pt based alloys, Co-Cr-Pt based alloys or Fe based alloys such as Fe-Pt based alloys. However, the present invention can be applied to already known ferromagnetic materials, and the mixing ratio of components required as a magnetic recording medium can be appropriately adjusted according to the purpose.
As the Co-based alloy, a sputtering target in which Cr is 0 mol% or more and 15 mol% or less, Pt is 5 mol% or more and 30 mol% or less, and the balance is made of Co and unavoidable impurities except for a nonmagnetic material. As the Fe-based alloy, a sputtering target in which Pt is more than 0 mol% and not more than 60 mol%, and the remainder is made of Fe and inevitable impurities except for a nonmagnetic material can be used.
These component compositions show a suitable numerical range for utilizing the characteristics as a ferromagnetic material, and needless to say, they can be applied to other numerical values.
　前記強磁性材に添加する非磁性材については、Ｂ２Ｏ３、ＣｏＯ、Ｃｏ３Ｏ４、ＭｎＯ、Ｍｎ２Ｏ３、ＳｉＯ２、ＴｉＯ２、Ｔｉ２Ｏ３、Ｃｒ２Ｏ３、Ｔａ２Ｏ５、ＷＯ２、ＷＯ３、ＺｒＯ２から選択した一種以上の酸化物であり、通常、ターゲット中に、これらを０．５～２０ｍｏｌ％含有させる。これらの酸化物は、必要とされる強磁性膜の種類に応じて、任意に選択し添加することができる。前記添加量は、添加の効果を発揮させるための有効量である。
　また、本発明のスパッタリングターゲットは、Ｍｇ、Ａｌ、Ｓｉ、Ｍｎ、Ｎｂ、Ｍｏ、Ｒｕ、Ｐｄ、Ｔａ、Ｗ、Ｂから選択した一種以上の元素を、０．５～１２ｍｏｌ％を添加することができる。これらは磁気記録媒体としての特性を向上させるために、必要に応じて添加される元素である。前記添加量は、添加の効果を発揮させるための有効量である。 Nonmagnetic materials to be added to the ferromagnetic material are B 2 O 3 , CoO, Co 3 O 4 , MnO, Mn 2 O 3 , SiO 2 , TiO 2 , Ti 2 O 3 , Cr 2 O 3 , Ta 2. One or more oxides selected from O 5 , WO 2 , WO 3 , and ZrO 2 , and usually 0.5 to 20 mol% of these are contained in the target. These oxides can be arbitrarily selected and added according to the type of ferromagnetic film required. The said addition amount is an effective amount for exhibiting the effect of addition.
In the sputtering target of the present invention, 0.5 to 12 mol% of one or more elements selected from Mg, Al, Si, Mn, Nb, Mo, Ru, Pd, Ta, W, and B may be added. it can. These are elements added as necessary in order to improve the characteristics as a magnetic recording medium. The said addition amount is an effective amount for exhibiting the effect of addition.
　また、本発明のスパッタリングターゲットの組織は、非磁性材粒子と非磁性材粒子が分散したＣｏもしくはＦｅを含む金属相及び金属粒とから構成されるが、該金属粒はＣｏ又はＦｅからなることが好ましい。
　この金属粒は、組成の異なる金属素地（非磁性材粒子が分散した金属相）よりも最大透磁率が高く、金属素地からなる周囲の組織によって各々が分離された構造になっている。このような組織を有するターゲットにおいて、漏洩磁界が向上する理由は現時点で必ずしも明確ではないが、ターゲット内部の磁束に密な部分と疎な部分が生じ、均一な透磁率を有する組織と比較して静磁エネルギーが高くなるため、磁束がターゲット外部に漏れ出た方がエネルギー的に有利になるためと考えられる。 The structure of the sputtering target of the present invention is composed of non-magnetic material particles and a metal phase and metal particles containing Co or Fe in which the non-magnetic material particles are dispersed, and the metal particles are composed of Co or Fe. Is preferred.
The metal grains have a maximum magnetic permeability higher than that of metal bases having different compositions (metal phases in which non-magnetic material particles are dispersed), and have a structure in which the metal grains are separated from each other by surrounding structures made of the metal base. In the target having such a structure, the reason why the leakage magnetic field improves is not necessarily clear at the present time, but a dense part and a sparse part are generated in the magnetic flux inside the target, compared with a structure having a uniform magnetic permeability. This is because the magnetostatic energy increases, and it is considered that it is advantageous in terms of energy to leak the magnetic flux outside the target.
　本発明のスパッタリングターゲットは、粉末冶金法によって作製することができる。粉末冶金法の場合、後述する金属粗粉を除き、Ｃｏ、Ｃｒ、Ｐｔ、Ｆｅなどの金属原料粉とＳｉＯ２などの非磁性材原料粉、必要に応じて、Ｒｕなどの添加金属粉を用意する。原料の粒度は、金属粉で平均粒径１０μｍ以下、非磁性材粉で５μｍ以下のものを用いることが望ましい。非磁性材原料粉はできるだけ球状に近い方が、本発明の微細組織を達成しやすい。また、各金属元素の粉末の代わりにこれら金属の合金粉末を用意してもよい。なお、粉末の粒径はレーザー回折式粒度分布計（ＨＯＲＩＢＡ　ＬＡ－９２０）で測定することができる。 The sputtering target of the present invention can be produced by powder metallurgy. In the case of powder metallurgy, metal raw material powders such as Co, Cr, Pt and Fe, non-magnetic material raw material powders such as SiO 2 and, if necessary, additive metal powders such as Ru are prepared, except for metal coarse powder described later. To do. As for the particle size of the raw material, it is desirable to use metal powder having an average particle diameter of 10 μm or less and non-magnetic material powder of 5 μm or less. The non-magnetic material raw powder is more likely to be as spherical as possible to achieve the microstructure of the present invention. Moreover, you may prepare the alloy powder of these metals instead of the powder of each metal element. The particle size of the powder can be measured with a laser diffraction particle size distribution analyzer (HORIBA LA-920).
　そして、これらの金属粉末及び合金粉末を所望の組成になるように秤量し、ボールミル等の公知の手法を用いて粉砕を兼ねて混合する。混合時間を短縮して生産性を高めるためには、高エネルギーボールミルを用いることが好ましい。ここで、金属原料粉について、粒径を５０μｍ以上３００μｍ以下の範囲とした少なくとも１成分の金属粗粉を少量混ぜることが好ましい。その際、ボールミルを用いて長時間混合した後に添加するか、あるいは、ミキサーのような粉砕性のない弱い混合機にて混合することが粒径を維持する上で好ましい。または、ボールミル混合の途中で添加して、短時間のボールミル混合を行ってもよい。これにより金属粒は扁平状となり、長径と短径との差が大きくなる。 Then, these metal powders and alloy powders are weighed so as to have a desired composition, and mixed by pulverization using a known method such as a ball mill. In order to shorten the mixing time and increase the productivity, it is preferable to use a high energy ball mill. Here, with respect to the metal raw material powder, it is preferable to mix a small amount of at least one component metal coarse powder having a particle size in the range of 50 μm to 300 μm. In this case, it is preferable to add after mixing for a long time using a ball mill, or to mix with a weak mixer having no pulverizability such as a mixer in order to maintain the particle size. Or you may add in the middle of ball mill mixing, and may perform ball mill mixing for a short time. As a result, the metal particles become flat and the difference between the major axis and the minor axis increases.
　このようにして金属粒を球形又は扁平状（片状）とすることができるが、この球形又は扁平状の金属粒は、それぞれ形状に応じた利害得失を備えている。この形状の選択は、ターゲットの使用目的に応じて選択することが望ましい。
　具体的には、球形の方が、焼結法でターゲット素材を作製する際、金属素地（Ａ）と相（Ｂ）の境界面に空孔が生じにくく、ターゲットの密度を高めることができる。また、同一体積では球形の方が、表面積が小さくなるので、ターゲット素材を焼結させる際に金属素地（Ａ）と相（Ｂ）との間で金属元素の拡散が進みにくい。なお、ここでいう球形とは、真球、擬似真球、扁球（回転楕円体）、擬似扁球を含む立体形状を表す。いずれも、長軸と短軸の差が０～５０％であるものを言う。
　一方、金属粒を扁平状とした場合、まさに楔の効果でスパッタ時に周囲の金属素地（Ａ）から金属粒が脱離するのを防ぐ効果を有する。また、球形を破壊することによって、球形のときに生じやすいエロージョン速度の偏りを軽減することができ、エロージョン速度の異なる境界起因のパーティクル発生を抑制することができる。 In this way, the metal particles can be spherical or flat (strip-shaped), but each of the spherical or flat metal particles has advantages and disadvantages depending on the shape. It is desirable to select this shape according to the intended use of the target.
Specifically, when the target material is produced by the sintering method in the spherical shape, holes are less likely to be generated at the interface between the metal substrate (A) and the phase (B), and the target density can be increased. In addition, since the spherical surface area is smaller in the same volume, the diffusion of the metal element is less likely to proceed between the metal substrate (A) and the phase (B) when the target material is sintered. The spherical shape here represents a solid shape including a true sphere, a pseudo-true sphere, an oblate (spheroid), and an artificial oblate. In either case, the difference between the major axis and the minor axis is 0 to 50%.
On the other hand, when the metal particles are made flat, it has the effect of preventing the metal particles from detaching from the surrounding metal substrate (A) at the time of sputtering due to the wedge effect. Further, by destroying the spherical shape, it is possible to reduce the bias of the erosion speed that is likely to occur in the spherical shape, and it is possible to suppress the generation of particles due to the boundary having different erosion speeds.
　本発明において、重要なことは、前記の通り、ターゲット中の研磨面で観察される組織内の非磁性材粒子の外周上にある任意の２点の距離の最大値を最大径とし、平行な２本の直線で同粒子を挟んだときの２直線間の距離の最小値を最小径とした場合、最大径と最小径の差が０．７μｍ以下とすることである。
　また、本発明において、特に重要なことは、ターゲット中の研磨面で観察される金属粒の外周上にある任意の２点の距離の最大値を最大径とし、平行な２本の直線で同金属粒を挟んだときの２直線間の距離の最小値を最小径とした場合、その最大径と最小径の和が３０ｍｍ以上の金属粒が１ｍｍ２視野内に平均１個以上存在することである。
　最大径と最小径の算出は、ターゲット中の研磨面の顕微鏡画像をＰＣに映し、画像処理解析ソフトを用いて行う。画像処理解析ソフトは、キーエンス社製形状解析ソフト（ＶＫ－Ａｎａｌｙｚｅｒ　ＶＫ－Ｈ１Ａ１）を使用した。 In the present invention, what is important is that, as described above, the maximum value of the distance between any two points on the outer periphery of the nonmagnetic material particles in the structure observed on the polished surface in the target is the maximum diameter, and is parallel. When the minimum value of the distance between two straight lines when the same particle is sandwiched between two straight lines is defined as the minimum diameter, the difference between the maximum diameter and the minimum diameter is 0.7 μm or less.
Further, in the present invention, it is particularly important that the maximum value of the distance between two arbitrary points on the outer periphery of the metal grain observed on the polished surface in the target is the maximum diameter, and the two parallel straight lines are the same. If the minimum distance between two straight lines when sandwiching the metal grains as the minimum diameter, when the sum of the maximum diameter and the minimum diameter is 30mm or more metal particles are present average of one or more 1mm in 2 field is there.
The maximum diameter and the minimum diameter are calculated by projecting a microscope image of the polished surface in the target on a PC and using image processing analysis software. As the image processing analysis software, Keyence Corporation shape analysis software (VK-Analyzer VK-H1A1) was used.
　以上のように得られる混合粉をホットプレスや熱間静水圧プレスを用いて焼結を行う。ターゲットの成分組成にもよるが、上記原料の混合条件、焼結条件の設定により非磁性材粒子が真球状になる条件及び金属粒が扁平状となる条件を見出して、その製造条件を固定すれば、常時そのような非磁性材粒子や金属粒が分散した焼結体ターゲットを得ることができる。 The mixed powder obtained as described above is sintered using a hot press or a hot isostatic press. Depending on the composition of the target, find the conditions for non-magnetic material particles to become spherical and the conditions for metal particles to be flat by setting the mixing conditions and sintering conditions for the above raw materials, and fix the manufacturing conditions. Thus, a sintered body target in which such non-magnetic material particles and metal particles are always dispersed can be obtained.
　以下、実施例および比較例に基づいて説明する。なお、本実施例はあくまで一例であり、この例によって何ら制限されるものではない。すなわち、本発明は特許請求の範囲によってのみ制限されるものであり、本発明に含まれる実施例以外の種々の変形を包含するものである。 Hereinafter, description will be made based on examples and comparative examples. In addition, a present Example is an example to the last, and is not restrict | limited at all by this example. In other words, the present invention is limited only by the scope of the claims, and includes various modifications other than the examples included in the present invention.
（実施例１）
　金属原料粉末として、平均粒径４μｍのＣｏ粉末、平均粒径５μｍのＣｒ粉末、平均粒径３μｍのＰｔ粉末を、非磁性材粉末として平均粒径１．２μｍのＴｉＯ２粉末、平均粒径０．７μｍの球形ＳｉＯ２粉末、平均粒径１μｍのＣｒ２Ｏ３粉末を用意した。また、粒径が５０μｍ以上１５０μｍ以下の範囲となるように調整したＣｏ粗粉を準備し、平均粒径４μｍのＣｏ粉末と前記Ｃｏ粗粉との比率を重量比で７：３とした。これらの粉末を以下の組成比で２０００ｇ秤量した。
　組成：６９Ｃｏ－１８Ｐｔ－２Ｃｒ－５ＳｉＯ２－２ＴｉＯ２－４Ｃｒ２Ｏ３（ｍｏｌ％） (Example 1)
As the metal raw material powder, Co powder having an average particle diameter of 4 μm, Cr powder having an average particle diameter of 5 μm, Pt powder having an average particle diameter of 3 μm, and TiO 2 powder having an average particle diameter of 1.2 μm as the nonmagnetic material powder, an average particle diameter of 0 A spherical SiO 2 powder having a thickness of 7 μm and a Cr 2 O 3 powder having an average particle diameter of 1 μm were prepared. Moreover, Co coarse powder adjusted so that a particle size might be in the range of 50 micrometers or more and 150 micrometers or less was prepared, and the ratio of Co powder with an average particle diameter of 4 micrometers and the said Co coarse powder was set to 7: 3 by weight ratio. These powders were weighed 2000 g with the following composition ratio.
Composition: 69Co-18Pt-2Cr-5SiO 2 -2TiO 2 -4Cr 2 O 3 (mol%)
　次に、Ｃｏ粗粉を除き、秤量した粉末を粉砕媒体のタングステン合金ボールと共に容量１０リットルのボールミルポットに封入し、１２０時間回転させて混合した。その後、Ｃｏ粗粉をボールミルポットに追加で添加して、１時間混合した。このようにして得られた混合粉をカーボン製の型に充填し、真空雰囲気中、温度１１００°Ｃ、保持時間２時間、加圧力３０ＭＰａの条件のもとホットプレスして焼結体を得た。さらにこれを旋盤で切削加工して直径が１８０ｍｍ、厚さが５ｍｍの円盤状のターゲットを得た。 Next, the Co coarse powder was removed, and the weighed powder was enclosed in a ball mill pot with a capacity of 10 liters together with a tungsten alloy ball as a grinding medium, and rotated and mixed for 120 hours. Thereafter, Co coarse powder was additionally added to the ball mill pot and mixed for 1 hour. The mixed powder thus obtained was filled in a carbon mold and hot-pressed in a vacuum atmosphere under conditions of a temperature of 1100 ° C., a holding time of 2 hours, and a pressure of 30 MPa to obtain a sintered body. . Further, this was cut with a lathe to obtain a disk-shaped target having a diameter of 180 mm and a thickness of 5 mm.
　このようにして得られたターゲットの平均漏洩磁束密度を測定した結果、３０％であった。なお、漏洩磁束の測定は、ＡＳＴＭ　Ｆ２０８６－０１（Standard Test Method for　Pass Through Flux of Circular Magnetic Sputtering Targets, Method 2）に則して実施した。具体的には、ターゲットの中心を固定し、０度、３０度、６０度、９０度、１２０度と回転させて測定した漏洩磁束密度を、ＡＳＴＭで定義されているreference fieldの値で割り返し、１００を掛けてパーセントで表した。そして、これら５点について平均した結果を、平均漏洩磁束密度（％）とした。 As a result of measuring the average leakage magnetic flux density of the target thus obtained, it was 30%. The measurement of leakage magnetic flux was carried out in accordance with ASTM F2086-01 (Standard Test Method for Pass Flow Through Flux of Crystal Circular Magnetic Sputtering Targets, Method 2). Specifically, the magnetic flux leakage density measured by fixing the center of the target and rotating it at 0 degrees, 30 degrees, 60 degrees, 90 degrees, and 120 degrees is divided by the value of the reference field defined by ASTM. , Multiplied by 100 and expressed as a percentage. And the result averaged about these 5 points | pieces was made into the average leakage magnetic flux density (%).
　このターゲット表面を研磨して組織を顕微鏡で観察したところ図１に示すように非磁性材粒子が金属相に分散した組織中に、金属粒が点在していることが分かる。金属粒の外周上にある任意の２点の距離の最大値を最大径とし、平行な２本の直線で同金属粒を挟んだときの２直線間の距離の最小値を最小径とした場合、その最大径と最小径の和が３０μｍ以上の金属粒が１ｍｍ２視野内に平均４０個確認された。
　また、非磁性材粒子を観察するため、図１を拡大したものを図２に示す。非磁性材粒子の外周上にある任意の２点の距離の最大値を最大径とし、平行な２本の直線で同粒子を挟んだときの２直線間の距離の最小値を最小径とした場合、最大径と最小径の差が０．７μｍ以下である酸化物粒子が顕微鏡視野内において８５％存在しており、平均粒径は０．７５μｍであった。
　なお、酸化物粒子の最大径、最小径、平均粒径を算出するにあたっては、図３に示すように、顕微鏡像をＰＣ画面に映し出し、画像解析処理（二値化処理）して、酸化物粒子（黒い部分）の輪郭を明確にした上で、これらを算出した。 When the surface of the target is polished and the structure is observed with a microscope, it can be seen that metal particles are scattered in the structure in which the nonmagnetic material particles are dispersed in the metal phase as shown in FIG. When the maximum value of the distance between any two points on the outer periphery of the metal particle is the maximum diameter, and the minimum value of the distance between the two lines when the metal particle is sandwiched between two parallel lines is the minimum diameter In addition, an average of 40 metal grains having a maximum diameter and a minimum diameter of 30 μm or more were confirmed within a 1 mm 2 field of view.
FIG. 2 shows an enlarged view of FIG. 1 in order to observe the non-magnetic material particles. The maximum value of the distance between any two points on the outer periphery of the nonmagnetic material particle is the maximum diameter, and the minimum value of the distance between the two lines when the particle is sandwiched between two parallel lines is the minimum diameter. In this case, 85% of the oxide particles having a difference between the maximum diameter and the minimum diameter of 0.7 μm or less were present in the microscopic field, and the average particle diameter was 0.75 μm.
In calculating the maximum diameter, the minimum diameter, and the average particle diameter of the oxide particles, as shown in FIG. 3, a microscopic image is projected on a PC screen, and image analysis processing (binarization processing) is performed. These were calculated after clarifying the outline of the particle (black part).
　次に、このターゲットをＤＣマグネトロンスパッタ装置に取り付けスパッタリングを行った。スパッタ条件は、スパッタパワー１．２ｋＷ、Ａｒガス圧１．５Ｐａとし、２ｋＷｈｒのプレスパッタを実施した後、４インチ径のシリコン基板上へ目標膜厚１０００ｎｍでスパッタした。そして、基板上へ付着したパーティクルの個数をパーティクルカウンターで測定した。このときのシリコン基板上のパーティクル数は４個であった。
　なお、スパッタリングしない場合でも、パーティクルカウンターで測定すると、シリコン基板上にパーティクル数が０～５個とカウントされる場合があるので、本実施例のパーティクル数４個は、極めて少ないレベルにあると言える。 Next, this target was attached to a DC magnetron sputtering apparatus, and sputtering was performed. The sputtering conditions were a sputtering power of 1.2 kW, an Ar gas pressure of 1.5 Pa, and after performing 2 kWhr pre-sputtering, sputtering was performed on a 4-inch diameter silicon substrate with a target film thickness of 1000 nm. The number of particles adhering to the substrate was measured with a particle counter. At this time, the number of particles on the silicon substrate was four.
Even when sputtering is not performed, the number of particles on the silicon substrate may be counted as 0 to 5 when measured with a particle counter. Therefore, it can be said that the number of particles in this embodiment is at an extremely small level. .
（実施例２）
　金属原料粉末として、平均粒径４μｍのＣｏ粉末、平均粒径３μｍのＰｔ粉末、平均粒径７μｍのＲｕ粉末、平均粒径６μｍのＴａ粉末、酸化物粉末として平均粒径１．２μｍのＴｉＯ２粉末、平均粒径０．７μｍの球形ＳｉＯ２粉末、平均粒径０．８μｍのＣｏＯ粉末、平均粒径５μｍのＢ２Ｏ３粉末を用意した。また、粒径が５０μｍ～３００μｍの範囲となるように調整したＣｏ粗粉を準備し、平均粒径４μｍのＣｏ粉末と前記Ｃｏ粗粉との比率を重量比で７：３とした。これらの粉末を以下の組成比で２０００ｇ秤量した。
　組成：６１．２Ｃｏ－２２Ｐｔ－３Ｒｕ－０．８Ｔａ－６ＳｉＯ２－２ＴｉＯ２－４ＣｏＯ－１Ｂ２Ｏ３（ｍｏｌ％） (Example 2)
As the metal raw material powder, Co powder having an average particle diameter of 4 μm, Pt powder having an average particle diameter of 3 μm, Ru powder having an average particle diameter of 7 μm, Ta powder having an average particle diameter of 6 μm, and TiO 2 having an average particle diameter of 1.2 μm as an oxide powder. A powder, a spherical SiO 2 powder having an average particle size of 0.7 μm, a CoO powder having an average particle size of 0.8 μm, and a B 2 O 3 powder having an average particle size of 5 μm were prepared. Further, Co coarse powder adjusted to have a particle size in the range of 50 μm to 300 μm was prepared, and the ratio of Co powder having an average particle size of 4 μm to the Co coarse powder was set to 7: 3 by weight. These powders were weighed 2000 g with the following composition ratio.
Composition: 61.2Co-22Pt-3Ru-0.8Ta-6SiO 2 -2TiO 2 -4CoO-1B 2 O 3 (mol%)
　次に、Ｃｏ粗粉を除き、秤量した粉末を粉砕媒体のタングステン合金ボールと共に容量１０リットルのボールミルポットに封入し、１２０時間回転させて混合した。その後、Ｃｏ粗粉をボールミルポットに追加で添加して、１時間混合した。このようにして得られた混合粉をカーボン製の型に充填し、真空雰囲気中、温度１０００°Ｃ、保持時間２時間、加圧力３０ＭＰａの条件のもとホットプレスして焼結体を得た。さらにこれを旋盤で切削加工して直径が１８０ｍｍ、厚さが５ｍｍの円盤状のターゲットを得た。 Next, the Co coarse powder was removed, and the weighed powder was enclosed in a ball mill pot with a capacity of 10 liters together with a tungsten alloy ball as a grinding medium, and rotated and mixed for 120 hours. Thereafter, Co coarse powder was additionally added to the ball mill pot and mixed for 1 hour. The mixed powder thus obtained was filled into a carbon mold and hot-pressed in a vacuum atmosphere under the conditions of a temperature of 1000 ° C., a holding time of 2 hours, and a pressure of 30 MPa to obtain a sintered body. . Further, this was cut with a lathe to obtain a disk-shaped target having a diameter of 180 mm and a thickness of 5 mm.
　実施例２のターゲットの平均漏洩磁束密度は、２８％であった。このターゲット表面を研磨して組織を顕微鏡で観察したところ図４に示すように非磁性材粒子が金属相に分散した組織中に、金属粒が点在していることが分かる。実施例１と同様に評価した最大径と最小径の和が３０μｍ以上の金属粒は１ｍｍ２視野内に平均１９個確認された。また、非磁性材粒子を観察するため、図４を拡大したものを図５に示す。実施例１と同様に評価した最大径と最小径の差が０．７μｍ以下の非磁性材粒子の割合は６４％であり、平均粒径は１．２６μｍであった。 The average leakage magnetic flux density of the target of Example 2 was 28%. When the surface of the target is polished and the structure is observed with a microscope, it can be seen that metal particles are scattered in the structure in which the nonmagnetic material particles are dispersed in the metal phase as shown in FIG. In the same manner as in Example 1, an average of 19 metal grains having a sum of the maximum diameter and the minimum diameter of 30 μm or more were confirmed in a 1 mm 2 visual field. FIG. 5 shows an enlarged view of FIG. 4 in order to observe the non-magnetic material particles. The ratio of the non-magnetic material particles having a difference between the maximum diameter and the minimum diameter of 0.7 μm or less evaluated in the same manner as in Example 1 was 64%, and the average particle diameter was 1.26 μm.
　次に、このターゲットをＤＣマグネトロンスパッタ装置に取り付けスパッタリングを行った。スパッタ条件は、実施例１と同様とし、スパッタパワー１．２ｋＷ、Ａｒガス圧１．５Ｐａとし、２ｋＷｈｒのプレスパッタを実施した後、４インチ径のシリコン基板上へ目標膜厚１０００ｎｍでスパッタした。そして、基板上へ付着したパーティクルの個数をパーティクルカウンターで測定した。このときのシリコン基板上のパーティクル数は４個であった。 Next, this target was attached to a DC magnetron sputtering apparatus, and sputtering was performed. The sputtering conditions were the same as in Example 1. The sputtering power was 1.2 kW, the Ar gas pressure was 1.5 Pa, and after 2 kWhr of pre-sputtering, sputtering was performed on a 4-inch diameter silicon substrate with a target film thickness of 1000 nm. The number of particles adhering to the substrate was measured with a particle counter. At this time, the number of particles on the silicon substrate was four.
　（実施例３）
　金属原料粉末として、平均粒径４μｍのＣｏ粉末、平均粒径３μｍのＰｔ粉末、平均粒径７μｍのＣｏ－Ｂ粉末、酸化物粉末として平均粒径１．２μｍのＴｉＯ２粉末、平均粒径０．７μｍの球形ＳｉＯ２粉末、平均粒径０．８μｍのＭｎＯ粉末、平均粒径２μｍのＣｏ３Ｏ４粉末を用意した。また、粒径が５０μｍ～３００μｍの範囲となるように調整したＣｏ粗粉を準備し、平均粒径４μｍのＣｏ粉末と前記Ｃｏ粗粉との比率を重量比で７：３とした。これらの粉末を以下の組成比で２０００ｇ秤量した。
　組成：６３Ｃｏ－２１Ｐｔ－３Ｂ－６ＳｉＯ２－２ＴｉＯ２－４ＭｎＯ－１Ｃｏ３Ｏ４（ｍｏｌ％） (Example 3)
As the metal raw material powder, Co powder with an average particle diameter of 4 μm, Pt powder with an average particle diameter of 3 μm, Co—B powder with an average particle diameter of 7 μm, TiO 2 powder with an average particle diameter of 1.2 μm as an oxide powder, average particle diameter of 0 A 7 μm spherical SiO 2 powder, a MnO powder having an average particle diameter of 0.8 μm, and a Co 3 O 4 powder having an average particle diameter of 2 μm were prepared. Further, Co coarse powder adjusted to have a particle size in the range of 50 μm to 300 μm was prepared, and the ratio of Co powder having an average particle size of 4 μm to the Co coarse powder was set to 7: 3 by weight. These powders were weighed 2000 g with the following composition ratio.
Composition: 63Co-21Pt-3B-6SiO 2 -2TiO 2 -4MnO-1Co 3 O 4 (mol%)
　次に、Ｃｏ粗粉を除き、秤量した粉末を粉砕媒体のタングステン合金ボールと共に容量１０リットルのボールミルポットに封入し、１２０時間回転させて混合した。その後、Ｃｏ粗粉をボールミルポットに追加で添加して、１時間混合した。このようにして得られた混合粉をカーボン製の型に充填し、真空雰囲気中、温度１０００°Ｃ、保持時間２時間、加圧力３０ＭＰａの条件のもとホットプレスして焼結体を得た。さらにこれを旋盤で切削加工して直径が１８０ｍｍ、厚さが５ｍｍの円盤状のターゲットを得た。 Next, the Co coarse powder was removed, and the weighed powder was enclosed in a ball mill pot with a capacity of 10 liters together with a tungsten alloy ball as a grinding medium, and rotated and mixed for 120 hours. Thereafter, Co coarse powder was additionally added to the ball mill pot and mixed for 1 hour. The mixed powder thus obtained was filled into a carbon mold and hot-pressed in a vacuum atmosphere under the conditions of a temperature of 1000 ° C., a holding time of 2 hours, and a pressure of 30 MPa to obtain a sintered body. . Further, this was cut with a lathe to obtain a disk-shaped target having a diameter of 180 mm and a thickness of 5 mm.
　実施例３のターゲットの平均漏洩磁束密度は、３１％であった。このターゲット表面を研磨して組織を顕微鏡で観察したところ非磁性材粒子が金属相に分散した組織中に、金属粒が点在していることが分かる。実施例１と同様に評価した最大径と最小径の和が３０μｍ以上の金属粒は１ｍｍ２視野内に平均１８個確認された。また、実施例１と同様に評価した最大径と最小径の差が０．７μｍ以下の非磁性材粒子の割合は６０％であり、平均粒径は１．１６μｍであった。 The average leakage magnetic flux density of the target of Example 3 was 31%. When the surface of the target is polished and the structure is observed with a microscope, it can be seen that metal particles are scattered in the structure in which the nonmagnetic material particles are dispersed in the metal phase. In the same manner as in Example 1, an average of 18 metal particles having a sum of the maximum diameter and the minimum diameter of 30 μm or more were confirmed in a 1 mm 2 field of view. Further, the proportion of non-magnetic material particles having a difference between the maximum diameter and the minimum diameter evaluated in the same manner as in Example 1 of 0.7 μm or less was 60%, and the average particle diameter was 1.16 μm.
　次に、このターゲットをＤＣマグネトロンスパッタ装置に取り付けスパッタリングを行った。スパッタ条件は、実施例１と同様とし、スパッタパワー１．２ｋＷ、Ａｒガス圧１．５Ｐａとし、２ｋＷｈｒのプレスパッタを実施した後、４インチ径のシリコン基板上へ目標膜厚１０００ｎｍでスパッタした。そして、基板上へ付着したパーティクルの個数をパーティクルカウンターで測定した。このときのシリコン基板上のパーティクル数は５個であった。 Next, this target was attached to a DC magnetron sputtering apparatus, and sputtering was performed. The sputtering conditions were the same as in Example 1. The sputtering power was 1.2 kW, the Ar gas pressure was 1.5 Pa, and after 2 kWhr of pre-sputtering, sputtering was performed on a 4-inch diameter silicon substrate with a target film thickness of 1000 nm. The number of particles adhering to the substrate was measured with a particle counter. At this time, the number of particles on the silicon substrate was five.
　（実施例４）
　金属原料粉末として、平均粒径４μｍのＦｅ粉末、平均粒径３μｍのＰｔ粉末、平均粒径７μｍのＦｅ－Ｂ粉末、酸化物粉末として平均粒径０．８μｍの球形ＳｉＯ２粉末を用意した。また、粒径が５０μｍ～３００μｍの範囲となるように調整したＦｅ粗粉を準備し、平均粒径４μｍのＦｅ粉末と前記Ｆｅ粗粉との比率を重量比で８：２とした。これらの粉末を以下の組成比で２０００ｇ秤量した。
　組成：５２Ｆｅ－２５Ｐｔ－５Ｂ－１８ＳｉＯ２（ｍｏｌ％） Example 4
Fe powder having an average particle diameter of 4 μm, Pt powder having an average particle diameter of 3 μm, Fe—B powder having an average particle diameter of 7 μm, and spherical SiO 2 powder having an average particle diameter of 0.8 μm were prepared as metal raw material powders. In addition, coarse Fe powder adjusted to have a particle size in the range of 50 μm to 300 μm was prepared, and the ratio of Fe powder with an average particle size of 4 μm to the coarse Fe powder was 8: 2. These powders were weighed 2000 g with the following composition ratio.
Composition: 52Fe-25Pt-5B-18SiO 2 (mol%)
　次に、Ｆｅ粗粉を除き、秤量した粉末を粉砕媒体のタングステン合金ボールと共に容量１０リットルのボールミルポットに封入し、１２０時間回転させて混合した。その後、Ｆｅ粗粉をボールミルポットに追加で添加して、１時間混合した。このようにして得られた混合粉をカーボン製の型に充填し、真空雰囲気中、温度１３００°Ｃ、保持時間２時間、加圧力３０ＭＰａの条件のもとホットプレスして焼結体を得た。さらにこれを旋盤で切削加工して直径が１８０ｍｍ、厚さが５ｍｍの円盤状のターゲットを得た。 Next, the Fe coarse powder was removed, and the weighed powder was enclosed in a ball mill pot with a capacity of 10 liters together with a tungsten alloy ball as a grinding medium, and rotated and mixed for 120 hours. Thereafter, Fe coarse powder was additionally added to the ball mill pot and mixed for 1 hour. The mixed powder thus obtained was filled in a carbon mold and hot-pressed in a vacuum atmosphere under the conditions of a temperature of 1300 ° C., a holding time of 2 hours, and a pressure of 30 MPa to obtain a sintered body. . Further, this was cut with a lathe to obtain a disk-shaped target having a diameter of 180 mm and a thickness of 5 mm.
　実施例４のターゲットの平均漏洩磁束密度は、６１％であった。このターゲット表面を研磨して組織を顕微鏡で観察したところ非磁性材粒子が金属相に分散した組織中に、金属粒が点在していることが分かる。実施例１と同様に評価した最大径と最小径の和が３０μｍ以上の金属粒は１ｍｍ２視野内に平均４個確認された。実施例１と同様に評価した最大径と最小径の差が０．７μｍ以下の非磁性材粒子の割合は６５％であり、平均粒径は１．２９μｍであった。 The average leakage magnetic flux density of the target of Example 4 was 61%. When the surface of the target is polished and the structure is observed with a microscope, it can be seen that metal particles are scattered in the structure in which the nonmagnetic material particles are dispersed in the metal phase. In the same manner as in Example 1, an average of four metal particles having a maximum diameter and a minimum diameter of 30 μm or more were confirmed in a 1 mm 2 field of view. The ratio of the nonmagnetic material particles having a difference between the maximum diameter and the minimum diameter of 0.7 μm or less evaluated in the same manner as in Example 1 was 65%, and the average particle diameter was 1.29 μm.
　次に、このターゲットをＤＣマグネトロンスパッタ装置に取り付けスパッタリングを行った。スパッタ条件は、実施例１と同様とし、スパッタパワー１．２ｋＷ、Ａｒガス圧１．５Ｐａとし、２ｋＷｈｒのプレスパッタを実施した後、４インチ径のシリコン基板上へ目標膜厚１０００ｎｍでスパッタした。そして、基板上へ付着したパーティクルの個数をパーティクルカウンターで測定した。このときのシリコン基板上のパーティクル数は６個であった。 Next, this target was attached to a DC magnetron sputtering apparatus, and sputtering was performed. The sputtering conditions were the same as in Example 1. The sputtering power was 1.2 kW, the Ar gas pressure was 1.5 Pa, and after 2 kWhr of pre-sputtering, sputtering was performed on a 4-inch diameter silicon substrate with a target film thickness of 1000 nm. The number of particles adhering to the substrate was measured with a particle counter. At this time, the number of particles on the silicon substrate was six.
（比較例１）
　金属原料粉末として、平均粒径４μｍのＣｏ粉末、平均粒径５μｍのＣｒ粉末、平均粒径３μｍのＰｔ粉末、酸化物粉末として平均粒径１．２μｍのＴｉＯ２粉末、平均粒径０．７μｍの芯状ＳｉＯ２粉末、平均粒径１μｍのＣｒ２Ｏ３粉末を用意した。そして、これらの粉末を以下の組成比で２０００ｇ秤量した。
　組成：６９Ｃｏ－１８Ｐｔ－２Ｃｒ－５ＳｉＯ２－２ＴｉＯ２－４Ｃｒ２Ｏ３（ｍｏｌ％） (Comparative Example 1)
As a metal raw material powder, Co powder with an average particle size of 4 μm, Cr powder with an average particle size of 5 μm, Pt powder with an average particle size of 3 μm, TiO 2 powder with an average particle size of 1.2 μm as an oxide powder, Average particle size of 0.7 μm Core-like SiO 2 powder and Cr 2 O 3 powder having an average particle diameter of 1 μm were prepared. Then, 2000 g of these powders were weighed at the following composition ratio.
Composition: 69Co-18Pt-2Cr-5SiO 2 -2TiO 2 -4Cr 2 O 3 (mol%)
　次に、秤量した粉末を粉砕媒体のタングステン合金ボールと共に容量１０リットルのボールミルポットに封入し、１２０時間回転させて混合した。このようにして得られた混合粉をカーボン製の型に充填し、実施例１と同様に、真空雰囲気中、温度１１００°Ｃ、保持時間２時間、加圧力３０ＭＰａの条件のもとホットプレスして焼結体を得た。さらにこれを旋盤で切削加工して直径が１８０ｍｍ、厚さが５ｍｍの円盤状のターゲットを得た。 Next, the weighed powder was enclosed in a ball mill pot with a capacity of 10 liters together with a tungsten alloy ball as a grinding medium, and rotated and mixed for 120 hours. The mixed powder thus obtained was filled into a carbon mold and hot-pressed in the same manner as in Example 1 in a vacuum atmosphere at a temperature of 1100 ° C., a holding time of 2 hours, and a pressure of 30 MPa. Thus, a sintered body was obtained. Further, this was cut with a lathe to obtain a disk-shaped target having a diameter of 180 mm and a thickness of 5 mm.
　比較例１のターゲットの平均漏洩磁束密度は、１８％であった。このターゲット表面を研磨して組織を顕微鏡で観察したところ、実施例１と同様に評価した最大径と最小径の和が３０μｍ以上の金属粒は１ｍｍ２視野内に平均１個なかった。また、実施例１と同様に評価した最大径と最小径の差が０．７μｍ以下の非磁性材粒子の割合は８９％であり、平均粒径は０．７１μｍであった。 The average leakage magnetic flux density of the target of Comparative Example 1 was 18%. When the surface of the target was polished and the structure was observed with a microscope, metal particles having a maximum diameter and a minimum diameter of 30 μm or more evaluated in the same manner as in Example 1 were not averaged in a 1 mm 2 field of view. Further, the ratio of the non-magnetic material particles having a difference between the maximum diameter and the minimum diameter of 0.7 μm or less evaluated in the same manner as in Example 1 was 89%, and the average particle diameter was 0.71 μm.
　次に、このターゲットをＤＣマグネトロンスパッタ装置に取り付けスパッタリングを行った。スパッタ条件は、実施例１と同様に、スパッタパワー１．２ｋＷ、Ａｒガス圧１．５Ｐａとしたが、安定した放電が得られなかったため、スパッタパワー１．７ｋＷ、Ａｒガス圧を２．８Ｐａとして放電を安定させ、２ｋＷｈｒのプレスパッタを実施した後、４インチ径のシリコン基板上へ目標膜厚１０００ｎｍでスパッタした。そして、基板上へ付着したパーティクルの個数をパーティクルカウンターで測定した。このときのシリコン基板上のパーティクル数は９個であった。 Next, this target was attached to a DC magnetron sputtering apparatus, and sputtering was performed. As in the case of Example 1, the sputtering conditions were a sputtering power of 1.2 kW and an Ar gas pressure of 1.5 Pa. However, since a stable discharge was not obtained, the sputtering power was 1.7 kW and the Ar gas pressure was 2.8 Pa. After discharging was stabilized and pre-sputtering of 2 kWhr was performed, sputtering was performed on a 4-inch diameter silicon substrate with a target film thickness of 1000 nm. The number of particles adhering to the substrate was measured with a particle counter. At this time, the number of particles on the silicon substrate was nine.
（比較例２）
　金属原料粉末として、平均粒径４μｍのＣｏ粉末、平均粒径５μｍのＣｒ粉末、平均粒径３μｍのＰｔ粉末、酸化物粉末として平均粒径１．２μｍのＴｉＯ２粉末、平均粒径０．７μｍの芯状ＳｉＯ２粉末、平均粒径１μｍのＣｒ２Ｏ３粉末を用意した。また、粒径が５０μｍ～３００μｍの範囲となるように調整したＣｏ粗粉を準備し、平均粒径４μｍのＣｏ粉末と前記Ｃｏ粗粉との比率を重量比で７：３とした。これらの粉末を以下の組成比で２０００ｇ秤量した。
　組成：６９Ｃｏ－１８Ｐｔ－２Ｃｒ－５ＳｉＯ２－２ＴｉＯ２－４Ｃｒ２Ｏ３（ｍｏｌ％） (Comparative Example 2)
As a metal raw material powder, Co powder with an average particle size of 4 μm, Cr powder with an average particle size of 5 μm, Pt powder with an average particle size of 3 μm, TiO 2 powder with an average particle size of 1.2 μm as an oxide powder, Average particle size of 0.7 μm Core-like SiO 2 powder and Cr 2 O 3 powder having an average particle diameter of 1 μm were prepared. Further, Co coarse powder adjusted to have a particle size in the range of 50 μm to 300 μm was prepared, and the ratio of Co powder having an average particle size of 4 μm to the Co coarse powder was set to 7: 3 by weight. These powders were weighed 2000 g with the following composition ratio.
Composition: 69Co-18Pt-2Cr-5SiO 2 -2TiO 2 -4Cr 2 O 3 (mol%)
　次に、Ｃｏ粗粉を除き、秤量した粉末を粉砕媒体のタングステン合金ボールと共に容量１０リットルのボールミルポットに封入し、７０時間回転させて混合した。その後、Ｃｏ粗粉をボールミルポットに追加で添加して、１時間混合した。このようにして得られた混合粉をカーボン製の型に充填し、真空雰囲気中、温度１１００°Ｃ、保持時間２時間、加圧力３０ＭＰａの条件のもとホットプレスして焼結体を得た。さらにこれを旋盤で切削加工して直径が１８０ｍｍ、厚さが５ｍｍの円盤状のターゲットを得た。 Next, the coarse Co powder was removed, and the weighed powder was enclosed in a ball mill pot with a capacity of 10 liters together with a tungsten alloy ball as a grinding medium, and rotated and mixed for 70 hours. Thereafter, Co coarse powder was additionally added to the ball mill pot and mixed for 1 hour. The mixed powder thus obtained was filled in a carbon mold and hot-pressed in a vacuum atmosphere under conditions of a temperature of 1100 ° C., a holding time of 2 hours, and a pressure of 30 MPa to obtain a sintered body. . Further, this was cut with a lathe to obtain a disk-shaped target having a diameter of 180 mm and a thickness of 5 mm.
　比較例２のターゲットの平均漏洩磁束密度は、２９％であった。このターゲット表面を研磨して組織を顕微鏡で観察したところ、実施例１と同様に評価した最大径と最小径の和が３０μｍ以上の金属粒は１ｍｍ２視野内に平均３６個確認された。また、実施例１と同様に評価した最大径と最小径の差が０．７μｍ以下の非磁性材粒子の割合は５４％であり、平均粒径は１．８７μｍであった。 The average leakage magnetic flux density of the target of Comparative Example 2 was 29%. When the surface of the target was polished and the structure was observed with a microscope, an average of 36 metal grains having a maximum diameter and a minimum diameter of 30 μm or more evaluated in the same manner as in Example 1 were confirmed in a 1 mm 2 field of view. Further, the ratio of the nonmagnetic material particles having a difference between the maximum diameter and the minimum diameter of 0.7 μm or less evaluated in the same manner as in Example 1 was 54%, and the average particle diameter was 1.87 μm.
　次に、このターゲットをＤＣマグネトロンスパッタ装置に取り付けスパッタリングを行った。スパッタ条件は、実施例１と同様とし、スパッタパワー１．２ｋＷ、Ａｒガス圧１．５Ｐａとし、２ｋＷｈｒのプレスパッタを実施した後、４インチ径のシリコン基板上へ目標膜厚１０００ｎｍでスパッタした。そして、基板上へ付着したパーティクルの個数をパーティクルカウンターで測定した。このときのシリコン基板上のパーティクル数は２８個と多かった。 Next, this target was attached to a DC magnetron sputtering apparatus, and sputtering was performed. The sputtering conditions were the same as in Example 1. The sputtering power was 1.2 kW, the Ar gas pressure was 1.5 Pa, and after 2 kWhr of pre-sputtering, sputtering was performed on a 4-inch diameter silicon substrate with a target film thickness of 1000 nm. The number of particles adhering to the substrate was measured with a particle counter. At this time, the number of particles on the silicon substrate was as large as 28.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　本発明は、スパッタリングターゲットの組織構造、特に非磁性材粒子と金属粒の形状を調整することにより、スパッタリング時の漏洩磁界の向上と、非磁性材による異常放電を抑制するので、本発明のターゲットを使用すれば、マグネトロンスパッタ装置でスパッタリングする際に安定した放電が得られる。さらに、非磁性材の異常放電を抑制し、異常放電が原因となるスパッタリング中のパーティクル発生を減少させ、歩留まり向上によるコスト改善効果を得ることができるという優れた効果を有するので、磁気記録媒体の磁性体薄膜、特にハードディスクドライブ記録層の成膜に使用される強磁性材スパッタリングターゲットとして有用である。 The present invention adjusts the structure of the sputtering target, particularly the shape of the nonmagnetic material particles and metal particles, thereby improving the leakage magnetic field during sputtering and suppressing abnormal discharge due to the nonmagnetic material. Is used, a stable discharge can be obtained when sputtering with a magnetron sputtering apparatus. Furthermore, the magnetic recording medium has an excellent effect of suppressing the abnormal discharge of the nonmagnetic material, reducing the generation of particles during sputtering caused by the abnormal discharge, and obtaining the cost improvement effect by improving the yield. It is useful as a ferromagnetic sputtering target used for forming a magnetic thin film, particularly a hard disk drive recording layer.

Claims (5)

  1. 　Ｃｏ又はＦｅを含有する磁性材の中に非磁性材粒子が分散した材料からなる焼結体スパッタリングターゲットであって、前記ターゲット中の研磨面で観察される組織が平均粒径１．８μｍ以下の非磁性材粒子と該非磁性材粒子が分散したＣｏ又はＦｅを含有する金属相及び金属粒とから構成されており、前記非磁性材粒子の外周上にある任意の２点の距離の最大値を最大径とし、平行な２本の直線で同粒子を挟んだときの２直線間の距離の最小値を最小径とした場合、その最大径と最小径の差が０．７μｍ以下である非磁性材粒子が前記ターゲット中の研磨面で観察される組織内の非磁性材粒子に対して６０％以上占めており、かつ、前記金属粒の外周上にある任意の２点の距離の最大値を最大径とし、平行な２本の直線で同金属粒を挟んだときの２直線間の距離の最小値を最小径とした場合、その最大径と最小径の和が３０μｍ以上の金属粒が１ｍｍ２視野内に平均１個以上存在することを特徴とするスパッタリングターゲット。 A sintered sputtering target made of a material in which non-magnetic material particles are dispersed in a magnetic material containing Co or Fe, and the structure observed on the polished surface in the target has an average particle size of 1.8 μm or less It is composed of a non-magnetic material particle and a metal phase and metal particle containing Co or Fe in which the non-magnetic material particle is dispersed, and the maximum value of the distance between any two points on the outer periphery of the non-magnetic material particle When the minimum diameter is the minimum distance between two straight lines when the same particle is sandwiched between two parallel straight lines, the difference between the maximum diameter and the minimum diameter is 0.7 μm or less. The material particles occupy 60% or more of the non-magnetic material particles in the structure observed on the polished surface in the target, and the maximum value of the distance between any two points on the outer periphery of the metal particles is When the same diameter is sandwiched between two parallel straight lines When the minimum value of the distance between the two straight lines is defined as the minimum diameter, there is an average of one or more metal grains having a sum of the maximum diameter and the minimum diameter of 30 μm or more in a 1 mm 2 field of view. .
  2. 　前記非磁性材粒子が、Ｂ２Ｏ３、ＣｏＯ、Ｃｏ３Ｏ４、ＭｎＯ、Ｍｎ３Ｏ４、ＳｉＯ２、ＳｎＯ２、ＴｉＯ２、Ｔｉ２Ｏ３、Ｃｒ２Ｏ３、Ｔａ２Ｏ５、ＷＯ２、ＷＯ３、ＺｒＯ２から選択した一種以上の酸化物であり、これらを０．５～２０ｍｏｌ％含有することを特徴とする請求項１記載のスパッタリングターゲット。 The non-magnetic material particles are B 2 O 3 , CoO, Co 3 O 4 , MnO, Mn 3 O 4 , SiO 2 , SnO 2 , TiO 2 , Ti 2 O 3 , Cr 2 O 3 , Ta 2 O 5 , The sputtering target according to claim 1, wherein the sputtering target is one or more oxides selected from WO 2 , WO 3 and ZrO 2 , and contains 0.5 to 20 mol% of these.
  3. 　Ｃｒが０ｍｏｌ％以上１５ｍｏｌ％以下、Ｐｔが５ｍｏｌ％以上３０ｍｏｌ％以下、非磁性材料を除き残部がＣｏ及び不可避的不純物であることを特徴とする請求項１又は２記載のスパッタリングターゲット。 3. The sputtering target according to claim 1, wherein Cr is 0 mol% or more and 15 mol% or less, Pt is 5 mol% or more and 30 mol% or less, and the remainder is Co and inevitable impurities except for a nonmagnetic material.
  4. 　さらにＭｇ、Ａｌ、Ｓｉ、Ｍｎ、Ｎｂ、Ｍｏ、Ｒｕ、Ｐｄ、Ｔａ、Ｗ、Ｂから選択した一種以上の元素を、０．５ｍｏｌ％以上１２ｍｏｌ％以下含有することを特徴とする請求項３記載のスパッタリングターゲット。 Furthermore, 0.5 mol% or more and 12 mol% or less of 1 or more types of elements selected from Mg, Al, Si, Mn, Nb, Mo, Ru, Pd, Ta, W, and B are contained. Sputtering target.
  5. 　前記金属粒が、Ｃｏ又はＦｅからなることを特徴とする請求項１～４のいずれか一項に記載のスパッタリングターゲット。 The sputtering target according to any one of claims 1 to 4, wherein the metal particles are made of Co or Fe.
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CN104903488A (en) 2015-09-09
JP6332869B2 (en) 2018-05-30
JPWO2014125897A1 (en) 2017-02-02
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TWI608114B (en) 2017-12-11
CN104903488B (en) 2018-02-16

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